HomeMy WebLinkAboutDraft Environmental Assessment (Pahala LCC Replacement Project) September 2018DRAFT ENVIRONMENTAL ASSESSMENT
for the
P hala Large Capacity Cesspool (LCC)
Replacement Project
EPA Grant XP-96942401
P hala, District of Ka‘u, County of Hawai‘i, Hawai‘i
U.S. Environmental Protection Agency Region 9 75 Hawthorne Street San Francisco, California 94105
County of Hawai‘i 25 Aupuni Street Hilo, HI 96720
DRAFT September 2018
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TITLE PAGE
Prepared for:
U.S. Environmental Protection Agency and the County of Hawai‘i
Prepared By:
Brown & Caldwell – contractor to the County of Hawai‘i
Wilson Okamoto Corporation – subcontractor to Brown & Caldwell Eastern Research Group, Inc. (ERG) – contractor to the U.S. Environmental Protection Agency
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LIST OF PREPARERS
Eastern Research Group, Inc. (ERG):
Braden Rosenberg Patrick Goodwin J.J. Johnson April Eilers Kettie Rupnik Wilson Okamoto Corporation:
Earl Matsukawa
John Sakaguchi Brown & Caldwell:
Craig Lekven
District, Hawai‘i
September 2018
PREFACE
The National Environmental Policy Act (NEPA) of 1969, as amended (42 U.S.C. § 4321 – 4347), requires a federal agency proposing to undertake a project to consider the potential environmental impacts of the proposed project. Use of federal funds for a project is among the criteria set forth
in NEPA that require preparation of environmental review documentation under NEPA and procedural requirements at 40 C.F.R. Parts 1500-1508 (Council on Environmental Quality (CEQ) regulations), and 40 CFR Part 6 (U.S. Environmental Protection Agency (EPA) regulations). The
Large Capacity Cesspool Replacement Project will be constructed with funds provided by EPA. EPA Region 9 has determined that NEPA requirements for the proposed project can be fulfilled by preparing an Environmental Assessment (EA) with an anticipated Finding of No
Significant Impact (FONSI).
Comparably, Chapter 343, Hawai‘i Revised Statues (HRS), as amended, and implementing rules under Hawai‘i Administrative Rules (HAR) Title 11, Chapter 200 (State of Hawai‘i Department of Health) require state and local governmental agencies undertaking projects utilizing state or county lands or funds to consider the potential environmental impacts of a proposed project by preparing environmental review documentation. The P hala Large Capacity Cesspool Replacement project will be constructed by the County of Hawai‘i Department of Environmental Management (DEM) using County funds. The DEM has determined that the requirements of Chapter 343, HRS can be fulfilled by preparing an EA with an anticipated FONSI.
Federal NEPA regulations at 40 C.F.R. § 1506.2 direct federal agencies to cooperate with state and local agencies to the fullest extent possible to reduce duplication between NEPA and state
and local requirements. See also 40 C.F.R. §§ 6.200 and 6.201. Hawai‘i law and regulations similarly direct agencies subject to Chapter 343, HRS to cooperate with federal agencies to the fullest extent possible (HRS 343-5(h), HAR 11-200-25(2)). This EA has been prepared to jointly
meet the content and procedural requirements of both NEPA and federal cross-cutting authorities, and Chapter 343, HRS, as amended.
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Table of Contents
ACRONYMS .............................................................................................................................. iii
PREFACE .................................................................................................................................... i
1 SUMMARY ...................................................................................................................1-1
2 PROPOSED PROJECT DESCRIPTION ......................................................................2-1
2.1 Background ...................................................................................................... 2-1
2.1.1 ................................................................................2-1
2.1.2 Project Funding .....................................................................................2-1
2.1.3 Large Capacity Cesspools .....................................................................2-3
2.1.4 ......................................2-3
2.2 Purpose and Need for Action ........................................................................... 2-3
2.3 Proposed Action – Site 7 Alternative (Preferred Alternative) ............................ 2-3
2.3.1 Acquire Site 7 and Construct New Secondary Wastewater Treatment and Disposal Facility ....................................................................................2-4
2.3.2 Construct New Wastewater Collection System .................................... 2-10
2.3.3 Close and Abandon Two Existing Large Capacity Cesspools .............. 2-12
2.3.4 Close and Abandon Existing Wastewater Collection System ............... 2-13
2.4 Proposed Action – Site 8 Alternative .............................................................. 2-13
2.5 Proposed Action – Site 9 Alternative .............................................................. 2-14
2.6 No-Action Alternative ..................................................................................... 2-14
2.7 Development of Site Alternatives and Selection of Preferred Alternative ........ 2-14
2.8 Alternatives Considered but Not Carried Forward .......................................... 2-19
2.8.1 Other Site Alternatives ......................................................................... 2-19
2.8.2 Other Wastewater Treatment Alternatives ........................................... 2-20
2.8.3 Other Effluent Management Options ................................................... 2-22
2.9 Relationship to 2007 Final Environmental Assessment .................................. 2-22
2.10 Other Considerations ..................................................................................... 2-23
2.10.1 Zoning Considerations ......................................................................... 2-23
2.10.2 Land Transfer ...................................................................................... 2-23
2.10.3 §205 Considerations ........... 2-24
3 DESCRIPTION OF EXISTING CONDITIONS, IMPACTS AND MITIGATION MEASURES .................................................................................................................3-1
3.1 Climate ............................................................................................................ 3-1
3.1.1 Existing Conditions ................................................................................3-1
3.1.2 Impacts and Mitigation Measures ..........................................................3-1
3.2 Topography ...................................................................................................... 3-2
3.2.1 Existing Conditions ................................................................................3-2
3.2.2 Impacts and Mitigation Measures ..........................................................3-3
3.3 Geology ........................................................................................................... 3-4
3.3.1 Existing Conditions ................................................................................3-4
3.3.2 Impacts and Mitigation Measures ..........................................................3-4
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3.4 Seismic Hazard ................................................................................................ 3-4
3.4.1 Existing Conditions ................................................................................3-4
3.4.2 Impacts and Mitigation Measures ..........................................................3-5
3.5 Volcanic Hazard ............................................................................................... 3-5
3.5.1 Existing Conditions ................................................................................3-5
3.5.2 Impacts and Mitigation Measures ..........................................................3-6
3.6 Soils ................................................................................................................. 3-6
3.6.1 Existing Conditions ................................................................................3-6
3.6.2 Impacts and Mitigation Measures ..........................................................3-8
3.7 Surface Water .................................................................................................. 3-8
3.7.1 Existing Conditions ................................................................................3-8
3.7.2 Impacts and Mitigation Measures – Construction Activities ...................3-9
3.7.3 Impacts and Mitigation Measures – Operation of Wastewater System 3-10
3.8 Ground Water ................................................................................................ 3-11
3.8.1 Existing Conditions .............................................................................. 3-11
3.8.2 Impacts and Mitigation Measures ........................................................ 3-12
3.9 Flood Risk ...................................................................................................... 3-13
3.9.1 Existing Conditions .............................................................................. 3-13
3.9.2 Impacts and Mitigation Measures ........................................................ 3-13
3.10 Agricultural Lands .......................................................................................... 3-14
3.10.1 Existing Conditions .............................................................................. 3-14
3.10.2 Impacts and Mitigation Measures ........................................................ 3-17
3.11 Solid and Hazardous Waste ........................................................................... 3-18
3.11.1 Existing Conditions .............................................................................. 3-18
3.11.2 Impacts and Mitigation Measures ........................................................ 3-18
3.12 Flora .............................................................................................................. 3-19
3.12.1 Existing Conditions .............................................................................. 3-19
3.12.2 Impacts and Mitigation Measures ........................................................ 3-20
3.13 Fauna ............................................................................................................ 3-20
3.13.1 Existing Conditions .............................................................................. 3-20
3.13.2 Impacts and Mitigation Measures ........................................................ 3-21
3.14 Air Quality ...................................................................................................... 3-22
3.14.1 Existing Conditions .............................................................................. 3-22
3.14.2 Impacts and Mitigation Measures ........................................................ 3-23
3.15 Archaeological and Cultural Resources ......................................................... 3-24
3.15.1 Existing Conditions .............................................................................. 3-24
3.15.2 Impacts and Mitigation Measures ........................................................ 3-25
3.16 Socioeconomic Characteristics ...................................................................... 3-26
3.16.1 Existing Conditions .............................................................................. 3-26
3.16.2 Impacts and Mitigation Measures ........................................................ 3-28
3.17 Traffic ............................................................................................................. 3-28
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3.17.1 Existing Conditions .............................................................................. 3-28
3.17.2 Impacts and Mitigation Measures ........................................................ 3-29
3.18 Noise ............................................................................................................. 3-30
3.18.1 Existing Conditions .............................................................................. 3-30
3.18.2 Impacts and Mitigation Measures ........................................................ 3-31
3.19 Visual Considerations and Light Pollution ...................................................... 3-31
3.19.1 Existing Conditions .............................................................................. 3-31
3.19.2 Impacts and Mitigation Measures ........................................................ 3-32
3.20 Public Services – Police Protection ................................................................ 3-33
3.20.1 Existing Conditions .............................................................................. 3-33
3.20.2 Impacts and Mitigation Measures ........................................................ 3-33
3.21 Public Services – Fire Protection ................................................................... 3-33
3.21.1 Existing Conditions .............................................................................. 3-33
3.21.2 Impacts and Mitigation Measures ........................................................ 3-33
3.22 Infrastructure – Water System........................................................................ 3-34
3.22.1 Existing Conditions .............................................................................. 3-34
3.22.2 Impacts and Mitigation Measures ........................................................ 3-34
3.23 Infrastructure – Drainage System ................................................................... 3-35
3.23.1 Existing Conditions .............................................................................. 3-35
3.23.2 Impacts and Mitigation Measures ........................................................ 3-35
3.24 Infrastructure – Electrical and Communications Systems ............................... 3-35
3.24.1 Existing Conditions .............................................................................. 3-35
3.24.2 Impacts and Mitigation Measures ........................................................ 3-36
4 CUMULATIVE EFFECTS .............................................................................................4-1
4.1 Scope of Analysis ............................................................................................ 4-1
4.1.1 Past, Present, and Reasonably Foreseeable Actions ............................4-1
4.1.2 Actions Considered but Excluded from Analysis ....................................4-1
4.2 Cumulative Improvements and Impacts Analysis ............................................. 4-2
5 FEDERAL CROSS CUTTER REQUIREMENTS ..........................................................5-1
5.1 Archaeological and Historic Preservation Act (54 U.S.C. § 312502)................. 5-1
5.2 Bald and Golden Eagle Protection Act (16 U.S.C. §§ 668-668c) ...................... 5-2
5.3 Clean Air Act (42 U.S.C. § 7401) ..................................................................... 5-2
5.4 Coastal Barrier Resources Act (U.S.C. §3501) ................................................ 5-2
5.5 Coastal Zone Management Act (16 U.S.C. §1451) .......................................... 5-3
5.6 Endangered Species Act (16 U.S.C. §1531) .................................................. 5-7
5.7 Environmental Justice Executive Order 12898 ................................................. 5-8
5.8 Farmland Protection Policy Act (7 U.S.C. §4201) ............................................. 5-9
5.9 Fish and Wildlife Coordination Act (16 U.S.C §661) ....................................... 5-9
5.10 Floodplain Management (Executive Order 19888, as amended by Executive
Orders 1248 and 13690) ................................................................................ 5-10
5.11 Magnuson-Stevens Fishery Conservation and Management Act, 16 U.S.C.
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§1801 ............................................................................................................. 5-10
5.12 Marine Mammal Protection Act (16 U.S.C. §§ 703 et seq.) ............................ 5-11
5.13 Migratory Bird Treaty Act (16 U.S.C. §§ 703 et seq.) ..................................... 5-11
5.14 National Historic Preservation Act (U.S.C. 54 §300101)................................. 5-11
5.15 Protection of Wetlands (Executive Order 11990 (1977), as amended by
Executive Order 12608 (1997)) ...................................................................... 5-12
5.16 Rivers and Harbors Act (33 U.S.C. § 403) ..................................................... 5-12
5.17 Safe Drinking Water Act (42 U.S.C. §300f) .................................................... 5-13
5.18 Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) ........................................ 5-13
6 PLANS, POLICIES AND CONTROLS ..........................................................................6-1
6.1 State Land Use Plans and Policies .................................................................. 6-1
6.1.1 Hawai‘i State Plan .................................................................................6-1
6.1.2 State Functional Plans ...........................................................................6-4
6.1.3 State Land Use District ..........................................................................6-5
6.1.4 Chapter 344, State Environmental Policy ..............................................6-6
6.1.5 Hawai‘i Coastal Zone Management Program ........................................6-6
6.2 Hawai‘i County Land Use Plans and Policies ................................................. 6-11
6.2.1 Hawai‘i County General Plan ............................................................... 6-11
6.2.2 .................................................... 6-14
6.2.3 County of Hawai‘i Zoning ..................................................................... 6-19
6.2.4 County of Hawai‘i Special Management Area ...................................... 6-19
7 PUBLIC PARTICIPATION ............................................................................................7-1
8 FINDINGS AND DETERMINATION .............................................................................8-1
8.1 – Department of Environmental Management (DEM) Anticipated Finding of No Significant Impact (FONSI) ..... 8-1
8.1.1 Significance Criteria ..............................................................................8-1
8.1.2 Determination ........................................................................................8-4
8.2 National Environmental Policy Act – EPA Preliminary Finding of No Significant Impact (FONSI) ................................................................................................ 8-4
8.2.1 Project Location and Description ...........................................................8-4
8.2.2 Purpose and Need for Proposed Project ...............................................8-5
8.2.3 Environmental Consequences ...............................................................8-5
9 LIST OF PERMITS AND APPROVALS ........................................................................9-1
10 CONSULTED PARTIES ............................................................................................. 10-1
10.1 Pre-Assessment Consultation ........................................................................ 10-1
10.2 Agencies and Organizations Consulted on the Draft EA ................................ 10-3
11 REFERENCES ........................................................................................................... 11-1
List of Figures
........................................ 2-2
Figure 2.2. Elements of the Proposed Action .......................................................................... 2-5
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Figure 2.3. Preliminary Site Plan for New Wastewater Treatment and Disposal Facility
at Site 7 (Preferred Alternative) ............................................................................ 2-6
Figure 2.4. Preliminary Process Schematic for New Wastewater Treatment and
Disposal Facility at Site 7 (Preferred Alternative) .................................................. 2-8
Figure 2.5. Example of Shade Ball Floating Cover in a Lagoon ............................................... 2-9
Figure 2.6. Preliminary Collection System Plan with New Wastewater Treatment and
Disposal Facility at Site 7 (Preferred Alternative) ................................................ 2-11
Figure 2.7. Site 8 Alternative – Preliminary Site Plan for New Wastewater Treatment and
Disposal Facility ................................................................................................. 2-15
Figure 2.8. Site 9 Alternative – Preliminary Site Plan for New Wastewater Treatment and
Disposal Facility ................................................................................................. 2-16
Figure 2.9. Locations of Nine Candidate Sites Considered for New Wastewater
Treatment and Disposal Facility ......................................................................... 2-18
Figure 3.1. Area Soils Map .......................................................................................... 3-7
.......................................... 3-15
Figure 3.3. Area Agricultural Lands of Importance to the State of Hawai‘i (ALISH) Classification Map .............................................................................................. 3-16
Figure 6.1. Community Development Plan Land Use Policy Map .......................................... 6-17
List of Tables
Table 3.1. Hawai‘i County ................................................................................................... 3-27
Table 3.2. Permissible Sound Levels by Zoning District ........................................................ 3-30
Table 6.1. Hawai‘i State Plan Objectives and Policies ............................................................. 6-1
Appendices
APPENDIX A. Responses to Pre-Assessment Consultation Letters
APPENDIX B. June 2018 Preliminary Engineering Report (PER)
APPENDIX C. August 2018 Biological Survey Report
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ACRONYMS
AAQS Ambient air quality standards
AC Asphaltic concrete
ACS American Community Survey
AHPA Archaeological and Historic Preservation Act
AIS Archaeological Inventory Survey
ALISH Agricultural Lands of Importance to the State of Hawai‘i
AOC Administrative Order on Consent
ASTM American Society for Testing and Materials
BMP Best management practice
BOD5 Five-day biochemical oxygen demand
CAA Clean Air Act
CBRA Coastal Barrier Resources Act
CBRS Coastal Barrier Resources System
CEQ Council on Environmental Quality
COE (United States Army) Corps of Engineers
CWRM Commission on Water Resource Management
CWSRF Clean Water State Revolving Fund
CZM Coastal Zone Management
CZMA Coastal Zone Management Act
CZMP Coastal Zone Management Program
dBA A-weighted decibel scale
DBEDT
DEM (County of Hawai‘i) Department of Environmental Management
DLNR
DOH
DWS (County of Hawai‘i) Department of Water Supply
EA Environmental Assessment
EFH Essential Fish Habitat
EO Executive Order
EPA (United States) Environmental Protection Agency
ESA Environmental Site Assessment
FEMA Federal Emergency Management Agency
FIRM Flood Insurance Rate Map
FONSI Finding of No Significant Impact
FPPA Farmland Protection Policy Act
FWS (United States) Fish and Wildlife Service
GAC Granular activated carbon
HAR Hawai‘i Administrative Rules
HCC Hawai‘i County Code
HDPE High-density polyethylene
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HELCO
HRS Hawai‘i Revised Statues
IBC International Building Code
LCC Large capacity cesspool
LF Linear feet
LSB (University of Hawai‘i) Land Study Bureau
MBTA Migratory Bird Treaty Act
MMPA Marine Mammal Protection Act
msl Mean sea level
NAAQS National ambient air quality standards
NEPA National Environmental Policy Act
NHPA National Historic Preservation Act
NLAA Not likely to adversely affect
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollutant Discharge Elimination System
NRCS Natural Resources Conservation Service
NWI National Wetland Inventory
OEQC
OSHA Occupational Safety and Health Administration
PER Preliminary Engineering Report
PM Particulate matter
PVC Polyvinyl chloride
REC Recognized environmental concern
ROW Right-of-way
SDWA Safe Drinking Water Act
SF Square feet
SHPD (Hawai‘i) State Historic Preservation Division
SIP State Implementation Plan
SMA Special Management Area
SO2 Sulfur dioxide
SUP Special Use Permit
SWPPP Stormwater Pollution Prevention Plan
TMK Tax Map Key
TSS Total suspended solids
U.S.C. United States Code
UIC Underground Injection Control
USGS United States Geological Survey
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1 SUMMARY
Proposing County Agency: County of Hawai‘i Department of Environmental Management
Hilo, HI 96720
Proposing Federal Agency: U.S. Environmental Protection Agency, Region 9 75 Hawthorne Street
San Francisco, CA 94131
EA Preparers: Wilson Okamoto Corporation 1907 South Beretania Street, Suite 400 Honolulu, HI 96826 Contact: Earl Matsukawa, AICP, Project Manager Tel: 808.946.2277; Fax: 808.946.2253
Eastern Research Group, Inc. (ERG) 14555 Avion Parkway, Suite 200 Chantilly, VA 20151
Contact: Braden Rosenberg, Project Manager Tel: 774.277.0503
Project Location:
Recorded Fee Owner: Kamehameha Schools
Tax Map Key: 9-6-002:018
Area: 14.9 acres project site 42.5 acres parcel
State Land Use Classification: Urban Agricultural
County Zoning: Various residential County of Hawai‘i streets
AG-20 Agricultural
Proposed Action: The proposed wastewater collection system would be located
within five streets in the western portion of the community (Maile,
Streets).
The proposed wastewater treatment and disposal facility would occupy about 14.9 acres and would consist of a headworks and
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September 2018 Page 1-2
an odor control unit, an operations building, four lined aerated lagoons, a subsurface flow constructed wetland to remove
nitrogen and an adjacent disinfection system to remove pathogens and four slow-rate land treatment basins for disposal of the treated effluent.
Impacts: No significant impacts are anticipated from construction and use of the collection system and the wastewater treatment and disposal facility.
Agencies Consulted in Pre-Draft Assessment: Federal
U.S. Army Corps of Engineers (COE)
U.S. Fish and Wildlife Service (FWS)
U.S. Department of Agriculture National Resources Conservation Service
National Oceanic and Atmospheric Administration (NOAA)
Department of Agriculture
Department of Accounting and General Services
Department of Business, Economic Development and Tourism (DBEDT)
DBEDT,
DBEDT, Land Use Commission
DBEDT, Office of Planning
Department of Health (DOH)
DOH, Office of Environmental Quality Control
DOH, Office of Director
DOH, Environmental Management Division
DOH, Environmental Planning Office
DOH, Clean Water Branch
DOH, Safe Drinking Water Branch
DOH, Wastewater Branch
Department of Land and Natural Resources (DLNR)
Engineering Division
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Division of Forestry and Wildlife
Historic Preservation Division
Commission on Water Resources Management
Department of Transportation
Department of Hawaiian Home Lands
Office of Hawaiian Affairs
Hilo Regional Library
Co
Department of Parks and Recreation
Planning Department
Police Department
Department of Public Works
Department of Water Supply
Elected Officials
Congresswoman Tulsi Gabbard
State Senator Russell Ruderman
State Representative Richard H.K. Onishi
Councilmember Maile Medeiro
Native Hawaiian Organizations
Association of Hawaiian Civic Clubs
Hawaiian Civic Club of Hilo
Kamehameha Schools
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Office of Hawaiian Affairs
Pacific Agricultural Land Management Systems
Partners in Development Foundation
Pi ihonua Hawaiian Homestead Community Association
Other
Hawaiian Electric Light Company
Hawaiian Telcom
Mr. Stason Nishimura
Mr. Lance Uno
Ms. Julia Neal
The comments and responses are shown in Appendix A.
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2 PROPOSED PROJECT DESCRIPTION
2.1 Background
2.1.1 Community
The community of P hala is located about 52 miles southwest of Hilo, in the Ka‘ District, Island of . P hala is located west (mauka) of M malahoa Highway (State Route 11) about 3.8 miles from the shoreline. Most of the community lies between 980 feet above mean sea level (msl) on the western end and approximately 800 feet above msl on the eastern end. Figure 2.1
ly settled areas in the Hawaiian Islands, it remains a vast remote area. Only a fraction of a percent has been developed with residential properties, and
the remainder is largely used for agricultural purposes or is undeveloped. situated at the southern tip of the island and extends across the southern and southeastern flanks of Mauna Loa. The (approximately 590,000 acres), with over 80 miles of virtually undeveloped coastline. Nearly two-thirds of its total land area is in the Conservation district. hich the community is the largest, with a population of approximately 1,405 persons in 2016, the most
recent estimate. The distance to the communities of Hilo and Kailua- District is relatively isolated from the major infrastructure systems found in these communities, including wastewater treatment and disposal facilities.
Founded in 1826, C. Brewer and Company, Ltd. (C. Brewer) was both the oldest company in and a major developer of the sugar industry in P hala. The operations were closed in 1996, meaning that the sugar industry was no longer the major region. However, agriculture is still the major source of economic activity in the region. Today, macadamia nuts are the major crop grown within the District; however, growing competition from foreign producers is beginning to affect the industry.
2.1.2 Project Funding
(a) EPA Special Appropriation Grant
In 2006, an EPA Special Appropriation Grant was awarded to the County Large Capacity Cesspool Replacement Project Grant (XP-96942401). The grant’s federal funding amount is $1.842 million and currently expires in October 2020. The purpose of the award is for the design and construction of wastewater system improvements to replace LCCs in the District. The grant award and current work plan provide funding to replace the LCCs serving the P hala community.
(b) State Revolving Fund
This project may also be funded by the State of DOH Clean Water State Revolving Fund (CWSRF) Program. The CWSRF Program was created by the federal Water Quality Act of 1987
and authorizes low interest loans for the construction of publicly owned wastewater treatment works. In 1988, the State Legislature passed Act 365, now Chapter 342D, Revised Statues (HRS), to establish the State Water Pollution Control Revolving Fund to receive the
federal capitalization grant. Chapter 342D [Part V.], Water Pollution Control Financing, and HRS 342D-81 set forth that the State’s policy is to promote water pollution prevention and control, including the use of recycled water, by financing eligible projects consistent with applicable federal and state laws.
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Figure 2.1. Location
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2.1.3 Large Capacity Cesspools
In 1999, EPA promulgated regulations under the Safe Drinking Water Act’s Underground Injection
Control (UIC) Program which prohibited the construction of new large capacity cesspools (LCCs) as of April 2000 and required the closure of all existing LCCs by April 5, 2005 (see 40 C.F.R. § 144.88). Under federal regulations, an LCC is a cesspool which serves multiple dwellings, or for
non-residential facilities has the capacity to serve 20 or more persons per day. Cesspools can release disease-causing pathogens and other pollutants (e.g., nitrates) into ground water aquifers, streams, and eventually the ocean, thus leading to public health and environmental concerns.
In June 2017, EPA and the County entered into an Administrative Order on Consent (AOC) to close the LCCs serving the P hala Community by June 2021.
2.1.4 History of Wastewater Management in
dard gravity lines that convey sewage to two LCCs serving approximately 109 parcels, which were previously owned and operated by C. Brewer. In 1996, C. Brewer shut down its sugar growing and In 2003, C. Brewer requested assistance from the County to close their LCCs. Subsequently, the County held a community meeting to present sewer system replacement alternatives. Voting took place via mail for preferred sewer improvement alternative resulting in 87 percent of the returned ballots in favor of
the installation of a new sewer collection system and a treatment and disposal system to be operated and maintained by the County.
Around 2006, C. Brewer requested that the County construct and maintain a new and improved
community sewer system. A County Council Resolution approved the C. Brewer request. In anticipation of C. Brewer's dissolution, C. Brewer proposed, and the County agreed, to enter into a formal agreement to not only construct and maintain a new and improved community sewer system but to assume ownership of the existing system including the LCC's by April 30, 2010.
2.2 Purpose and Need for Action
The purpose of the actions considered in this Environmental Assessment (EA) is to provide the infrastructure necessary to enable the County to comply with the SDWA and fulfill the compliance provisions of the AOC between EPA and the County with respect to closure of the LCCs by June 2021.
The need for action is driven by the public health and environmental concerns associated with LCCs, as described in Section 2.1.3.
2.3 Proposed Action – Site 7 Alternative (Preferred Alternative)
This section describes the Preferred Alternative under the Proposed Action.
Under the Preferred Alternative, the County of would perform the following actions:
1) Acquire, or otherwise obtain the right to develop and use, a portion of the 42.5-acre Site 7 that is currently owned by Kamehameha Schools, then construct a new secondary wastewater treatment and disposal facility within a portion of the parcel (see Figure 2.3);
2) Construct a wastewater collection system, primarily within the public right-of-way (ROW)
and two short segments within easements , to collect and convey sanitary waste from the residential lots to the new treatment and disposal facility;
3) Close and abandon two LCCs, according to DOH closure procedures; and
4) Abandon the existing wastewater collection system in place.
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These actions are described in further detail below and are depicted in Figure 2.2.
2.3.1 Acquire Site 7 and Construct New Secondary Wastewater Treatment and Disposal
Facility
Under the Preferred Alternative, the County would acquire, or obtain the right to develop and use, a 14.9-acre portion of the parcel identified as Site 7 for construction of a new secondary
wastewater treatment and disposal facility. This 42.5-acre parcel (Tax Map Key (TMK): 9-6-002:018), located about 0.5 miles (2,600 feet) south of the developed area of the community, is owned by Kamehameha Schools and used as a macadamia nut orchard. It is located adjacent to LCC #1. An at-grade irrigation system runs in a north-south direction which allows vehicle access between the rows. Slopes throughout Site 7 are between approximately 3 and 10 percent.
The County would work with the current landowner to subdivide the 42.5-acre parcel into two parcels: 1) a 14.9-acre parcel that would be owned by the County; and 2) a 27.6-acre parcel that would include a 25-foot-wide by 1,500-foot-long utility easement and would continue to be owned by the current owner. See Figure 2.3 for a preliminary site plan showing the proposed location of the treatment and disposal facility within the southeast portion of Site 7. This location is east (makai) of an existing access road to the adjacent parcel in the northwest corner of the Maile Street and Highway intersection outside of the State of Department of Transportation right-of-way. Access to the parcel would be provided from an access driveway on Maile Street sited about 200 feet east of the adjacent parcel access road and approximately 650
feet west (mauka) of the Maile Street and Highway intersection.
The County developed wastewater flow projections for the treatment and disposal facility using the City and County of Honolulu current wastewater standards, most recently updated during
2017. Based on these standards, the treatment and disposal facility would be designed to provide an average dry weather flow capacity of 190,000 gallons per day, which would be sufficient capacity to allow closure of the two LCCs.
The wastewater treatment and disposal facility would consist of the following primary components:
Headworks preliminary treatment system. The headworks would protect the downstream
system operations from large objects, debris, and rags that may be present in the incoming flows. It would include a below-grade concrete tank with channels to control flows; a fiberglass or aluminum cover plate to facilitate foul air collection; an above-grade screening system; a granular activated carbon (GAC) scrubber for odor control; and influent flow measurement and sampling equipment. A free-standing roof structure over the headworks would protect operators and equipment from rain and sun conditions.
Aerated lagoon treatment system. A series of three 0.4-acre partial-mix aerated lagoons would provide biological wastewater treatment. Partial-mix aerated lagoons allow the
solids to settle while providing enough aeration and mixing to meet the oxygen demands of the naturally occurring micro-organisms in the system. The lagoons would be equipped with high-speed floating aerators and high-density polyethylene (HDPE) liners to prevent wastewater seepage into the subsurface.
Subsurface flow constructed wetland. The 0.6-acre wetland would provide additional
treatment of the effluent from the aerated lagoons via a process called denitrification, which would decrease the land area required for the slow rate land application (see below). The subsurface flow wetland would consist of a shallow HDPE-lined basin filled with gravel media and planted with emergent wetland vegetation. Effluent from the lagoons would flow through the gravel media layer, with the effluent level being maintained below the gravel surface at all times. Treatment would occur through physical, chemical, and biological mechanisms.
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Figure 2.2. Elements of the Proposed Action
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Figure 2.3. Preliminary Site Plan for New Wastewater Treatment and Disposal Facility at Site 7 (Preferred Alternative)
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Covered lagoon and disinfection. The 0.8-acre covered lagoon (Lagoon 4) would allow for effluent storage and algae removal, followed by disinfection to kill pathogens or render them incapable of reproduction or harm to humans. The lagoon would feature a floating cover of HDPE shade balls to prevent algae growth while allowing rainwater to pass
through. Disinfection would occur through contact with chlorine solution derived from solid calcium hypochlorite in a chlorine contact tank, providing the necessary contact time for the disinfection process to occur.
Slow-rate land application system. Disposal of the treated and disinfected effluent would be accomplished through land treatment in four groves of native, water-tolerant native trees occupying a total area of approximately 8.0 acres. Application of the effluent would be rotated to a different grove each day, resulting in a wet/dry cycle of 1-day wetting and 3-days drying.
Figure 2.4 shows a preliminary process schematic for the proposed secondary treatment and disposal facility. Figure 2.5 illustrates an example of a lagoon using a floating cover of shade balls.
EPA defines land treatment as “the application of appropriately pre-treated municipal and industrial wastewater to the land at a controlled rate in a designed and engineered setting. The purpose of the activity is to obtain beneficial use of these materials, to improve environmental quality, and to achieve treatment goals in a cost-effective and environmentally sound manner.”
Land treatment systems rely on soil and vegetation to achieve treatment objectives, rather than energy-intensive mechanical equipment. As such, they are considered to be a form of “natural” treatment. The slow-rate land application concept is to intermittently apply wastewater to vegetation growing in permeable soils. As the applied effluent percolates through the soil matrix or is taken up by the crop, it is treated by physical filtration and biological mechanisms. After an application period or wetting period, the surface is allowed to dry, and oxygen can enter the soil matrix, which aids aerobic biological treatment. The frequent wetting and drying of the soils also maintains the infiltration rate through the soil surface and minimizes clogging. This treatment process is effective for five-day biochemical oxygen demand (BOD5), total suspended solids (TSS), trace organics, phosphorus, metals and pathogen removal. Furthermore, nitrogen removal can be significant if it is necessary to manage the system for that objective.
The facility would also include an operations building (approximately 1,620 square feet (SF)), which would include an electrical room, chlorinator room, restroom, and maintenance/storage room. A standby power system would be provided by a pad-mounted diesel generator and
aboveground fuel tank with capacity to support three consecutive days of operation. An electrical service panel would be equipped with a manual transfer switch and generator receptacle. This would provide a connection to a trailer-mounted generator, in the event of emergency generator
failure during an extended power outage.
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Figure 2.4. Preliminary Process Schematic for New Wastewater Treatment and Disposal Facility at Site 7 (Preferred Alternative)
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Figure 2.5. Example of Shade Ball Floating Cover in a Lagoon
The entire wastewater treatment and disposal facility would be enclosed with a six-foot-high
chain-link fence and posted to prevent public access. Gate(s) to the facility would be locked, except when County personnel are present. A 25-foot-wide by 1,500-foot-long easement located along the northern edge of the parcel would be used to provide access to utilities from Maile Street
to the treatment and disposal facility. The easement would contain the incoming sewer line from the collection system, potable water line, and above-ground electric service from the Electric and Light Company (HELCO) system. The easement would not be improved as an access
road. The above-ground electric service would likely consist of 480-volt, three-phase electrical power via a pole-mounted transformer to a service panel with a meter. Provided utilities would also include a land-line or cellular telephone telemetry system to connect the facility to the County of Hawai i Department of Environmental Management (DEM) operations staff based in Hilo. Exterior site lighting would be limited to one shielded light mounted under the roof overhang of the operations building and one shielded light near the headworks. The exterior lighting would be manually switched and used only for emergency purposes; the facility would normally be unlit at night.
Construction of the wastewater treatment and disposal facility would require extensive site modifications, including the following:
Clearing and grubbing of approximately 14.9 acres of macadamia nut trees within the southeast portion of Site 7 to accommodate the new facility, and clearing of up to approximately 0.9 acres of trees from within the utility easement – these trees would be disposed of at an approved site or re-used for some other purpose;
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Excavation to a depth of approximately 10 feet to provide the necessary capacity for the lagoons;
Excavation to a depth of approximately 4 feet to provide the necessary depth for the media in the subsurface constructed wetland;
Excavation to a depth of approximately 6 feet to provide sufficient depth for the planted groves and disposal of the effluent; and
Construction of a berm (with approximate 4-foot height) on all four sides of the groves to contain rainfall from a 100-year, 24-hour storm event, with perimeter roads on the top of the berms to provide operator access.
Construction of internal service roads to provide access to the new facilities.
Prior to construction of the treatment and disposal facility, the County would need to obtain the necessary discretionary and ministerial approvals from various Federal, State, and County agencies.
2.3.2 Construct New Wastewater Collection System
Under the Preferred Alternative, the County would construct a new sewer collection system in the to replace and expand upon the existing system of substandard gravity lines that convey sewage to the two LCCs. The new collection system would consist of a total of approximately 12,150 linear feet (LF) (2.3 miles) of corrosion-resistant polyvinyl chloride (PVC) piping almost entirely within the public ROW of seven public streets. This includes five streets in the western ) and two
collection system would convey sewage to the new wastewater treatment and disposal facility at Site 7. Figure 2.6 shows the collection system plan.
The County would construct the collection system in two phases to ensure that residential units
can maintain sewer system access all times. Phase 1 would construct segments totaling approximately 2,510 LF to divert sewage flows from the existing LCC collection system to the new treatment and disposal facility and would connect individual properties to this new collection
system. Specifically, Phase 1 would include the following:
A new 1,730-LF, 16-inch diameter line within the Maile Street ROW to intercept flows from
the existing , Huapala, , and Hala Streets and convey this sewage to the new wastewater treatment and disposal facility at Site 7. This new line would be sized to accommodate the flows from the entire community.
A new 780-LF, 14-inch diameter line partially within the Pikake Street ROW that would connect LCC 1 to the new line on Maile Street described above. A 350-LF portion of this
line would run through an easement on a privately-owned parcel to access LCC 1.
Phase 2 would complete the new collection system by constructing segments totaling approximately 9,630 LF throughout , installing pumps on selected properties, and connecting individual properties to the new collection system. These lines would range from a 14-inch line on Pikake Street to mostly 8-inch lines on the remaining streets and would run primarily within County ROWs for ease of access. However, an approximately 1,100-LF segment would follow the existing system alignment in an industrial area between Ilima and Maile Streets. The property (TMK 9-6-005:036) is owned by Edmund Olsen and leased to M L Macadamia Orchards. The County would obtain an easement within this area to access the site.
Phase 1 and Phase 2 streets would have a total of 120 lots connected to the wastewater collection system. These same lines can accommodate 65 newly accessible lots on the public streets.
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Figure 2.6. Preliminary Collection System Plan with New Wastewater Treatment and Disposal Facility at Site 7 (Preferred Alternative)
Construction of the new collection system would involve temporary impacts within the public ROWs of seven streets. The streets within the community are under the jurisdiction the County, with the exception of a privately-owned portion of Pikake Street for which the County would obtain
an easement. The streets have been improved with asphaltic concrete (AC) surfaces; most shoulder areas are somewhat improved or consist of grassy swales. Most of the streets have two travel lanes, are approximately 22 to 24 feet wide (plus shoulders), and do not have curbs or
gutters. Residential lots along the streets have driveways with direct access to the travel lanes. Overhead utility poles are located outside the travel lanes. Typical sewer trenches would be about 3 feet wide and at least 6 feet deep to allow the placement of the lines to meet County standards. The existing pavement would be sawcut, the trench would be excavated, sewer pipe installed,
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and then the trench would be backfilled and compacted. The cut portion of the AC pavement would then be patched with new AC material.
The new collection system would be subject to the County of Code Chapter 21, Sewers. Specifically, Article 2 (Public Sewers), Section 21-5 states the following:
“(a) Owners of all dwellings, buildings, or properties used for human occupancy, employment,
recreation, or other purposes, which are accessible to a sewer are required at their
expense to connect directly with the public sewer within 180 days after date of official notice.
(b) If, due to rock, wastewater collection system depth, or other construction problems, a
building cannot be practically served, the owner shall install, operate and maintain a residential pumping station.
(c) The director may grant a variance/exemption of the foregoing connection requirements to
owners of single-family dwellings existing at the time of installation of the public wastewater system, if the following is found:
(1) There are special or unusual circumstances applying to the subject real property which
exist that render the ability to connect to a wastewater system an extreme physical or financial hardship; and
(2) There are no other reasonable alternatives; and
(3) The variance is consistent with the general purpose of the chapter and will not be
materially detrimental to public health, safety, or welfare.”
Accordingly, additional newly accessible properties in would be required to connect to the new wastewater collection system after it becomes operational. These other properties are near
the existing service area and are presently connected to individual wastewater systems. Under the Preferred Alternative, the design of the new collection system would include stub-outs to accommodate the eventual connection of these newly accessible properties. However, the
respective property owners would be responsible for the design and completion of these connections and for the proper closure of their individual wastewater systems.
Additionally, as discussed in Section 4, the State Department of Education will c and Shelter to the new collection system following completion of the Proposed Action.
2.3.3 Close and Abandon Two Existing Large Capacity Cesspools
Under the Preferred Alternative, following completion of Phase 1 of the new collection system, the County would close and abandon LCC 1 and LCC 2 as instructed by DOH Safe Drinking Water Branch UIC requirements. HAR §11-23-19 sets forth the plugging and abandonment requirements, which state the following:
“(a) any owner who wishes to abandon an injection well shall submit an application, in
accordance with Section 11-23-12, containing the details of the proposed
abandonment. The DOH may require an abandoned well to be plugged in a manner which will not allow detrimental movement of fluids between formations. If required,
plugging shall be completed by grouting with the tremie method in accordance with
the Honolulu Board of Water Supply's "Water System Standards", dated March, 1977; or by some other method found appropriate and acceptable to the DOH; (b) The DOH
may order an injection well to be plugged and abandoned when it no longer performs
its intended purpose, or when it is determined to be a threat to the ground water
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resource. The owner shall schedule the plugging so that DOH staff may be present to monitor the abandonment operation.”
The specific methods to be used for closure of the LCCs have not yet been determined but would be consistent with the requirements described above.
LCC 1 is located in a parcel
that has been previously cleared and is currently overgrown with tall grasses. It may be necessary to clear a path for construction vehicles and equipment to access the LCC 1. Clearing an access road (or other similar work) would not be necessary to access LCC 2, which is located in the backyard of a residential lot with access via the house driveway.
2.3.4 Close and Abandon Existing Wastewater Collection System
Under the Preferred Alternative, following completion of Phase 2 of the new collection system, the County would close and abandon the existing C. Brewer wastewater collection system. This system includes some lines located in the back yards of residential lots and some within public streets; therefore, abandoning the lines in place would minimize impacts related to their excavation and removal. The cut ends of the abandoned laterals to the collection system would be plugged with concrete to prevent unauthorized use of the old system and to prevent maintaining an unused underground hydraulic conduit.
2.4 Proposed Action – Site 8 Alternative
Under the Site 8 Alternative, the County would perform the same actions as described in Section 2.4 for the Preferred Alternative, with the following exceptions:
The new secondary wastewater treatment and disposal facility would be constructed at Site 8 instead of Site 7; and
The new wastewater collection system would require approximately 1,600 feet of additional pipe within the ROW of Lower Maoula Road to reach Site 8.
The County would acquire, or obtain the right to develop and use, the parcel identified as Site 8 for construction of the new secondary wastewater treatment and disposal facility (see Figure 2.7). This 45.2-acre parcel (TMK: 9-6-002:021) is southwest of and adjacent to Site 7, across Maile As with Site 7, it is owned by Kamehameha Schools and used as a macadamia nut orchard. Site 8 is more steeply sloped than Site 7, with slopes between approximately 10 and 20 percent. An unnamed branch of Hi‘onamoa Gulch crosses the site from northwest to southeast near the center of the parcel.
The secondary wastewater treatment and disposal facility at Site 8 would consist of the same treatment components, and would require the same support facilities and infrastructure, as the facility described in Section 2.4 for the Preferred Alternative. However, because of the steeper slopes in Site 8, use of this site would require larger slow-rate land application groves totaling approximately 12 acres. Also, depending on the selected configuration of the wastewater treatment facility and the land application groves, this alternative could require trenching and construction of piping across Hi‘onamoa Gulch within the site.
As with the Preferred Alternative, the Site 8 Alternative would close and abandon LCC 1 and LCC 2 following completion of Phase 1 of the new collection system and would close and abandon the existing C. Brewer wastewater collection system following completion of Phase 2 of the new
collection system.
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2.5 Proposed Action – Site 9 Alternative
Under the Site 9 Alternative, the County would perform the same actions as described in Section 2.4 for the Preferred Alternative, with the following exceptions:
The new secondary wastewater treatment and disposal facility would be constructed at Site 9 instead of Site 7; and
The new wastewater collection system would require approximately 3,200 feet of additional pipe within the ROW of Maile Stree
Site 9.
The County would acquire, or obtain the right to develop and use, the parcel identified as Site 9 for construction of the new secondary wastewater treatment and disposal facility (see Figure 2.8). This 157-acre parcel (TMK: 9-6-002:049) is southeast of Sites 7 and 8, across Highway. As with Sites 7 and 8, it is owned by Kamehameha Schools and used as a macadamia nut orchard. Slopes throughout Site 9 are between approximately 3 and 10 percent. A branch of Hi‘onamoa Gulch crosses the site from northwest to southeast near the upper portion of the parcel.
The secondary wastewater treatment and disposal facility at Site 9 would consist of the same treatment components, and would require the same support facilities and infrastructure, as the facility described in Section 2.4 for the Preferred Alternative, and the slow-rate land application
groves would total approximately 8 acres. However, because the site is located across Highway utilities within the highway ROW, which would require approval by the State of
of Transportation. Also, depending on the selected configuration of the wastewater treatment facility and the land application groves, this alternative could require trenching and construction of piping across Hi‘onamoa Gulch within the site.
As with the Preferred Alternative, the Site 9 Alternative would close and abandon LCC 1 and LCC 2 following completion of Phase 1 of the new collection system and would close and abandon the existing C. Brewer wastewater collection system following completion of Phase 2 of the new collection system.
2.6 No-Action Alternative
Under the No-Action Alternative, the County would continue to use the two existing LCCs in
existing substandard gravity sewer lines, and individual septic systems. No additional properties would be added to the community sewer system under this alternative.
This alternativ
collection, treatment, and disposal system; would not fulfill the purpose and need for action described in Section 2.2; and would result in non-compliance with the AOC between EPA and the County.
2.7 Development of Site Alternatives and Selection of Preferred Alternative
For several years, the County has considered various alternative sites in the construction of a new wastewater treatment and disposal facility. The County has primarily
considered sites that could be obtained at “minimal or no” cost and currently vacant sites to avoid displacement and relocation.
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Figure 2.7. Site 8 Alternative – Preliminary Site Plan for New Wastewater Treatment and Disposal Facility
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Figure 2.8. Site 9 Alternative – Preliminary Site Plan for New Wastewater Treatment and Disposal Facility
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The County identified candidate sites based on three primary criteria. First, the site would have to be appropriate for the preliminary design of the treatment and disposal facility. For example,
the site would need to have sufficient area to accommodate the facility and have soil conditions that are suitable for effluent management purposes. Second, access to the site would allow the County to meet the various requirements of the AOC that stipulated closure of the LCCs by June
2021. Third, the environmental impacts of construction of the treatment and disposal facility should be considered. For example, the site would need to be located where a treatment and disposal facility would not create nuisance impacts (e.g., odor or visual impacts) to the community.
community obtained during Community Outreach meetings in December 2017, the County identified nine candidate sites for the proposed wastewater treatment and disposal facility. Figure 2.9 shows the locations of these nine sites, identifies the land owners for each, and depicts their proximity to the existing LCCs. The County evaluated the suitability of each candidate site according to the following process:
1. Twenty-one criteria within four general categories (environmental, social and cultural; location and site; land use and availability; and collection system and service area) were established and defined for the analysis.
2. Six “fatal flaw” conditions were identified. Sites with a fatal flaw were eliminated from further consideration.
3. Relative weighting factors were established for each category and criteria. Environmental, social and cultural considerations, and location and site characteristics were weighted highest (35 percent each), the collection system and service area
category was weighted at 20 percent, and the land use and availability category was weighted at 10 percent.
4. Sites were mapped using GIS. Data such as soil type, location of subsurface and surface water, topography, zoning and prevailing wind direction were determined.
5. Each site was evaluated and scored for the twenty-one criteria.
6. A weighted ranking was determined for each site based on the weighting factors established in Step 3.
7. A preferred site was identified, based on the weighted high scores.
As a result of this process, the County identified three sites (Sites 7, 8, and 9) as reasonable alternatives for construction of the wastewater treatment and disposal facility under the Proposed Action. The final scores for Sites 7, 8, and 9 were 4.33, 4.06, and 4.10 respectively, out of a total possible score of 5. Based on this analysis, Site 7 was selected as the Preferred Alternative. The site is easily accessible, has good soils for a land application system, and is close to the existing LCCs. Site 8 has a stream bisecting the parcel lengthwise that complicates siting of the treatment
and disposal facility. Site 9 also has some surface water within the parcel but is also more difficult to access given its location relative to existing roads. Site 9 would require construction of additional access roads to facilitate construction and operation of the treatment and disposal
facility and would also require a longer transmission line given its distance from the existing LCCs.
Additional information on the specific scoring criteria and the results of the weighted analysis can be found in the June 2018 Pahala Wastewater Treatment Plant Preliminary Engineering Report
(PER), which is included as Appendix B.
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Figure 2.9. Locations of Nine Candidate Sites Considered for New Wastewater Treatment and Disposal Facility
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Section 2.3 describes the Preferred Alternative under the Proposed Action, including the preferred site (Site 7) for construction of the treatment and disposal facility. Sections 2.4 and 2.5 describe
the other two sites (Sites 8 and 9, respectively) identified as reasonable alternatives for construction of the treatment and disposal facility under the Proposed Action. Section 2.8.1 describes the six sites (Sites 1-6) that were eliminated from consideration as reasonable
alternatives.
2.8 Alternatives Considered but Not Carried Forward
2.8.1 Other Site Alternatives
During evaluation of site alternatives, six “fatal flaw” conditions were identified, and sites with a “fatal flaw” were eliminated from further consideration. For more information on fatal flaw conditions, refer to the PER (Appendix B).
(a) Alternative Site 1: LCC Parcel
Site 1 (TMK 9-6-precluding it from being suitable for a wastewater treatment facility due to parcel size. As a result
of this “fatal flaw,” Site 1 was removed from further consideration.
(b) Alternative Site 2: Macadamia Nut Plant Site
Site 2 (TMK 9-6-002:016) is located adjacent to the 0.41-acre County LCC parcel. This parcel
occupies about 64.8 acres, is privately-owned and contains an active macadamia nut processing facility that occupies only a portion of the entire parcel. community meaning it would be close the collection system, limiting the environmental impacts related to construction of the influent and fire protection lines.
However, due to the soil type, Site 2 would require an area of approximately 200 acres to accommodate the slow rate land application basins. The unoccupied area of Site 1 is located on the northern portion of the parcel. As a result, the proposed treatment and disposal site would be nearly adjacent to a residential area and the Hongwanji Mission. Use of this site would
potentially have adverse impacts to residents and the Hongwanji Mission. For these reasons, use of Site 2 for the treatment and disposal facility is not considered a reasonable and feasible alternative.
(c) Alternative Site 3: HELCO Substation
Site 3 (TMK 9-6-002:043) is owned by HELCO and occupies 4.46 acres. It is currently used as a
Commission made use of Site 3 for the treatment and disposal facility not a reasonable and feasible alternative.
(d) Alternative Site 4: Mauna Loa Macadamia Nut Parcel
Site 4 (TMK 9-6-002:048) is located occupies about 339 acres. The parcel is privately owned and contains an active macadamia orchard. An unnamed gulch runs east-west between the highway and orchard area that would need to be crossed by influent
and fire protection lines. The State may require a Stream Channel Alteration Permit should the two lines alter the stream banks. Placing the lines below the stream might require separate pump stations for the lines to access the treatment and disposal facility. The only access to Site 4 is ld be needed to construct within the right -of-way. Due to the soil type, Site 4 would require an area of approximately 200 acres to accommodate the slow rate land application basins. For these reasons, use of Site 4 for the treatment and disposal facility is not considered a reasonable and feasible alternative.
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(e)
Site 5 (TMK 9-6-002:005), a vacant parcel owned by the State of , is located about 3,300
occupies about 2,160 acres. Hi‘onamoa and Moa‘ula gulches lie between Maile Street and Site 3 and influent and fire protection lines would need to cross the gulches to reach the site. A Stream Channel Alteration Permit would be
required should the two lines alter the stream banks. Approval would also be required to construct within the state right-of-way. Due to the soil type at Site 5, approximately 200 acres would be required to accommodate the slow rate land application basins. For these reasons, use of Site 5 for the treatment and disposal facility is not considered a reasonable and feasible alternative.
(f)
Site 6 (TMK 9-6-002:013), a vacant parcel owned by the State of , is located about 1.25 miles feet south of Maile Stre occupies about 75.8 acres. Influent and fire protection lines would need to cross two, and possibly three, gulches to reach the site. A Stream Channel Alteration Permit would be required if the lines alter the stream banks. Approval would also be required to construct utilities within the highway ROW. Because Site 6 lies above the highway, one or two pump stations might be required for the influent line. Due to the soil type at the site, approximately 200 acres of this soil type would be required to accommodate the slow rate land application basins. For these reasons, use of Site 6 for the treatment and disposal facility is not considered a reasonable and feasible alternative.
2.8.2 Other Wastewater Treatment Alternatives
(a) Septic Tank Alternatives
Several septic tank alternatives were identified and considered. Additional details on each
alternative can be found in the PER (Appendix B).
Community Septic Tank. Based on current design criteria and current flow projections, an approximately 800,000-gallon community septic tank would be necessary to provide the extended detention times needed to optimize treatment performance, to avoid the need for frequent septage pumping, and to account for peak flow rates. A community septic tank
of this size would require pumping on a 3-year interval. Septic tanks produce hydrogen sulfide, reduced sulfur compounds, and other odorous gases; a community septic tank would concentrate these emissions to a single point source, requiring treatment with a dual-stage scrubber to avoid nuisance odor conditions. More significantly, a community septic tank would not be capable of achieving the effluent quality standards (less than 30 mg/L of both BOD5 and TSS) specified in HAR 11-62-23.1. Therefore, use of a community
septic tank is not considered to be feasible.
Converting LCC to Seepage Pit. Converting LCC 1 to a seepage pit regulated as an
injection well (LCC 2 could not be converted as it is on private land) would lead to numerous potential compliance issues with HAR 11-23-07, which regulates injection wells. The condition and structure of LCC 1 is unknown, and HAR 11-62-25 requires all new and proposed effluent disposal systems are required to have a backup system. No such system could be feasibly constructed as new injection wells are not allowed.
Leachfield Disposal. To meet DOH’s leachfield design criteria, a minimum of 30 acres of land would be required to meet loading rate and redundancy requirements. Achieving even distribution of effluent over a leachfield of this size would be challenging. Therefore, leachfield disposal is not considered to be feasible.
construct individual septic systems, and for those that couldn’t accommodate a septic
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tank, the soils have percolation rates that are too slow to allow for seepage pits based on HAR 11-62-34 regulations. Residents with sufficient space for a seepage pit would need
to import fill soil to create elevated mound systems. Conversion to individual wastewater systems is therefore not considered feasible.
(b) Other Treatment Alternatives
Several other treatment alternatives were considered for the project. Additional details can be found in the PER (Appendix B).
Option 1: Aerated Lagoons/Constructed Wetland/Land Application (Proposed Treatment Method). Option 1 consists of an aerated lagoon treatment system with a constructed wetland and disinfection, followed by land application for effluent management. This is the
Option 2: R-1 Treatment/Land Application. Option 2 consists of a treatment system
-1 recycled water criteria. The R-1 treatment system would be followed by land application.
Option 3: R-1 Treatment/Seasonal Water Recycling. Option 3 consists of a treatment system similar to Option 2 to produce R-1 recycled water. The recycled water would then be used to irrigate nearby macadamia nut orchards. A water recycling analysis no
irrigation is typically needed between October and March because precipitation exceeds evaporation during those months. During months when irrigation is unnecessary, recycled water could be land applied.
Option 4: R-1 Treatment and Storage for 100 Percent Recycling. Option 4 adds a seasonal storage reservoir for recycled water. HAR 11-62 requires a disposal system for all recycled
water systems to provide a means for disposal of water that does not meet R-1 standards or disposal of excess water should the seasonal storage reservoir capacity be exceeded during an exceptionally wet year. Storage in open reservoirs can also lead to algae growth and odor issues, requiring additional treatment to meet R-1 criteria before irrigation.
Option 5: Maximum Practical Treatment. Option 5 consists of implementing advanced
wastewater treatment processes that represent maximum practical treatment, eventually producing R-1 water. The same issues associated with utilizing or storing R-1 water described for Options 3 and 4 would apply to Option 5.
The treatment alternatives described above were removed from consideration due for several reasons, as described below. Additional details can be found in the PER (Appendix B).
Labor Requirements. Options 2 through 5 require daily site visits from operators based in Hilo to conduct sampling required for R-1 compliance. These options also consist of mechanical treatment technology that requires more operator attention. Option 1 (preferred alternative) requires weekly visits by treatment plant operators based in Hilo, with periodic maintenance visits as needed.
Operational Complexity. Options 2 through 5 require Grade IV certification through HAR 11-61 due to the complexity of treatment processes. Generally, the County has difficulty attracting and retaining Grade IV operators. Option 1 requires an operator certification level of Grade 1, the lowest level established by HAR 11-61.
Energy Consumption. Options 2 through 5 require a substantial amount of electrical
energy due to the use of mechanical processes. Option 1 requires significantly less energy due to the use of natural treatment systems.
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Sludge Management. Options 2 through 5 would require an anaerobic digester for sludge management, with solids trucked to a landfill on a weekly basis. Option 1 would require sludge removal from lagoons approximately once every 15 to 20 years. The resulting solids are well-digested and inoffensive.
Additionally, Living Machine® technology was suggested during community outreach meetings. The technology has been implemented in buildings but there is no evidence of the technology being used at a municipal scale. The proposed non-proprietary treatment system (aerated
lagoons and subsurface flow wetland) uses essentially the same natural treatment processes as the Living Machine®, but on a municipal scale.
2.8.3 Other Effluent Management Options
Several effluent management options were evaluated for feasibility as an alternative to land application. The options described below were removed from consideration due to their lack of feasibility and other concerns as outlined herein.
Ocean Discharge. Ocean discharge of treated effluent is not considered a viable option
an outfall, stringent receiving water quality standards, high ocean water monitoring costs, and the difficulty and length of time required to secure permits.
Subsurface Disposal via Injection Wells. Per HAR, Title 11, Chapter 23, disposal to ground water via an injection well is not allowed west (mauka) of the DOH UIC line. Because the
Water Recycling. Water recycling was considered as an alternative effluent management
and DOH requirements for all water recycling programs to have a 100-percent backup system. Storage systems could be constructed but could lead to issues as described in Section 2.8.2.
Drain Field. A drain field (i.e., a leachfield) is an alternative effluent management option, but was removed from consideration due to the reasons outlined in Section 2.8.2, most
notably the large amount of land required for a drain field and difficulties with distributing effluent across such a large area.
2.9 Relationship to 2007 Final Environmental Assessment
In August 2007, the issued a Final EA -Capacity Cesspool Conversion project. The County then made a Negative Declaration, also referred to as a Finding of No Significant Impact (FONSI), regarding the project on August 10,
2007, and published a notice of the determination in the August 23, 2007 issue of the Office of Environmental Quality Control (OEQC) publication The Environmental Notice.
As described in that Final EA, the County DEM initiated the project to address the closure of the
Although that Final EA addressed both communities, the proposed improvements were essentially similar for both communities. For primarily within the public ROWs and to replace the existing LCCs with six DOH-approved septic tanks for wastewater treatment and reuse of LCC 1 as a seepage pit for the effluent disposal system.
After the issuance of the Final EA and Negative Declaration/FONSI in 2007, the County conducted additional study and evaluation of the proposed LCC conversion project. The County eventually concluded that the LCC conversion project described in the 2007 Final EA would not meet the need to provide a collection system and a treatment and disposal facility, close the
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LCCs, and provide for . This determination was based on several factors, including the following:
The capacity, structure, and condition of LCC 1 are not known; the County attempted to determine the structure and condition of LCC 1 via inspection by closed circuit television
but could not ascertain its condition due to technological limitations. Additionally, poor results from soil percolation tests influenced the County to consider looking at larger land to construct a secondary treatment system to fulfill a longer-term vision of a higher level
of wastewater treatment and options for plant expansion for possible community growth.
HAR 11-62-25 requires new and proposed effluent disposal systems to have a backup disposal system capable of handling the peak flow. However, a second seepage pit would most likely not be allowed as the site is located mauka of the UIC line. Also, if the existing seepage pit were to fail, a replacement could not be constructed.
The Community Plan was adopted as Ordinance No. 2017-66 in October 2017. This plan requires the County to provide for eventual construction of a collection system and
lthough the Community Plan was LCC conversion project would need to be consistent with the plan. Increasing flow to the converted existing
LCC used as a seepage pit would not be allowed because it is located mauka of the UIC line. Therefore, the use of the existing LCC as a disposal system could prevent the County from providing the community’s desired future wastewater needs.
As discussed in Section 2.8.2(a), the use of a community septic tank would present odor concerns and would not be capable of meeting state effluent quality standards.
Based on the above considerations, the County has decided not to move forward with the community LCC conversion project described in the 2007 Final EA and Negative Declaration/FONSI, and is instead evaluating the alternatives described in this Draft EA.
2.10 Other Considerations
2.10.1 Zoning Considerations
The wastewater treatment and disposal project site is designated “Agricultural”.
The 14.9-acre treatment and disposal facility would be owned by the County of Hawai i and managed and operated by the County of DEM. The treatment and disposal facility would
be a “public use” as defined by the County Code (HCC) Chapter 25, Zoning, Section 25-1-5, as a use conducted by or a structure or building owned or managed by the federal government, the State of or the County to fulfill a governmental function, activity, or service for public benefit and in accordance with public policy.
To ensure compliance with relevant code, the County would obtain a Plan Approval from the Planning Department for the treatment and disposal facility. Also, the County would submit a Special Use Permit (SUP) application to the County Planning Commission.
2.10.2 Land Transfer
Construction of the portions of the collection system located within County ROWs would not require further land transfer approvals. As previously discussed, two short segments of the planned collection system would be located with privately owned parcels. The County would obtain easements from the land owner(s) as part of the construction process.
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The County Code Chapter 23, Subdivisions, states that all subdivision plats and all streets or ways within the County created for the purpose of partitioning land shall be approved by the
County Planning Department Director. Further, Section 23-11 includes requirements on lot sizes. This section states the following:
“standards of this chapter shall not be applicable to public utility or public rights-of-way
subdivisions and their remnant parcels; provided that the Planning Department
Director, upon conferring with the County Director of Public Works and Manager-Chief Engineer of the Department of Water Supply, may require necessary improvements to
further the public welfare and safety.”
Lastly, Section 23-12 (Submission of application and plans; filing) states the following:
“(a) A person desiring to subdivide land or desiring to partition land by creation of a
street within the County shall submit an application for subdivision and preliminary and
final plans and documents for approval as provided in this chapter and State law; (b)
No subdivision plat may be filed with the Bureau of Conveyances or Land Court until
submitted to and approved by the Planning Department Director.”
The County has conducted a Phase 1 Environmental Site Assessment of the entire 42.5-acre parcel comprising Site 7. This review did not identify any recognized environmental
concerns or liabilities associated with acquiring portions of Site 7.
2.10.3 Revised Statutes (HRS) Chapter §205 Considerations
as “Urban” by the State Land Use Commission. The wastewater treatment and disposal project site is designated as “Agricultural”.
According to HRS Chapter §205-4.5, permissible uses within the agricultural districts are the following:
“(a) Within the agricultural district, all lands with soil classified by the Land Study Bureau's
detailed land classification as overall (master) productivity rating class A or B shall be
restricted to the following permitted uses:
(1) Cultivation of crops, including crops for bioenergy, flowers, vegetables, foliage, fruits,
forage, and timber;
(2) Game and fish propagation;
(3) Raising of livestock, including poultry, bees, fish, or other animal or aquatic life that
are propagated for economic or personal use;
(4) Farm dwellings, employee housing, farm buildings, or activities or uses related to
farming and animal husbandry.
(5) Public institutions and buildings that are necessary for agricultural practices;
(6) Public and private open area types of recreational uses, including day camps, picnic
grounds, parks, and riding stables, but not including dragstrips, airports, drive-in
theaters, golf courses, golf driving ranges, country clubs, and overnight camps;
(7) Public, private, and quasi-public utility lines and roadways, transformer stations,
communications equipment buildings, solid waste transfer stations, major water
storage tanks, and appurtenant small buildings such as booster pumping stations, but not including offices or yards for equipment, material, vehicle storage, repair or
maintenance, treatment plants, corporation yards, or other similar structures;
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(b) Uses not expressly permitted in subsection (a) shall be prohibited, except the uses permitted as provided in Sections 205-6 and 205-8.”
HRS Chapter §205-6 (Special permit) states the following:
“(a) The county planning commission may permit certain unusual uses within agricultural and rural districts other than those for which the district is classified. Any
person who desires to use the person's land within an agricultural or rural district other
than for an agricultural or rural use, as the case may be, may petition the planning commission of the county within which the person's land is located for permission to
use the person's land in the manner desired. Each county may establish the
appropriate fee for processing the special permit petition.”
Based on the above, a SUP application for the treatment and disposal facility would be prepared by DEM for submittal to the Planning Commission.
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3 DESCRIPTION OF EXISTING CONDITIONS, IMPACTS AND
MITIGATION MEASURES
3.1 Climate
3.1.1 Existing Conditions
(a) All Alternative Sites
Climate on the Island of Hawai‘i and more broadly throughout the state can be characterized as having low day-to-day and month-to-month variability. Differences in the climate of various areas
are generally attributed to local differences in geology and topography that create microclimates with different temperature, humidity, wind and rainfall, and associated local ecosystems (Department of Geography, 1998).
The climate of District. The National Oceanic and Atmospheric Administration (NOAA) designates the area as a Humid Tropical Zone with transitional lowland areas in locations between windward and leeward regions. The area receives less orographic rainfall since it is not oriented normal to trade wind flow and exhibits a distinctive summer dry season.
een 70 and 80 degrees Fahrenheit during daylight hours and between 60 and 70 degrees Fahrenheit during night hours. The National Hawai‘i Rainfall Summary shows a total of 40.of 57.00 inches. Below-average totals were also observed at two other rainfall gauges nearby at Kahuku Ranch and South Point.
Prevailing trade winds in the District area are from the southeast and usually dominate from April to November. Wind speeds average about 15 miles per hour and vary between approximately 10 to 20 miles per hour. Winds from the southwest occur less frequently, mainly
during the winter associated with “Kona” storms (Department of Geography, 1998).
3.1.2 Impacts and Mitigation Measures
(a) All Alternative Sites
There is the potential for construction-related and operational greenhouse gas emissions under the proposed action. Heavy equipment during construction may temporarily emit greenhouse gases during their operation and trucks used to transport supplies and equipment may cause emissions outside of the area. Operation of the wastewater system under the Proposed Action also has the potential for minor greenhouse gas emissions due to operations at, and one-per-week vehicle trips to, the proposed treatment and disposal facility site. These emissions are expected to be minor and are not expected to contribute substantially to emissions from the area.
Climate conditions in the District are likely to change in coming decades. Changes in average annual temperature are unlikely to impact the proposed wastewater treatment and disposal facility and its effluent because there is no discharge to surface water sources and therefore the
temperature of streams in the area is unlikely to be impacted by the project. Average annual precipitation is also likely to change, but climate models are uncertain in projections for Hawai‘i, with projections for the area surrounding ranging from a minor decrease in annual
precipitation (up to a 4-percent decrease) to up to 20-percent increase depending on the model
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September 2018 Page 3-2
scenario (hot/dry vs. warm/wet), based on modeling conducted by EPA (USEPA, 2017). Another climate concern for coastal areas and islands is sea level rise. Because the community
lies about 3.8 miles from the coast and between 800 to 1,000 feet above msl, sea level rise is not expected to impact the proposed project.
Climate models also predict changes in the intensity of storm events. An ensemble model
projection developed by EPA indicates anywhere from a 1.0-percent to a 19.8-percent increase in 100-year storm intensity by 2035 depending on the scenario used for the modeling (“stormy” vs. “not as stormy”). By 2060, projections range from 1.9 percent to 38.5 percent. The large amount of uncertainty in projections makes it difficult to determine potential impacts of increased storm intensity on the project, but it is likely that there is some change in storm intensity in the next few decades. The Proposed Action will be designed to collect sanitary wastewater only; the community’s stormwater would be managed by other means. Some nominal inflow of stormwater into wastewater collection systems through manhole covers and other hydraulic pathways is normal and can be expected to increase with increasing storm intensity in the future. Because the proposed wastewater treatment and disposal facility does not intercept stormwater flows, there is unlikely to be a direct impact on inflow to the plant, although more intense or more frequent storms could impact the open aerated lagoons, subsurface flow constructed wetland, and land application processes from precipitation falling directly on these systems. All potentially affected processes would be bermed to contain the 100-year, 24-hour storm event while maintaining at least two feet
of freeboard to account for the uncertainty of the climate model projection uncertainties.
(b) No-Action Alternative
Under the No-Action Alternative, the existing LCCs are at risk of impacts due to climate change,
specifically changes in precipitation and storm intensity. The nature of the LCCs makes them more exposed to these threats, potentially leading to impacts to ground water, surface water, and other resource areas.
3.2 Topography
3.2.1 Existing Conditions
a , west (mauka) of M malahoa Highway and occupies an area of about 0.61 square miles. The developed area of slopes down at about 6 percent from the northwest to the southeast, from an elevation of 1,000 feet above msl to 800 feet above msl over a distance of 3,500 feet. The slope of the streets in the community
approximately follows the contours to maintain level or appropriately sloped grades to allow vehicle travel. On certain streets, this condition results in house lots on the downhill side of the street to be several feet below the road surface, while those on the uphill side lie several feet above.
(a) Preferred Alternative (Site 7)
The 42.5-acre preferred location for the Proposed Action is generally situated on a southeast
facing slope with an average slope of approximately 8.7 percent and a maximum of 18.9 percent. The elevation of the parcel ranges from 580 to 780 feet above msl.
(b) Alternative Site 8
The 45.2-acre Site 8 parcel faces approximately southeast with an average slope of approximately 9 percent and a maximum of 28.2 percent. The elevation of the parcel ranges from approximately 540 to 740 feet above msl. An unnamed branch of Hionamoa Gulch crosses the site from northwest to southeast near the center of the parcel.
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(c) Alternative Site 9
The 157-acre Site 9 parcel faces approximately southeast with an average slope of approximately
7 percent and a maximum of 10 percent. The elevation of the parcel ranges from approximately 300 to 600 feet above msl. Two unnamed south-flowing branches of Hionamoa Gulch cross portions of the parcel.
3.2.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
Construction of the new wastewater collection system would require trenching in locations throughout the , primarily within the ROW of public streets plus two short segments within easements. Trenches would typically be about 3 feet wide and at least 6 feet deep. Due to the existing topography, several locations may also require installation of pumps. Once the line is placed in the trench, the affected area would be backfilled to restore the existing topography, resulting in minimal localized effects to the site topography.
The construction of the wastewater treatment and disposal facility would involve grading, excavating, and fill activities on approximately 14.9 acres at Site 7. Excavation to depths of approximately 4 to 10 feet would be required to provide necessary capacity for the lagoons, constructed wetlands, and planted groves. An approximately 4-foot tall berm would be constructed on all four sides of the groves to contain rainfall from a 100-year, 24-hour storm event. As discussed in Section 3.7.2, stormwater and erosion control plans would be developed,
necessary construction permits would be obtained, and appropriate stormwater and erosion control measures would be implemented.
Abandonment of the two LCCs and the existing wastewater collection system would not affect
topography within the affected areas.
(b) Alternative Site 8
Under this alternative, the topographic impacts and mitigation measures would be similar to those
described above for the Preferred Alternative (Site 7), with the following differences:
Construction of an additional 1,600 feet of collection system piping to reach Site 8 would
require additional trenching. The affected areas would be backfilled to restore the existing topography.
Due to the steeper slopes at Site 8, construction of the wastewater treatment and disposal facility would require grading, excavating, and fill activities on approximately 4 additional acres to accommodate the terracing required to construct the slow-rate land application
groves on the steeper site.
(c) Alternative Site 9
Under this alternative, the topographic impacts and mitigation measures would be similar to those
described above for the Preferred Alternative (Site 7); however, an additional 3,200 feet of trenching would be required to extend the collection system piping, potable water line, and fire protection line to Site 9. The affected areas would be backfilled to restore the existing topography.
(d) No-Action Alternative
The No-Action Alternative would not involve grading, excavation, or fill activities, and therefore would not impact topography in the
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3.3 Geology
3.3.1 Existing Conditions
(a) All Alternative Sites
The Island of Hawai‘i was formed by the activity of five shield volcanoes. These shield volcanoes are Kohala (extinct), Mauna Kea (has had activity during recent geologic time), Hualalai (last erupted in 1801), and Mauna Loa and Kilauea (both of which are still active).
The project site is situated at the eastern end of the island and on the lower, southeastern flank of the Mauna Loa Volcano. This volcano appears to be made up of at least two huge shield
volcanoes built around two separate eruptive centers, referred to as the Mauna Loa shield. The Mauna Loa shield has been built principally by eruptions along two rift zones that extend in a southwest and east-northeast direction from the caldera. Rift zones are elongated areas of ground
fissures where volcanic activity such as earthquakes and volcanic eruptions are concentrated. In contrast, few eruptions have taken place along the lower northeast rift zone.
is situated on the slopes of Mauna Loa. The surrounding area consists of several inter-
stratified beds of volcanic ash that sit upon the exposed bedrock. area is known to contain lava tubes, which often occur in many places around the Island of Hawai‘i. Generally, a lava tube is a natural conduit or void that forms when molten lava flows beneath the hardened
surface of a previous lava flow. When the volcanic eruption stops, and the lava drains out, a lava tube forms in the void. Lava tubes can range in size from a few inches to more than 25 feet in diameter. The tubes are generally not visible from the surface and the diameter and length can usually be identified only through subsurface probing or geophysical surveys.
3.3.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The presence of lava tubes at each of the alternative wastewater treatment and disposal facility
sites is possible but unknown. A geotechnical investigation of the selected site would occur during
the design and engineering process. Grading, excavating, and fill activities during construction of
the facility and the new collection system would occur no deeper than approximately 10 feet below grade and thus would have negligible impacts on the geology in the area. If/when bedrock is encountered during excavation for the Proposed Action, removal would be accomplished using
hydraulic and/or pneumatic hammers consistent with other construction activities on the Hawaiian
Islands.
Abandonment of the two LCCs and the existing wastewater collection system would not affect geology within the affected areas.
Impacts and mitigation measures associated with seismic hazards are discussed in Section 3.4.
(b) No-Action Alternative
The No-Action Alternative does not involve any construction activities or modification to the
existing conditions, and therefore would not cause any impacts to geology in the area.
3.4 Seismic Hazard
3.4.1 Existing Conditions
(a) All Alternative Sites
Earthquakes in the Hawaiian Islands are primarily associated with volcanic eruptions resulting from the inflation or shrinkage of magma reservoirs beneath, which shift segments of the volcano.
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The Island of Hawai‘i experiences thousands of earthquakes each year; however, most are so small that they can only be detected by instruments. Although difficult to predict, an earthquake
of sufficient magnitude could cause structural or other damage to public facilities including wastewater collection systems. The seismic risk classification of the Island of Hawai‘i is Zone 4 (USGS, 1997).
Earthquakes may occur before or during an eruption or may result from the underground movement of magma that comes close to the surface. On the Island of Hawai‘i, earthquakes directly associated with the movement of magma are concentrated beneath the active Kilauea and Mauna Loa Volcanoes. Typically, the risk of seismic activity and degree of ground movement decreases with the distance from these active volcanoes. A few of the island’s earthquakes are less directly related to volcanism. These originate in the zones of structural weakness at the base of the volcanoes or deep within the earth beneath the island.
Several destructive earthquakes have occurred on the Island of Hawai‘i. The locations of larger damaging on-island earthquakes since 1868 have generally occurred in the southeast portion of the island near Kilauea, with the most recent destructive earthquake on this south flank occurring on June 26, 1989 with a magnitude of 6.1. More recently, a Magnitude 6.9 earthquake occurred on May 4, 2018 offshore and east of Kilauea, though this earthquake was classified as non-destructive.
3.4.2 Impacts and Mitigation Measures
(a) All Alternative Sites
Hawai‘i County Code Chapter 5 (Building), Section 5.3 indicates the “International Building Code, 2006 Edition” (IBC) – copyrighted and published in 2006 by the International Code Council,
Incorporated – is adopted by the County. Chapter 5 is the applicable code for the construction of buildings, structures, and facilities in the County. The purpose of the seismic provisions in the IBC is primarily to safeguard against major structural failures and loss of life; limiting damage or
maintaining functions is not a primary purpose. At a minimum, structures are to be designed and constructed to resist the effects of ground motions from seismic events. The seismic hazard characteristics described in the IBC are based on the seismic zone and proximity of the site to active seismic sources.
The wastewater treatment and disposal facility would be designed and constructed to meet the requirements of the 2006 IBC and Hawai‘i County Code Chapter 5 and would comply with seismic loadings established for the County of . This would minimize the potential for an uncontrolled release of untreated or partially treated sanitary wastewater, emergency generator diesel fuel, or disinfection chemicals from the facility during a seismic event.
(b) No-Action Alternative
The No-Action Alternative includes no construction or modification to existing conditions, and
therefore would not impact seismic hazard in the
3.5 Volcanic Hazard
3.5.1 Existing Conditions
(a) All Alternative Sites
In 1997, the U.S. Geological Survey prepared an updated volcanic hazard zone map for the Island of Hawai‘i. The map shows lava flow hazard zones for the five on-island volcanoes. The current map divides this island into zones ranked from 1 (highest hazard) through 9 (lowest hazard) based on the probability of coverage by lava flows. Hazard zones from lava flows are based mainly on
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the location and frequency of both historic and prehistoric eruptions. Hazard zones also consider the larger topographic features of volcanoes that affect the distribution of lava flows.
has been assigned a rating of Zone 3, which designates areas that are less hazardous than Zones 1 and 2 because of the greater distance from recently active vents and (or) because of topography. One to five percent of Zone 3 areas have been covered by eruptions since 1800,
and 15 to 75 percent have been covered within the past 750 years.
3.5.2 Impacts and Mitigation Measures
(a) All Alternative Sites
Based on the volcanic hazard map, the potential for damage is moderate, given the distance between y and active vents and hazards. At this time, the County has no construction restrictions in Zone 3 areas. Thus, at this time, the volcanic hazard designation would not affect the construction and operation of a collection system or treatment and disposal facilities. Although the potent
likely that damage would occur to residences, the treatment and disposal facilities, the collection system, and other assets in the area. There are no mitigation measures to prevent the potential impacts from volcanic activity, and the impacts would be similar regardless of the location of the treatment and disposal site or treatment system employed.
(b) No-Action Alternative
The No-Action Alternative involves no change to the status quo, so the current risk faced by
3.6 Soils
3.6.1 Existing Conditions
(a) All Alternative Sites
Figure 3.1 shows the soil types in the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) Soil Survey of the Island. Soils at all alternative sites for the proposed wastewater treatment and disposal facility are primarily classified as series 521 – approximately 17 inches of medial silt loam over hydrous silty clay loam with a depth to bedrock greater than 59 inches. This soil series has moderately-high to high permeability characteristics,
and generally consists of well-drained soils that formed in volcanic ash. As shown in Figure 3.1, the northwest half of Site 8 is composed of a slightly different soil type, series 522 – medial silty clay loam, 10 to 20 percent slopes.
The western portion of the collection system and the wastewater treatment and disposal facility alternative sites consist of ash fields on p hoehoe lava fields with soils that are well drained with a runoff class of low. The remainder of the area for the collection system project has a soil
-lava flows. Soils in these areas are somewhat excessively drained with a runoff class of very low.
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Figure 3.1. Area Soils Map
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3.6.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The collection system would be constructed below the travelways or shoulders of the streets in the originally constructed, and therefore the collection system would not create new adverse impacts
to soils in the area.
Construction of the wastewater treatment and disposal facility would require removal of macadamia nut trees and clearing and excavating for construction of various improvements as described in Section 2.4. The soils within the proposed treatment and disposal facility at Site 7, as well as similar locations at Sites 8 and 9 that are also part of the macadamia nut orchard, were previously disturbed during planting of the macadamia nut trees. An HDPE liner would be placed below the excavated areas for the lagoons and subsurface flow wetland, mitigating adverse impacts to soils in the area as well as ground water.
The proposed location for slow-rate land application basins would also require excavation to allow placement of the soil medium (approximately 8 acres for Sites 7 and 9, and approximately 12 acres for Site 8). Although the soils would be disturbed, the natural permeability characteristics of the soil would mitigate adverse impacts due to construction. The Proposed Action would incorporate appropriate stormwater and erosion control measures in accordance with approved plans to ensure that soil erosion and transport during construction activities are minimized.
Continued operation of the land application basins is not expected to cause adverse impacts to surrounding soils due to the physical and biological treatment that would occur as effluent percolates through the soil and is taken up by planted vegetation.
Abandonment of the two LCCs and the existing wastewater collection system would not affect soils within the affected areas.
(b) No-Action Alternative
The No-Action Alternative would not involve any direct or indirect impacts to soils. Continued use
of the existing LCCs and wastewater collection system would not result in impacts to soils in the
.
3.7 Surface Water
3.7.1 Existing Conditions
community is located between two surface water sources and east, and an unnamed branch of Hionamoa Gulch to the south and west. The USGS , while the
unnamed branch flows into Hionamoa Gulch about 3,000 feet southwest of Maile Street. Flows from Hionamoa Gulch end about 6,000 feet from the coast. Figure 3.1 illustrates the known
(a) Preferred Alternative (Site 7)
There are no surface water sources located within the proposed wastewater collection system or the existing LCCs. Similarly, there are no surface water sources located within Site 7.
(b) Alternative Site 8
The unnamed branch of Hionamoa Gulch crosses the Site 8 parcel from northwest to southeast near the center of the parcel. The gulch is classified as a riverine wetland in the National Wetland
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Inventory (NWI), but it is unknown whether this has been confirmed through a field survey and delineation. There are no other wetlands or surface water bodies located on this parcel.
(c) Alternative Site 9
Two unnamed south-flowing branches of Hionamoa Gulch cross portions of the Site 9 parcel. Also, an unnamed east-flowing branch of originates in the Site 9 parcel near the
southeast boundary of the Site 7 parcel; this branch flows into approximately 4,000 feet east of the Site 9 parcel. These gulches are classified as riverine wetlands in the NWI, but it is unknown whether this has been confirmed through a field survey and delineation. There are no other wetlands or surface water bodies located on this parcel.
3.7.2 Impacts and Mitigation Measures – Construction Activities
(a) Preferred Alternative (Site 7)
Given the cumulative areal extent of disturbance for the wastewater treatment and disposal facility and the new collection system, the Proposed Action would require coverage under a National Pollutant Discharge Elimination System (NPDES) construction stormwater permit. The NPDES permit would include best management practice (BMP) measures such as use of silt fences or filter socks along the perimeter of each construction site and sediment traps at drainage inlets. Further, to minimize the potential for inadvertent leaks or spills of fuels and other petroleum products, construction vehicles and equipment would be well maintained and kept at a temporary staging area where runoff is controlled.
Construction trenches would require the contractor to submit erosion control and stormwater control plans to the County and the DOH. Typically, the plans would require installation of erosion and sediment control BMPs. This may include the use of perimeter controls, such as silt fences
or filter socks. These BMPs would be used to surround all construction sites, including material storage and staging areas and all construction sites related to the collection system, to control pollutants in stormwater flow from the sites during construction.
The construction contract documents would require that a Site-Specific Construction BMP plan be prepared, addressing the measures that will be implemented onsite to prevent stormwater pollution. This may include spill response measures, waste management procedures, and other pollution prevention activities. The NPDES permit would also require periodic BMP inspections (and maintenance of associated documentation) to ensure the construction activities are compliant with the BMPs, Stormwater Pollution Prevention Plan (SWPPP), and NPDES permit.
Construction of the treatment and disposal facility would result in an increase in impervious surfaces. Hawai‘i County Code, Chapter 27, Section 20, requires an on-site drainage plan to accommodate any runoff caused by a proposed development, and requires all runoff to be retained within the site. An on-site drainage system within the developed area would collect runoff via grated inlets or swales. These flows would be conveyed to on-site drainage detention systems,
such as subsurface linear infiltration or depressed detention basins, to detain flows and volumes to their pre-development condition. Typically, a 1-hour, 10-year storm event is used to determine the size of the on-site drainage system. As stated in Hawai‘i County Code, Chapter 27, Section
20:
(e) All developments requiring a site drainage plan under Section 25-2-72(3) shall submit such a plan for review and approval by the director of public works. The site
drainage plan shall comply with sections 27-20(a) and (b) and section 27-24, and shall
include a storm water disposal system to contain run-off caused by the proposed development, within the site boundaries, up to the expected one-hour, ten year storm
event, as shown in the department of public works “Storm Drainage Standards,” dated
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October 1970, or any approved revision, or by any nationally-recognized method meeting with approval of the director of public works. Runoff calculations shall include
the effects of all improvements.
(f) Storm water shall be disposed into dry wells, infiltration basins, or other approved infiltration methods. The development shall not alter the general drainage pattern
above or below the development.
To ensure that there is no adverse impact on adjacent or downstream properties due to post-development flows, landscape buffers with dirt berms would be constructed around most of the perimeter of the property, acting as secondary containment in the event of a large storm event. The planted groves for the land application system would be constructed with an approximately 4-foot-high berm on all four sides to contain the peak treated effluent flows plus rainfall from a 100-year, 24-hour storm event. Once the berms are constructed, no adverse effects to the surrounding areas would be likely during operation of the treatment and disposal facility for a storm of that magnitude.
Overall, the potential for construction-related impacts on surface water resources is temporary and adherence to BMPs will minimize the potential for these impacts to occur.
Abandonment of the two LCCs and the existing wastewater collection system would not affect surface waters within the affected areas. A single NPDES permit would be secured for all elements of the project, including LCC closure.
(b) Alternative Sites 8 and 9
All of the same information presented above for the Preferred Alternative (Site 7) is relevant to Alternative Sites 8 and 9. The same permits would be required, and the same or similar
construction practices and BMPs would be implemented to mitigate potential impacts.
One difference between the Preferred Alternative (Site 7) and Alternative Sites 8 and 9 is the presence of south-flowing branches of Hionamoa Gulch in Sites 8 and 9, as shown in Figure 3.1.
Depending on the selected configuration of the wastewater treatment facility and the land application groves, Alternative Sites 8 or 9 could require trenching and construction of piping across the gulch. A Stream Channel Alteration Permit would be required should the piping alter the stream banks. Extra attention would be required to ensure that BMPs are implemented to prevent erosion and sedimentation that could impact the surface water bodies. The potential for impacts to surface water is greater at Sites 8 and 9 due to the presence of these gulches.
(c) No-Action Alternative
The No-Action Alternative includes no construction activities, and therefore would not lead to a construction-related impact to surface water.
3.7.3 Impacts and Mitigation Measures – Operation of Wastewater System
(a) Preferred Alternative (Site 7)
EPA defines land treatment as “the application of appropriately pre-treated municipal and industrial wastewater to the land at a controlled rate in a designed and engineered setting. The purpose of the activity is to obtain beneficial use of these materials, to improve environmental
quality, and to achieve treatment goals in a cost-effective and environmentally sound manner” (USEPA, 2006).
The soils at the Preferred Alternative site (Site 7) are suitable for slow-rate land treatment. Slow-
rate land treatment consists of irrigation of land and vegetation with treated effluent. Significant further treatment is provided as the water percolates through the soil, the vegetation uses the nutrients in the effluent as fertilizer and transpires a portion of the applied water. The proposed
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wastewater treatment and disposal facility would be designed to intermittently apply treated effluent to native trees and vegetation growing on permeable soils. After an application period or
wetting period, the surface can dry, and oxygen can enter the soil matrix, which aids aerobic biological treatment. The proposed project estimates a reduction of greater than 99 percent in the annual load of five-day biochemical oxygen demand (BOD5), total suspended solids (TSS), and
phosphorus to the environment compared to the current LCCs, and a decrease of 83 percent in the annual load of nitrogen compared to the existing LCCs. As a result, operation of the collection system and the treatment and disposal facilities would not create adverse impacts to surface
(b) Alternative Sites 8 and 9
All of the same potential impacts described for the Preferred Alternative (Site 7) would apply for
Alternative Sites 8 and 9. However, the presence of streams on both Sites 8 and 9, as shown in Figure 3.1, heightens the risk of potential impact from the wastewater treatment and disposal facility on surface water resources. BMPs could help mitigate these potential impacts, and siting
of the facility and land application sites would be important to avoid adverse impacts to surface
water sources.
(c) No-Action Alternative
The No-Action Alternative includes no modifications to the existing landscape. As such, any impacts to surface water resources would be caused by the existing LCCs. Closure of the LCCs is mandated by EPA regulations due to increased risk of impacts to water supplies and public health from continued use of LCCs.
3.8 Ground Water
3.8.1 Existing Conditions
Ground water occurs within portions of geologic formations where aquifers receive and store water. Depending on geology of the area, many areas on the island rely on ground water wells to obtain drinking water. To protect the quality of underground sources of drinking water from
contamination by subsurface disposal of fluids, Hawai‘i has adopted the UIC program administered by the State DOH Safe Drinking Water Branch. Chapter 340 E, HRS, and Title 11, HAR Department of Health Chapter 23, Underground Injection Control set forth the requirements related to protection of underground sources of drinking water.
Under HAR Chapter 11-62, Appendix F, a minimum separation of 1,000 feet from existing wells is required for wastewater treatment sites.
(a) Preferred Alternative (Site 7)
On April 3, 2018, in response to the pre-assessment notification, the DOH Safe Drinking Water Branch indicated that the proposed wastewater treatment and disposal project site at Site 7 is located above the UIC line and, as such, on top of underground sources of drinking water. To avoid impacts to drinking water wells, sewage injection wells cannot be constructed above the UIC line.
The State of Hawai‘i Department of Land and Natural Resources Commission on Water Resource Management (CWRM) maintains information on various types of wells throughout the state. The
confirmed that the County well and storage tank are located approximately 5,000 feet north of Site 7. The USGS topographic map shows the tank lies at about 1,040 feet above msl, which is
approximately 400 feet higher in elevation than Site 7. The private well is located within TMK: 9-
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6-002:016, the parcel that contains the existing LCC and lies adjacent to Site 7. The CWRM has indicated this well is used for agricultural purposes, not for domestic purposes.
(b) Alternative Sites 8 and 9
The existing conditions discussed above for the Preferred Alternative (Site 7) are similar to Alternative Sites 8 and 9. Compared to the Preferred Alternative (Site 7) parcel, Site 8 is located
a similar distance away, while Site 9 lies further away from the existing County drinking water well and the private well. There is a well to the southeast of the Site 9 parcel, but the parcel is not located within a 1,000-foot radius of the well.
3.8.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
The approximately 6-foot trenches needed to support the collection system would be relatively
collection system would not affect ground water resources in the area.
The treatment and disposal facility would require excavation for the lagoons, subsurface constructed wetland, and the planted groves. Preliminary plans show the lagoons would require about 10 feet of excavation, the subsurface constructed wetland about 4 feet and the planted groves about 6 feet. Construction activities would follow an approved SWPPP to minimize potential adverse impacts to ground water resources and stormwater during construction activities.
The lagoons and the subsurface constructed wetlands would be lined to prevent infiltration to the ground water. As previously described, the incoming sewage would be treated in the lagoons, further treated in the subsurface wetland, and then disinfected prior to application of effluent to
the planted groves. The use of a slow-rate land application system following treatment in lagoons and the subsurface constructed wetlands would be very effective at removing pollutants and nutrients from the effluent. Compared to the existing LCCs, the proposed wastewater treatment
and disposal facility would decrease loading of BOD5, TSS, and phosphorus by greater than 99 percent, and the release of nitrogen by 83 percent.
For these reasons, and because of the separation (both elevation and horizontal distance) between Site 7 and the uphill County drinking water well, construction and operation of the
While use of the two LCCs has not resulted in documented impacts to ground water or drinking water resources, abandonment of the LCCs would remove a potential source of such impacts. Abandonment of the existing wastewater collection system would not affect ground water within the affected areas.
(b) Alternative Sites 8 and 9
The ground water impacts and mitigation measures discussed above for the Preferred Alternative
(Site 7) would also apply to Sites 8 and 9. The construction of the proposed collection system and the treatment and disposal facility at either Site 8 or Site 9 would not affect ground water resources in the
of adverse impacts to ground water and drinking water resources.
(c) No-Action Alternative
The No-Action alternative has the potential to adversely impact ground water resources due to
the continued operation of the existing LCCs. EPA regulations mandate the closure of LCCs to prevent potential impacts on ground water resources.
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3.9 Flood Risk
3.9.1 Existing Conditions
(a) All Alternative Sites
community is located between two surface water sources and east, and an unnamed branch of Hionamoa Gulch to the south and west. The USGS the coast, while the unnamed branch flows into Hionamoa Gulch about 3,000 feet southwest of Maile Street. Flows from Hionamoa Gulch end about 6,000 feet from the coast. The unnamed branch of Hionamoa
Gulch runs through Alternative Sites 8 and 9 and approximately 200 to 600 feet west of the Site 7 parcel.
The Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM),
Community Panel No. 155166 1800F, effective date September 29, 2017 shows that most of the
Zone X, which designates areas determined to be outside the 0.2- percent annual chance (500-year) floodplain. A small portion of the community of ,
including some land within the collection system project site, is located within Zone X – Other
Flood Areas, indicating areas within the 0.2-percent annual chance (500-year) floodplain, or areas with a 1-percent annual chance of flooding with average flood depths less than 1 foot.
According to the FIRM, both existing LCCs are also located within Zone X. However, LCC-1 is very close to the edge of the 500-year floodplain.
On April 16, 2018, in response to the pre-assessment notification, the State of Hawai‘i Department of Land and Natural Resources Engineering Division stated the responsibility for conducting research as to the flood hazard designation for the project site lies with the project proponent. Also on April 16, 2018 and in response to the pre-assessment notification, the County of Hawai‘i Department of Public Works confirmed that the proposed treatment and disposal project site at Site 7 is designated as Zone X on the FIRM and is outside the 500-year floodplain. See Appendix
A for the responses to pre-assessment consultation letters.
3.9.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The Proposed Action would not result in construction of new facilities within the 500-year
floodplain. Although a small portion of the proposed collection system is located within the 500-
year floodplain, the associated trenching operations would be temporary and would not alter the 500-year floodplain. Thus, no impacts to the existing floodplain are expected.
Abandonment of the two LCCs and the existing wastewater collection system would not affect floodplains within the affected areas.
(b) No-Action Alternative
The No-Action Alternative, specifically the continued operation of LCC-1, could lead to impacts
during a flooding event. LCC-1 is located very close to an area mapped as within the 0.2-percent
annual chance (500-year) floodplain. The existing collection system is substandard and in poor
condition. A large flood could potentially cause the collection system and/or LCC to overflow as a
result of stormwater inflow and result in an uncontrolled release of raw sewage, thus potentially contaminating flooded areas and creating a public health hazard.
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3.10 Agricultural Lands
3.10.1 Existing Conditions
In November 1965, the Land Study Bureau (LSB) at the University of Hawai‘i issued L.S. Bulletin No. 6, Detailed Land Classification–Island of Hawai‘i. The LSB compiled and interpreted data on geology, topography, climate, water resources, soils, and crops and conducted field investigations to create a land classification for the island. Bulletin No. 6 assigned two types of ratings for each land type: the overall or master productivity rating, which reflects degree of overall suitability for agricultural use, ranging from A (Very Good) to E (Very Poor); and selected use ratings, which
indicate the degree of suitability for selected use alternatives. Bulletin No. 6 has not been revised or re-issued and remains as the reference document for lands classified by the LSB.
In addition to the LSB rating, the State of Hawai‘i has developed the Agricultural Lands of
Importance to the State of Hawai‘i (ALISH) Classification System. This system was developed and compiled in 1977 by the State Department of Agriculture with assistance from the NCRS, U.S. Department of Agriculture (formerly the Soil Conservation Service) and the College of
Tropical Agriculture at the University of Hawai‘i as part of a national effort to inventory important farmlands. Lands not considered for classification within this system are developed urban lands (over ten acres), natural or artificial bodies of water (over ten acres), public use lands, forest
reserves, lands with slopes in excess of thirty-five percent, and military installations (except undeveloped areas over ten acres). The ALISH Classification System identifies the following three categories of land (equivalent NRCS categories in parentheses):
Prime Agricultural Lands (Prime Farmlands) – Land that has the soil quality, growing season, and moisture supply needed to produce sustained high yields of crops
economically when treated and managed according to modern farming methods.
Unique Agricultural Lands (Unique Farmlands) – Land that has a special combination of
soil quality, location, growing season, and moisture supply, and is used to produce sustained high-quality yields of a specific crop when treated and managed according to modern farming methods.
Other Important Agricultural Land (Additional Farmland of Statewide and Local Importance) – Land other than Prime or Unique Agricultural Land that is also of statewide
or local importance to agricultural use.
Figure 3.2 and Figure 3.3 show the LSB and ALISH classifications, respectively, in the project areas.
The 2012 Census of Agriculture-County provides the most recent information related to acreage planted for various fruits and nuts across the state and for each county. These data show a total of 18,006 acres of macadamia nuts were planted in the state, 17,387 acres of which were planted in the County, comprising about 96.6 percent of the state total.
(a) Preferred Alternative (Site 7)
The LSB rating indicates the collection system project site as “U” (urban), the rating assigned to developed communities, and a master productivity rating of “D 129” (poor) for the proposed wastewater treatment and disposal facility at Site 7. D 129 includes soils from the
series, deep depth, volcanic ash, stony, well drained, and very poorly suited for machine tillability.
The ALISH map shows the collection system is located in “unclassified” lands. The ALISH map shows the proposed wastewater treatment and disposal facility at Site 7 would be located on
approximately 20 percent “prime”, 40 percent “other” and 40 percent “unclassified” land.
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Figure 3.2.
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Figure 3.3. Area Agricultural Lands of Importance to the State of Hawai‘i (ALISH) Classification Map
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(b) Alternative Site 8
Site 8 is located on a mix of “prime” and “other” agricultural land, with slightly more than 50 percent
classified as “prime.” There is no “unclassified” land at Site 8. Depending on the selected site plan, the land application groves would potentially be located on land classified as “prime.”
(c) Alternative Site 9
Site 9 is made up primarily of “unclassified” land, with sections of both “prime” land (northwest corner of the parcel) and “other” land (northeast and southwest edges of the parcel). The proposed facility would likely be sited at the northern end of Site 9, on land that is a mix of “unclassified” and “prime” land.
3.10.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
Construction of the collection system within the County roads would not affect agricultural lands or the acreage utilized for the macadamia nut orchard. Construction of the wastewater treatment and disposal facility at Site 7 would require removal of approximately 14.9 acres of macadamia nut trees. This removal would amount to less than 0.1 percent of the total County lands planted with macadamia nut trees, which would not substantially affect the total macadamia nut acreage in the state or the County.
Abandonment of the two LCCs would reduce the potential for contamination of ground water that is used for irrigation of agricultural lands. Otherwise, Abandonment of the LCCs and the existing
wastewater collection system would not affect agricultural lands within the affected areas.
(b) Alternative Site 8
As discussed above, construction of the collection system within the County roads would not
affect agricultural lands or the acreage utilized for the macadamia nut orchard. Construction of the wastewater treatment and disposal facility at Site 8 would require removal of approximately 18.9 acres of macadamia nut trees, which would not substantially affect the total macadamia nut
acreage in the state or the County.
Under Chapter 205, HRS, use of agricultural lands for non-agricultural purposes greater than 15.0 acres requires approval of a Special Permit by the Land Use Commission. The approval process involves a contested case public hearing before the Land Use Commission requiring attorneys and sworn testimony by witnesses from both the applicant, the County, and interveners. This entire process is considered quasi-judicial and would require at least 12 to 18 months to complete. The time required for the discretionary Special Permit approval would make it difficult for Site 8 to meet the conditions of the AOC.
(c) Alternative Site 9
As discussed above, construction of the collection system within the County roads would not affect agricultural lands or the acreage utilized for the macadamia nut orchard. Construction of
the wastewater treatment and disposal facility at Site 9 would require removal of approximately 14.9 acres of macadamia nut trees, which would not substantially affect the total macadamia nut acreage in the state or the County.
(d) No-Action Alternative
The No-Action Alternative would not impact agricultural lands. Continued operation of the existing LCCs could introduce pathogens and other contaminants to ground water that is used for irrigation
of agricultural lands.
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3.11 Solid and Hazardous Waste
3.11.1 Existing Conditions
(a) All Alternative Sites
In July 2017, a Phase 1 Environmental Site Assessment (ESA) was prepared for the County of
Society for Testing and Materials (ASTM) Standard Practice E 1527-13 (ASTM E 1527-13). The Phase 1 ESA was conducted on the entire 42.5-acre parcel comprising Site 7 (preferred alternative), including the 14.9-acre location for the proposed treatment and disposal facility.
Details on the Phase 1 ESA objectives and guidelines can be found by reviewing ASTM E 1527-13.
A review was conducted of standard environmental (regulatory) records and specified historical
records covering Site 7. A review of historical aerial photographs (1972, 1977, 1985, 1992 and 2001) identified no recognized environmental concerns (RECs). The site was identified as sugar cane land from 1972 to 1977 and was converted to a macadamia nut orchard by 1985.
The surrounding area, including Sites 8 and 9, consisted primarily of sugar cane and vacant land prior to use for macadamia nut production. No properties adjacent to Site 7 had a historical use that would represent a REC.
The Phase 1 ESA concluded no further assessment of the Site 7 parcel and proposed project site for RECs is recommended at this time. While no Phase 1 ESA was conducted for Sites 8 and 9, similar results to those for Site 7 might be expected given their similar historical and current uses.
3.11.2 Impacts and Mitigation Measures
(a) All Alternative Sites
Construction activities would involve the use of equipment containing fuel and other petroleum products that could be hazardous if released. Construction contract documents would require that a Site-Specific Construction Best Management Practices (BMP) plan be prepared, and that
materials and equipment to clean up leaks or spills be kept on the project site during construction. In addition, contract documents would include specifications for weekly inspections and reports to ensure the construction activities comply with BMPs. These measures would mitigate adverse impacts to the project site and surrounding area from potential releases of these materials.
The proposed wastewater treatment and disposal facility would have an emergency generator that would use diesel fuel stored in an above-ground double-walled, concrete encased tank. A
leak from the inner tanks would be contained in the interstitial space between the walls of the tank. Tanks of this nature are equipped with a monitor system to detect leaks in the inner wall. It is expected that at least a 250-gallon fuel capacity would be required to provide the desired 3-day backup supply of fuel for the proposed project. According to EPA, above-ground double-walled concrete tanks do not require an additional secondary spill containment system around its base. The fuel tank design would incorporate overfill prevention features to minimize potential spills.
With the exception of the emergency generator fuel, the only material used for the Proposed Action that could be classified as hazardous waste would be the calcium hypochlorite used to disinfect the effluent before it is used in the planted groves. Calcium hypochlorite is a solid form of chlorine commonly used in tablet or granular form. It would be transported and stored in manufacturer packaging typically consisting of sealed plastic tubs. The solid calcium hypochlorite
would be dissolved to create a chlorine water solution (similar to household bleach) that is added to the effluent. The concentrations of chlorine in the effluent would not be at a level considered hazardous. Safe handling practices would be utilized to ensure proper disposal in the unlikely
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case of there being any unused tablets/pellets/granular calcium hypochlorite, and the unused material would stored indoors and kept dry and away from contact with other chemicals.
Ongoing operation of the proposed collection system and treatment and disposal facility is not expected to result in the creation of any hazardous waste on a regular basis.
The lagoons would need to be cleaned of sludge approximately every 20 years, and the
material removed at that point would be substantially degraded from biological activity. Municipal sewage sludge is typically not considered a hazardous waste, and the material would be tested prior to end use or disposal to verify compliance with applicable requirements. The sludge removed from the facility could be landfilled, composted, or applied to land as a soil amendment and fertilizer in accordance with state and Federal requirements.
underground injection wells and are regulated by EPA and the State of Hawai‘i DOH’s UIC rules. Under the Proposed Action, the existing LCCs are considered waste management units and would be closed in accordance with DOH UIC regulations.
Abandonment of the existing wastewater collection system would not result in the generation of solid or hazardous waste. Any sanitary wastewater remaining in the existing collection system would be diverted to the new collection system prior to closure.
(b) No-Action Alternative
The No-
LCCs are considered waste management wells and are regulated by the DOH UIC program. Ongoing operation of LCCs is no longer allowed by EPA and their closure is mandated.
3.12 Flora
3.12.1 Existing Conditions
(a) All Alternative Sites
In August 2018, a botanical field study was undertaken along the streets and areas adjacent to
the proposed wastewater collection system and at the preferred location (Site 7) for the proposed wastewater treatment and disposal facility. Botanical field studies were not conducted for Site 8 or Site 9; however, similar results to those for Site 7 might be expected since these sites are also currently used for macadamia nut production.
The area surveyed for the proposed collection system is along existing roadways within The survey in these areas indicated the vegetation to be composed of maintained yards with
ornamental plants.
The field survey for the proposed 14.9-acre wastewater treatment and disposal facility at Site 7 indicated 52 species of vascular plants: two ferns, one gymnosperm, and 49 species of angiosperms (flowering plants). Only two species (Ipomoea indica and Waltheria indica, 4 percent of the total number of observed species) are regarded as native to the Hawaiian Islands and both are indigenous (native, but also distributed elsewhere in the Pacific). Being widely distributed
indigenous species, neither is listed as threatened, endangered, or of any special concern.
The field study indicated no species of plants currently listed or proposed for listing under either Federal or State of Hawai‘i endangered species are present along the alignment for the proposed wastewater collection system and at the preferred site (Site 7) for the wastewater treatment and disposal facility. The field survey determined that Federally-delineated Critical Habitat is not present in the area. No equivalent designation exists under State law in Hawai‘i.
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The macadamia nut orchard at Sites 7, 8, and 9 is a valuable commercial botanical resource but not an environmentally-sensitive one. Similarly, the Cook pines (Araucaria columnaris) that line
Maile Street along the western border of Site 7 and elsewhere are considered an important part of the community landscape element.
3.12.2 Impacts and Mitigation Measures
(a) All Alternative Sites
Based on the results of the botanical field study, construction of the new collection system and new wastewater treatment and disposal facility is not likely to cause any adverse impacts on botanical species of importance in the area and would not impact Federally-delineated Critical Habitat. The Cook pines (Araucaria columnaris) that line Maile Street along the western border of Site 7 and elsewhere would be retained.
On April 23, 2018, as part of the pre-assessment consultation process, the U.S. Fish and Wildlife Service (FWS) provided a letter (01EPIF00-2018-TA-0275) with recommended measures to avoid and minimize impacts to flora (see Appendix A). Prior to finalization of this EA and initiation of the Proposed Action, EPA and the County of Hawai‘i will conclude consultation with FWS in accordance with Section 7 of the Endangered Species Act and, if necessary per this consultation, will incorporate additional impact avoidance and minimization measures.
Abandonment of the two LCCs and the existing wastewater collection system would not affect flora within the affected areas.
(b) No-Action Alternative
The No-Action Alternative includes no modifications to the existing LCC system, and therefore would not impact flora.
3.13 Fauna
3.13.1 Existing Conditions
(a) All Alternative Sites
Mammalian Survey:
In August 2018, a biological field survey was conducted for mammalian species at the preferred site (Site 7). With the exception of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus), or as it is known locally, all terrestrial mammals currently found on the Island e alien species, and most are ubiquitous. The biological survey was limited to visual and auditory detection coupled with visual observation of scat, tracks, and other animal signs.
The survey identified no mammalian species within the survey area at Site 7. There was also no indication that pigs (Sus scrofa) utilize the survey area, despite reports from the community that the area is occasionally used for hunting. The biological survey report is included as Appendix C.
Biological field surveys were not conducted for Site 8 or Site 9; however, similar results to those for Site 7 might be expected since these sites are also currently used for macadamia nut production.
Avian Survey:
The biological field survey conducted in August 2018 also identified avian species in the Site 7 area. Six avian count stations were sited roughly equidistant from each other; two were placed along the proposed wastewater collection system alignment and four were placed within the proposed location for the 14.9-acre wastewater treatment and disposal facility at Site 7.
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The avian survey found a total of 175 individual birds of 13 species representing nine separate families. Avian diversity and densities were very low, which is consistent with the current site use
as a mature macadamia nut orchard with limited ground cover and few weedy or shrubby species. All of the recorded avian species are established alien species. No native avian species were recorded during this survey of Site 7. Biological field surveys were not conducted for Site 8 or Site
9; however, similar results to those for Site 7 might be expected since these sites are also currently used for macadamia nut production.
The findings of the avian survey are consistent with the location of Site 7 (and Sites 8 and 9) and the monoculture of macadamia nut trees present at all sites. The field survey report indicated that endemic Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus newelli) have been recorded flying over the general area between April and the end of November each year. The petrel is listed as endangered and the shearwater as threatened under both Federal and State endangered species statutes. As discussed in the August 2018 report, these seabirds are susceptible to impacts from outdoor lighting, which can result in seabird disorientation, fallout, and injury or mortality. Seabirds are attracted to lights and after circling the lights they may become exhausted and collide with nearby wires, buildings, or other structures or they may land on the ground. Downed seabirds are subject to increased mortality due to collision with automobiles, starvation, and predation by dogs, cats, and other predators. Young birds (fledglings) traversing the project area between September 15 and December 15, in their first
flights from their mountain nests to the sea, are particularly vulnerable.
3.13.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The field survey recorded no species of animals currently listed or proposed for listing under either the Federal or State endangered species statutes. The preliminary proposed site plan shows no new infrastructure constructed above the existing tree line that could present a hazard to
waterbirds.
The operations building at the proposed wastewater treatment and disposal facility would include down-shielded light fixtures mounted below the roof overhang. The light fixtures near the headworks would also be down-shielded. These lights would be used only in the event of an emergency at night. All fixtures would meet requirements for outdoor lighting as set forth in Hawai‘i Code Chapter 14 (General Welfare). These measures would help avoid or minimize any potential adverse impacts to the Hawaiian Petrel and Newell’s Shearwater.
After construction of the wastewater treatment and disposal facility is completed, the new lagoons would potentially attract various species of waterbirds, including the listed Hawaiian Coot (Fulica
alai), the endemic sub-species of the black-necked stilt (Himantopus mexicanus knudseni), and . Experi ence at other County wastewater facilities with aerated lagoons (e.g., the Kealakehe
wastewater treatment plant) has demonstrated that the aerated lagoon wastewater treatment process can present a highly attractive breeding area for local bird species.
On April 23, 2018, as part of the pre-assessment consultation process, the FWS provided a letter
(01EPIF00-2018-TA-0275) with information on various avoidance and minimization measures to avoid adverse impacts to listed species (see Appendix A). The letter included measures for the . FWS also recommended further consultation
to determine whether the lagoons, despite their potential attractiveness to nesting seabirds, could represent a sub-optimal breeding environment. Prior to finalization of this EA and initiation of the Proposed Action, EPA and the County of Hawai‘i will conclude consultation with FWS in accordance with Section 7 of the Endangered Species Act and will incorporate additional impact
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avoidance and minimization measures as necessary to result in a finding of Not Likely to Adversely Affect (NLAA) protected species.
Abandonment of the two LCCs and the existing wastewater collection system would not affect fauna within the affected areas.
(b) No-Action Alternative
The No-Action Alternative includes no modifications to the existing LCC system, and therefore would not be likely to impact fauna.
3.14 Air Quality
3.14.1 Existing Conditions
(a) All Alternative Sites
Ambient air quality standards (AAQS) have been established at both the national (NAAQS) and
state level for six criteria pollutants: carbon monoxide, nitrogen dioxide, sulfur dioxide, lead, ozone, and particulate matter (PM10 and PM2.5). The State has also set a standard for hydrogen sulfide. Hawai‘i ambient air quality standards are comparable to the national standards, although
in some cases the Hawai‘i standards are more stringent than the national standards, such as for carbon monoxide. For some other parameters, such as particulate matter, the national standards are more restrictive.
The DOH operates a network of air quality monitoring stations at various locations around the State. In December 2016, the DOH issued the Annual Summary 2015 Air Quality Data report (the most recent report) which provides the results from the network of air quality monitoring stations. The DOH maintains a monitoring station at the Ka‘ High School and Elementary School. Established August 2007, the station was placed to monitor SO2 and PM2.5 from volcanic emissions. Criteria pollutant levels remain below Federal and State ambient air quality standards throughout the State.
Existing air quality in the project area is affected mostly by air pollutants from vehicular, industrial,
natural and/or agricultural activities and processes. Also, volcanic emissions affect air quality on the Island of Hawai‘i more than the other islands in the State. Since 1983, volcanic emissions
A recent analysis by the USGS shows the composition of volcanic smog (vog) depends on how much time the volcanic plume has had to react with the atmosphere. In areas closer to the volcano, 2) gas. SO2
gas is colorless and invisible, but the tiny particles in vog create a visible light-colored haze by scattering sunlight and thus reduce visibility.
Vog concentrations on the Island are primarily dependent on the amount of SO2 emitted from e from the source vents, and the wind direction and speed on a given day. From May through September, the main wind direction in the Hawaiian Islands is from the northeast (trade winds) which occur about 80 to 95 percent of the time. Under trade wind
conditions, vog travels around the southern part of the island. Most of the vog stays below 6,000 to 8,000 feet above msl, the usual height of the trade wind inversion. This layer of the atmosphere increases in temperature with altitude, inhibiting the rise of cooler, vog-laden air. When trade winds are absent, which occurs most often during winter months, the entire Island, or even the entire State can be affected by vog.
Volcanic eruptions are considered natural events and therefore EPA may exclude the exceedances of the 1-hour NAAQS from attainment determinations.
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Consistent with its area has no major stationary sources of air pollution.
limit mobile sources of emissions.
3.14.2 Impacts and Mitigation Measures
(a) All Alternative Sites
Short-term impacts on air quality could occur during construction of the proposed wastewater collection system and the wastewater treatment and disposal facility. Short-term impacts from fugitive dust emissions would likely occur during the construction phases. To a lesser extent, exhaust emissions from mobile construction equipment, traffic disruption associated with wastewater collection system construction, and from workers commuting to the construction site may also affect air quality during the period of construction. State HAR, Title 11, Chapter 60-11.1 “Air Pollution Control,” requires that there be no visible fugitive dust emissions at the property line. Hence, an effective dust control plan would be implemented to ensure compliance with State regulations. During construction, fugitive dust emissions would be controlled to a large extent by watering of active work areas, the use of wind screens, keeping adjacent paved roads clean, and by covering open-bodied trucks. Other dust control measures may include limiting the area that can be disturbed at any given time and/or mulching or chemically stabilizing areas where construction is not actively occurring. These dust control measures would be most applicable to construction activities at the wastewater treatment and disposal facility project site.
After construction, motor vehicle traffic from County employees and others visiting the treatment and disposal facility project site would be a minor source of increased air pollutant emissions. As discussed in Section 3.17 (Traffic), management of the facility requires weekly visits by a single
operator based in Hilo and any intermittent visits for maintenance purposes. Given the low ambient levels of pollutants and infrequent visits to the facility, any increases would not result in exceedance of federal or State AAQS for the six criteria pollutants.
The treatment and disposal facility would have an emergency standby diesel-powered generator for use during periods of outage of the commercial electrical service. The generator would also be operated periodically for testing to ensure proper operation. The operation and testing should not cause an exceedance of air quality standards.
Wastewater treatment plants can be a source of nuisance odors to the surrounding community if not properly designed or operated. Typically, nuisance odors are most commonly associated with anaerobic (without oxygen) conditions and with processing of residual solids. Incoming raw sewage flows to the proposed wastewater treatment and disposal facility would first be routed to the headworks, which is the facility where the solids are removed from the flows.
To mitigate potential nuisance odors, the headworks would be equipped with an odor control system with a GAC scrubber to remove odor. A package GAC scrubber passes the odorous air
through a bed of activated carbon, which adsorbs the odorous constituents within the pore spaces of the carbon. The County currently operates GAC scrubbers at other facilities, and it has been proven to be an effective means of odor control both locally and nationwide. The treatment
lagoons would be equipped with mechanical aerators capable of maintaining sufficiently aerobic (with oxygen) conditions within the water column, which would prevent nuisance odor conditions from occurring. The disposal groves would be irrigated with fully-treated and aerobic secondary effluent from the treatment process; irrigation with secondary effluent is not associated with development of nuisance odor conditions.
Overall, construction and operation of the wastewater collection system and treatment and disposal facility would not likely result in significant . Mitigation measures would be implemented, as appropriate, to minimize any potential impacts.
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Abandonment of the two LCCs and the existing wastewater collection system would not affect air quality within the .
(b) No-Action Alternative
The No-Action Alternative includes no modifications to the current LCC system, and therefore is not likely to impact ambient air quality in the
area has met ambient standards during operation of the LCCs.
3.15 Archaeological and Cultural Resources
3.15.1 Existing Conditions
(a) Preferred Alternative (Site 7)
A survey of available information identified the presence of one historic site in the immediate vicinity of the proposed wastewater collection system
Elementary School is listed on the State of Hawai‘i register of historic places. No other historic sites were identified within the areas planned for improvements.
In November 2016, as part of the initial planning for LCC closure, the County contracted for a 1-
day archaeological field inspection of Site 7, including the preferred location for the proposed wastewater treatment and disposal facility. The purpose of the inspection, which involved pedestrian sweeps of the entire 42.5-acre parcel, was to determine if any historic properties or
significant archaeological features were present. The inspection report stated that it is apparent that ground modifications undertaken during the plantation period destroyed any evidence of pre-contact agriculture or settlement activities. Furthermore, bulldozing associated with the creation of the macadamia nut orchard appears to have leveled any plantation-era land features.
The 2016 inspection identified surface artifacts as the only evidence of past human activity on Site 7. Artifacts included a single traditional artifact as well as more numerous late post-contact artifacts. The single traditional artifact was a crudely-shaped discoidal hammerstone found on the ground surface near the northern edge of Site 7 near Maile Street. No other cultural material
(either traditional or post-contact) was observed in this area, suggesting that the hammerstone reflects an isolated artifact rather than a buried cultural deposit. Given the possible agricultural activity that may have taken place in the region during the pre-contact period, it is not surprising that a traditional artifact was found within the inspection parcel.
While the historical ground modifications have likely limited the archaeological potential of the site, the discovery of both pre- and post-contact surface artifacts within the 42.5-acre Site 7 parcel,
as well as evidence from plantation-era documents that the opening of a lava tube containing human remains once existed in the southeastern corner of the parcel, indicate that further archaeological studies may be necessary by the Hawai‘i State Historic Preservation Division (SHPD) before any development can be initiated. The 2016 inventory report stated that, at minimum, an Archaeological Inventory Survey (AIS) was necessary to fully document, map, date and collect the surface artifacts. It may also be necessary to test for the presence of subsurface cultural deposits through hand excavation or mechanical trenching.
As part of this EA, the County is undertaking an AIS of the preferred location for the proposed 14.9-acre treatment and disposal facility, including subsurface testing within the proposed sites for the lagoons and land application groves. To conduct an AIS, SHPD must approve an AIS plan within a 30-day period. To meet this requirement, the County submitted the AIS plan to SHPD on
March 22, 2018. On April 25, 2018, SHPD requested clarification. Responses were submitted to SHPD on July 31, 2018 including the findings from the 2016 field survey report and a map of the proposed wastewater treatment and disposal facility. The map showed that the preferred site for the facility would avoid the area in which the traditional artifact was found during the 2016
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inventory. SHPD approved the AIS plan on August 20, 2018, and the County intends to perform the AIS of the preferred location in September 2018.
In addition to an AIS, the County is required to comply with the National Historic Preservation Act (NHPA). On March 29, 2018, the County initiated consultation for this project pursuant to Section 106 of the NHPA. Consultation letters were delivered to invite comments from organizations that
may attach religious or cultural significance to properties affected by the Proposed Action. A total of 15 letters were mailed to various Native Hawaiian Organizations requesting comments (see Chapter 10); as of August 2018, no responses have been submitted to the County.
(b) Alternative Sites 8 and 9
Alternative Sites 8 and 9 have similar existing conditions for historical resources as presented above. Although Sites 8 and 9 were not surveyed, they are both currently used as macadamia nut orchards and thus would be expected to exhibit similar ground modifications as Site 7. The ground modifications from the plantation period would have destroyed any evidence of pre-contact agriculture or settlement activities, in addition to extensive disturbance from bulldozing during creation of the macadamia nut orchard.
3.15.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
Preliminary analysis at Site 7 indicates that the proposed wastewater treatment and disposal facility would be constructed in an area that does not contain archaeological resources. An AIS,
including subsurface testing, is being conducted to confirm the presence or absence of resources on the 14.9-acre proposed wastewater treatment and disposal facility site.
The construction contract documents would state that, should archaeological sites such as walls,
platforms, pavement or mounds, or remains such as artifacts, burial sites, concentrations of shells or charcoal, be encountered during construction activities, work shall cease immediately and the find shall be protected from further damage. The contractor would immediately contact SHPD (at
808.981.2979), who would assess the significance of the find and recommend appropriate mitigation measures, if necessary.
Prior to finalization of this EA and initiation of the Proposed Action, EPA and the County of Hawai‘i will conclude consultation with SHPD in accordance with Section 106 of the NHPA and will incorporate additional impact avoidance and minimization measures as necessary to result in a finding of no adverse effects to historic properties.
Abandonment of the two LCCs and the existing wastewater collection system would not affect archaeological and cultural resources within the affected areas.
(b) Alternative Sites 8 and 9
Under these alternatives, the potential impacts to archaeological and cultural resources and the necessary impact avoidance and minimization measures would likely be similar to those
described above for the Preferred Alternative (Site 7). If Site 8 or Site 9 are selected for development, an AIS, including subsurface testing, would be conducted to confirm the presence or absence of resources on the proposed wastewater treatment and disposal facility site. If
archaeological sites are discovered during construction, work would cease and SHPD would be contacted (at 808.981.2979) to determine appropriate mitigation measures, if necessary. EPA and the County of Hawai‘i would consult with SHPD in accordance with Section 106 of the NHPA
and would incorporate impact avoidance and minimization measures as necessary to result in a finding of no adverse effects to historic properties.
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(c) No-Action Alternative
The No-Action Alternative would not result in any disturbance to land within the area and
is therefore not expected to have any adverse impacts on archaeological or cultural resources.
3.16 Socioeconomic Characteristics
3.16.1 Existing Conditions
(a) All Alternative Sites
Tourism released 2016 population estimates for the state and counties. This analysis estimates
that in 2016, which represents an annual increase of 1.2 percent from 2010.
The U.S. Census Bureau provides the American Community Survey (ACS), which updates
selected demographic, social, and economic information for various years. This includes age, racial composition, and economic information, including employment and household income by County. The most recent version of the
ACS is the 2012-2016 5-Year Estimates, released in 2017. See Table 3.1 below.
Hawai‘i County, although
compared to 41.8 years for the County.
Overall, is characterized by a racial composition that includes a greater proportion of minorities than the County at large. The racial distribution includes a much lower proportion of White residents, a much higher proportion of Filipino residents, and lower populations of other minority groups, including Native Hawaiians when compared to the County. There are also more residents of two or more races in than in the County.
has a higher proportion of residents that have completed high school and some college
than the County overall, but a lower proportion with college degrees (bachelor’s and graduate or professional degrees). From an economic perspective, generally has more households in lower income brackets than the County, and a lower median household income.
proportion of employment in agriculture, forestry, fishing, hunting, and construction (31.9 percent), and in education and health care (22.1 percent), compared to the County (12.6 percent and 19.7 percent, respectively).
A subset of social resources is environmental justice. Environmental justice considers sensitive populations, such as children, minorities, and low-income communities. Sensitive populations are identified in two Executive Orders (EOs):
EO 12898, Federal Actions to Address Environmental Justice in Minority and Low-Income Populations, serves to avoid the disproportionate placement of adverse environmental, economic, social, or health impacts from federal actions and policies on minority and low-income populations.
EO 13045, Protection of Children from Environmental Health Risks and Safety Risks, states that federal agencies will identify and address environmental health and safety risks from their activities, policies, or programs that may disproportionately affect children.
Sensitive populations, such as low-income families, minorities, and children, are present within the area. Areas within the community have sensitive populations with higher minority and low-income populations than the state averages.
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Table 3.1 Demographic, Economic and Social Characteristics of P hala and Hawai‘i County
Item
Hawai‘i County
Total Percent Total Percent
Demographic Characteristics
Total population 1,341 ----- 193,680 -----
Under 5 to 19 years 383 28.5 47,195 24.40
20 to 34 years 192 14.3 34,623 17.8
35 to 59 years 305 22.7 61,809 31.9
60 to 74 years 367 27.4 36,863 19.1
75 years and over 94 7.1 13,190 6.8
Median age 42.4 ----- 41.8 -----
Race
White 106 7.9 64,255 33.2
African American (incl. American Indian/Alaska Native) 0 0.0 1,213 0.6
Chinese 10 0.7 1,844 1.0
Filipino 484 36.1 17,794 9.2
Japanese 54 4.0 17,981 9.3
Other Asian 46 3.4 3,722 1.9
Native Hawaiian 50 3.7 20,980 10.8
Other Pacific Islander 18 1.3 4,725 2.4
Some other race 1 0.1 3,230 1.7
2 or more races 572 42.7 54,564 28.2
Social Characteristics
Less than 9th grade 98 10.9 3,681 2.7
High school to HS graduate 489 54.5 50,586 37.3
Some college to associate degree 204 22.7 43,761 32.3
Bachelor’s degree 97 10.8 24,704 18.2
Graduate or professional degree 10 1.1 12,649 9.3
Household Income Characteristics
Less than $24,999 130 33.7 17,337 26.3
$25,000 to 49,999 73 18.9 13,655 20.6
$50,000 to $99,999 126 32.6 20,323 30.7
$100,000 to $199,999 48 12.4 12,201 18.5
$200,000 or more 10 2.6 2,563 3.9
Median household income $47,625 ----- $53,936 -----
Employment Characteristics
Agriculture, forestry, fishing and hunting 120 26.2 3,713 4.4
Construction 26 5.7 6,806 8.2
Manufacturing and wholesale-trade 0 0 3,701 4.5
Retail trade 16 3.5 10,858 13.0
Transportation, warehousing, and utilities 14 3.1 4,250 5.1
Information tech, finance, insurance, and real estate 9 2.0 5,677 6.8
Professional, scientific, and technical services 0 0 3,736 -----
Education and health care 101 22.1 16,437 19.7
Arts, entertainment, recreation 0 0 2,466 -----
Other services, public administration 49 10.7 10,015 12.0
Source: 2012-2016 American Community Survey (5-Year Estimates) Hawai‘i Geographic Area Profiles – Census Designated Places: Neighbor Islands.
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3.16.2 Impacts and Mitigation Measures
(a) All Alternative Sites
In the short term, construction projects under the Proposed Action would require a number of contractors and their subcontractors. Construction contract documents would reference HRS 103B, which requires the contractor (including subcontractors) to include not less than 80 percent
Hawai‘i residents in the work force. This would limit the importation of workers from outside the local area and the associated increase in demand for local housing.
The Proposed Action would generate employment as the contractor would need workers to undertake construction of the improvements for the wastewater collection system and the wastewater treatment and disposal facility. This employment would generate wages and salaries paid to the contractor and subcontractor work forces. The wages and salaries paid to the work force would in turn generate purchases of goods and services, which would result in taxes paid to the State of Hawai‘i. In addition, the contractor and their subcontractors would need to purchase equipment, supplies, and materials, some of which would be purchased from local suppliers and vendors. Direct purchases of equipment, supplies, and materials by the contractor would also generate taxes. Overall, the Proposed Action would result in positive employment benefits which would result in higher levels of income and overall economic benefits to the local economy.
Despite the relatively low household income in compared to the County overall, the Proposed Action is not expected to result in disproportionate impacts on sensitive populations.
The proposed wastewater treatment and disposal facility would be located more than two miles from homes in and is not designed to encourage or accommodate substantial population growth. Noise, odor, and other adverse impacts of the Proposed Action would not
disproportionately impact lower-income residents of . Overall, the Proposed Action is expected to benefit residents by providing a cleaner and longer-lasting wastewater treatment system.
The Proposed Action is not likely to directly impact long-term employment or education trends because the wastewater operator would likely be based in Hilo, meaning the project would not involve long-term relocation of any staff to .
Abandonment of the two LCCs, which do not require substantial maintenance and operation, and Abandonment of the existing wastewater collection system would have no impact on socioeconomic resources within .
(b) No-Action Alternative
The No-Action Alternative includes no modifications to the current sewage system, and therefore is not expected to impact socioeconomic or demographic conditions in the area.
3.17 Traffic
3.17.1 Existing Conditions
(a) All Alternative Sites
Highway (State Highway Route 11) is the major north-south roadway for the Parea. This minor arterial highway provides two lanes, one lane in each direction, and shoulders within a 60-roads, Kamani Street on the northern end and Maile Street on the southern end.
In November 2010, State of Hawai‘i Department of Transportation conducted the most recent P a au Bridge, mile marker 51.32, located just north of Kamani Street. The counts provide 24-hour and peak-hour counts for traffic in both
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directions. The 24-hour period counts show a total two-way volume of 2,449 vehicles, with 1,212 vehicles southbound and 1,237 vehicles northbound. The peak morning hours occurred between
7:00am to 8:00am and had a total two-way volume of 186 vehicles with 108 vehicles southbound and 78 vehicles northbound. The peak afternoon hours occurred between 4:00pm to 5:00pm and had a two-way volume of 219 vehicles with 104 vehicles southbound and 115 vehicles
northbound.
Within Hawai‘i. The streets typically carry two-way traffic, one lane in each direction, within roadways with improved surfaces of 22 to 24 feet wide with no curbs and sidewalks. The shoulders consist mostly of grass swales which also serve to carry surface runoff along with the streets. These roadways carry vehicle traffic from adjacent and nearby residential areas. As a result, the traffic volumes are relatively low, which is consistent with traffic generation by a rural community.
The wastewater collection system and the wastewater treatment and disposal project site are located outside of the M malohoa Highway ROW.
3.17.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7) and Alternative Site 8
Under these two alternatives, the wastewater collection system and the wastewater treatment
require any disturbance or other impacts within the Highway ROW.
Work on the collection system would require excavation of open trenches in road ROWs. The contractor would be required to prepare traffic control plans in the area of each open trench site that provide procedures for controlling traffic in the work area, including the placement of signs,
traffic delineators or barriers, lane closures, flaggers to direct traffic, and special duty officers to oversee conditions at the site. The traffic control plans would provide directions to temporarily divert traffic or close travel lanes during the construction period. Normally, such plans call for
these diversions or closures during non-peak travel times to minimize disruptions to traffic flow. When not in use, trenches would be covered with steel plates or surrounded by traffic barriers to prevent accidents. The County would be required to approve any traffic control plans.
Construction of the proposed treatment and disposal facility would require transport of construction equipment and supplies to the construction site, including excavators and other heavy equipment. Deliveries to the construction site could require temporary stoppage of traffic on Maile Street to safely unload equipment and supplies. To minimize traffic disruptions, contractors typically try to conduct these activities during off-peak traffic hours.
The wastewater treatment and disposal facility would require only weekly visits by a single operator based in Hilo and intermittent visits for maintenance purposes. As such, no impacts to traffic are expected from wastewater treatment and disposal facility staff. Sludge removal would
occur approximately every 20 years, so no impacts to traffic are expected due to truck activity associated with sludge removal.
Abandonment of the two LCCs and the existing wastewater collection system would not affect
(b) Alternative Site 9
Transportation impacts under this alternative would be identical to those for the Preferred
Alternative (Site 7) and Site 8, except it would require construction of piping and other utilities within the Highway ROW to provide connections to the new wastewater treatment and disposal facility in Site 9. This would require obtaining an easement from the State of Hawai‘i for work within the highway ROW and could delay the start of construction.
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(c) No Action Alternative
The No-
to the current system would be made.
3.18 Noise
3.18.1 Existing Conditions
(a) All Alternative Sites
The A-weighted decibel scale (dBA) is a logarithmic scale generally used to measure noise levels because it can account for the sensitivity of the human ear across the frequency spectrum. The
Occupational Safety and Health Administration (OSHA) regulates workplace noise with standards for two different types of noise: constant and impulse. The OSHA limit for constant noise is 90 dBA for eight hours; however, the National Institute for Occupational Safety and Health
recommends a constant noise limit of 85 dBA for eight hours to minimize hearing loss induced by occupational noise. The OSHA maximum sound level for impulse noise is 140 dBA. In areas where workplace noise exceeds these sound levels, employers must provide workers with
personal protective equipment to reduce noise exposure.
HAR Title 11 Department of Health Chapter 46, Community Noise Control, sets forth various maximum noise limits by zoning districts or land uses. According to Chapter 46, §11-46-3 and
§11-46-4: Class A zoning districts include all areas equivalent to lands zoned as residential, conservation, preservation, public space, open space, or similar type. Class B zoning districts include all areas equivalent to lands zoned for multi-family dwellings, apartment, business, commercial, hotel, resort, or similar type. Class C zoning districts include all areas equivalent to lands zoned agriculture, country, industrial, or similar type.
All alternative sites for the proposed wastewater treatment and disposal facility are in Class C zoning districts. The proposed wastewater collection system would primarily be located in Class A zoning districts. The maximum permissible sound levels in each zoning district are presented
below in Table 3.2 and apply to stationary noise sources and equipment related to agricultural, construction, industrial activities.
Table 3.2 Permissible Sound Levels by Zoning District
Zoning District Daytime: 7am to 10pm Nighttime: 10pm to 7am
Class A 55 dBA 45 dBA
Class B 60 dBA 50 dBA
Class C 70 dBA 70 dBA
According to HAR Chapter §11-46-5, Exemptions (4), the operation of emergency generators can be exempted if they are installed and used as required for the purpose of protecting public health and safety.
There are no current significant sources of noise impacting the proposed project areas. The proposed wastewater treatment and disposal facility would be located in active macadamia nut orchards where the primary source of noise is ongoing orchard operations. The proposed wastewater collection system would primarily be located in residential areas with background noise levels typical of a residential zone.
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3.18.2 Impacts and Mitigation Measures
(a) All Alternative Sites
along the wastewater collection system and at the site of the proposed wastewater treatment and disposal facility. Noise is expected to be intermittent and unavoidable because construction
vehicles and heavy equipment generate noise as part of normal operations. Mitigation of noise from construction activities to inaudible levels is not practical in all cases due to the intensity and exterior nature of the work.
Construction activities for the Proposed Action would need to comply with provisions of HAR Title 11, Chapter 46, Community Noise Control. These regulations require a noise permit if the noise level from construction is expected to exceed allowable levels as stated in Chapter 11-46. Construction contractors are responsible for minimizing noise by properly maintaining mufflers and other noise-attenuating equipment and to maintain noise levels within regulatory limits. The construction contractor would obtain appropriate permits or approvals for the Proposed Action. Potential noise impacts would be mitigated somewhat because the majority of construction activity would occur during daytime hours.
Depending on the results of geotechnical surveys, construction of the wastewater treatment and disposal facility could involve excavation to a depth that would require removal of bedrock. If necessary, this would likely be accomplished by using backhoe-mounted hydraulic and/or
pneumatic hammers to break up the bedrock for removal, resulting in temporarily elevated impulse noise levels. This construction would occur only during daytime hours and is not expected to result in exceedances of the 70 dBA Class C zoning district noise threshold outside of the
property boundary or in residential areas. Additionally, construction contract documents would require that workers are provided with, and wear, appropriate personal protective equipment to reduce noise exposure to below the OSHA maximum sound level.
After construction, the proposed wastewater treatment and disposal facility is not expected to be a significant source of additional ambient noise during routine operation. Operational noise would be confined to the aerators within the lagoons, emergency generator operation, and vehicle movements at the facility. Emergency generator operation would occur only during emergencies and periodic testing and thus would be infrequent. Best available control technology would be implemented to mitigate noise associated with emergency generator operation. Therefore, the
area.
Abandonment of the two LCCs and the existing wastewater collection system would not affect the
(b) No-Action Alternative
The No-Action Alternative involves no construction activities or changes to the current system.
area would occur.
3.19 Visual Considerations and Light Pollution
3.19.1 Existing Conditions
(a) All Alternative Sites
The February 2005 County General Plan identified a number of sites as important visual resources contributing to the natural beauty of the . These visual resources typically consist of scenic resources including major land forms, open spaces, viewing points, scenic drives, and other physical features. The natural beauty of the landscape in the southern part of
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the is characterized by vistas from the mountain slopes to the oceans. The coastline is highlighted by Manuka Bay, Green Sands Beach, and Punaluu Black Sand Beach. Some of
the natural beauty sites identified in the most pertinent to the area include: 1) view of Mauna Loa from the highway; 2) scenic view of the shoreline between and Punaluu; and 3) the lava flows of 1868, 1887, and 1907.
The community consists almost entirely of single-family residential units and the related utility lines that service the homes. Generally, residential units are set back from the adjacent roadway so the views of nearby areas are not obstructed.
Exterior lighting is often used to enhance the safety and security of persons and property. Excessive and inappropriate exterior lighting, however, can generate light pollution. As described in Section 3.13.1, outdoor lighting can also result in adverse effects to seabirds by attracting them at night and causing disorientation, fallout, and injury or mortality. The County of Hawai‘i regulates outdoor lighting under Section 14-50 of the Hawai‘i County Code. Streets in the community are lined with street lights mounted on utility poles. The three alternative sites for the proposed wastewater treatment and disposal facility (Sites 7, 8, and 9) are used for macadamia nut production, with no existing outdoor lighting.
3.19.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
The Proposed Action is not expected to adversely affect the views or viewsheds identified in the
County General Plan. The wastewater collection system would be installed below the streets and therefore would not impact views. The operations building, headworks cover structure, and low berms around the basins would be the only above-grade structures. The existing pine trees along
Maile Street, most of which would remain with no changes, would continue to obstruct the viewplanes from Maile Street. The facility site would be adjacent (makai) to, and visible from, M malahoa Highway (State Route 11); however, impacts to the viewplane would be mitigated by
the planted trees in the basins and by the rise in elevation between the highway and the facility.
Exterior lighting at the proposed wastewater treatment and disposal facility would be designed in accordance with Section 14-50 of the Hawai‘i County Code and would be limited to manually-switched lights under the roof overhang at the entrance to the operations/electrical building and at the headworks area. Lights would be installed with down-shielding to prevent excess light pollution. When an operator or maintenance staff are not present on-site, lights would not be on. If necessary as a result of the consultation with FWS, the Proposed Action would incorporate additional impact avoidance measures related to lighting (e.g., avoidance of nighttime construction activities during seabird fledging period).
Abandonment of the two LCCs and the existing wastewater collection system would not affect visual resources or light pollution within the affected areas.
(b) Alternative Sites 8 and 9
Under Alternative Sites 8 and 9, the visual and light pollution impacts and mitigation measures would be similar to those discussed above for the Preferred Alternative (Site 7). Pine trees would
be maintained between the wastewater treatment and disposal facility and public views from the adjacent streets to minimize visual impacts, except where necessary to accommodate the driveway into the facility. The planted trees in the proposed slow-rate land application basins
would partially replace removed trees and exterior lighting at the facility would be minimal.
(c) No-Action Alternative
The No-Action Alternative would not change the curvisual impacts would occur.
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3.20 Public Services – Police Protection
3.20.1 Existing Conditions
(a) All Alternative Sites
, which
is bound by the Kona District at Kaulanamauna and the Puna District at Keauhou Landing. Its officers operate out of a central station in Na alehu and a substation in Hawai‘i Ocean View
Estates subdivision.
3.20.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The Proposed Action is expected to create no additional demand for police protection and related services since it will not increase the resident population or visitors to the area. The Proposed Action should have minimal impact on the police department’s operations or ability to provide
adequate protection services to the surrounding community. If necessary, off-duty police staff may be hired to assist with directing traffic during construction activities.
Operation of the proposed wastewater treatment and disposal facility is not expected to impact
the Police Department. The facility would have a security fence around the perimeter with a locked entry gate.
Abandonment of the two LCCs could reduce the need for police protection services to handle public health threats in the event that there is damage to the LCCs (e.g., from volcanic or seismic activity). Otherwise, Abandonment of the two LCCs and the existing wastewater collection system would not affect police protection services in the County.
(b) No-Action Alternative
The No-Action Alternative would not impact police protection services due to continued operation
of the existing LCCs. In the event that there is damage to the LCCs from some unforeseen event (e.g., volcanic or seismic activity), police protection services may be required to handle public health threats resulting from damage to the LCCs.
3.21 Public Services – Fire Protection
3.21.1 Existing Conditions
(a) All Alternative Sites
Fire protection and related services are provided from a fire station located in . The station and a volunteer station provide 24-hour fire protection and emergency medical services (EMS). The County has contracted with the State Department of Health for emergency medical ambulance services.
3.21.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The proposed wastewater treatment and disposal facility would include a fire protection line to be used in the event of a fire. The emergency generator would include a double-walled diesel fuel tank of a type allowed by the County. The Proposed Action would not affect the operations of fire
protection and EMS services in and the proposed wastewater treatment and disposal
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facility would not require additional fire protection services on site. The construction plans would be submitted to the Fire Department for review during the project design phase.
Abandonment of the two LCCs could reduce the need for fire protection services to handle public health threats in the event that there is damage to the LCCs (e.g., from volcanic or seismic activity). Otherwise, Abandonment of the two LCCs and the existing wastewater collection system
would not affect fire protection services in the County.
(b) No-Action Alternative
The No-Action Alternative would not impact fire protection services due to continued operation of the existing LCCs. In the event that there is damage to the LCCs from some unforeseen event (e.g., severe flood, volcanic or seismic activity), fire protection services may be required to handle public health threats resulting from damage to the LCCs.
3.22 Infrastructure – Water System
3.22.1 Existing Conditions
(a) All Alternative Sites
The County of Hawai‘i community from ground water sources. The water lines are primarily located along or under the roadways in the area. In response to the pre-assessment notification, on April 5, 2018, the DWS
noted that the wastewater treatment and disposal project site is not serviced by the DWS. The nearest point of connection to the DWS system is at an existing 6-inch waterline at the intersection of Huapala Street and Maile Street, approximately 2,000 feet northeast of Site 7. Sites 8 and 9 are an additional 1,600 to 3,200 feet, approximately, from the DWS connection point.
3.22.2 Impacts and Mitigation Measures
(a) Preferred Alternative (Site 7)
The proposed wastewater treatment and disposal facility would require potable water and fire protection lines from the end of the existing DWS system to the preferred location of the
headworks operations building. The lines would require trenching, primarily on Maile Street, and construction plans would identify the horizontal and vertical clearances required to avoid existing water system and collection system lines. As required by DWS, construction plans would show the estimated maximum daily water usage calculations prepared by a professional engineer licensed in the State of Ha. After review of the calculations, DWS would determine if enough water is available and a water commitment could be issued.
Abandonment of the two LCCs and the existing wastewater collection system would not affect water system infrastructure in .
(b) Alternative Sites 8 and 9
Under Alternative Sites 8 and 9, the water system infrastructure impacts and mitigation measures
would be similar to those described above for the Preferred Alternative (Site 7). Compared to Site
7, approximately 1,600 feet of additional pipe within the ROW of Lower Maoula Road would need to be installed to provide Site 8 with potable water and fire protection lines. To provide Site 9 with potable water and fire protection lines, approximately 3,200 feet of additional pipe within the ROW would need to be installed.
(c) No-Action Alternative
The No-Action Alternative includes no modifications to the existing water infrastructure, and therefore would not cause any impacts to the water system in .
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3.23 Infrastructure – Drainage System
3.23.1 Existing Conditions
(a) All Alternative Sites
There is no existing County stormwater drainage system in District generally collects along the paved roadways within each subdivision and sheet flows towards Highway, then disperses into open swales or grassed areas.
3.23.2 Impacts and Mitigation Measures
(a) All Alternative Sites
The Proposed Action would incorporate appropriate stormwater and erosion control measures in accordance with approved plans to ensure that soil erosion and transport during construction activities are minimized. Construction of the proposed wastewater collection system would require
trenches for new lines, and silt fences or filter socks would be used to minimize runoff from the disturbed area. The proposed wastewater treatment and disposal facility would include an on-site drainage system to address stormwater surface runoff caused by new impervious surfaces at the
facility. The site would include a system to collect runoff via grated inlets or swales, and flows would be conveyed to on-site drainage detention systems, such as subsurface linear infiltration or depressed detention basins. Landscape buffers with dirt berms would also be constructed
around most of the perimeter of the facility to act as secondary containment in the event of a large storm event. The on-site stormwater management system would meet the requirements of Hawai‘i County Code, Chapter 27, Section 20, which mandates drainage plans to accommodate runoff caused by the facility for a 1-hour, 10-year storm event.
Abandonment of the two LCCs and the existing wastewater collection system would not affect drainage or runoff in the affected areas.
(b) No-Action Alternative
The No-Action Alternative would not result in a change to the impervious area within or near
and would therefore not lead to an increase in runoff or other impacts to drainage in the area.
3.24 Infrastructure – Electrical and Communications Systems
3.24.1 Existing Conditions
(a) All Alternative Sites
Electrical serviceny (HELCO) via pole-mounted overhead lines located along the roadways. Hawaiian Telcom is the primary telecommunications provider within the County of Hawai‘i. The HELCO lines are located along Highway, leading to a substation west of the intersection of Kamani Street and the highway. HELCO is regulated by the State and owns and operates a number of power generation facilities in the County.
HELCO presently has overhead electrical lines situated on utility poles routed along the streets
within the service.
Draft EA, District, Hawai‘i
September 2018 Page 3-36
3.24.2 Impacts and Mitigation Measures
(a) All Alternatives
The wastewater treatment and disposal facility would require electrical power. It is anticipated that HELCO would bring overhead power lines to the selected site and supply 480-volt, 3-phase power to the facility via a pole-mounted transformer. This would be connected to a service panel with a
meter. The floating surface aerators would consume the majority of the electricity supplied to the site. An electrical room would house the electrical gear and plant control equipment. Exterior lighting at the site would be limited to manually switched lights at the entrance to the operations/electrical building and at the headworks area. A standby power system would be provided in the form of a pad-mounted diesel generator and aboveground fuel tank with capacity to support three consecutive days of operation. In addition, the electrical service panel would be equipped with a manual transfer switch and generator receptacle to allow connection of a trailer-mounted generator in the event of emergency generator failure during an extended power outage.
A land-line and/or cellular telephone telemetry system would be used to connect the wastewater treatment and disposal facility to DEM and facilitate communication with staff in Hilo.
To avoid damaging existing buried infrastructure during construction, the construction contractor would be required to call the one-call center prior to any construction activities to allow demarcation of underground utilities to occur.
Abandonment of the two LCCs and the existing wastewater collection system would not affect
electrical and communications infrastructure in the area.
(b) No-Action Alternative
The No-Action Alternative does not require any electrical power and includes no construction
activities that could disrupt buried utility infrastructure. Therefore, no impacts to electrical and telecommunications infrastructure would occur.
September 2018 Page 4-1
4 CUMULATIVE EFFECTS
The Proposed Action (construction of a new wastewater treatment and disposal facility and a new collection system, closure of existing LCCs, and connection of newly accessible properties to the sewer system), in combination with other past, present, or reasonably foreseeable actions at or
improvements and impacts on certain environmental resources. Cumulative effects can result from individually minor but collectively significant actions taking place over a period of time.
4.1 Scope of Analysis
This section identifies the other past, present, or reasonably foreseeable actions at that were considered and evaluated in this cumulative improvements and impacts analysis.
4.1.1 Past, Present, and Reasonably Foreseeable Actions
– specifically, the -half mile north of the site of the Proposed Action. The gym was constructed to also serve as a community shelter during emergencies. Construction began in October 2012 and completed in early 2016.
The school’s LCC was previously replaced with a DOH-approved septic system that included two new laterals at the property line on Hala Street and Kamani Street to allow eventual connection to the new collection system. Following completion of the Proposed Action, the State Department
of Education will District Gym and Shelter) to the new collection system and will properly close the onsite septic system.
system) are planned based on Community Development Plan.
4.1.2 Actions Considered but Excluded from Analysis
options for closure of LCCs and development of a new wastewater treatment system. The
significant cause-and-effect relationship with the direct and indirect effects of the Proposed Action.
processes that will identify potential impacts for that project separately from wastewater system improvements.
Community Development Plan includes potential long-term improvements including a
in preliminary design of potential influent flows to the treatment system. However, the Community Development Plan does
not present a timeline for this expansion; no substantial planning or scoping of a collection system expansion has been conducted, and this expansion is unlikely to occur within the next 10 to 20 years. This action was therefore excluded from this analysis of cumulative improvements and impacts.
September 2018 Page 4-2
4.2 Cumulative Improvements and Impacts Analysis
This analysis identified the following potential cumulative effects resulting from the Proposed High School
Installation of new exterior lighting, resulting in potential nighttime light pollution and distraction to night-flying birds;
Removal of vegetation and construction of new impervious surfaces, resulting in a
potential increase in stormwater runoff; and
Increa
new wastewater treatment and disposal facility.
District Gym and Shelter construction have incorporated mitigation measures to reduce nighttime light pollution and impacts to night-flying birds. District Gym and Shelter incorporated minimal use of security lighting, which are shielded in accordance with the County’s exterior lighting standards, and outdoor parking lights are turned off at 11:00 pm to avoid impacts to birds and bats. As discussed in Section 3.19.2, the Proposed Action would incorporate lighting that complies with the County’s exterior lighting standards and FWS guidance, and the new facility would generally be dark at night, with exterior lighting used only for emergency maintenance purposes. Adherence to these requirements would minimize the potential cumulative light pollution impacts from these projects.
District Gym and Shelter incorporated new dry wells and
Department. The Proposed Action would incorporate permanent BMPs such as subsurface linear infiltration or depressed detention basins to detain flows and volumes to their pre-development
district, any increases in stormwater runoff generated by these projects are anticipated to infiltrate to groundwater without presenting cumulative erosion concerns.
wastewater treatment and disposal facility would increase the treatment capacity requirements for the facility, this was accounted for in the facility’s preliminary design.
Based on the above, the Proposed Action is not expected to result in any significant cumulative improvements or impacts to the environment in combination with other past, present, or reasonably foreseeable actions.
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5 FEDERAL CROSS CUTTER REQUIREMENTS
This project may be funded by federal funds provided by the U.S. Environmental Protection Agency (EPA) through the State of Hawai‘i's Clean Water State Revolving Fund (CWSRF) Program. As such, the State of Hawai‘i Department of Health (DOH) must conduct an
environmental review of projects funded under the CWSRF as required under the Code of Federal Regulations (CFR), using the EPA-approved State Environmental Review Process. In addition, the State must comply with the Federal cross-cutting authorities set forth in 40 CFR §35.3145 for
the CWSRF. These requirements are set forth as “cross cutters” described as follows.
5.1 Archaeological and Historic Preservation Act (54 U.S.C. § 312502)
The Archaeological and Historic Preservation Act (AHPA), also known as the Archaeological Recovery Act and the Moss-Bennett bill, was passed and signed into law in 1974. It amended and expanded the Reservoir Salvage Act of 1960. The AHPA built upon the national policy, set out in the Historic Sites Act of 1935, "to provide for the preservation of historic American sites,
buildings, objects, and antiquities of national significance". The AHPA expanded the policy by focusing attention on significant resources and data but does not require that they be shown to be of "national" significance. The AHPA required that federal agencies provide for "...the
preservation of historical and archeological data (including relics and specimens) which might
otherwise be irreparably lost or destroyed as the result of...any alteration of the terrain caused as a result of any Federal construction project of federally licensed activity or program.”
54 U.S.C. §312502, (a) states: “When any Federal agency finds, or is notified, in writing, by an
appropriate historical or archeological authority, that its activities in connection with any Federal construction project or federally licensed project, activity, or program may cause irreparable loss
or destruction of significant scientific, prehistorical, historical, or archeological data, the agency
shall notify the Secretary, in writing, and shall provide the Secretary with appropriate information concerning the project, program, or activity…”
54 U.S.C. 312502 (b) states: “When any Federal agency provides financial assistance by loan,
grant, or otherwise to any private person, association, or public entity, the Secretary, if the Secretary determines that significant scientific, prehistorical, historical, or archeological data
might be irrevocably lost or destroyed, may, with funds appropriated expressly for this purpose-
(A) Conduct, with the consent of all persons, associations, or public entities having a legal interest in the property, a survey of the affected site; and
(B) Undertake the recovery, protection, and preservation of the data (including
analysis and publication).”
The proposed collection system would be constructed primarily within existing County streets and two short segments within private easements that have been previously disturbed when the streets were constructed. Preliminary analysis shows the proposed treatment
and disposal facility would be constructed in an area that does not contain archaeological resources. An Archaeological Inventory Survey (AIS), including subsurface testing, will be conducted to confirm the presence/absence of archaeological resources on the preferred site.
The contract drawings will state that, should archaeological sites such as walls, platforms, pavements or mounds, or remains such as artifacts, burials, concentrations of shell or charcoal be encountered during construction activities, work shall cease immediately and the find shall be
protected from further damage. The contractor shall immediately contact the State Historic Preservation Division (SHPD), who will assess the significance of the find and recommend an appropriate mitigation measure, if necessary.
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5.2 Bald and Golden Eagle Protection Act (16 U.S.C. §§ 668-668c)
The Bald Eagle Protection Act (16 U.S.C. §§ 668-668c) prohibits any act to take, possess, sell, purchase, barter, offer to sell, purchase or barter, transport, export or import, at any time or in any manner any bald eagle commonly known as the American eagle or any golden eagle, alive or dead, or any part, nest, or egg thereof of the foregoing eagles.
No bald or golden eagles are found in Hawai‘i.
5.3 Clean Air Act (42 U.S.C. § 7401)
The Federal Air Pollution Control Act 42 U.S.C. §7506(c), Clean Air Act (CAA), was preceded by a series of legislation affecting air quality. Over the years, there have been a number amendments adopted related to air quality and all called the CAA. The first federal legislation regarding air pollution control was the Clean Air Act of 1963. The Clean Air Act of 1970 (1970 CAA) authorized the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources.
The 1970 CAA set forth four major regulatory programs affecting stationary sources: the National Ambient Air Quality Standards (NAAQS), State Implementation Plans (SIPs), New Source Performance Standards, and National Emission Standards for Hazardous Air Pollutants. In Hawai‘i, the DOH, Clean Air Branch, Air Quality program is defined by HAR Chapter 11-60 and serves as the SIP approved by the Environmental Protection Agency (EPA).
The DOH operates a network of air quality monitoring stations at various locations around the State. In December 2016, the DOH issued the Annual Summary 2015 Air Quality Data report (the
most recent report) which provides the results from the network of air quality monitoring stations. The DOH maintains a monitoring station the grounds of the Kau High and Pahala Elementary School. Established August 2007, the station was placed to monitor SO2 and PM2.5 from volcanic
emissions. In 2015, Hawai‘i was in attainment of the state annual SO2 standard. In 2015, Hawai‘i was in attainment with the annual PM2.5 NAAQS.
Volcanic eruptions are considered natural events and therefore EPA may exclude the
exceedances of the 1-hour NAAQS from attainment determinations.
. Further, the low level of vehicle traffic on Mamalahoa Highway and on the streets in the community would limit mobile sources of emissions.
The quality of are emissions from motor vehicles trave . Potential short-term effects from dust and exhaust due to construction activities will be minimized with BMPs such as water sprinkling and proper equipment maintenance. No long-term impacts on air quality resulting from operation of the collection system and the treatment and disposal facility are anticipated.
5.4 Coastal Barrier Resources Act (U.S.C. §3501)
In 1982, Congress passed the Coastal Barrier Resources Act (CBRA) (16 U.S.C. §3501) to encourage the conservation of hurricane prone, biologically rich coastal barriers by restricting
federal expenditures that encourage development, such as Federal flood insurance through the National Flood Insurance Program.
The Coastal Barrier Resources Reauthorization Act of 2000 reauthorized the CBRA and directed the U.S. Fish and Wildlife Service to complete a Digital Mapping Pilot Project that includes digitally produced draft maps for up to 75 John H. Chafee Coastal Barrier Resources System (CBRS) areas and a report to Congress that describes the feasibility and costs for completing digital maps for all CBRS areas.
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The purpose the CBRA is to minimize the loss of human life, wasteful expenditure of federal revenues, and the damage to fish, wildlife, and other natural resources associated with the coastal
barriers along the Atlantic and Gulf coasts and along the Great Lakes by restricting future federal expenditures and financial assistance which have the effect of encouraging development of coastal barriers.
Based on its location, the CBRA is not applicable to Hawai'i.
5.5 Coastal Zone Management Act (16 U.S.C. §1451)
The Coastal Zone Management Act of 1972 (CZMA), 16 U.S.C § 1451-1464, was passed to
establish a national policy to preserve, protect, develop, and where possible, restore or enhance, the resources of the Nation's coastal zone for this and succeeding generations and to encourage coastal states to develop and implement coastal zone management programs (CZMPs). Each
federal agency activity within or outside the coastal zone that affects any land or water use or natural resource of the coastal zone shall be carried out in a manner which is consistent to the maximum extent practicable with the enforceable policies of approved State management
programs. Each federal agency carrying out an activity subject to the Act shall provide a consistency determination to the relevant State agency designated under section 1455(d)(6) of this title at the earliest practicable time.
In 1977, Hawai'i enacted Chapter 205A, HRS, Hawai'i Coastal Zone Management (CZM) Program. The CZM area encompasses the entire state, including all marine waters seaward to the extent of the state’s police power and management authority, including the 12-mile U.S. territorial sea and all archipelagic waters. The objective and policies of the CZM is set forth §205A-2, HRS. See detail discussion in Section 6 Plans, Policies and Controls. A summary follows.
(1) Recreational Resources
Objective:
Provide coastal recreational opportunities accessible to the public.
Policies: (A) Improve coordination and funding of coastal recreational planning and management; and
(i) Provide adequate, accessible, and diverse recreational opportunities in the coastal zone management area by: Protecting coastal resources uniquely suited for
recreational activities that cannot be provided in other areas; (ii) Requiring replacement of coastal resources having significant recreational value,
including but not limited to surfing sites, fishponds, and sand beaches, when such resources will be unavoidably damaged by development; or requiring reasonable
monetary compensation to the state for recreation when replacement is not feasible or desirable;
(iii) Providing and managing adequate public access, consistent with conservation of natural resources, to and along shorelines with recreational value;
(iv) Providing an adequate supply of shoreline parks and other recreational facilities suitable for public recreation;
(v) Ensuring public recreational use of county, state, and federally owned or controlled shoreline lands and waters having recreational value consistent with public safety
standards and conservation of natural resources; (vi) Adopting water quality standards and regulating point and nonpoint sources of pollution
to protect, and where feasible, restore the recreational value of coastal waters. (vii) Developing new shoreline recreational opportunities, where appropriate, such as
artificial lagoons, artificial beaches, and artificial reefs for surfing and fishing; and (viii) Encouraging reasonable dedication of shoreline areas with recreational value for public
use as part of discretionary approvals or permits by the land use commission, board of
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land and natural resources, and county authorities; and crediting such dedication against the requirements of section 46-6.
coastal resources.
(2) Historic Resources
Objective:
(A) Protect, preserve and, where desirable, restore those natural and manmade historic and prehistoric resources in the coastal zone management area that are significant in Hawaiian
and American history and culture.
Policies: (A) Identify and analyze significant archaeological resources;
(B) Maximize information retention through preservation of remains and artifacts or salvage operations; and
(C) Support state goals for protection, restoration, interpretation, and display of historic resources.
The proposed wastewater collection system would be constructed along the existing County streets and two short segments within easements in that have been previously disturbed when the streets were constructed. Preliminary analysis shows the treatment and disposal facility would be constructed in an area that does not contain archaeological
resources. An AIS, including subsurface testing, will be conducted to confirm the presence or absence of archaeological resources on the project site.
The contract drawings will state that, should archaeological sites such as walls, platforms, pavements or mounds, or remains such as artifacts, burials, concentrations of shell or charcoal be encountered during construction activities, work would cease immediately and the find would be protected from further damage. The contractor would immediately contact the SHPD, who will
assess the significance of the find and recommend an appropriate mitigation measure, if necessary.
(3) Scenic and Open Space Resources
Objective:
(A) Protect, preserve, and where desirable, restore or improve the quality of coastal scenic and open space resources.
Policies:
(A) Identify valued scenic resources in the coastal zone management area;
(B) Ensure that new developments are compatible with their visual environment by designing
and locating such developments to minimize the alteration of natural landforms and existing public views to and along the shoreline;
(C) Preserve, maintain, and, where desirable, improve and restore shoreline open space and scenic resources; and
(D) Encourage those developments which are not coastal dependent to locate in inland areas.
and open space resources would not be affected.
(4) Coastal Ecosystems Objective:
(A) Protect valuable coastal ecosystems, including reefs, from disruption and minimize adverse impacts on all coastal ecosystems.
Policies:
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September 2018 Page 5-5
(A) Exercise an overall conservation ethic, and practice stewardship in the protection, use, and development of marine and coastal resources;
(B) Improve the technical basis for natural resource management; (C) Preserve valuable coastal ecosystems, including reefs, of significant biological or
economic importance; (D) Minimize disruption or degradation of coastal water ecosystems by effective regulation of
stream diversions, channelization, and similar land and water uses, recognizing competing water needs; and
(E) Promote water quantity and quality planning and management practices that reflect the tolerance of fresh water and marine ecosystems and maintain and enhance water quality
through the development and implementation of point and nonpoint source water pollution control measures.
ecosystems would not be adversely affected.
(5) Economic Uses
Objective:
(A) Provide public or private facilities and improvements important to the State’s economy in suitable locations.
Policies:
(A) Concentrate coastal dependent development in appropriate areas; (B) Ensure that coastal dependent developments such as harbors and ports, and coastal
related development such as visitor facilities and energy generating facilities, are located, designed, and constructed to minimize adverse social, visual, and environmental impacts
in the coastal zone management area; and (C) Direct the location and expansion of coastal dependent developments to areas presently
designated and used for such developments and permit reasonable long-term growth at such areas, and permit coastal dependent development outside of presently designated
areas when:
(i) Use of presently designated locations is not feasible;
(ii) Adverse environmental effects are minimized; and (iii) The development is important to the State’s economy.
. The collection system and the treatment and disposal facility would be community.
(6) Coastal Hazards
Objectives: (A) Reduce hazard to life and property from tsunami, storm waves, stream flooding, erosion,
subsidence, and pollution.
Policies:
(A) Develop and communicate adequate information about storm wave, tsunami, flood,
erosion, subsidence, and point and nonpoint source pollution hazards; (B) Control development in areas subject to storm wave, tsunami, flood, erosion, hurricane,
wind, subsidence, and point and nonpoint pollution hazards; (B) Ensure that developments comply with requirements of the Federal Flood Insurance
Program; (C) Prevent coastal flooding from inland projects.
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September 2018 Page 5-6
shoreline. The proposed collection system and treatment and disposal facility do not include improvements related to tsunami, storm
waves, stream flooding erosion, subsidence and pollution.
(7) Managing Development Objective:
(A) Improve the development review process, communication, and public participation in the management of coastal resource and hazards.
Policies:
(A) Use, implement, and enforce existing law effectively to the maximum extent possible in managing present and future coastal zone development;
(B) Facilitate timely processing of applications for development permits and resolve overlapping or conflicting permit requirements; and
(C) Communicate the potential short- and long-term impacts of proposed significant coastal developments early in their life cycle and in terms understandable to the public to facilitate
public participation in the planning and review process.
In December 2017, a total of 5 community outreach sessions regarding the project were
, which is located about 3.8 miles from the shoreline. The collection system and treatment and disposal facility does not involve management of coastal resources and hazards.
(8) Public Participation
Objective: (A) Stimulate public awareness, education, and participation in coastal management.
Policies:
(A) Promote public involvement in coastal zone management processes;
(B) Disseminate information on coastal management issues by means of educational materials, published reports, staff contact, and public workshops for persons and organizations concerned with coastal issues, developments, and government activities;
and
(C) Organize workshops, policy dialogues, and site-specific mediations to respond to coastal
issues and conflicts.
community which is located about 3.8 miles from the shoreline.
(9) Beach Protection
Objective:
(A) Protect beaches for public use and recreation.
Policies: (A) Locate new structures inland from the shoreline setback to conserve open space, minimize
interference with natural shoreline processes, and minimize loss of improvements due to erosion;
(B) Prohibit construction of private erosion-protection structures seaward of the shoreline, except when they result in improved aesthetic and engineering solutions to erosion at the
sites and do not interfere with existing recreational and waterline activities; and (C) Minimize the construction of public erosion-protection structures seaward of the shoreline.
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September 2018 Page 5-7
. The collection system and the treatment and disposal facility project does not include improvements that would affect public use beaches.
(10) Marine Resources
Objective: (A) Promote the protection, use, and development of marine and coastal resources to assure
their sustainability.
Policies: (D) Ensure that the use and development of marine and coastal resources are ecologically and
environmentally sound and economically beneficial; (E) Coordinate the management of marine and coastal resources and activities to improve
effectiveness and efficiency;
(F) Assert and articulate the interests of the State as a partner with federal agencies in the
sound management of ocean resources within the United States exclusive economic zone; (G) Promote research, study, and understanding of ocean processes, marine life, and other
ocean resources in order to acquire and inventory information necessary to understand
how ocean development activities relate to and impact upon ocean and coastal resources;
and
(H) Encourage research and development of new, innovative technologies for exploring, using,
or protecting marine and coastal resources.
reline . The collection system and
the treatment and disposal facility project does not include improvements that would affect development of marine and coastal resources.
5.6 Endangered Species Act (16 U.S.C. §1531)
On December 28, 1973, the Endangered Species Act, Pub L 93-205, was passed and, over the years, has been amended a number of times. The Act is set forth in 16 U.S.C. §1531. The stated purpose of the original Act to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved, to provide a program for the conservation of such endangered species and threatened species, and to take such steps as may
be appropriate to achieve the purposes of various related the treaties and conventions. The provisions of the Act are administered by the U.S. Department of the Interior Fish and Wildlife Service (FWS) and the U.S. Department of the Interior National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS). The FWS has primary responsibility for terrestrial and freshwater organisms, while NOAA/NMSF is mainly responsible for marine wildlife.
16 U.S.C. § 1536, Interagency Cooperation (Section 7 of the Act), states each federal agency shall, in consultation with and with the assistance of the Secretary of the Interior, ensure that any
action authorized, funded, or carried out by such agency (an "agency action") is not likely to jeopardize the continued existence of any endangered species or threatened species or result in the destruction or adverse modification of habitat of such species which is determined, after
consultation as appropriate with affected States, to be critical, unless such agency has been granted an exemption for such action.
In August 2018, a biological resources field survey was conducted on the preferred project site. The results of the survey show that, due to the proposed alignment of the collection system along existing roadways, vegetation consists entirely of maintained yards with ornamental plants.
The field survey of the 14.9-acre preferred site for the proposed treatment and disposal facility indicates that the site is comprised of a macadamia nut orchard of mature trees, unmaintained
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areas outside the orchard dominated by Guinea grass, lanes of windbreak trees oriented between orchard units, and (mostly) mowed road verge areas. A total of 52 species of vascular plants: 2
ferns, one gymnosperm, and 49 species of angiosperms (flowering plants) were identified during the survey. Only two species (4%) identified during the survey are regarded as native to the Hawaiian Islands and both are indigenous (native, but also distributed elsewhere in the Pacific).
Being widely distributed indigenous species, neither is listed as threatened or endangered or of any special concern
The August 2018 field survey included assessment of mammalian species. With the exception of the endangered Hawaiian hoary bat (Lasiurus cinereus semotuslocally, all terrestrial mammals currently found on are ubiquitous. The field survey reported no mammalian species within the survey area. This also included no indication that pigs (Sus scrofa) utilize the survey area.
The field survey also included an assessment of avian species, and recorded a total of 175 individual birds of 13 species, representing nine separate families, during station counts. Avian diversity and densities were very low, in keeping with the current usage of the site as a mature macadamia nut orchard, with minimal ground cover and few weedy or shrubby species. All of the avian species recorded during the course of the survey are established alien species. No native avian species were recorded during the course of the survey.
The field survey recorded no species of plants or animals currently listed or proposed for listing
under either the Federal or State of Hawai‘i endangered species statutes. Based on this finding, and the lack of critical habitat in the potential construction area, the Proposed Action is not likely to adversely affect biological resources, and EPA will informally consult with FWS to receive
concurrence of this determination.
5.7 Environmental Justice Executive Order 12898
Executive Order 12898, Environmental Justice (full title Federal Actions to Address Environmental
Justice to Minority and Low Income Populations), was signed on February 11, 1994. The intent of Executive Order 12898 is to avoid disproportionately high adverse human health or environmental effects of projects on minority and low income populations. Executive Order 12898 also requires federal agencies ensure that minority and low income communities have adequate access to public information related to health and the environment.
The intent of Executive Order 12898 is to avoid disproportionately high adverse human health or
environmental effects of projects on minority and low income populations. Executive Order 12898 also requires federal agencies ensure that minority and low income communities have adequate access to public information related to health and the environment.
The 2017 American Community Survey (5-Year Estimates) is the most recent information related to socioeconomic conditions in the state and County. The 2017 American Community Survey includes Hawai‘i Geographic Area Profiles – Census Designated Places: Neighbor Islands. The
ACS noted it is the Census Bureau's Population Estimates Program that produces and disseminates the official estimates of the population for the nation, states, counties, cities and towns and estimates of housing units for states and counties.
The American Community Survey Under 5 to 19 age category (30.0 percent compared to 23.4 for the County). years for the County.
(10.5 percent compared to 32.6 percent for the County). (29.9
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percent compared to 9.5 percent for the County). Other Minority Populations, including Native Hawai‘ians than Hawai‘i County.
has a higher portion that has completed high school and some college (81.5 percent) than the County (69.6 percent), and lower portions with bachelor degree and graduate or professional degree (12.3 percent compared to 27.6 percent in the County).
usehold incomes less than $49,999 (49.9 percent) than the County (45.8 percent), and a higher portion between $50,000 to $99,000 (35.2 percent) than the County (30.3 percent). ($50,125) than the County ($55,750).
(29.2 percent) compared to the County (10.4 percent), and education and health care (27.1 percent) compared to the County (19.9 percent).
la has a higher proportion in minority groups (47.3 percent) compared to the County (38.3 percent). Analysis of the household income categories shows that cover the range from $25,000 to $99,000. These incomes groups account for about 53.5 percent of residents in . Othan the County, but household incomes, especially the “middle income” groups, are almost same
Based on the above, construction and operation of the collection system and the treatment and disposal facility would not have a disproportionately high adverse impact on the minority and low income population in
5.8 Farmland Protection Policy Act (7 U.S.C. §4201)
The Agriculture and Food Act (Public Law 97-98) was passed in 1981 and contained the Farmland Protection Policy Act (FPPA), Subtitle I of Title XV, Section 1539-1549. The stated
purposes of the FPPA are to: 1) minimize the extent to which Federal programs contribute to the unnecessary and irreversible conversion of farmland to nonagricultural uses; and 2) assure that federal programs are administered in a manner that, to the extent practicable, will be compatible with State, unit of local government, and private programs and policies to protect farmland. “Farmland” subject to FPPA requirements does not have to be currently used for cropland.
The FPPA is administered by the U.S. Department of Agriculture (USDA), National Resources
Conservation Service. “Farmland”, as used in the FPPA, includes prime farmland, unique farmland, and land of statewide or local importance, as defined by the State of Hawai‘i Department of Agriculture.
The proposed collection system would be located primarily within the streets and shoulders in and therefore would not affect farmlands. The preferred location for the proposed treatment and disposal site is located within an existing macadamia nut orchard. The 2012
Census Agriculture shows about 17,378 acres in the County are planted with macadamia nuts. As such, removal of the 14.9-acre area required for the Proposed Action at the preferred site would not significantly affect macadamia nut production in the State or the County.
5.9 Fish and Wildlife Coordination Act (16 U.S.C §661)
The Fish and Wildlife Coordination Act, 16 U.S.C §661, enacted on March 10, 1934, was amended on August 12, 1958. The purpose of Act is to recognize vital contribution of wildlife resources to the Nation, the increasing public interest and significance, and to provide that wildlife conservation shall receive equal consideration and be coordinated with other features of water-resource development programs through the effectual and harmonious planning, development,
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maintenance, and coordination of wildlife conservation. 16 U.S.C. §666b defines wildlife and wildlife resources as birds, fishes, mammals and all other classes of wild animals, and all types
of aquatic and land vegetation upon which wildlife is dependent.
The Secretary of the Interior is authorized (1) to provide assistance to, and cooperate with, Federal, State, and public or private agencies and organizations in the development, protection,
rearing, and stocking of all species of wildlife, and their habitat, in controlling losses of the from disease or other causes, in minimizing damages from overabundant species, in providing public shooting and fishing areas, including easements across public lands (2) to make surveys and investigations of the wildlife of the public domain, including lands and waters acquired or controlled by any agency; and (3) to accept donations of land and contributions of funds in furtherance of the purposes of the Act.
16 U.S.C. §665 states that the Secretary of the Interior, through the FWS and the U. S. Bureau of Mines, is authorized to make such investigations as he deems necessary to determine the effects of domestic sewage, mine, petroleum, and industrial wastes, erosion silt, and other polluting substances on wildlife, and to make reports to the Congress concerning such investigations and of recommendations for alleviating dangerous and undesirable effects of such pollution. These investigations shall include (1) the determination of standards of water quality for the maintenance of wildlife; (2) the study of methods of abating and preventing pollution, including methods for the recovery of useful or marketable products and byproducts of wastes; and (3) the
collation and distribution of data on the progress and results of such investigations for the use of Federal, State, municipal, and private agencies, individuals, organizations, or enterprises.
The field survey recorded no species of plants or animals currently listed or proposed for listing under either the Federal or State of Hawai‘i endangered species statutes. No critical habitat was identified at the preferred location (Site 7). As a result, the Proposed Action is not likely to adversely affect any flora or fauna, or habitat on which they rely.
5.10 Floodplain Management (Executive Order 19888, as amended by Executive Orders 1248 and 13690)
Executive Order 11988, Floodplain Management, dated May 24, 1977 requires federal agencies to avoid, to the extent possible, the long- and short-term adverse impacts associated with the occupancy and modification of flood plains and to avoid direct and indirect support of floodplain development wherever there is a practicable alternative.
In accomplishing this objective, "each agency shall provide leadership and shall take action to reduce the risk of flood loss, to minimize the impact of floods on human safety, health, and welfare, and to restore and preserve the natural and beneficial values served by flood plains in carrying out its responsibilities.
The Proposed Action is not located within a floodplain area and therefore would not have a significant impact on floodplains in the area.
5.11 Magnuson-Stevens Fishery Conservation and Management Act, 16 U.S.C. §1801
The 1996 Sustainable Fishery Act amendments to the Magnuson-Stevens Fishery Conservation and Management Act and subsequent Essential Fish Habitat (EFH) Regulatory Guidelines
(NOAA, 2002) describe provisions to identify and protect habitats of federally-managed marine and anadromous fish species. Under the various provisions, federal agencies that fund, permit, or undertake activities that may adversely affect EFH are required to consult with the NMFS.
Congress defines EFH as “those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity.” EFH is further defined by the existing regulations (MSFCMA, 1996;
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NOAA, 2002). “Waters” include aquatic areas and their associated physical, chemical, and biological properties that are used by fish and may include aquatic areas historically used by fish
where appropriate; “substrate” includes sediment, hard bottom, structures underlying the waters, and associated biological communities; “necessary” means the habitat required to support a sustainable fishery and the managed species' contribution to a healthy ecosystem; and
"spawning, breeding, feeding, or growth to maturity" covers a species' full life cycle.
. The Proposed Action would not adversely impact EFH.
5.12 Marine Mammal Protection Act (16 U.S.C. §§ 703 et seq.)
The Marine Mammal Protection Act (MMPA), 16 U.S.C. §§1361 et seq., protects all marine mammals. The MMPA includes a general moratorium on the taking and importing of marine
mammals, and prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas, and the importation of marine mammals and marine mammal products into the U.S. Jurisdiction for MMPA is shared by the FWS and NMFS. The FWS
Branch of Permits is responsible for issuing take permits when exceptions are made to MMPA. Under the exception for incidental taking, the FWS or the NMFS must find that the total taking over the five-year period will have a “negligible impact” and will not adversely affect the availability
of the marine mammal species or stock for subsistence use by natives.
Proposed Action would not adversely impact marine mammal communities and would not encourage any “take” of marine mammals.
5.13 Migratory Bird Treaty Act (16 U.S.C. §§ 703 et seq.)
The Migratory Bird Treaty Act (MBTA) and EO 13186 (Responsibilities of Federal Agencies to
Protect Migratory Birds) provide for the protection of migratory birds. The MBTA of 1918, as amended (16 U.S.C. 703-712) makes it unlawful to, among other things, pursue, hunt, take, capture, kill, transport or import any species listed under the Act. The Act implements conventions
between the U.S., Great Britain, Mexico, Japan, and the former Soviet Union.
EO 13186 was issued to assist federal agencies with their efforts to comply with the MBTA. It should be noted that the EO does not constitute any legal authorization that in any way supersedes the requirements outlined in the MBTA. The EO directs federal agencies undertaking actions that have or are likely to have a measurable adverse impact on migratory bird populations to develop and implement a Memorandum of Agreement with the FWS addressing the conservation of these populations.
The field survey at the preferred site (Site 7) recorded no species of plants or animals currently listed or proposed for listing under either the Federal or State of Hawai‘i endangered species statutes. The field survey did indicate that endemic Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus newelli) have been recorded flying over the general area
between April and the end of November each year. Impact avoidance and minimization measures would be implemented, including down-shielding of lights and other measures to prevent impacts to migratory birds.
5.14 National Historic Preservation Act (U.S.C. 54 §300101)
The National Historic Preservation Act (NHPA) of 1966 (Public Law 89-665; U.S.C. 54 §300101 requires a federal agency undertaking an action/project consider of the effect of the project on any historic property defined as a district, site, building, structure, or object that is included in or eligible for inclusion in the National Register Historic Places.
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U.S.C. 54 §306108 (commonly called Section 106 of the NHPA) requires a federal agency having direct or indirect jurisdiction over a federal or federally assisted undertaking to take into account
the effect of the undertaking on any historic property. 54 U.S.C § 306102 requires the federal agency’s preservation-related activities to be carried out in consultation with other federal, State, and local agencies, Indian tribes, Native Hawaiian organizations.
The proposed collection system would be constructed along the existing County streets and two short segments within private easements ity that have been previously disturbed when the streets were constructed. Preliminary analysis shows the proposed treatment and disposal facility would be constructed in an area that does not contain archaeological resources. An AIS, including subsurface testing, will be conducted to confirm the presence or absence of archaeological resources on the project site.
The contract drawings will state that, should archaeological sites such as walls, platforms, pavements or mounds, or remains such as artifacts, burials, concentrations of shell or charcoal be encountered during construction activities, work would cease immediately and the find would be protected from further damage. The contractor would immediately contact the SHPD, who will assess the significance of the find and recommend an appropriate mitigation measure, if necessary.
5.15 Protection of Wetlands (Executive Order 11990 (1977), as amended by Executive Order 12608 (1997))
Executive Order 11990, Protection of Wetlands, dated 1977 requires federal agencies to avoid,
preserve, or mitigate effects of new construction projects on lands which have been designated wetlands. EO 11990 states in order to avoid to the extent possible the long- and short-term adverse impacts associated with the destruction or modification of wetlands and to avoid direct
or indirect support of new construction in wetlands wherever there is a practicable alternative, it is hereby ordered as follows: Section 1. (a) Each agency shall provide leadership and shall take action to minimize the destruction, loss or degradation of wetlands, and to preserve and enhance
the natural and beneficial values of wetlands in carrying out the agency's responsibilities for (1) acquiring, managing, and disposing of Federal lands and facilities; and (2) providing Federally undertaken, financed, or assisted construction and improvements; and (3) conducting Federal activities and programs affecting land use, including but not limited to water and related land resources planning, regulating, and licensing activities.
The field survey conducted in August 2018 at the preferred location for the proposed treatment and disposal facility (Site 7) identified no wetlands at the site. The survey report indicated that the National Wetlands Inventory (NWI) Wetlands Mapper identifies no features occurring within the
area do not flow all the way to the sea, but terminate on Keone‘ele‘ele Flat to the southwest. Based on this information, the Proposed Action is not expected to adversely impact wetland
resources.
5.16 Rivers and Harbors Act (33 U.S.C. § 403)
Originally enacted on March 3, 1899, the "Rivers and Harbors Appropriation Act of 1899" affects navigable waters of the U.S. The Act states the creation of any obstruction not affirmatively authorized by Congress, to the navigable capacity of any of the waters of the United States is prohibited; and it shall not be lawful to build or commence the building of any wharf, pier, dolphin, boom, weir, breakwater, bulkhead, jetty, or other structures in any port, roadstead, haven, harbor, canal, navigable river, or other water of the United States, outside established harbor lines, or where no harbor lines have been established, except on plans recommended by the Chief of
Engineers and authorized by the Secretary of the Army; and it shall not be lawful to excavate or fill, or in any manner to alter or modify the course, location, condition, or capacity of, any port,
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roadstead, haven, harbor, canal, lake, harbor or refuge, or inclosure within the limits of any breakwater, or of the channel of any navigable water of the United States, unless the work has
been recommended by the Chief of Engineers and authorized by the Secretary of the Army prior to beginning the same.
preferred location for
the proposed treatment and disposal facility is sited about 1,500 feet east of the center line of Hionamoa Gulch. The USGS topographic map shows the gulch stops about 5,500 feet from the shoreline. Based on this, the collection system and the treatment and disposal facility would not affect navigable waters.
5.17 Safe Drinking Water Act (42 U.S.C. §300f)
The Safe Drinking Water Act (SDWA), 42 U.S.C. §300f was established to protect the quality
of all waters actually or potentially designed for drinking use from both underground and aboveground sources. The SDWA authorizes EPA to establish minimum standards to protect potable water with which all owners or operators of public water systems must comply; to
oversee the agencies which can be approved to implement these rules on EPA's behalf, such as State governments; and to encourage attainment of secondary standards (nuisance-related). The SDWA also establishes the Sole Source Aquifer Program, under which EPA also may
evaluate Federal-funded projects to determine whether they have the potential to contaminate a sole source aquifer.
The SDWA was originally passed by Congress in 1974 to protect public health by regulating the nation's public drinking water supply. The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources, rivers, lakes, reservoirs, springs, and ground water wells. (SDWA does not regulate private wells which serve fewer than 25 individuals.) SDWA authorizes the EPA to set national health-based standards for drinking water to protect against both naturally-occurring and man-made contaminants that may be found in drinking water. The
EPA, states, and water systems then work together to make sure that these standards are met.
Section 1424(e) of the SDWA of 1974 (Public Law 93-523, 42 U.S.C. 300 et. seq), also established the Sole Source Aquifer program which states that no commitment for federal financial assistance (through a grant, contract, loan guarantee, or otherwise) may be entered into for any project which the EPA Administrator determines may contaminate such aquifer through a recharge zone so as to create a significant hazard to public health.
that do not meet current County standards for a wastewater collection system. Further, the existing disposal system consists of two LCCs that discharge untreated sewage into the subsurface. Lastly, the two LCCs are located within the underground injection control area designated as a drinking water source.
The Proposed Action would include installation of a gravity collection system consisting of PVC
corrosion-resistant lines placed in trenches that meets current County standards. The proposed treatment and disposal facility would treat incoming flows through a series of lagoons and a subsurface flow constructed wetland and disinfection system, with final disposal in land application basis with media and trees for further treatment. Therefore, the Proposed Action is not expected to adversely impact drinking water sources and would replace the existing outdated
system that does pose a threat to drinking water currently.
5.18 Wild and Scenic Rivers Act (16 U.S.C. 1271-1287)
The Wild and Scenic Rivers Act, 16 U.S.C. 1271-1287, declares that certain selected rivers with their immediate environments, which possess outstandingly remarkable scenic, recreational,
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geologic, fish and wildlife, historical, cultural, or other similar values, shall be preserved in their free-flowing condition for the enjoyment of present and future generations.
The State of Hawai‘i has no designated wild and scenic rivers. The Wild and Scenic Rivers Act is not applicable to this project.
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6 PLANS, POLICIES AND CONTROLS
This section discusses the State and County of Hawai‘i land use plans, policies and controls relating to the proposed project.
6.1 State Land Use Plans and Policies
6.1.1 Hawai‘i State Plan
The Hawai‘i State Plan, Chapter 226, HRS, as amended, provides goals, objectives, policies, and priorities for the State. as a guide for the future long-range development of the State; identify the goals, objectives, policies, and priorities for the State; provide a basis for determining priorities and allocating limited resources, such as public funds, services, human resources, land, energy, water, and other
resources; improve coordination of federal, state, and county plans, policies, programs, projects, and regulatory activities; and to establish a system for plan formulation and program coordination to provide for an integration of all major state, and county activities. The proposed project’s consistency with applicable objectives and policies are discussed in Table 6.1.
Table 6.1 Hawai‘i State Plan Objectives and Policies
Objectives and Policies of the Hawai‘i State Plan Discussion
§226-4 State goals. In order to ensure, for present and future generations, those elements of choice and mobility that ensure that individuals and groups may approach their desired levels of self-reliance and self-determination, it shall be the goal of the State to achieve: (1) A strong, viable economy, characterized by stability, diversity, and growth, that enables the fulfillment of the needs and expectations of Hawai‘i’s present and future generations. (2) A desired physical environment, characterized by beauty, cleanliness, quiet, stable natural systems, and uniqueness, that enhances the mental and physical well-being of the people. (3) Physical, social, and economic well-being, for individuals and families in Hawaii, that nourishes a sense of community responsibility, of caring, and of participation in community life.
State economy by providing a wastewater collection system and a treatment and disposal facility to enhance the community and the physical well-being of the community.
§226-5 Objective and policies for population. (a) It shall be the objective in planning for the State's population to guide population growth to be consistent with the achievement of physical, economic, and social objectives contained in this chapter.
facilities or improvements that could guide or otherwise affect population
§226-6 Objectives and policies for the economy--in general. (a) Planning for the State's economy in general shall be directed toward achievement of the following objectives: facilities or improvements that affect
§226-7 Objectives and policies for the economy--agriculture. (a) Planning for the State's economy with regard to agriculture shall be directed towards achievement of the following objectives: facilities or improvements which would affect agriculture of this area of
treatment and disposal facility will not adversely impact the total macadamia nut production on the state or County.
§226-8 Objective and policies for the economy--visitor industry. (a) Planning for the State's economy with regard to the visitor industry shall be directed towards the achievement of the objective of a visitor industry that
facilities or improvements that would affect the visitor industry of this area of
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Table 6.1 Hawai‘i State Plan Objectives and Policies
Objectives and Policies of the Hawai‘i State Plan Discussion
§226-9 Objective and policies for the economy--federal expenditures. (a) Planning for the State's economy with regard to federal expenditures shall be directed towards achievement of the objective of a stable federal investment base as an integral component of Hawai‘i’s economy.
Thexpenditures to provide a collection system and treatment and disposal facility for the community.
§226-10 Objective and policies for the economy--potential growth and innovative activities. (a) Planning for the State's economy with regard to potential growth and innovative activities shall be directed towards achievement of the objective of development and expansion of potential
economic base.
facilities or improvements that would affect the potential growth of this area
§226-10.5 Objectives and policies for the economy--information industry. (a) Planning for the State's economy with regard to telecommunications and information technology shall be directed toward recognizing that broadband and wireless communication capability and infrastructure are foundations for an innovative economy and positioning Hawai‘i as a leader in broadband and wireless communications and applications in the Pacific Region.
facilities or improvements that would affect the information industry of this
§226-11 Objectives and policies for the physical environment--land-based, shoreline, and marine resources. (b) To achieve the land-based, shoreline, and marine resources objectives, it shall be the policy of this State to: (1) Exercise an overall conservation ethic in the use of Hawai‘i’s natural resources. (3) Take into account the physical attributes of areas when planning and designing activities and facilities.
900 feet mean sea level and about 3.8 miles from the shoreline. As such, it would not affect shoreline or marine resources.
§226-12 Objective and policies for the physical environment--scenic, natural beauty, and historic resources. (b) To achieve the scenic, natural beauty, and historic resources objective, it shall be the policy of this State to: (3) Promote the preservation of views and vistas to enhance the visual and aesthetic enjoyment of mountains, ocean, scenic landscapes, and other natural features.
facilities or improvements that would affect the scenic, natural beauty and historic resources of this area of
§226-13 Objectives and policies for the physical environment--land, air, and water quality. (b) To achieve the land, air, and water quality objectives, it shall be the policy of this State to: (2) Promote the proper management of Hawai‘i’s land and water resources. (3) Promote effective measures to achieve desired quality in Hawai‘i’s surface, ground, and coastal waters.
project does not include facilities or improvements that would affect the physical environment of this
§226-14 Objective and policies for facility systems--in general. r facilities.
§226-15 Objectives and policies for facility systems--solid and liquid wastes. facilities or improvements that would affect liquid waste facilities. The project provides a collection system and treatment and disposal facility for
conformance with EPA requirements.
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Table 6.1 Hawai‘i State Plan Objectives and Policies
Objectives and Policies of the Hawai‘i State Plan Discussion
§226-16 Objective and policies for facility systems--water. (a) Planning for the State's facility systems with regard to water shall be directed towards achievement of the objective of the provision of water to adequately accommodate domestic, agricultural, commercial, industrial, recreational, and other needs within resource capacities.
facilities or improvements that would affect water facilities.
§226-17 Objectives and policies for facility systems--transportation. (a) Planning for the State's facility systems with regard to transportation shall be directed towards the achievement of the following objectives:
ala project does not include facilities or improvements that would adversely affect transportation systems
§226-18 Objectives and policies for facility systems--energy. (a) Planning for the State's facility systems with regard to energy shall be directed toward the achievement of the following objectives, giving due consideration to all:
facilities or improvements that would affect energy systems. Electrical service will be provided by HELCO.
[§226-18.5] Objectives and policies for facility systems--telecommunications. (a) Planning for the State's telecommunications facility systems shall be directed towards the achievement of dependable, efficient, and economical statewide telecommunications systems capable of supporting the needs of the people.
facilities or improvements that would affect telecommunications.
§226-19 Objectives and policies for socio-cultural advancement--housing. (a) Planning for the State's socio-cultural advancement with regard to housing shall be directed toward the achievement of the following objectives:
facilities or improvements that would affect housing.
§226-20 Objectives and policies for socio-cultural advancement--health. (a) Planning for the State's socio-cultural advancement with regard to health shall be directed towards achievement of the following objectives: facilities or improvements that would
§226-21 Objective and policies for socio-cultural advancement--education. (a) Planning for the State's socio-cultural advancement with regard to education shall be directed towards achievement of the objective of the provision of a variety of educational opportunities to enable individuals to fulfill their needs, responsibilities, and aspirations
facilities or improvements that would affect the educational opportunities in
§226-22 Objective and policies for socio-cultural advancement--social services. (a) Planning for the State's socio-cultural advancement with regard to social services shall be directed towards the achievement of the objective of improved public and private social services and activities that enable individuals, families, and groups to become more self-reliant and confident to improve their well-being.
facilities or improvements that would affect social services of this area of
§226-23 Objective and policies for socio-cultural advancement--leisure. (a) Planning for the State's socio-cultural advancement with regard to leisure shall be directed towards the achievement of the objective of the adequate provision of resources to accommodate diverse cultural, artistic, and recreational needs for present and future generations.
facilities or improvements that would affect the leisure activities.
§226-24 Objective and policies for socio-cultural advancement--individual rights and personal well-being. (a) Planning for the State's socio-cultural advancement with regard to individual rights and personal well-being shall be directed towards achievement of the objective of
increased opportunities and protection of individual rights to enable individuals to fulfill their socio-economic needs and aspirations.
facilities or improvements that would affect individual rights.
§226-25 Objective and policies for socio-cultural advancement--culture. (a) Planning for the State's socio-cultural advancement with regard to culture shall be directed toward the achievement of the objective of enhancement of cultural identities, traditions, values, customs, and arts of Hawai‘i’s people.
facilities or improvements that would affect the cultural advancement.
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Table 6.1 Hawai‘i State Plan Objectives and Policies
Objectives and Policies of the Hawai‘i State Plan Discussion
§226-26 Objectives and policies for socio-cultural advancement--public safety. (a) Planning for the State's socio-cultural advancement with regard to public safety shall be directed towards the achievement of the following objectives:
facilities or improvements that would adversely affect public safety of this
§226-27 Objectives and policies for socio-cultural advancement--government. (a) Planning the State's socio-cultural advancement with regard to government shall be directed towards the achievement of the following objectives:
facilities or improvements that would affect the advancement of government.
§226-101 Purpose. The purpose of this part is to establish overall priority guidelines to address areas of statewide concern. [L 1978, c 100, pt of §2; am L 1984, c 236, §14] facilities or improvements that would affect overall priority guidelines of statewide concern.
6.1.2 State Functional Plans
The Hawai‘i State Plan directs appropriate State agencies to prepare Functional Plans to address
Statewide needs, problems, and issues through recommended policies and actions. A total of 14 Functional Plans were prepared to implement the State Plan provisions in the areas of agriculture, transportation, conservation lands, education, tourism, water resources, energy, recreation, historic preservation, health, housing, higher education, employment, and human services. The following presents a review of the Functional Plans which are applicable to the proposed project.
(a) Agriculture Functional Plan
Objective B: Achievement of an orderly agricultural marketing system through product
promotion and industry organization.
Policy B.2
Objective C: Achievement of optimal contribution by agriculture to the state’s economy. Discussion: . The 2012 Census of
macadamia trees, of which 17,378 acres were locat . Though the proposed wastewater treatment and disposal facility project site is currently planted with macadamia trees,
-acre project site is relatively small compared to the 17,378 acres dedicated to macadamia . Moreover, the project site is situated on poorer-quality agriculture
land. According to the Land Study Bureau Agricultural Productivity Ratings Map about 50 percent of the project site is classified as having Good productivity, while the 50 percent has a productivity rating of Poor. Furthermore, according to the Agricultural Lands of Importance to the State of the treatment and disposal project site is considered Prime Lands with roughly 40 percent deemed Other Lands, while the remaining 40 percent is Unclassified. Overall, the proposed wastewater treatment and disposal facility will be sited and designed to minimize the use of agricultural lands for non-agricultural purposes. Removal of 14.9 acres from macadamia nut production would not adversely affect the total macadamia nut acreage in the state or the County. Further, use of the 14.9-acre area for the treatment and disposal facility will not be contrary to the objective of contribution of agriculture to the state’s economy.
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(b) Historic Preservation Functional Plan
Objective B: Protection of Historic Properties
Policy B.2. Establish and make available a variety of mechanisms to better protect historic properties.
Objective C: Management and Treatment of Historic Properties
Policy C.3. Explore innovative means to better manage historic properties.
Policy C.4. Encourage proper preservation techniques. Discussion: The wastewater collection system will be constructed primarily within the existing
were constructed. Preliminary analysis shows the treatment and disposal facility will be constructed in an area that does not contain archaeological resources. An Archaeological Inventory Survey (AIS), including subsurface testing, will be conducted to confirm the presence or absence of archaeological resources on the project site.
The contract drawings will state that, should archaeological sites such as walls, platforms,
pavements or mounds, or remains such as artifacts, burials, concentrations of shell or charcoal be encountered during construction activities, work shall cease immediately and the find shall be protected from further damage. The contractor shall immediately contact the State Historic
Preservation Division (SHPD), who will assess the significance of the find and recommend an appropriate mitigation measure, if necessary.
6.1.3 State Land Use District
The State Land Use Law, Chapter 205, HRS, is intended to preserve, protect and encourage the development of lands in the State for uses that are best suited to the public health and welfare of Hawai‘i’s people. Under Chapter 205, HRS all lands in the State of Hawai‘i are classified by the State Land Use Commission into four major categories referred to as State Land Use Districts. These districts are identified as the Urban District, Agricultural District, Conservation District, and Rural District.
Discussion: The treatment and disposal facility is located in the Agricultural District. Uses in the Agricultural District are governed by Chapter 205, Hawai‘i Revised Statutes. Permissible uses in the Agricultural District are set forth in Chapter 205, HRS, §205-4.5 (7) “Public, private, and quasi-public utility lines and roadways, transformer stations, communications equipment buildings, solid waste transfer stations, major water storage tanks, and appurtenant small buildings such as
booster pumping stations, but not including offices or yards for equipment, material, vehicle storage, repair or maintenance, or treatment plants, or corporation yards, or other like structures”.
§205-4.5(b) states: Uses not expressly permitted in subsection (a) shall be prohibited, except the
uses permitted as provided in §205-6, Special Permit. §206-6(a) states: subject to this section, the County Planning Commission may permit certain unusual and reasonable uses within agricultural and rural districts other than those for which the district is classified. Any person who
desires to use the person's land within an agricultural or rural district other than for an agricultural or rural use, as the case may be, may petition the planning commission of the county within which the person's land is located for permission to use the person's land in the manner desired. Based on the above, the County will apply for a Special Permit which will require approved by the County Planning Commission.
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6.1.4 Chapter 344, State Environmental Policy
The State’s Environmental Policy is contained in Chapter 344, HRS. The purpose of the Chapter
344, HRS, State Environmental Policy is to “establish a state policy which will encourage
productive and enjoyable harmony between people and their environment, promote efforts which will prevent or eliminate damage to the environment and biosphere and stimulate the health and
welfare of humanity, and enrich the understanding of the ecological systems and natural
resources important to the people of Hawai‘i.”
§344-3 Environmental policy provides: It shall be the policy of the State, through its programs, authorities, and resources to:
Conserve the natural resources, so that land, water, mineral, visual, air and other natural resources are protected by controlling pollution, by preserving or augmenting natural
resources, and by safeguarding the State’s unique natural environmental characteristics
in a manner which will foster and promote the general welfare, create and maintain conditions under which humanity and nature can exist in productive harmony, and fulfill
the social, economic, and other requirements of the people of Hawai‘i. Enhance the quality of life by:
(D) Establishing a commitment on the part of each person to protect and
resources.
§344-4 Guidelines states. In pursuance of the state policy to conserve the natural resources and enhance the quality of life, all agencies, in the development of programs, shall, insofar as
practicable, consider the following guidelines:
(2) Land, water, mineral, visual, air, and other natural resources. (A) Encourage management practices which conserve and fully utilize all
natural resources;
(B) Promote irrigation and waste water management practices which conserve and fully utilize vital water resources;
(C) Promote the recycling of waste water;
Discussion: One of the purposes of the project is to close the LCCs which have been used for . Although use of the LCCs has not resulted in known adverse effects to groundwater resources or the drinking water sources for the community, closure of the LCCs will remove this possible source of contamination. Thus, the LCC Replacement Project will enhance the groundwater resources in the area. This will be compatible with the objective to prevent or eliminate damage to the environment.
6.1.5 Hawai‘i Coastal Zone Management Program
The Coastal Zone Management (CZM) Program was created through passage of the Coastal Zone Management Act of 1972. Hawai‘i’s CZM Program, adopted as Chapter 205A, HRS, provides a basis for protecting, restoring and responsibly developing coastal communities and
resources. The Hawai‘i CZM area includes all lands within the State and the areas seaward to the extent of the State’s management jurisdiction. Thus, area. A discussion of the project’s consistency with the objectives and policies of the CZM
Program is provided below.
(a) Recreational Resources
Objective:
Provide coastal recreational opportunities accessible to the public.
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Policies:
(D) Improve coordination and funding of coastal recreational planning and
management; and (i) Provide adequate, accessible, and diverse recreational opportunities in the
coastal zone management area by: Protecting coastal resources uniquely
suited for recreational activities that cannot be provided in other areas; (ii) Requiring replacement of coastal resources having significant recreational
value, including but not limited to surfing sites, fishponds, and sand beaches,
when such resources will be unavoidably damaged by development; or requiring reasonable monetary compensation to the state for recreation when
replacement is not feasible or desirable;
(iii) Providing and managing adequate public access, consistent with conservation of natural resources, to and along shorelines with recreational value;
(iv) Providing an adequate supply of shoreline parks and other recreational facilities suitable for public recreation; (v) Ensuring public recreational use of county, state, and federally owned or
controlled shoreline lands and waters having recreational value consistent with public safety standards and conservation of natural resources;
(vi) Adopting water quality standards and regulating point and nonpoint sources of
pollution to protect, and where feasible, restore the recreational value of coastal waters.
(vii) Developing new shoreline recreational opportunities, where appropriate, such
as artificial lagoons, artificial beaches, and artificial reefs for surfing and fishing; and
(viii) Encouraging reasonable dedication of shoreline areas with recreational value
for public use as part of discretionary approvals or permits by the land use commission, board of land and natural resources, and county authorities; and
crediting such dedication against the requirements of section 46-6.
Discussion: would not affect coastal resources.
(b) Historic Resources
Objective: (B) Protect, preserve and, where desirable, restore those natural and manmade
historic and prehistoric resources in the coastal zone management area that are significant in Hawaiian and American history and culture.
Policies: (D) Identify and analyze significant archaeological resources;
(E) Maximize information retention through preservation of remains and artifacts or
salvage operations; and (F) Support state goals for protection, restoration, interpretation, and display of historic
resources.
The wastewater collection system will be constructed primarily within the existing County streets ch has been previously disturbed when the streets were constructed. Preliminary analysis shows the treatment and disposal facility will be constructed in an area that does not contain archaeological resources. An AIS, including subsurface testing, will be conducted to confirm the presence or absence of archeological resources on the project site.
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The contract drawings will state that, should archaeological sites such as walls, platforms, pavements or mounds, or remains such as artifacts, burials, concentrations of shell or charcoal
be encountered during construction activities, work shall cease immediately and the find shall be protected from further damage. The contractor shall immediately contact the SHPD, who will assess the significance of the find and recommend an appropriate mitigation measure, if
necessary.
(c) Scenic and Open Space Resources
Objective:
(B) Protect, preserve, and where desirable, restore or improve the quality of coastal
scenic and open space resources.
Policies:
(E) Identify valued scenic resources in the coastal zone management area; (F) Ensure that new developments are compatible with their visual environment by
designing and locating such developments to minimize the alteration of natural
landforms and existing public views to and along the shoreline; (G) Preserve, maintain, and, where desirable, improve and restore shoreline open
space and scenic resources; and (H) Encourage those developments which are not coastal dependent to locate in
inland areas.
Discussion: coastal scenic and open space resources would not be affected.
(d) Coastal Ecosystems
Objective: (A) Protect valuable coastal ecosystems, including reefs, from disruption and minimize
adverse impacts on all coastal ecosystems.
Policies:
(F) Exercise an overall conservation ethic, and practice stewardship in the protection,
use, and development of marine and coastal resources; (G) Improve the technical basis for natural resource management;
(H) Preserve valuable coastal ecosystems, including reefs, of significant biological or
economic importance; (I) Minimize disruption or degradation of coastal water ecosystems by effective
regulation of stream diversions, channelization, and similar land and water uses, recognizing competing water needs; and
(J) Promote water quantity and quality planning and management practices that
reflect the tolerance of fresh water and marine ecosystems and maintain and enhance water quality through the development and implementation of point and
nonpoint source water pollution control measures.
Discussion: coastal ecosystems would not be adversely affected.
(e) Economic Uses
Objective: (B) Provide public or private facilities and improvements important to the State’s
economy in suitable locations.
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Policies: (D) Concentrate coastal dependent development in appropriate areas;
(E) Ensure that coastal dependent developments such as harbors and ports, and
coastal related development such as visitor facilities and energy generating facilities, are located, designed, and constructed to minimize adverse social,
visual, and environmental impacts in the coastal zone management area; and
(F) Direct the location and expansion of coastal dependent developments to areas presently designated and used for such developments and permit reasonable long-
term growth at such areas, and permit coastal dependent development outside of
presently designated areas when: (iv) Use of presently designated locations is not feasible;
(v) Adverse environmental effects are minimized; and
(vi) The development is important to the State’s economy.
Discussion: . The collection system and the treatment and disposal facility have been sited in suitable locations to serve the
(f) Coastal Hazards
Objectives: (A) Reduce hazard to life and property from tsunami, storm waves, stream flooding,
erosion, subsidence, and pollution.
Policies:
(C) Develop and communicate adequate information about storm wave, tsunami,
flood, erosion, subsidence, and point and nonpoint source pollution hazards; (D) Control development in areas subject to storm wave, tsunami, flood, erosion,
hurricane, wind, subsidence, and point and nonpoint pollution hazards;
(E) Ensure that developments comply with requirements of the Federal Flood Insurance Program;
(F) Prevent coastal flooding from inland projects.
Discussion: . The proposed collection system and treatment and disposal facility do not include improvements related to tsunami, storm waves, stream flooding erosion, subsidence and pollution.
(g) Managing Development
Objective:
(A) Improve the development review process, communication, and public participation in the management of coastal resource and hazards.
Policies: (D) Use, implement, and enforce existing law effectively to the maximum extent
possible in managing present and future coastal zone development;
(E) Facilitate timely processing of applications for development permits and resolve overlapping or conflicting permit requirements; and
(F) Communicate the potential short- and long-term impacts of proposed significant
coastal developments early in their life cycle and in terms understandable to the public to facilitate public participation in the planning and review process.
Discussion: In December 2017, a total of 5 community outreach sessions regarding the project iles from the shoreline.
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The collection system and treatment and disposal facility does not involve management of coastal resources and hazards.
(h) Public Participation
Objective: (B) Stimulate public awareness, education, and participation in coastal management.
Policies: (D) Promote public involvement in coastal zone management processes;
(E) Disseminate information on coastal management issues by means of educational
materials, published reports, staff contact, and public workshops for persons and organizations concerned with coastal issues, developments, and government
activities; and
(F) Organize workshops, policy dialogues, and site-specific mediations to respond to coastal issues and conflicts.
Discussion: In December 2017, a total of 5 community outreach sessions were conducted in the
(i) Beach Protection
Objective: (A) Protect beaches for public use and recreation.
Policies: (I) Locate new structures inland from the shoreline setback to conserve open space,
minimize interference with natural shoreline processes, and minimize loss of
improvements due to erosion; (J) Prohibit construction of private erosion-protection structures seaward of the
shoreline, except when they result in improved aesthetic and engineering solutions
to erosion at the sites and do not interfere with existing recreational and waterline activities; and
(K) Minimize the construction of public erosion-protection structures seaward of the
shoreline.
Discussion: 3.8 miles from the shoreline. The collection system and the treatment and disposal facility project does not include improvements which would affect public use beaches.
(j) Marine Resources
Objective: (A) Promote the protection, use, and development of marine and coastal resources to
assure their sustainability.
Policies:
(L) Ensure that the use and development of marine and coastal resources are
ecologically and environmentally sound and economically beneficial; (M) Coordinate the management of marine and coastal resources and activities to
improve effectiveness and efficiency;
(N) Assert and articulate the interests of the State as a partner with federal agencies in the sound management of ocean resources within the United States exclusive
economic zone;
(O) Promote research, study, and understanding of ocean processes, marine life, and
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other ocean resources in order to acquire and inventory information necessary to understand how ocean development activities relate to and impact upon ocean
and coastal resources; and
(P) Encourage research and development of new, innovative technologies for exploring, using, or protecting marine and coastal resources.
. The collection system and the treatment and disposal facility project does not include improvements which would affect development of marine and coastal resources.
6.2 Hawai‘i County Land Use Plans and Policies
6.2.1 Hawai‘i County General Plan
The existing General Plan was adopted in 2005. According to that plan, a comprehensive review process is to be initiated no more than 10 years after the previous review. A lot has happened on Hawai‘i Island since 2005, including population growth, natural disasters, technological advancements, and the emphasis on sustainability. These factors are being considered in the
2015 General Plan. The Planning Director is responsible for leading the review process and recommending amendments to the Plan. Since this review has not been completed, the 2005 General Plan will be used for analysis.
The February 2005 General Plan serves as a policy document outlining long range comprehensive development on the island of Hawai‘i, providing broad goals, objectives, policies, and implementing actions that portray the desired direction of the County’s future. Purposes of the General Plan include:
Guide the pattern of future development in this County based on long-term goals.
Identify the visions, values, and priorities important to the people of this County.
Provide the framework for regulatory decisions, capital improvement priorities,
acquisition strategies, and other pertinent government programs within the County organization and coordinated with State and Federal programs.
Improve the physical environment of the County as a setting for human activities; to make it more functional, beautiful, healthful, interesting, and efficient.
Promote and safeguard the public interest and the interest of the County as a whole.
Facilitate the democratic determination of community policies concerning the
utilization of its natural, man-made, and human resources.
Effect political and technical coordination in community improvement and
development.
Inject long-range considerations into the determination of short-range actions and
implementation.
The planning process utilized for the current comprehensive review and revision of the General Plan included an assessment of the General Plan elements relative to new data, laws, and methods of analysis. Each study element was then analyzed and evaluated in relation to all other elements, County and district goals, and the land use pattern. Potentially, a change in one element
could affect other elements as well as the land use pattern. Similarly, a change in County and district goals could potentially be reflected in all elements and in the land use pattern.
The comprehensive review of the General Plan gathered and assessed the data related to each
element to identify present conditions and problems and future possibilities. The study elements utilized in the General Plan included the following:
Economic: Describes the human, capital, and natural resources used to produce goods
and services for consumption in local and overseas markets.
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Energy: Describes the energy situation for the County and explains the incentive for promoting energy conservation and the development of indigenous energy resources
including solar, wind, hydrologic, and geothermal.
Environmental Quality: Identifies the factors affecting the island's environmental quality and describes the precautions and safeguards necessary to maintain and improve the
quality of the environment for the physical, psychological, and social wellbeing of residents
and visitors.
Flooding and Other Natural Hazards: Pertains to the conservation and protection of life,
improvements, and natural resources from excess runoff due to either man-made
improvements, natural causes, or inundation from tsunamis and heavy seas.
Historic Sites: Identifies sites and buildings of historical and cultural importance.
Natural Beauty: Identifies areas of unique natural beauty that are a principle asset of the
island, and encourages programs for their conservation, preservation, and integration with other elements.
Natural Resources and Shoreline: Describes the valuable and often irreplaceable
natural assets of the island and encourages programs for their proper management and protection.
Housing: Addresses the requirements for and the quantity, quality, and distribution of housing units in the County. This element also addresses critical housing problems of the
County.
Public Facilities: Pertains to the location and distribution of facilities for education, public safety, social, health services and other government operations.
Public Utilities: Describes the distribution of power, light, and water; the collection and
disposal of solid waste and sewage; and the provision of other communication utilities that are essential to the efficient functioning of a community.
Recreation: Examines the requirements of the County for active and passive outdoor
activities, cultural events and pastimes, as well as attendant facilities and areas.
Transportation: Describes the requirements for air and water transport terminal facilities
linking the County with the rest of the State and overseas areas, and the island's network
of streets, highways, and roads.
Land Use: Studies the relationship of human activities to the uses of land and the location,
spatial relationship, and topography. This element is subdivided into the following
designations according to uses:
Agricultural: Encompasses all types of agricultural endeavors and specified industrial
uses, residential and ancillary community and public and accessory uses.
Commercial: Comprised of industries in the retail trade and service categories and certain
non-noxious enterprises from other industrial classifications.
Industrial: Includes uses that may not be compatible with commercial areas (such as manufacturing and processing, wholesaling, large storage and transportation facilities,
power plants, and government baseyards) as well as other industrial, manufacturing, or
wholesaling uses.
Multiple Residential: Includes duplexes, apartments, town houses and similar types of
residential structures and ancillary community and public uses.
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Open Space: Includes conservation lands, forest and water reserves, natural and scientific preserves, and potential natural hazard areas.
Public Lands: Includes Federal, State, County, and University owned lands.
Resort: Consists primarily of areas with basic amenities and attributes that attract developments of visitor accommodations and related facilities.
Single-Family Residential: Consists of single-family detached houses and ancillary
community and public uses.
Discussion: LCC Replacement project will be consistent with the Public Utilities element by providing a wastewater collection system designed to the applicable current standards used by the County. As previously described, the current collection system includes lines located the backyard of many of the parcels in the community. The County must obtain permission from each landowner to access lines on private property to inspect, maintain, repair, or replace the lines. The proposed collection system will be located within the public streets in the community or within accessible easements which allow the County to inspect, maintain, repair or replace the lines, all of which are essential to an efficient functioning community.
LCCs, which have been banned by the EPA. The proposed secondary treatment to replace the LCCs consists of aerated lagoons, a subsurface flow wetland, and a disinfection system. The disposal system consists of a slow-rate land application system that is a form of land treatment that is recognized by the EPA. The treatment
and disposal facility will provide a system to replace the banned LCCs which will be essential to an efficient functioning community.
The General Plan discusses sewers in Section 11.6. The plan states:
Adequate sewer disposal systems are vital to safeguard public health and preserve the
environment. An adequate system is one that minimizes contamination of both the groundwater supply and the coastal waters, beaches and waterborne recreational areas
and is not a visual and odor nuisance.
About 77 per cent of the County's population is served by cesspools. There is an increasing need to create a better system than individual cesspools, particularly in highly
urbanized and shoreline areas. This is due to the possible pollution of groundwater as well
as cesspool seepage into coastal waters. More stringent pollution controls, especially in water quality standards, are being imposed by regulatory agencies. The State Department
of Health (DOH) intends to promulgate rules that will prohibit cesspools in the County of
Hawaii. [In 2017, the State passed Act 125 requiring all cesspools statewide to be upgraded/closed by 2050.]
Hawai‘i Count. The remaining communities are served by private wastewater
treatment facilities or individual facilities such as cesspools or septic tanks.
In August 1991, the State Department of Health adopted rules that require the use of septic systems in the most critical wastewater disposal areas. Critical wastewater disposal
areas are areas around the island where cesspools are permitted. Sewerage disposal
system designs must be examined with the particular area in mind. However, it is important to note that the critical wastewater disposal areas may be eliminated in the near future
when the State Department of Health implements the prohibition of cesspools.
Specific standards are discussed in Section 11.6.3 Standards which includes the following.
(a) Incorporate sewage works standards proposed in the "Sewerage Study for All Urban
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Plan for the Coun
(b) Sewerage systems shall be designed for a particular area, depending on topography,
geology, density of population, costs, and other considerations of the specific area. (c) There shall be a minimum of visual and odor pollution emanating from sewerage
treatment facilities.
(d) Applicable standards and regulations of the State Department of Health, Chapter 23 "Underground Injection Control."
(e) Applicable standards and regulations of the State Department of Health, Chapter 54
"Water Quality Standards." (f) Applicable standards and regulations of the State Department of Health, Chapter 55
"Water Pollution Control."
(g) Applicable standards and regulations of the State Department of Health, Chapter 62, HRS, "Wastewater Systems."
(h) Applicable standards and regulations of Chapter 342, HRS; Act 282, Session Laws of Hawai‘i 1985; and Act 302, Session Laws of Hawai‘i 1986, Relating to
Environmental Quality.
(i) All wastewater disposal systems shall conform to the applicable provisions of Chapter 11-62, Hawai‘i Administrative Rules for the Department of Health to ensure proper
treatment and disposal of wastewater and to prevent further contamination of
waterways, underground water sources, and the coastal waters.
Discussion: The proposed secondary treatment to replace the LCCs consists of aerated lagoons,
a subsurface flow wetland, and a disinfection system. The disposal system consists of a slow-rate land application system that is a form of land treatment that is recognized by the EPA. The treatment and disposal facility will be designed to meet rules and regulations applicable to the facility which will replace the banned LCCs. The design drawings and related calculations and analysis will be submitted to the DOH for review and comment. The design of the facility will require approval by the DOH before the DOH will issue an approval to operate the treatment and disposal facility.
6.2.2 Ka‘ Community Development Plan
The County of Hawai‘i General Plan calls for the preparation of community development plans (CDPs) “to translate the broad General Plan statement to specific actions as they apply to specific geographical areas.” Hawai‘i County. In October 2017, the -66. The purpose of CDPs is to implement the broad goals within the General Plan on a regional basis and to translate the broad General Plan statements into specific actions. CDPs are the forum for community input into managing growth
and coordinating the delivery of government services to the community. CDPs designate detailed development patterns and direct physical development and public improvements by detailing land use policies and infrastructure priorities.
There are two types of County policies in the CDP:
area and shall be implemented through all County of Hawai‘i actions. In addition, the Land Use Policies shall inform County recommendations to other agencies, including the State Land Use Commission regarding district boundary amendments, special permits, and
There are two aspects of Land Use Policies:
Policy Intent: These are general statements that express policy aims or objectives. From
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a legal standpoint, these “hortatory” policies are open to interpretation when applied in specific instances.
Policy Controls: These limit the range of decisions that can be made in the future, like land use policies that specifically designate future settlement or transportation patterns. These binding, sometimes restrictive policy controls often include use of the term “shall,” which,
from a legal standpoint, means the policy is imperative or mandatory.
The CDP distinguishes these two aspects of Land Use Policy. The applicable one is:
2. “County Actions” are the official County policies to guide future County priorities and
initiatives, including operating and capital budgets. These policies are not mandated,
legally‐binding, or self‐implementing; rather, they often require additional legislative and
administrative directives before being implemented (e.g., land acquisition, capital improvement appropriations, code changes, incentive measures).
All of the CDP Land Use Policies are designed to preserve the preferred future settlement pattern . There are Land Use Policies designed to
protect coastal areas, agricultural lands, mauka forests, scenic areas, sensitive ecosystems, cultural resources, and public access. The following Land Use Policies speak more generally to
residential, commercial, industrial, and resort areas.
Figure 6.1 shows the land use policy map for .
Policy 1 Rehabilitate and develop within existing zoned urban areas already served by
basic infrastructure, or close to such areas, instead of scattered development.
Policy 2 Concentrate commercial uses within and surrounding central core areas in
development outside of the designated urban areas.
Policy 3 Commercial facilities shall be developed in areas adequately served by
necessary services, such as water, utilities, sewers, and transportation
systems. Should such services not be available, the development of more intensive uses should be in concert with a localized program of public and
private capital improvements to meet the expected increased needs.
Policy 4 Industrial development shall be located in areas adequately served by
transportation, utilities, and other essential infrastructure.
Policy 7 . Future land use decisions in the
boundaries, designations, and policies herein, unless the CDP and the General Plan are in direct conflict.
Policy 8 In the “Low Density Urban (LDU)” Land
CDP planning area, changes of zone shall only be permitted to Single-Family Residential (RS), Multiple-Family Residential (RM-7.5 or higher), Residential-
Commercial Mixed Use (RCX-7.5 or higher), or Open (O).
, this policy supports a rezone of TMKs (3)9 -6-002:016 & 023:034 from Agricultural (A-1a) and Industrial (ML-20 and MG-1a) to RS and/or O to take advantage
of existing water and road infrastructure.
Policy 9 If infill capacity is exceeded in areas designated “Low Density Urban (LDU)” on
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(3)9-6-005:001 as LDU to take advantage of existing water and road
connections.
Policy 39 The urban growth boundary between agricultural areas (designated “Important Agricultural Land” or “Extensive Agriculture”) and developed areas (designated
“Rural,” “Low/Medium/High Density Urban,” “Industrial,” or “Resort”) is parcel-
Low/Medium Density Urban and Industrial nodes in Ocean View. Areas outside
designated developed areas shall be preserved as agricultural lands, open
space, scenic view planes, and natural beauty areas, unless the CDP and the General Plan are in direct conflict.
Policy 44 Through permit conditions, development agreements, deed restrictions, and/or
other means, ensure that areas in the “Important Agricultural Land” and “Extensive Agriculture” Land Use Policy Map categories continue to be utilized
for agricultural uses and not for speculative or other residential development.
Policy 69 Protect, restore, and enhance the sites, buildings, and objects of significant historical and cultural importance to Hawai‘i.
Policy 70 Protect all rights, customarily and traditionally exercised for subsistence, cultural and religious purposes and possessed by ahupua‘a tenants who are
descendants of native Hawaiians who inhabited the Hawaiian Islands prior to
1778, subject to the right of the State to regulate such rights.
Policy 71 Review and comment by DLNR’s State Historic Preservation Division (SHPD)
shall be requested for any permit or entitlement for use which may affect any
building, structure, object, district, area, or site that is over fifty years old, except as provided in HRS section 6E-42.2.
Policy 72 In the “Low Density Urban” (LDU) and “Medium Density Urban” Land Use
Policy Map categories, in those cases where provisions of the zoning and subdivision codes are inconsistent with the character of surrounding
neighborhoods, variances or PUDs that maintain consistent village/town
character should be encouraged.
Policy 73 The development of commercial facilities should be designed to fit into the
locale with minimal intrusion while providing the desired services. Appropriate
infrastructure and design concerns shall be incorporated into the review of such developments.
Policy 74 As appropriate to maintain community character while also accommodating drainage, walkability, maintenance, and other site-specific needs when
road design, including pavement width and lack of curbs, gutters, sidewalks, or paved shoulders and swales.
Policy 75 As appropriate to maintain community character while also accommodating
drainage, walkability, maintenance, and other site-specific needs, new roads
without curbs, gutters, sidewalks, or paved shoulders and swales.
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Figure 6.1. Community Development Plan Land Use Policy Map
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Discussion: LCC Replacement Project is consistent with land uses policies as the improvements are designed to serve the designated areas shown in the Land Use Policy Map,
. The collection system and the treatment and disposal facility will be consistent with the policy related to infill of commercial development within . The collection system improvements are consistent with the policy to
maintain the community character as the improvements will retain the existing pavement, including retention of streets, shoulders, and drainage systems.
Section 4.3 of the CDP protects agricultural land and open space from non-agricultural development with the CDP Land Use Policy Map, urban growth boundaries, limits on Special Permits and lots sizes, and restrictions on residential development. It also prioritizes agricultural subdivision standards, revisions in water catchment variance rules, stronger farm dwelling regulations and tax incentive programs, development of transfer of development rights and land bank programs, State Important Agricultural Land designations, and expedited lot consolidation in existing rural subdivisions.
Policy 40 Special permits of any kind in the “Important Agricultural Land” and “Extensive Agriculture” Land Use Policy Map categories should not be permitted in the
chapter 25):
Agriculture and Related Economic Infrastructure: Animal hospitals,
Veterinary establishments, Fertilizer yards utilizing only manure and soil, for commercial use
Cottage Industry related to Agriculture: Bed and breakfast establishments, Guest ranches, Lodges, Home occupations
Community Facilities: Community buildings, Public uses and
structures, Shooting ranges, ATV courses (in areas without cultural, natural resource, or scenic value)
Quarries whose permit conditions address geotechnical, engineering, safety, private road use, oversight, and any site-specific issues.
Urban Uses in Ocean View: Uses consistent with the LDU, MDU, and
Policy Map in Ocean View, until the SLU boundaries are amended
(from Agriculture to Urban).
The Planning Commission shall also include in any Special Permit approval (or recommend for
approval to the State Land Use Commission) appropriate performance conditions to achieve CDP
objectives and implement CDP policies. (HRS 205-6(c) and Planning Commission Rules 6-3(a)(5)(G), 6-7, & 6-8)
Discussion: The collection system and the treatment and disposal facility will be owned the County of Hawai‘i and managed and operated by the County of Hawai‘i Department of
Environmental Management. As such, the improvements will be a public use and structure. The Department of Environmental Management will file a Special Permit for review and approval by the Planning Commission.
Section 5 of the CDP prioritizes improvements in infrastructure, facilities, and services, including Section 5.8 applicable to Environmental Management as shown below.
Environmental management facilities, including expanded sewer lines, the Ocean View
Policy 120 Extend the primary wastewater colle
infill development projects can connect wastewater systems built for new
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subdivisions to the County systems.
Discussion: The collection system will be consistent with policy 120 as the improvements for the
LCC Replacement Project . Similarly, the treatment and disposal facility has been designed to accommodate the wastewater
6.2.3 County of Hawai‘i Zoning
Chapter 25 of the Hawai‘i County Code (HCC) regulates land use in accordance with adopted land use policies. The County Code presents permitted uses and structures, development standards, and height controls for each zoning district.
The treatment and disposal facility will be owned the County of Hawai‘i and managed and operated by the County of Hawai‘i Department of Environmental Management. The treatment and disposal facility would be a “public use” as defined by the HCC Chapter 25, Zoning, Section 25-1-5, as a use conducted by or a structure or building owned or managed by the federal government, the State of Hawai‘i or the County to fulfill a governmental function, activity or service for public benefit and in accordance with public policy.
HCC Section 25-2-71 (c)(1) states: Plan approval shall be required in all applicable districts prior to the construction or establishment of public uses, structures and buildings and community
buildings, as permitted under section 25-4-11.
HCC Section 25-4-11(c) states: Public uses, structures and buildings and community buildings
are permitted uses in any district, provided that the director has issued plan approval for such
use.
6.2.4 County of Hawai‘i Special Management Area
Pursuant to the Hawai‘i CZM Program, Chapter 205A, HRS, the counties have enacted ordinances establishing Special Management Areas (SMAs). Any “development” within the SMA requires an SMA Use permit administered by the County of Hawai‘i Planning Department.
Through the SMA permit system, the County assesses and regulates developments proposed for areas located within the SMA. LCC Replacement Project community which lies about 3.8 miles from the shoreline area. As such, the project will not be subject to requirements of an SMA use permit.
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7 PUBLIC PARTICIPATION
LCC replacement project and to work with affected residents and the general community on how to implement the project on both personal and community levels.
These talk story sessions are designed to optimize community conversations in informal and comfortable sessions. The first round of community outreach on the current effort to implement LCC replacement project included five sessions as follows:
1. Tuesday, December 12, 2017 at 6:00 PM – Ka‘-Purpose Conference Room
2. Wednesday, December 13, 2017 at 10:00 AM –
3. Wednesday, December 13, 2017 at 6:00 PM –
4. Thursday, December 14, 2017 at 10:00 AM – Gym Multi-Purpose Conference Room
5. Thursday, December 14, 2017 at 6:00 PM –
The target outcomes for the first round of engagement were the following:
Assure residents the project team was there to listen. In these talk story sessions, the project team emphasized the need to listen to understand the community and how to
continue conversations. Further, the project team stressed in each session that these community outreach discussions are taking place very early in the planning and implementation process. Hence, it was stressed that, while there may be limited
information at this time, the team was there to listen and convey questions and comments to DEM. That way, in the next round of meetings, DEM will be able to provide more information to address community concerns.
Help residents understand what is being proposed. It was important to present project information in ways that are simple, accurate, relevant and conducive to continuing dialogue.
Establish a point of departure to move towards future actions and solutions.
residents have had different experiences with wastewater disposal over the years. For some, they transitioned from a plantation-operated system to a County-run operation. For others, they installed their own systems. The talk story sessions were intended to clearly differentiate between previous efforts and the current proposed project.
Comply with EPA deadline of December 15, 2017, to hold initial public meeting. DEM and EPA established a schedule for completion of key milestones. The talk story sessions comprised several initial public meetings and were organized to comply with this schedule.
recognizing that the project will affect some people directly during construction and operation of the new collection system and new wastewater treatment and disposal facility.
Invitations and announcements for the talk story sessions were intended to reach all audiences, as follows:
Property owners with C. Brewer lines on their property were mailed letters from DEM inviting them to these sessions. The letters included stamped, mail-in postcards to facilitate the RSVP process.
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Fliers were hand-delivered to “newly-accessible properties.”
Organizational leaders were provided copies of fliers announcing meetings and asked to circulate among their members.
Fliers were posted in public venues, such as the post office, the Community Center
Several online announcements were included in http://haunewsbriefs.blogspot.com/.
The format for each meeting was as follows:
1. : Participants were asked to introduce themselves and describe generational presence, length of residence, schools and so on.
2. : Participants were asked to discuss:
Their i
3. Experience with the existing sewer system: Participants were asked to share their They were also asked
to share what they knew about the proposed project.
4. The proposed project: Project background and overview were presented in a slide presentation.
5. Questions and comments: Project representatives encouraged participants to ask questions and voice their reactions.
6. What one message do you want DEM to hear? Each participant was asked to share “one thing” that they wanted to share with the County.
This first round of community outreach met the following objectives:
Residents understood the project team was there to listen. Participants responded enthusiasti experience with wastewater disposal in their town and concerns and views about the proposed project. When the project team could not respond to questions, participants were assured that their comments were noted and there will be follow up.
Those who attended appeared to have acquired at least a rudimentary understanding about how the new collection, treatment, and disposal system would work. They were able to ask questions about transmission of wastewater to the treatment and disposal facility, and how the lagoons and land disposal system would work. Participants indicated they knew that this system is different from wastewater disposal systems they may have
previously experienced.
Participants were able to discuss their understanding, or lack thereof, of the wastewater system and their own personal situation. By the end of each session, they expressed understanding that the proposed project is a departure from previous discussions and current operations.
The milestone date for an initial community meeting (December 15, 2017) was met.
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meetings.
The proposed project was modified in response to the community input received and is described in this Draft EA. A second round of meetings with the community is planned to be conducted in concert with the Draft EA public review and comment period.
Based on the first round of community outreach, the following community outreach activities are being conducted to continue to engage constructive and meaningful community input.
Information Follow-up. Project representatives made a commitment to follow up on topics raised in the first round of community outreach. The following lists how topics are addressed in this Draft EA or other forms of communication.
Site selection process. Several participants asked why the tentative site was selected and suggested other sites. It is recommended that a summary table of previously
considered sites and selection rationale, as well a related map, be presented. See Section 2 for site selection discussion.
Flooding at tentative site. Participants claimed that this site is prone to flooding. If possible, there should be some response. See Section 3.9 for further discussion.
Cost range and homeowner assistance possibilities. Property owner participants had many questions about how project implementation would affect them financially and personally. In response, the DEM is convening separate meetings with property
owners of 1) former C. Brewer properties with sewer lines that will connect to the proposed collection system and 2) “Newly accessible” properties that front roadways in which new sewer lines will be located. Hawai‘i County Code, Chapter 21, Sewers,
Section 21-5 requires that when new sewer lines are placed in public roadways, properties fronting such roadways must connect to these lines.
Clarification on sewer fee structure. There was often confusion about who pays what and why. Information on the fee structure should be presented clearly.
Short-and long-term Impact on macadamia nut cultivation. It is recommended that a preliminary order of magnitude cost of project impact be estimated and presented in terms of the overall macadamia nut cultivation operation in a. Further, the project
team should describe, in general terms, the possible lease arrangements with the future macadamia nut operator.
Conceptual plan of full buildout. Participants were concerned that the tentative site is not large enough to support ser while still maintaining visual buffers. It is recommended that a very preliminary schematic be presented that shows full
buildout. As discussed in Section 4.1expansion to accommodate future needs but does not present a timeline for this expansion. As of this writing, no substantial planning or scoping of a collection system expansion has been conducted and this expansion is unlikely to occur within the next 10 to 20 years. This action was therefore excluded from the analysis of cumulative improvements and impacts.
Other topics raised in the first round of community outreach tended to be related to details that will be determined as the project nears implementation. These topics are as follows, and
information will be shared with the community when it becomes available.
Conditions of existing pipes. Participants raised questions about what was on their
property and possible problems. It is recommended that information on previous
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County evaluation and potential future assessments be made available prior to or during construction.
Possible land application trees. Some information has already been provided, and status of selecting trees should be provided.
Fencing around perimeter of wastewater treatment and disposal facility. Options for fence location, height, and materials should be provided.
Tour of Honokaa wastewater treatment plant. Residents showed interest in attending a tour of the Honokaa plant with DEM and the project team.
Next Round of Meetings. The next round of community meetings will be conducted upon publication of the Draft EA:
Information meeting on the Draft EA. The community will have two opportunities to provide comments on this Draft EA. First, public notification will be posted in local media, public venues, and mailed to property owners directly affected by the Proposed Action. These notifications will include how the public can access the Draft EA on the OEQC website and submit comments. Second, COH DEM will convene a voluntary and optional informational meeting intended to provide an additional opportunity for public comments.
Meeting with property owners who will be directly affected by the proposed project. As noted earlier, COH DEM will be convening separate meetings with property owners of 1) former C. Brewer properties with sewer lines that will connect to the proposed collection system and 2) “newly accessible” properties that front roadways in which new sewer lines will be located. The purpose of these meetings is to discuss how the proposed project will affect individual property owners in terms of cost, financing and logistics, such as construction timing and activities.
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8 FINDINGS AND DETERMINATION
8.1 – Department of Environmental Management (DEM) Anticipated Finding of No Significant Impact (FONSI)
Short-term construction impacts include disruption to the project site and surrounding areas during construction, decline in air quality from construction activities, and increase in noise levels.
Once construction has been completed, the short-term adverse impacts will no longer occur.
Based on analysis of the impacts, the County anticipates a FONSI for the Cesspool (LCC) Replacement Project. The significance criteria to make this determination are set
forth below and in Administrative Rules Title 11, State of Department of Health (DOH), Chapter 200, Environmental Impact Statement Rules.
8.1.1 Significance Criteria
1) Involve an irrevocable commitment to loss or destruction of any natural or cultural
resources;
The do not provide habitat for federal or State of listed or candidate threatened or endangered species of flora or fauna. The collection system will be constructed primarily within areas that were disturbed during construction of the existing County streets, plus two short segments within easements . The treatment and disposal facility site has previously been cleared, graded, and planted with a macadamia nut orchard. Thus, the proposed use of the sites will not result in the loss or destruction of natural resources.
Preliminary analysis shows the treatment and disposal facility will be constructed in an area that
is unlikely to contain archaeological resources due to historical ground modifications. However, an Archaeological Inventory Survey (AIS), including subsurface testing, is planned for September 2018 to test for the presence of archaeological resources on the project site. Following completion
of the AIS, and in accordance with Section 106 of the National Historic Preservation Act (NHPA), the County and the U.S. Environmental Protection Agency (EPA) will continue to consult with the mitigation
measures are appropriate to avoid or minimize adverse effects to archaeological resources.
The contract drawings will state that, should archaeological sites such as walls, platforms, pavements or mounds, or remains such as artifacts, burials, or concentrations of shell or charcoal be encountered during construction activities, work shall cease immediately and the find shall be protect (at 808.981.2979), who will assess the significance of the find and recommend appropriate mitigation measures, if necessary.
Based on the above, and contingent on the findings of the AIS, construction of the wastewater treatment and disposal facility and related improvements is not expected to result in the loss or destruction of historic sites or cultural resources.
2) Curtail the range of beneficial uses of the environment;
use lands within have been used for County streets and planted with a macadamia nut orchard for a number of years. The treatment and disposal facility will occupy a total area of about 14.9 acres within a portion the
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September 2018 Page 8-2
macadamia nut orchard. The remainder of the orchard will still be available for the production of macadamia nuts. Thus, the
of the environment.
3) Conflict with the State's long-term environmental policies or goals as expressed in Chapter 344, HRS, and any revisions thereof and amendments thereto, court decisions, or executive
orders;
The will not involve actions or activities that would adversely affect natural resources of the project sites. The will be consistent with the guidelines of Chapter 344, HRS, as it will provide treatment and disposal for
construct a wastewater collection system according to County standards and a treatment and
allow closure of LCCs that have been used to dispose untreated sewage into the subsurface. As -term environmental policies or goals as expressed in Chapter 344, HRS.
4) Substantially affect the economic or social welfare of the community or state;
The will allow the County to provide wastewater collection, treatment and disposal facilities meeting the needs of integral part of the infrastructure needed to maintain the health and welfare of the community.
ill have a beneficial impact on the economic and social welfare of the community.
5) Substantially affect public health;
LCC Replacement Project will involve the design, construction and operation of wastewater collection, treatment and disposal facilities that will maintain and enhance the public LCC Replacement Project will have a beneficial
effect on public health.
6) Involve substantial secondary impacts, such as population changes or effects on public facilities;
The the most part, construction of the LCC Replacement Project is expected to involve the use of local contractors, which means that there will not be an extensive secondary effect on the population of the Island of Hawai‘e LCC Replacement Project will not create secondary impacts, such as population changes or effects on public facilities.
7) Involve a substantial degradation of environmental quality;
The LCC Replacement Project is anticipated to result in short-term impacts to noise, air
quality, and traffic in the immediate vicinity of the project site during the period of construction. The collection system and the treatment and disposal facility sites do not contain federal or State-listed or candidate threatened or endangered species of flora or fauna. As discussed under
Criterion #1, the project is not expected to result in the loss or destruction of historic sites or cultural resources, contingent on the outcome of the NHPA Section 106 consultation and findings of the AIS.
Based on the above findings, the LCC Replacement Project will not result in a substantial degradation of environmental quality.
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8) Have a cumulative effect upon the environment or involves a commitment for larger actions;
The ala LCC Replacement Project does not involve a commitment to further actions to other County of Hawai‘i related projects in the vicinity. As a result, the LCC Replacement Project will not have a cumulative effect upon the environment or involve a commitment by the County to
larger actions.
9) Affect a rare, threatened or endangered species;
The LCC Replacement Project sites do not contain federal or State-listed or candidate threatened or endangered species of flora. Also, the LCC Replacement Project sites do not provide habitat for federal or State-listed or candidate threatened or endangered species of fauna. Thus, the LCC Replacement Project sites will not affect a threatened or endangered species.
10) Detrimentally affect air or water quality or ambient noise levels;
Operation of construction equipment will increase noise and exhaust emission levels in the LCC Replacement Project sites during the construction period. Once construction h LCC Replacement Project will contribute almost no additional noise or air emissions to the local area or detrimentally affect air or water quality. The treatment and disposal facility will include an odor control system to limit odors typically associated with a wastewater treatment facility.
11) Affects or likely to suffer damage by being located in an environmentally sensitive area
such as a floodplain, tsunami zone, beach, erosion-prone area, geographically hazardous land, estuary, fresh water or coastal water;
The Flood Insurance Rate Map (FIRM), Community Panel No. 155166 1800F, effective date September 29, 2017 shows the n Zone X, area of minimal flood hazard above the 500-year flood level. This was confirmed by the County of Hawai‘i Department of Public
Works. A small portion of the collection system site is located within the Zone X defined as areas of 0.2-percent annual chance flood; areas of 1-percent annual chance flood with average depths of less than 1 foot.
LCC Replacement Project sites are not located within the tsunami evacuation zone. The sites are also outside of the County of Hawai‘i Special Management Area and coastal shoreline area. LCC Replacement Project sites are not located in an environmentally sensitive area.
12) Substantially affect scenic vistas and viewplanes identified in county or state plans or studies;
The wastewater collection system will be within the County roadways beneath the surface of the
The treatment and disposal facility will consist of an operations building, headworks with a cover structure, aeration lagoons, subsurface constructed wetlands, and a series of slow-rate land application basins with planted trees. The operations building, headworks cover structure, and
low berms around the basins will be the only above-grade structures. The existing pine trees along Maile Street, most of which will remain with no changes, will continue to obstruct the viewplanes from Maile Street. The facility site will be adjacent (makai) to, and visible from,
M malahoa Highway (State Route 11); however, impacts to the viewplane will be mitigated by the planted trees in the basins and by the rise in elevation between the highway and the facility. Thus, development of the LCC Replacement Project sites will not present an adverse impact to the public views from other areas.
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13) Require substantial energy consumption.
LCC Replacement Project is a new facility that will be planned and designed to
minimize use of electrical power. Thus, it will not create a substantial increase in energy consumption.
8.1.2 Determination
Based on these Replacement Project, the project does not require preparation of an Environmental Impact Statement and a FONSI is anticipated.
8.2 National Environmental Policy Act – EPA Preliminary Finding of No Significant Impact (FONSI)
In 2006, a U.S. Environmental Protection Agency (EPA) Special Appropriation Grant was Large Capacity Cesspool (LCC) Replacement Project Grant (XP-96942401). The grant’s federal funding amount is $1.842 million and currently expires in October 2020. The purpose of the award is for the design and construction of
wastewater system improvements to replace LCCs in the District. The grant award and current work plan provide funding to replace the LCCs serving the P hala community.
EPA’s award of a grant for the is a federal action requiring compliance with the National Environmental Policy Act (NEPA), 42 USC §§4321-4370f. In accordance with NEPA, Council of Environmental Quality Regulations at 40 CFR §§1500.1-1508.28, and EPA NEPA regulations at 40 CFR Part 6, EPA and the County have prepared a
Draft Environmental Assessment (EA) describing the potential environmental impacts associated with, and the alternatives to, the proposed project. This preliminary FONSI documents EPA’s finding that the proposed project is not expected to have a significant effect on the environment.
In accordance with 40 CFR 6.203(b)(1), this preliminary FONSI is being made available for public review and comment prior to EPA making a decision on the proposed action.
8.2.1 Project Location and Description
The is located within and immediately south of the community of P hala, which is about 52 miles southwest of Hilo, in the Ka‘ District, Island of . P hala is located west (mauka) of M malahoa Highway (State Route 11) about 3.8 miles from the shoreline. Most of the community lies between 980 feet above mean sea level (msl) on the western end and approximately 800 feet above msl on the eastern end.
Under the , the County of the following actions:
1) Acquire, or otherwise obtain the right to develop and use, a portion of a 42.5-acre site (identified as “Site 7”) that is currently owned by Kamehameha Schools, then construct a new secondary wastewater treatment and disposal facility within a portion of the parcel;
2) Construct a new wastewater collection system, primarily within the public right-of-way
convey sanitary waste from the residential lots to the new wastewater treatment and disposal facility;
3) Close and abandon two LCCs, according to DOH closure procedures; and
4) Abandon the existing wastewater collection system in place.
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8.2.2 Purpose and Need for Proposed Project
The purpose of the is to enable the County to comply with the
Safe Drinking Water Act (SDWA) and to fulfill the compliance provisions of the June 2017 Administrative Order on Consent (AOC) between EPA and the County with respect to closure of the LCCs by June 2021.
The need for action is driven by the public health and environmental concerns associated with LCCs. Cesspools can release disease-causing pathogens and other pollutants (e.g., nitrates) into ground water aquifers, streams, and eventually the ocean, thus leading to public health and environmental concerns.
8.2.3 Environmental Consequences
In compliance with NEPA, EPA has prepared a Draft EA that analyzes the environmental impacts of the . After considering a wide range of regulatory, environmental (both natural and human) and socio-economic factors, the Draft EA did not identify any significant impacts to the environment that will result from the implementation of the proposed project.
The collection system will be constructed primarily within areas that were disturbed during construction of County streets, plus two short segments within easements community. The treatment and disposal facility site has previously been cleared, graded, and planted with a macadamia nut orchard. The affected sites do not provide habitat for federal or
State of listed or candidate threatened or endangered species of flora or fauna. A biological field survey in August 2018 did not identify any native mammalian or avian species within Site 7, though the endangered Hawaiian Petrel (Pterodroma sandwichensis) and the
threatened Newell’s Shearwater (Puffinus newelli) have been recorded flying over the general area between April and the end of November each year. Consultation with the U.S. Fish and Wildlife Service is ongoing, and the construction and design of the wastewater treatment and disposal facility will incorporate impact avoidance measures as necessary to avoid or minimize adverse effects to protected avian species.
Preliminary analysis shows the wastewater treatment and disposal facility will be constructed in an area that is unlikely to contain archaeological resources due to historical ground modifications. However, an AIS, including subsurface testing, is planned for September 2018 to test for the presence of archaeological resources on the project site. Consultation Historic Preservation Division is ongoing, in accordance with Section 106 of the National Historic Preservation Act (NHPA), and construction of the wastewater treatment and disposal facility will incorporate additional mitigation measures as necessary to avoid or minimize adverse effects to archaeological resources. Contingent on the outcome of the NHPA Section 106 consultation and findings of the AIS, construction activities are not expected to result in adverse effects to historic
properties.
Consultation letters were delivered to invite comments from organizations that may attach religious or cultural significance to properties affected by the proposed action. A total of 15 letters
were mailed to various Native Hawaiian Organizations requesting comments. As of August 2018, no responses have been submitted to the County.
The roject will allow the County to provide wastewater collection,
treatment and disposal facilities meeting the needs of ill have a beneficial impact on the economic and social welfare of the community. The proposed action will not r result in minor, short-term impacts to noise, air quality, and traffic in the immediate vicinity of the project site during the period of construction; however, operation of the wastewater treatment and disposal
District, Hawai‘i
September 2018 Page 8-6
facility will contribute almost no additional light pollution, noise, or air emissions to the local area or detrimentally affect air or water quality. The facility will include an odor control system to limit
odors typically associated with a wastewater treatment facility.
After carefully considering the regulatory, environmental (both natural and human), and socioeconomic factors as described in the Draft EA, EPA has not identified any significant impacts
to the environment that will result from implementation of the proposed project.
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9 LIST OF PERMITS AND APPROVALS
State of Hawai i Department of Health
Approval to Construct
Approval to Use
National Pollutant Discharge Elimination System (NPDES) Construction Stormwater Permit
Underground Injection Well Abandonment
Noise Variance (only if required)
County of Hawai i
Special Permit
Plan Approval
Grading Permit
Building Permit
Fence Permit
Street Usage Permit
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10 CONSULTED PARTIES
10.1 Pre-Assessment Consultation
In accordance with the requirements of Hawai'i Administrative Rules Title 11, State of Hawai'i Department of Health, Chapter 200, Environmental Impact Statement Rules, Section 9, Early Consultation, the following agencies were consulted during the pre-assessment phase of the Draft Environmental Assessment. Each agency was sent a copy of a project summary and a request for their written comments on the project. Those who formally replied are indicated with All written comments and responses are reproduced in Appendix A.
Federal
U.S. Department of Agriculture National Resources Conservation Service
National Oceanic and Atmospheric Administration (NOAA)
Department of Agriculture
Department of Business, Economic Development and Tourism (DBEDT)
DBEDT, Land Use Commission
Department of Health (DOH)
DOH, Office of Environmental Quality Control
DOH, Office of Director
DOH, Environmental Management Division
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September 2018 Page 10-2
Historic Preservation Division
Commission on Water Resources Management
Office of Hawaiian Affairs
Lands
Hilo Regional Library
Department of Parks and Recreation
Elected Officials
Congresswoman Tulsi Gabbard
State Senator Russell Ruderman
State Representative Richard H.K. Onishi
Councilmember Maile Medeiro
Native Hawaiian Organizations
Association of Hawaiian Civic Clubs
Hawaiian Civic Club of Hilo
Kamehameha Schools
Na Koa Ikaika Ka L
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Office of Hawaiian Affairs
Pacific Agricultural Land Management Systems
Partners in Development Foundation
Pi ihonua Hawaiian Homestead Community Association
Other
Hawaiian Electric Light Company
Hawaiian Telcom
Mr. Stason Nishimura
Mr. Lance Uno
Ms. Julia Neal
10.2 Agencies and Organizations Consulted on the Draft EA
Availability of the Draft EA for review and comment will be published in the Office of Environmental Quality Control (OEQC) Environmental Notice dated September 23, 2018. EPA
will directly notify the agencies, organizations, and individuals listed in Section 10.1 regarding the availability of the Draft EA for review and comment. Legal notice will be posted in the Hawai i Tribune Herald, West Hawai i Today, and News Brief. Additionally, EPA and the storic Preservation Division in accordance with Section 106 of the National Historic Preservation Act, and with the U.S. Fish and Wildlife Service in accordance with Section 7 of the Endangered Species Act.
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11 REFERENCES
Atlas of Hawaiian Watersheds & Their Aquatic Resources, Island of Hawaii, Bishop Museum &
Division of Aquatic Resources. 1262 p. (3 volumes). Parham, J.E., G. R. Higashi, E. K. Lapp, D. G. K. Kuamo‘o, R. T. Nishimoto, S. Hau, J. M. Fitzsimons, D. A. Polhemus, and W. S.
Devick. 2008.
County of Hawai‘i, Planning Department. Draft for Public Review. March 2015.
2017-66. October 2017.
County of Hawai‘i, Planning Department. County of Hawai‘i General Plan. Ordinance No. 05-
025. February 2005.
County of Hawai‘i, Department of Environmental Management. Final Environmental Assessment – Finding of No Significant Impact, the N ‘lehu-
Conversion. August 2007.
County of Hawai‘i, Department of Public Works. Final Environmental Assessment and – Finding
Executive Order No. 12898, 59 FR 7629. 1994.
Executive Order No. 11988, 42 FR 26951, 3 CFR, p. 117, 1977, as amended by Executive Order Nos. 12148, 44 FR 43239, 3 CFR, p. 412, 1979 and 13690, 81 FR 57401, 44 CFR 9, p. 57401, 2016.
Executive Order No. 11990, 42 FR 26961, 3 CFR, p. 121, 1977, as amended by Executive
Order No. 12608, 52 FR 2923, 1987.
Hawai‘i County Code 1983 (2016 Edition, as amended). Chapter 21. Sewers
Hawai‘i County Code 1983 (2016 Edition, as amended). Chapter 25. Zoning
State of Hawai‘i. Department of Agriculture. 2012 Census of Agriculture – County Data 2012.
State of Hawai‘i. Department of Health. Annual Summary 2015 Air Quality Data. December 2016.
State of Hawai‘i. Title 11, Hawai‘i Administrative Rules Department of Health Chapter 62 Wastewater Systems. March 21, 2016.
State of Hawai‘i. Title 11 Hawai‘i Administrative Rules Department of Health Chapter 23, Underground Injection Control. October 11, 2011.
State of Hawai‘i. Title 11, Hawai‘i Administrative Rules Department of Health Chapter 54, Water Quality Standards revised November 15, 2014.
District, Hawai‘i
September 2018 Page 11-2
U.S. Census Bureau, 2012-2016 American Community Survey. U.S. Census Bureau’s American Community Survey Office, 2017. Web. 1 August 2018
Hawai‘i. February 1994.
16 U.S.C. § 469a-1. 1974.
16 U.S.C. § 668. 1940.
42 U.S.C. § 7506(c). 1970.
16 U.S.C. § 3501-3510. 2011.
16 U.S.C. § 1451-1464. 1972.
16 U.S.C. § 1531-1543. 1973.
7. U.S.C. § 4201-4209. 1981.
16 U.S.C. § 661-664. 1934.
16 U.S.C. § 1801 et seq. 1976.
16 U.S.C. § 1361 et seq. 1972.
16 U.S.C. § 703 et seq. 1918.
54 U.S.C. § 300101 et seq. 1966.
33 U.S.C. § 403. 1899.
42 U.S.C. § 300f-300j-9. 1974.
16 U.S.C. § 1271 et seq. 1968.
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Appendix A Responses to Pre-Assessment Consultation Letters
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September 2018
Appendix B
June 2018 Preliminary Engineering Report (PER)
Pahala Wastewater
Treatment Plant
Preliminary Engineering
Report
Prepared for
County of Hawaii, Department of
Environmental Management
June 2018
Pahala Wastewater Treatment Plant
Preliminary Engineering Report
Prepared for
County of Hawaii, Department of Environmental Management
June 2018
THIS WORK WAS PREPARED BY ME OR UNDER MY SUPERVISION.
April 30, 2020
Signature Expiration Date of the License
1955 Main Street, Suite 200
Wailuku, Hawaii 96793
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Table of Contents
List of Figures..............................................................................................................................................vi
List of Tables ...............................................................................................................................................vii
List of Abbreviations ....................................................................................................................................ix
1. Introduction ......................................................................................................................................1-1
1.1 Background ............................................................................................................................1-1
1.2 Existing System......................................................................................................................1-1
1.3 Report Contents.....................................................................................................................1-1
2. Flow and Load Projections...............................................................................................................2-1
2.1 Service Area ...........................................................................................................................2-1
2.2 Flow Projections.....................................................................................................................2-3
2.3 Influent Characteristics .........................................................................................................2-3
2.4 Influent Mass Loads ..............................................................................................................2-3
2.5 Mass Loads to the Environment via Existing LCCs..............................................................2-4
3. Effluent Management Options and Regulatory Requirements .....................................................3-1
3.1 Effluent Management Options..............................................................................................3-1
3.1.1 Ocean Discharge .....................................................................................................3-1
3.1.2 Subsurface Disposal via Injection Wells................................................................3-1
3.1.3 Water Recycling .......................................................................................................3-1
3.1.4 Land Treatment .......................................................................................................3-2
3.1.5 Drain Field................................................................................................................3-3
3.1.6 Recommendation....................................................................................................3-3
3.2 Treatment Requirements ......................................................................................................3-3
4. Wastewater Treatment Evaluations................................................................................................4-1
4.1 Preliminary Treatment...........................................................................................................4-1
4.1.1 Screening.................................................................................................................4-1
4.1.2 Influent Flow Measurement....................................................................................4-2
4.1.3 Influent Flow Sampling............................................................................................4-2
4.1.4 Preliminary Design of Headworks ..........................................................................4-2
4.1.5 Odor Control.............................................................................................................4-4
4.2 Aerated Lagoon Treatment System ......................................................................................4-5
4.2.1 Aerated Lagoon Kinetics.........................................................................................4-5
4.2.2 Aeration in Lagoon Systems ...................................................................................4-5
4.2.3 Aerated Lagoon Configuration................................................................................4-7
4.2.4 Lagoon Liner ............................................................................................................4-8
4.2.5 Lagoon Cover...........................................................................................................4-9
4.2.6 Lagoon Sludge Management................................................................................4-11
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Table of Contents
4.3 Subsurface Flow Constructed Wetland..............................................................................4-11
4.3.1 Denitrification in Subsurface Flow Constructed Wetlands .................................4-11
4.4 Disinfection ..........................................................................................................................4-12
4.4.1 Calcium Hypochlorite ............................................................................................4-12
4.4.2 Ultraviolet Light (UV) Disinfection.........................................................................4-16
4.4.3 UV System Design Summary ................................................................................4-16
4.4.4 Cost Evaluation......................................................................................................4-17
4.4.5 Disinfection Recommendation .............................................................................4-17
4.5 Effluent Management..........................................................................................................4-17
4.5.1 Design ....................................................................................................................4-18
4.6 Ancillary Systems .................................................................................................................4-20
4.6.1 Water......................................................................................................................4-20
4.6.2 Access Road ..........................................................................................................4-20
4.6.3 Stormwater Management.....................................................................................4-21
4.6.4 Pre-development Stormwater Conditions............................................................4-21
4.6.5 Electrical Systems .................................................................................................4-25
4.6.6 Telemetry Systems ................................................................................................4-26
4.6.7 Operations Building...............................................................................................4-26
4.6.8 Site Fencing ...........................................................................................................4-26
5. Preliminary Design of Improvements..............................................................................................5-1
5.1 Site Plan .................................................................................................................................5-1
5.2 Process Schematic ................................................................................................................5-1
5.3 Design Criteria .......................................................................................................................5-4
5.4 Environmental Benefits.........................................................................................................5-6
5.5 Cost Estimates .......................................................................................................................5-8
5.6 Future Expansion ...................................................................................................................5-8
5.6.1 Full Buildout Flows ..................................................................................................5-8
5.6.2 Improvements..........................................................................................................5-8
6. Implementation ................................................................................................................................6-1
7. Alternative Treatment Options Evaluation......................................................................................7-1
7.1 Option Descriptions ...............................................................................................................7-1
7.1.1 Option 1: Aerated Lagoons/Constructed Wetland/Land Application .................7-1
7.1.2 Option 2: R-1 Treatment/Land Application............................................................7-1
7.1.3 Option 3: R-1 Treatment/Seasonal Water Recycling...........................................7-2
7.1.4 Option 4: R-1 Treatment and Storage for 100% Water Recycling.......................7-4
7.1.5 Option 5: Maximum Practical Treatment..............................................................7-6
7.2 Cost Comparisons..................................................................................................................7-7
7.2.1 Capital Costs............................................................................................................7-7
7.2.2 Operation and Maintenance Costs.........................................................................7-7
7.2.3 Recycled Water Sale Proceeds...............................................................................7-8
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7.2.4 Life-Cycle Costs........................................................................................................7-8
7.3 Non-Economic Discussion.....................................................................................................7-9
7.3.1 Labor Requirements..............................................................................................7-10
7.3.2 Operational Complexity .........................................................................................7-10
7.3.3 Energy Consumption .............................................................................................7-11
7.3.4 Sludge Management.............................................................................................7-11
7.4 Living Machine®..................................................................................................................7-11
7.5 Septic Tank Alternatives......................................................................................................7-12
7.5.1 Community Septic Tank ........................................................................................7-12
7.5.2 Converting LCC to Seepage Pit.............................................................................7-12
7.5.3 Leachfield Disposal...............................................................................................7-13
7.5.4 Conversion to Individual Wastewater Systems....................................................7-13
8. Alternative Site Evaluation...............................................................................................................8-1
8.1 Methodology...........................................................................................................................8-1
8.2 Site Locations ........................................................................................................................8-1
8.3 Criteria ....................................................................................................................................8-3
8.4 Criteria Weighting Factors.....................................................................................................8-7
8.5 Raw Scores.............................................................................................................................8-8
8.6 Weighted Analysis..................................................................................................................8-9
8.7 Results..................................................................................................................................8-10
8.8 Conclusion............................................................................................................................8-10
9. References .......................................................................................................................................9-1
Appendix A: Cost Estimates......................................................................................................................A-1
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Table of Contents
List of Figures
Figure 1-1. Pahala Existing Sewer Collection System and LCC Service Area......................................1-2
Figure 2-1. Pahala WWTP Service Area.................................................................................................2-2
Figure 3-1. Irrigation Demand Assessment...........................................................................................3-2
Figure 4-1. In-Channel Cylindrical Screen .............................................................................................4-2
Figure 4-2. Headworks............................................................................................................................4-3
Figure 4-3. Activated Carbon Scrubber (GAC).......................................................................................4-4
Figure 4-4. High Speed Floating Aerator ...............................................................................................4-7
Figure 4-5. Normal Lagoon Configuration Schematic ..........................................................................4-7
Figure 4-6. Floating HDPE Shade Balls ...............................................................................................4-10
Figure 4-7. Floating shade balls with current and turbulence in reservoir. ......................................4-10
Figure 4-8. Subsurface Flow Constructed Wetland Concept .............................................................4-11
Figure 4-9. Typical Calcium Hypochlorite Feed System......................................................................4-13
Figure 4-10. Chlorine Contact Tank Configuration .............................................................................4-15
Figure 4-11. Land Application System Schematic..............................................................................4-19
Figure 4-12. Existing Drainage System................................................................................................4-22
Figure 4-13. Flood Insurance Rate Map..............................................................................................4-24
Figure 4-14. Operations Building Preliminary Floor Plan ...................................................................4-27
Figure 5-1. Preliminary Site Plan............................................................................................................5-2
Figure 5-2. Recommended Facility Process Schematic .......................................................................5-3
Figure 5-3. Environmental Benefits of Proposed Project .....................................................................5-7
Figure 7-1. Option 1 Schematic Diagram ..............................................................................................7-1
Figure 7-2. Option 2 Schematic Diagram ..............................................................................................7-2
Figure 7-3. Option 3 Schematic Diagram ..............................................................................................7-2
Figure 7-4. Irrigation Demand Assessment...........................................................................................7-3
Figure 7-5. Option 3 Recycled Water Demand Assessment ................................................................7-3
Figure 7-6. Comparison of Irrigation Demands at Pahala and Kealakehe .........................................7-4
Figure 7-7. Option 4 Schematic Diagram ..............................................................................................7-5
Figure 7-8. Seasonal Storage Reservoir Analysis .................................................................................7-6
Figure 7-9. Option 5 Schematic Diagram ..............................................................................................7-7
Figure 7-10. Life-Cycle Costs of Options................................................................................................7-9
Figure 7-11. Comparison of Electrical Energy Requirements ............................................................7-11
Figure 8-1. Pahala Site Alternatives ......................................................................................................8-2
vi
Pahala Wastewater Treatment Plant Preliminary Engineering Report Table of Contents
List of Tables
Table 2-1. Pahala WWTP Flow Projections............................................................................................2-3
Table 2-2. Summary of Assumed Influent Characteristics...................................................................2-3
Table 2-3. Projected Influent Mass Loads.............................................................................................2-3
Table 2-4. Mass Loads to the Environment via Existing LCCs .............................................................2-4
Table 3-1. Applicable HAR 11-62 Land Disposal Requirements .........................................................3-3
Table 4-1. Normal Configuration Aeration and Mixing Requirements.................................................4-8
Table 4-2. Lagoon Shade Ball Cover Application Parameters..............................................................4-9
Table 4-3. Calcium Hypochlorite Summary .........................................................................................4-13
Table 4-4. Chlorine Demand ................................................................................................................4-14
Table 4-5. Chlorine Contact Tank.........................................................................................................4-14
Table 4-6. UV Disinfection Design Summary.......................................................................................4-16
Table 4-7. Estimated Disinfection Costs .............................................................................................4-17
Table 4-8. Ultraviolet Disinfection – Advantages and Disadvantages...............................................4-17
Table 4-9. Potential Land Application System Tree Species ..............................................................4-18
Table 4-10. Potential Water Demands ................................................................................................4-20
Table 5-1. Preliminary Design Criteria ...................................................................................................5-4
Table 5-2. Environmental Benefits of Proposed Project.......................................................................5-7
Table 5-3. Pahala WWTP Order of Magnitude Construction Cost Estimate ........................................5-8
Table 5-4. Pahala WWTP Full Buildout Flow Projections......................................................................5-8
Table 6-1. Implementation Schedule ....................................................................................................6-1
Table 7-1. Summary of Capital Cost Estimates.....................................................................................7-7
Table 7-2. Summary of O&M Cost Estimates........................................................................................7-8
Table 7-3. Summary of Annual Recycled Water Sale Proceeds...........................................................7-8
Table 7-4. Summary of Life-Cycle Cost Estimates ................................................................................7-9
Table 7-5. Comparison of Operational Labor Requirements .............................................................7-10
Table 7-6. Comparison of Operator Certification Requirements per HAR 11-61 .............................7-10
Table 8-1. Environmental, Social and Cultural Criteria ........................................................................8-3
Table 8-2. Location and Site Characteristics ........................................................................................8-4
Table 8-3. Collection System and Service Area Criteria .......................................................................8-5
Table 8-4. Land Use and Availability Criteria.........................................................................................8-6
vii
Pahala Wastewater Treatment Plant Preliminary Engineering Report Table of Contents
Table 8-5. Relative Weighting Factors ...................................................................................................8-7
Table 8-6. Alternatives Analysis – Raw Scores .....................................................................................8-8
Table 8-7. Alternatives Analysis – Weighted Scoring............................................................................8-9
Table 8-8. Alternative Site Ranking .....................................................................................................8-10
viii
Pahala Wastewater Treatment Plant Preliminary Engineering Report Table of Contents
List of Abbreviations
AB aggregate base
AC asphalt concrete
BMP Best Management Practices
BOD5 5-day biochemical oxygen demand
CCH City and County of Honolulu
cfs cubic feet per second
COH County of Hawaii
CFR Code of Federal Regulations
DNA deoxyribonucleic acid
DEM Department of Environmental Management
DOH Department of Health
ELLF end-of-lamp-life
FIRM Flood Insurance Rate Map
FOG fats, oils, and grease
ft3 cubic feet
FTE full-time equivalent
GAC granular activated carbon
gpm gallons per minute
H2S hydrogen sulfide
HAR Hawaii Administrative Rules
HDPE high density polyethylene
HELCO Hawaii Electric Light Company
hp horsepower
hp/Mgal horsepower per million gallons
hr hour
hp-hr horsepower-hour
L liter
lbs pounds
LCC large capacity cesspools
LPHO low pressure high output
MBR membrane bioreactor
Mg milligrams
Mgal million gallons
mm millimeter
MSL mean sea level
N nitrogen
NPV net present value
O&M Operation and Maintenance
P Phosphorus
Psi pounds per square inch
RNA ribonucleic acid
ROW right-of-way
scfm standard cubic feet
SCS Soil Conservation Service
SR slow rate
TSS total suspended solids
UIC Underground Injection Control
USEPA United States Environmental Protection
Agency
UV ultraviolet
WQV Water Quality Volume
WWTP Wastewater Treatment Plant
ix
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Introduction
1.1 Background
The town of Pahala is located in the Kau district of the Island of Hawaii. According to the 2010
United States Census, the town population is approximately 1,350 persons.
The Pahala community was established as the result of the sugar operations of the C. Brewer
Company. A portion of the community is serviced by a sewer system that was privately built, owned,
and operated by the C. Brewer Company. The wastewater collected by the sewer system discharges
into large capacity “gang” cesspools. Many years after its establishment, the private sewer system
ownership was conveyed to the County of Hawaii (COH) Department of Environmental Management
(DEM).
In 1998, the U.S. Environmental Protection Agency (USEPA), promulgated regulations, 40 Code of
Federal Regulations (CFR) 144.14, that require the elimination of large capacity “gang” cesspools
(LCCs). The County intends to construct a new sewer collection system located within public right-of-
way (ROW) and replace the existing LCCs with a wastewater treatment plant to address the
wastewater treatment and disposal needs of the Pahala community.
This report summarizes a proposed wastewater treatment plant (WWTP) needed in order to treat and
dispose of the wastewater flow that is currently discharged to the LCCs, plus additional sewer
connections. The report presents the existing and estimated future flows and loads to the treatment
plant, the proposed treatment processes, recommendation for the WWTP upgrades needed to meet
the future treatment needs, and an initial opinion of the cost to construct the improvements project.
1.2 Existing System
Figure 1-1 shows the collection system network and service areas for the LCCs. The collection
system is a network of gravity sewers that discharge to two existing LCCs. A detailed analysis of the
existing wastewater collection system was completed by others (M&E Pacific, December 2004). The
report concluded that the Pahala community existing sewer system consists of about 3,000 linear
feet of 6-inch diameter and 10,000 linear feet of 4-inch diameter pipelines. Residential laterals
connect to 4-inch sewers that discharge into 6-inch sewer mains, predominately found in private
property, which transmit wastewater to the LCCs. There are approximately 8 manholes in the sewer
system. There are no pump stations and the system is not designed to collect stormwater.
1.3 Report Contents
Section 2 presents flow and load projections for the new WWTP. Section 3 evaluates effluent
management options, and the treatment requirements for the preferred option. Section 4 presents
evaluations conducted to develop the preliminary design of the proposed WWTP, which is presented
in Section 5. An implementation plan is briefly presented in Section 6, followed by discussion of
other treatment options that were considered and evaluated. The report concludes with a site
selection consideration in Section 8.
1-1
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±
0 1,000 2,000
Feet
LEGEND
Existing Condition to Large Capacity Cesspool (LCC)
Proposed Pahala WWTP Site
P Pahala Existing SMH and LCC
") Existing Large Capacity Cesspool (LCC)
Existing Sewer Mains
SCALE AS SHOWN
JOB NO.: 150440
PAHALA WASTEWATER TREATMENT PLANT
Pahala Existing Sewer Collection System and LCC Service Area
FIGURE
1-1
P
P
P
P
P
P
PP
P
P")
") PUAHALA ST PIKAKE ST PAKALANA
S
T
HINANO
S
T
HUA
P
A
L
A
S
T
KOKIO STKEAHI ST
KAMANI ST
KOALI
S
T
PA
A
U
A
U
P
L
MA
I
LE
S
T
WOOD VALLEY RDMEYER RD PAAUAU ST HAWAII BELT RD OHIA ST
ILIM
A
S
T
LOWER MAOULA RD
HO
L
E
I
S
T
PUMELI
S
T
ILIAU ST
Existing Large Capacity
Cesspool (LCC 1)
Existing Large Capacity
Cesspool (LCC 2)
Ka'u High &Pahala ElementarySchool
Proposed PahalaWWTP Site
Ka'uHospital
Flow and Load Projections
This section summarizes the flow and load projections for the new WWTP.
2.1 Service Area
Within the town of Pahala, there is an existing wastewater collection that services approximately 109
properties. The collection system is currently located within easements in private properties and is
treated and disposed through two LCCs. Figure 2-1 shows the service area for the new WWTP. The
Kau Community Development plan indicates that the sewer system may eventually be expanded to
service the entire community; however, the initial collection system and WWTP presented in this
report will service the properties currently connected to the LCCs or located adjacent to the new
collection system. Although this report does not include design for the full buildout service area, the
proposed WWTP has been designed to accommodate modifications within the proposed 14.9-acre
site for the anticipated future expansion of the service area.
2-1
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±
0 1,000 2,000
Feet
LEGEND
Existing Condition to Large Capacity Cesspool (LCC)
Initial Build Condition to WWTP Revised
Future Buildout Condition to WWTP (Ka'u CDP Service Area)
Proposed Pahala WWTP Site
Pahala Future County Sewer System
") Existing Large Capacity Cesspool (LCC)
SCALE AS SHOWN
JOB NO.: 150440
PAHALA WASTEWATER TREATMENT PLANT
Pahala WWTP Service Area
FIGURE
2-1 MEYER RD WOOD VALLEY RD
")
") PUAHALA ST PIKAKE ST OHIA ST
KA
M
A
N
I
S
T
PA
A
U
A
U
P
L
M
A
I
L
E
S
T
HU
A
P
A
L
A
S
T
ILIM
A
S
T
PAKALANA
S
T
PUMELI ST
HINANO
S
T
KEAHI ST KOALI ST KOKIO ST HAWAII BELT RD PAAUAU ST LOWER MAOULA RD ILIAU ST
Existing Large Capacity
Cesspool (LCC 1)
Existing Large Capacity
Cesspool (LCC 2)
Proposed PahalaWWTP Site
Ka'uHospital
Ka'u High &Pahala ElementarySchool
-
-
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 2
2.2 Flow Projections
Wastewater flow projections were developed using the City and County of Honolulu’s (CCH) current
(2017) wastewater standards. Table 2-1 summarizes the flow projections.
Table2 1. PahalaWWTPFlowProjections
Description Value Peaking Factor
Average dry weather flow 189,000 gallons per day 1.0
Peak day wet weather flow 662,000 gallons per day 3.5
Peak hour wet weather flow 630 gallons per minute 4.8
The WWTP will be designed to provide an average dry weather flow capacity of 190,000 gallons per
day.
2.3 Influent Characteristics
The properties within the existing service area are primarily residential, but do include several
commercial, apartment, and industrial zoned parcels. The wastewater characteristics of the WWTP
influent are assumed to be similar to typical domestic wastewater. Table 2-2 provides a summary of
the assumed influent characteristics.
Table2 2. SummaryofAssumedInfluentCharacteristics
Parameter Value
5-day biochemical oxygen demand (BOD5) 300 mg/L
Total suspended solids (TSS) 300 mg/L
Total nitrogen 40 mg/L
Total phosphorus 7 mg/L
2.4 Influent Mass Loads
Table 2-3 summarizes the projected loads to the WWTP, based on the proposed average dry weather
capacity of 190,000 gallons per day and the influent characteristics presented in Table 2-2.
Table2 3. ProjectedInfluentMassLoads
Description Value
BOD5 480 lbs./day
TSS 480 lbs./day
Total nitrogen 60 lbs./day
Total phosphorus 10 lbs./day
2-3
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 2
2.5 Mass Loads to the Environment via Existing LCCs
Currently, 109 properties discharge without treatment to two LCCs, as shown in Figure 2-2. These
types of cesspools are a public health and environmental concern because of their likelihood of
releasing disease causing pathogens and other contaminants, such as nitrate, to groundwater. The
current annual mass loads to the environment via the existing LCCs based on the flow projections
and assumed wastewater characteristics presented above are summarized in Table 2-4.
Table2 4. MassLoadstotheEnvironmentviaExistingLCCs
Parameter Annual Load
BOD5 174,000 lbs./year
TSS 174,000 lbs./year
Total N 23,000 lbs./year
Total P 4,000 lbs./year
2-4
Effluent Management Options and
Regulatory Requirements
Effluent management options are evaluated in this section, followed by an assessment of regulatory
requirements for the recommended effluent management system.
3.1 Effluent Management Options
Effluent management options are evaluated below.
3.1.1 Ocean Discharge
Ocean discharge of treated effluent is not considered a viable option for this small community due to
the long distance to the shoreline (approximately 3 miles), high cost to construct an outfall, stringent
receiving water quality standards, high receiving water monitoring cost due to the distance to Hilo
harbor, and difficulty and length of time required to secure the required permits.
3.1.2 Subsurface Disposal via Injection Wells
Per Hawaii Administrative Rules (HAR), Title 11, Chapter 23, disposal to groundwater via an injection
well is not allowed mauka of the State of Hawaii Department of Health (DOH) Underground Injection
Control (UIC) line. Since the town of Pahala is located mauka of the UIC line, an injection well is not a
viable option.
3.1.3 Water Recycling
An irrigation assessment was prepared to assess the viability of water recycling as the primary
effluent management system, assuming the recycled water would be used to irrigate macadamia nut
trees. Figure 3-1 is a summary of the assessment that shows there is typically no irrigation demand
for six months of the year due to high rainfall. In addition, the DOH requires that all water recycling
programs have a 100 percent backup disposal system in place to handle flow that does not meet
recycled water quality standards or when recycled water supply exceeds demand. Therefore, water
recycling is not a viable primary effluent management strategy for the community. However, water
recycling treatment, storage, and distribution systems could be added in the future.
3-1
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 3
8
7 Inches of Water 6
5
4
3
2
1
0
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Month
Precipitation Evapotranspiration Irrigation Requirement
Figure 3-1. Irrigation Demand Assessment
3.1.4 Land Treatment
The USEPA defines land treatment as “the application of appropriately pre-treated municipal and
industrial wastewater to the land at a controlled rate in a designed and engineered setting. The
purpose of the activity is to obtain beneficial use of these materials, to improve environmental
quality, and to achieve treatment goals in a cost-effective and environmentally sound manner”
(USEPA, September 2006).
Land treatment systems rely on soil and vegetation to achieve treatment objectives, rather than
energy-intensive mechanical equipment. As such, they are considered to be a form of “natural”
treatment (Crites, et. al., 2014).
Land treatment is not a new concept. “Land application of wastewater was the first ‘natural’
technology to be rediscovered (after passage of the Clean Water Act of 1972). In the 1840s in
England, it was recognized as avoiding water pollution as well as returning nutrients in wastewater
back to the land. In the 19
th century it was the only acceptable method for waste treatment, but it
gradually slipped from use with the invention of modern devices” (Crites, et. al., 2014).
The soils at the proposed WWTP location are suitable for slow rate (SR) land treatment. SR land
treatment consists of irrigation of land and vegetation with effluent. Significant treatment is
provided as the water percolates through the soil. The vegetation uses the nutrients in the effluent
as fertilizer, and transpires a portion of the applied water.
3-2
--
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 3
3.1.5 Drain Field
A drain field (i.e., leach field) could potentially be constructed for subsurface disposal of treated
effluent. Preliminary assessment of the concept based on the site soil characteristics indicate
approximately 20,000 linear feet of drain field trench would be required to accommodate the
anticipated flow. It would be difficult to evenly distribute effluent throughout a drain field of this size.
In addition, DOH regulations require a redundant drain field for subsurface disposal systems, making
this option expensive to implement. This option is considered impractical for the community.
3.1.6 Recommendation
A slow rate land treatment system is recommended for effluent management for the community.
3.2 Treatment Requirements
The DOH regulates land treatment as “land disposal” per Hawaii Administrative Rules (HAR) 11-62.
Table 3-1 lists the applicable effluent requirements for land disposal applicable to the project that
were in effect at the time this report was prepared.
Table3 1. ApplicableHAR11 62LandDisposalRequirements
Description Value HAR Reference
BOD5
30 mg/L monthly average
60 mg/L peak 11-62-26
TSS 30 mg/L monthly average
60 mg/L peak 11-62-26
Disinfection Except for subsurface disposal systems, continuous disinfection of the
treated effluent shall be provided 11-62-24
Setbacks Treatment units shall be not less than 25 feet from property lines nor
less than 10 feet from any building 11-62-23.1
Public accessibility control 6-foot-high fence surrounding treatment units 11-62-08
3-3
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Wastewater Treatment Evaluations
This section presents the evaluations conducted in development of the proposed WWTP.
4.1 Preliminary Treatment
The preliminary treatment system will include screening, influent flow measurement, and influent
sampling equipment.
4.1.1 Screening
Screening is recommended to protect the downstream system operations from large objects, debris,
and rags that can be present in wastewater. Aerated lagoon treatment systems require a minimum
of coarse screens to protect the aeration equipment. The industry trend is towards finer screening
systems that remove greater amounts of debris from the waste stream; screens with 6-millimeter
(mm) (¼-inch) openings are frequently used for activated sludge treatment systems. An aerated
lagoon treatment system can benefit from ¼-inch screening to reduce the amount of floatable debris
on the lagoon shoreline, creating a cleaner facility that is less attractive to birds. Since the Pahala
WWTP will not be continuously staffed, a screening process requiring minimal attention is desirable.
Furthermore, the screenings volume is expected to be small, subsequently screenings disposal is
expected to be infrequent; weekly at most. Therefore, the screenings must be washed of organic
debris to prevent the accumulation of nuisance odors and flies in the screenings barrel or bag
between screening disposal events.
4.1.1.1 In-channel cylindrical screen
We recommend an in-channel cylindrical screen for this installation. The in-channel cylindrical
screen combines screening, screenings washing, dewatering, compacting, and bagging/disposal
within a single unit. The screening portion consists of an inclined screen basket inserted into the
wastewater channel. The screening basket can consist of bars, perforated plates or sieves,
depending on the application and clear opening required. The controls can be set to allow a mat to
build up on the screening surface, allowing finer screening of the wastewater. Controlled by head
loss, a rake arm starts rotating within the screen basket, pushing the screenings off the rake and
into a perforated screenings hopper located at the screen’s central axis. A shafted auger along the
screen axis conveys the screenings from the hopper through an inclined tube, which dewaters and
compacts the screenings. The tube includes a perforated dewatering section. The discharged
screenings are about 40-percent dry, and can be discharged into a bin or directly into a bagging
system. Figure 4-1 illustrates the process. Manufacturers include Lakeside and Huber. The key
benefit to this system is the integrated screenings washing system, minimizing additional screenings
handling and odor potential.
For this installation, the headworks will include two in-channel cylindrical screens, one will be on-line
when the other is redundant, plus a bypass channel with manually cleaned bar rack.
4-1
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
Figure 4-1. In-Channel Cylindrical Screen
4.1.2 Influent Flow Measurement
Influent flow measurement is recommended to allow assessment of flows and loads to the biological
treatment process, and to assess the biological treatment process performance. A Parshall flume
will be provided upstream of the screening system to continuously record influent flow rates.
Parshall flumes work well for influent measurement because the flume can operate in an open-
channel configuration, can accommodate wide ranges of flows, and is self-cleaning. A straight
approach length of at least 20 times the flume throat width will be provided upstream of the flume to
provide favorable hydraulic conditions.
4.1.3 Influent Flow Sampling
An automatic refrigerated composite sampler is recommended to allow influent composite samples
to be collected. Influent composite samples, when combined with influent flow measurement, can
be used to calculate influent mass loading rates to the WWTP to assess the treatment performance
and optimization of aeration rates in the biological treatment process. Periodic influent sampling is
also recommended to monitor for changes in the influent characteristics.
4.1.4 Preliminary Design of Headworks
Figure 4-2 shows a plan and section of the proposed headworks. Influent wastewater will enter the
upstream end of the headworks channel. Stop plates will be used to divert the flow to one of the two
the in-channel cylindrical screens, or to the manually-cleaned bar rack. The slide gates will be
designed to allow automatic overflow to the other channels in the event of mechanical screen
failure. The washed and compacted screenings will be deposited in a bag or 55-gallon drum for
periodic disposal. The Parshall flume and automatic refrigerated composite sampler will be located
upstream of the screens. The channels will be covered with fiberglass or aluminum plate to facilitate
foul air collection, which will be conveyed to an odor control unit. In addition, a free-standing roof
structure will be constructed over the headworks to protect the operators and equipment from rain
and sun.
4-2
TOAERATEDLAGOONS55 GALLONDRUMINFLUENTBYPASSCHANNELSLIDEGATESPARSHALLFLUMEINFLUENT FLOWMETER ANDAUTOMATIC SAMPLERIN-CHANNELCYLINDRICALBAR SCREENMANUALLY-CLEANEDBAR RACKIN-CHANNEL CYLINDRICALBAR SCREEN55 GALLONDRUMSLIDEGATETOAERATEDLAGOONSINFLUENTPARSHALLFLUMESLIDEGATEFIBERGLASS ORALUMINUM PLATECOVERSFOUL AIRTO ODORCONTROLROOFOUTLINEA A' PLAN SECTION A - A' PAHALA WASTEWATER TREATMENT PLANTSCALE: FIGURE JOB NO: 150440 HEADWORKS 4-2
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.1.5 Odor Control
A notorious location for foul odor is the headworks of a wastewater treatment plant. This odor is
caused by hydrogen sulfide (H2S), which is formed under anaerobic conditions of the wastewater
collection system. Due to H2S low solubility in wastewater, when there is an excessive concentration
of H2S in the wastewater or if there is turbulence, H2S gas escapes into the atmosphere. This
release produces the distinct rotten egg smell. In addition to H2S, there are other foul odorous
compounds that can be released from wastewater, such as ammonia, amines, diamines,
mercaptans, skatole, and organic sulfides.
Treatment of foul odors can be approached in two ways: preventing odors through liquid treatment
or controlling odors in the gas phase. While liquid treatment provides control of odors prior to their
release, gas phase treatment involves the collection and treatment of gases once they have been
released from wastewater. Treatment methods can be aimed at one type of odor, or can treat a
range of odors.
4.1.5.1 Granular Activated Carbon
A granular activated carbon (GAC) scrubber is recommended for the Pahala WWTP headworks. A
GAC scrubber passes odorous air through a bed of activated carbon, which adsorbs the odorous
constituents within the pore spaces of the carbon.
Chemical oxidation or reduction of some compounds can also occur. As pore spaces become
occupied, efficiency degrades, and the carbon must be replaced or regenerated. Carbon is most
effective on higher molecular weight molecules such as the organic sulfur compounds, which makes
it the technology of choice. Package GAC scrubbers are available for small headworks and vessels
can be situated vertically, horizontally, or radially to optimize footprints and reduce structure
elevation profiles. Figure 4-3 illustrates the process. The County currently operates GAC scrubbers
at other facilities, and purchases the GAC media in bulk to reduce costs.
Figure 4-3. Activated Carbon Scrubber (GAC)
4-4
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.2 Aerated Lagoon Treatment System
The biological wastewater treatment needs at the Pahala WWTP will be met by a series of aerated
lagoons. A floating cover will be installed on the last cell to reduce algae in the effluent. The
preliminary design of the aerated lagoon treatment system is developed in this section.
4.2.1 Aerated Lagoon Kinetics
The Pahala WWTP design is reliant on partial mix aerated lagoon environments to provide the
community’s wastewater treatment needs for the initial buildout condition. Partial mix aerated
lagoon kinetics are described below.
4.2.1.1 Partial mix model
Partial mix aerated lagoons are based on the concept of allowing solids to settle in lagoons while
providing only enough aeration and mixing to meet the oxygen requirements of the naturally
occurring micro-organisms in the system. The solids tend to settle in areas of the lagoon that are
subject to less mixing energy, where they anaerobically decompose. Infrequent sludge removal is
required to maintain sufficient lagoon treatment volume.
Removal of BOD5 in partial-mix aerated lagoons depends on the hydraulic detention time. The
design model for partial mixed ponds of equal size in series is (Crites, et. al., 2006):
Cn 1 = Co [1+ (kt / n)n
Where Cn = effluent BOD5 concentration in cell n , mg/L
Co = influent BOD5 concentration, mg/L
k = partial-mix first-order reaction rate constant, day
-1
t = total hydraulic residence time in the lagoon system, day
n = number of cells in the series
If the lagoons in a system are of unequal size, then the equation must be applied to each lagoon in
the series. The Ten-States Standards recommends using a value of 0.276 day
-1 at 20 ºC for the
reaction rate constant (Great Lakes – Upper Mississippi River Board, 1997).
4.2.1.2 Mixing in Lagoon Systems
The energy required for mixing in aerated lagoon systems is generally provided by the aeration
system. For partial mix systems the aeration system is sized to provide enough oxygen to maintain
aerobic conditions and no more. For mechanical aeration systems energy input of at least 30
horsepower per million gallons (hp/Mgal) of lagoon volume is required to keep solids in suspension
(Rich, 1999).
4.2.2 Aeration in Lagoon Systems
Oxygen requirements in aerated lagoon systems are based on the organic loading entering the cell.
Supplying oxygen at a rate of 1.5 times the BOD5 mass entering the cell has been found to be
sufficient to treat the wastewater. The following equation is used to estimate the oxygen transfer
rate (Crites, et. al., 2006):
4-5
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
N N = a
α(Csw −CL ) (1.025)
(Tw−20)CS
Where N = Equivalent oxygen transfer to tap water at standard conditions (lbs/hr)
Na = Oxygen required to treat the wastewater (lbs/hr)
α = (oxygen transfer in wastewater)/(oxygen transfer in tap water)
C = β(C )P = oxygen saturation value of the waste, mg/L sw ss
β = wastewater saturation value/tap water oxygen saturation value = 0.9
Css = tap water oxygen saturation value at temperature Tw
P = ratio of barometric pressure at the site to barometric pressure at sea level
CL = minimum dissolved oxygen concentration to be maintained
CS = oxygen saturation value of tap water at 20ºC and 1 atm pressure
T = wastewater temperature, ºC w
Oxygen can be supplied to aerated lagoon systems using mechanical aerators or diffused aeration
systems. Mechanical aerators are commonly rated by the number of pounds of oxygen the units will
supply under standard conditions per horsepower-hour (lbs. O2/hp-hr). Diffused air requirements are
calculated using the following equation (Crites and Tchobanoglous, 1998):
W oxygenQair = (AOTE)(O )(γ )(1440)2 air
Where Q = Required air flow (ft
3/min) air
W = Oxygen requirements (lbs/day) oxygen
AOTE = Actual oxygen transfer efficiency, expressed as a fraction
O2 = Fractional percent of oxygen in air by weight (0.2315)
γ air = Specific weight of air (0.075 lbs/ft
3 at 1 atmosphere and 20ºC
The oxygen transfer efficiency of a diffused air system is a function of the air bubble size and the
depth of the water column. Smaller air bubbles result in higher oxygen transfer efficiencies than
larger bubbles, as do diffusers that are set at deeper depths within the water column.
4.2.2.1 High speed floating aerators
High-speed floating aerators are commonly used for aerated lagoon systems. The units consist of a
motor and impeller attached to a float. The units are typically anchored to the lagoon shore using
cables. High-speed floating aerators are designed to pump water from the lagoon and spray it into
the air, allowing oxygen to diffuse into the water droplets. The high-speed floating aerators can be
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
outfitted with draft tubes to enhance deep water lagoon mixing or anti-erosion plates to ensure water
is drawn from the surface. Figure 4-4 shows a typical high-speed floating aerator.
Figure 4-4. High Speed Floating Aerator
Advantages of this system include low capital costs, relatively high oxygen transfer efficiency, good
mixing efficiency, and simple operation and maintenance. The chief disadvantage of the system is
the creation of aerosols as the lagoon water is sprayed into the air.
Manufacturers of this type of aerator include Aqua-Aerobics, Aerator Products and Europlec/Aeromix
Systems Inc.
High-speed floating aerators are recommended for the Pahala WWTP due to their relatively high
oxygen transfer efficiency, low capital cost, and simple operation and maintenance. High-speed
floating aerators are easy to remove from service, and can be easily moved between lagoons or cells,
if needed.
4.2.3 Aerated Lagoon Configuration
The normal operating condition for the Pahala WWTP will be to operate the four lagoon cells in series
as partial mix environments. Figure 4-5 is a schematic representation of the normal operating mode.
The fourth cell will be outfitted with a floating cover to preclude algae growth. Having four lagoons
will allow the County to take a lagoon out of service for maintenance.
Figure 4-5. Normal Lagoon Configuration Schematic
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
Table 4-1 summarizes the results of the aeration and mixing calculations for the normal operational
configuration treating the design average dry weather flow rate of 190,000 gallons per day.
Comparison of the minimum aerator requirements shown in Table 4-1 with the proposed aerator
layout shown in Figure 4-4 reveals that the aerator power supplied exceeds the minimum
requirements. An aerator control system will be provided that will intermittently turn the aerators on
and off in accordance with the operator settings to supply sufficient oxygen to the system.
Table4 1. NormalConfigurationAerationandMixingRequirements
Cell Volume
(gal)
Influent BOD5
(mg/L)
Effluent BOD5
(mg/L)
Minimum Aerator
Requirement (hp)
Mixing Density
(hp/Mgal)
1 80,000 300 139 27 34
2 80,000 139 64 13 16
3 80,000 64 30 6 7
4 80,000 30 <30 2 3
4.2.4 Lagoon Liner
Lagoon liners are required to prevent wastewater seepage into the ground. The liner will be exposed
to sunlight, so resistance to ultraviolet light (UV) degradation is a key factor in the selection of the
liner material, as is the compatibility of the material with typical domestic wastewater characteristics
and ease of liner maintenance. An 80-mil textured high density polyethylene (HDPE) geomembrane
is recommend for this application.
Textured HDPE is known to have excellent UV resistance, good chemical resistance, and generally is
not affected by fats, oils, and grease (FOG). Maintenance of HDPE requires a specialty contractor
who can complete fusion weld repairs. Unlike smooth HDPE, textured HDPE presents minimal
slipping hazard to operations personnel. Furthermore, the anticipated useful service of an HDPE
liner in typical Hawaii municipal wastewater treatment conditions is 25 to 30 years.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.2.5 Lagoon Cover
In the normal operating mode, the final cell in the lagoon series will be covered in order to deprive
algae of sunlight. This will reduce the algae concentration, which can increase total suspended
solids (TSS) levels in the system effluent. The cover should float on the surface of the water, be UV
resistant, suitable for windy environments, and allow for rainwater to pass through the cover to
prevent ponding. A floating shade ball cover is proposed for this installation.
Floating shade balls covers have been used for decades in in the mining, water and wastewater
treatment industries. Figure 4-6 shows the design elements of a typical shade ball, and Figure 4-7
shows how shade balls provide cover on a reservoir. In addition to reducing algae growth, shade ball
covers deter waterfowl from storage ponds. The black, UV-stable HDPE resin has known to withstand
a range of challenging chemical and environmental conditions. Table 4-2 summarizes technical data
for the balls.
Table4 2. LagoonShadeBallCoverApplicationParameters
Requirement Description
Algae Control Balls – 90% shade coverage
Temperature 500C to 950C
Wind Resistance Balls ballasted with potable water tested in winds of 120 mph (category 3 hurricane)
Waterfowl Safety Waterfowl do not recognize ball-covered pond as a water body and will not nest on the
unstable surface
Lifecycle/Warranty The shade balls are warrantied for 10 years, with an expected resin life of 25+years
Operations and
Maintenance
Self-cleaning, self-levelling and require little to no maintenance
Balls will move out of the way of maintenance barge, and can be restrained with booms
Little installation effort required
Precipitation does not affect the cover
Sustainability
Resin is recyclable, paraben free and suitable for drinking water applications
Ballast is potable water
Resin can be made from recycled plastic
Environment
Balls have been installed in chemically harsh environments (mining industry), in drinking water
reservoirs, and in tropical locations
Balls reduce algae formation and corresponding disinfectant byproducts in chlorination
applications
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
Figure 4-6. Floating HDPE Shade Balls
Figure 4-7. Floating shade balls with current and turbulence in reservoir.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.2.6 Lagoon Sludge Management
Partial-mix aerated lagoons are designed to allow solids to settle to the bottom of the lagoon, forming
a sludge layer. The sludge slowly anaerobically digests in the bottom of the lagoon. The mechanical
aerators in the lagoon maintain an aerobic water cap at the surface of the lagoon that oxidizes any
odors that are released from the anaerobic sludge layer at the bottom of the lagoon. Sludge is
removed infrequently, typically every 15 to 30 years, when the sludge blanket thickness begins to
affect treatment performance or in conjunction with lagoon liner replacement. Aerated lagoon
operators typically monitor sludge blanket thicknesses semi-annually to assess sludge accumulation.
Sludge removal contractors are typically employed to dredge the solids, dewater, and haul to a
landfill for disposal. Sludge from aerated lagoons is typically not offensive when dewatered due to
the long residence time in the bottom of the lagoon.
Alternatively, the sludge can be recycled if a permitted land application site is available and the
sludge meets State and Federal requirements for land application or composted with green waste at
a permitted composting facility.
4.3 Subsurface Flow Constructed Wetland
A subsurface flow constructed wetland is recommended to provide additional treatment and
polishing of the aerated lagoon effluent. It is anticipated that the aerated lagoon system will convert
ammonia that is present in the wastewater influent into nitrate via a process called nitrification. A
subsurface flow constructed wetland will remove this nitrogen from the wastewater via a process
called denitrification. Reduction of nitrogen loading through the constructed wetland will decrease
the area required for overland flow effluent management.
Subsurface flow wetlands consist of shallow lined basins that are filled with gravel media and
planted with emergent wetland vegetation. Water is introduced to the gravel media layer and flows
horizontally through the basin. The water level in the wetland is maintained below the gravel surface
at all times. Treatment occurs through physical, chemical, and biological mechanisms as the water
flows horizontally through the gravel media bed. Figure 4-8 is an illustration of the concept.
Figure 4-8. Subsurface Flow Constructed Wetland Concept
4.3.1 Denitrification in Subsurface Flow Constructed Wetlands
Denitrification is a biological process whereby nitrate molecules are transformed into nitrogen gas
molecules by naturally-occurring bacteria. The denitrifying bacteria require five conditions for the
process to occur:
• A place to grow.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
• A source of nitrate.
• An anoxic (low-oxygen) environment.
• A source of carbon.
• Adequate water temperature.
The equation used to predict denitrification in subsurface flow constructed wetlands is shown below
(Crites, et.al., 2014).
= exp(− )
where:
= effluent nitrate-nitrogen concentration (mg/L)
= influent nitrate-nitrogen concentration (mg/L)
= temperature-dependent rate constant =1.00(1.15)( ) days-1 when T>1°C
= hydraulic residence time (days)
Subsurface flow constructed wetlands are capable of providing additional treatment benefits beyond
nitrogen reduction, such as removal of organic carbon, suspended solids, phosphorus, metals, trace
organics, and pathogens. The additional treatment benefits are not primary design parameters, but
should be considered as additional polishing treatment benefits that may be realized for the Pahala
WWTP.
4.4 Disinfection
Disinfection processes selectively kill pathogens or render them incapable of reproduction or harm to
humans. Disinfection at WWTPs is employed for the purposes of protection of public health,
reduction of organic matter, inorganics, nutrients, odor, aesthetics, and maintaining waste-
assimilative capacity of receiving water bodies. The protection of public health through the control of
disease-causing microorganisms is the primary reason for wastewater disinfection (WEF, 1996). As
the last barrier of protection from pathogenic organisms, disinfection at WWTPs is an important
process. To address disinfection, both a calcium hypochlorite system and a UV system were
evaluated.
4.4.1 Calcium Hypochlorite
Calcium hypochlorite is the most common solid form of hypochlorite used for disinfection. It can be
found as a powder, granules, pellets, or as tablets in concentrations up to 70 percent. Calcium
hypochlorite will degrade in strength at a rate of 3 to 5 percent per year. Once applied to the
wastewater, the chemistry is similar to that for sodium hypochlorite. Calcium hypochlorite
decomposes in an exothermic reaction if exposed to moisture.
The solid can be directly applied to wastewater at very small WWTPs. Figure 4-9 shows a typical
calcium hypochlorite feed system.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
Figure 4-9. Typical Calcium Hypochlorite Feed System
The advantages of using calcium hypochlorite for disinfection at small, remote WWTPs is that it is
available in concentrated form as powder, pellets, or tablets. This makes the transportation and
storage of disinfectant optimal for small WWTPs. Table 4-3 summaries calcium hypochlorite
characteristics.
Table4 3. CalciumHypochloriteSummary
Description Characteristic
Transported form Solid
Typical transported concentration 70%
Largest transported volume available 55 lb. pails
Decay Rate Decays 3-5% per year
pH N/A
Hazards Toxic if ingested (usually through dust or liquid form)
Storage constraints Must be stored in a cool, dry, dark place
Special equipment Tablet feeder
Particular issues Heats and combusts if not stored properly Scaling in pipes, Off gassing
4.4.1.1 Dose and Contact Time
The effectiveness of a chlorination system is highly dependent on the characteristics of the
wastewater, the initial mixing and contact time, and the chlorine dose used. For nitrified effluent, the
recommended dose is between 8 and 18 mg/L. The WWTP will discharge to a land application
system during normal flow and wet weather periods when the secondary effluent will be diluted by
precipitation falling onto the overland flow terraces. For planning purposes, a 10 mg/L dose was
assumed to be sufficient for the WWTP for most circumstances, but equipment will be sized to
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
provide chemical feed at a rate of up to 100 lbs./day, which will ensure an adequate chlorine dose
for peak wet weather discharge flows.
Table 4-4 lists the chlorine demand for various flow conditions.
Table4 4. ChlorineDemand
Description Flow Chlorine Demand
Average dry weather flow 0.19 mgd 16 lbs./day
Peak day wet weather flow 0.662 mgd 55 lbs./day
The recommended minimum contact time for chlorination is 15 minutes (Ten States Standards
Wastewater, Recommended Standards for Wastewater Facilities, 1997, Great Lakes – Upper
Mississippi River Board of State and Provincial Public health and Environmental Managers). The size
of the chlorine contact tank will need to accommodate a 15-minute contact time for the peak
discharge rate. For this application, the peak discharge rate will be equal to the peak day wet
weather flow, due to the flow equalization provided by the aerated lagoons. Table 4-5 summarizes
the contact tank dimensions, while Figure 4-10 shows a conceptual contact tank configuration.
Table4 5. ChlorineContactTank
Description Value
Peak discharge rate 460 gpm
Minimum chlorine contact tank 15 minutes
Tank volume required 920 cubic feet
Channel water depth 5 feet
Channel width 3 feet
Tank channel total length 61 feet
Tank dimensions including channel walls 13 feet x 24 feet
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WASTEWATER
EFFLUENT
DISINFECTED
EFFLUENT
13'-0" 24'-0" Path: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURESFile Name: 150440-FIG-ChlorContactTank Plot Date: March 22, 2018 4:32 PM Cadd User: Richard Sellona CHLORINE CHLORINESOLUTION CONTACTTO CHLORINATOR CHANNELBUILDING
SCALE: Field PAHALA WASTEWATER TREATMENT PLANT FIGURE
JOB NUMBER: 150440 CHLORINE CONTACT TANK 4-10
CONFIGURATION
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.4.2 Ultraviolet Light (UV) Disinfection
A common alternative to a chlorine disinfection is ultraviolet light (UV). Ultraviolet systems destroy
microorganisms by affecting their deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and impeding
their ability to reproduce. A UV disinfection system is comprised of lamps, a reactor, and control
panel. Wastewater can flow either parallel or perpendicular to the lamps in the reactor, while the
control box provides a starting voltage and maintains the continuous current needed. Currently,
most systems are equipped with an automated lamp cleaning system, to maintain lamp efficiency
levels.
A UV system’s effectiveness is dependent on the characteristics of the wastewater, the dose, and the
exposure time. In the case of UV radiation, the most important factor is the transmittance of the
water, which has a direct effect on the ability of UV light to penetrate through the liquid and reach
microorganisms present at the required intensity. Ideally, the discharge undergoing treatment
should not have a transmittance lower than 55 percent, with the intensity decreasing the farther the
microorganisms are from the lamp. The optimum wavelength to effectively inactivate
microorganisms is between 250 and 270 nanometer.
The main types of UV lamps used for wastewater disinfection are conventional low-pressure lamps,
low pressure high output (LPHO) lamps and medium pressure lamps. Several UV systems include
lamps with automated sleeve cleaning.
4.4.3 UV System Design Summary
A UV disinfection system requires a about the same size footprint as chlorine. Disinfection occurs as
the organism is exposed to the UV radiation as the water flows past the UV lightbulbs. The Trojan
UV3000+ system is used at numerous facilities across the US, including some treatment plants in
Hawaii. The estimated cost included in this report are based on an assumed UV transmittance of 65
percent. The amalgam lamp used with the UV3000+ system has an end-of-lamp-life factor (ELLF) of
0.98 indicating little loss in UV light output over the life of the lamp. This ELLF has been tested and
approved by the State of California and is also accepted by the State of Hawaii for reuse
applications. The system would use LPHO lamps with automatic sleeve cleaning. LPHO lamps are
energy efficient and the UV300+ system is furnished with automatic sleeve cleaning devices to
reduce labor requirements. Each UV lamp is enclosed in a quartz sleeve to separate it from the water
medium. Each lamp draws 254 watts at full output and is driven by electronic ballast. The
electronic ballast allows the lamps to be dimmed to conserve power based on a control signal from a
flow meter. The LPHO lamps will have a minimum life of 12,000 hours when operated in an
automatic mode and limited to a maximum of 4 on/off cycles per 24 hours. Table 4-6 summarizes
the size and design criteria for the UV system required to treat the WWTP discharge.
Table4 6. UVDisinfectionDesignSummary
Description Value
Peak Hour Wet Weather Discharge 630 gpm
Minimum UV transmittance 65 percent
No. of UV channels 1
Design dose 35,000 µWs/cm2
Disinfection limit 30 e-coli per 100mL
Validation factors 0.98 end of lamp factor
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.4.4 Cost Evaluation
A summary of capital and life-cycle estimated costs for both chlorination and UV disinfection is
presented in Table 4-7 for comparison.
The capital costs include the materials and equipment costs, construction costs, electrical,
instrumentation and control, soft costs, and contingency. As shown in the table, the UV option incurs
higher capital costs. The life cycle costs look at the impact of the capital costs along with the annual
operations and maintenance costs, including power, materials, chemicals, and labor costs over the
next 30 years. The life-cycle costs for chlorination option appear to be about 78 percent of the UV
option.
Table4 7. EstimatedDisinfectionCosts
Description Chlorination UV System
Capital Cost $200,000 $800,000
Annual Operations and Maintenance $15,000 $6,000
Life-cycle Cost (30-Year Net Present Value) $746,000 $947,000
4.4.4.1 Non-Economic Evaluation
Table 4-8 presents a summary of advantages and disadvantages of using an ultraviolet light for
disinfection.
Table4 8. UltravioletDisinfection AdvantagesandDisadvantages
Advantages Disadvantages
Effective at inactivating most viruses, spores, and cysts
Low dosage may not be effective on some pathogens and
some organisms can repair and reverse the destructive
effects of UV
It’s a physical process, instead of chemical – it
eliminated the need to transport, handle, store toxic or
corrosive chemicals
Turbidity and TSS in the wastewater can reduce UV
disinfection effectiveness
No harmful residual compounds created that are toxic to
humans or aquatic life
Will likely require more call-outs by operators due to
alarms caused by “dirty power”.
Shorter contact time (less than a minute)
The relative intensity of equipment maintenance
requirements, including staffing training and on-island
avaliablity.
4.4.5 Disinfection Recommendation
A tablet chlorination system is the recommended disinfection option over the UV system for the
WWTP because it incurs lower capital and lifecycle costs. In addition, tablet chlorination will be
more-reliable than UV due to frequent “dirty power” conditions on the island.
4.5 Effluent Management
For effluent management, a slow-rate land application system is proposed. The concept is to
intermittently apply wastewater to crops growing in permeable soils. As the applied water percolates
through the soil matrix or is taken up by the crop, it is treated by physical filtration and by biological
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
mechanisms. After an application period or wetting period, the surface can dry and oxygen can enter
the soil matrix, which aids aerobic biological treatment. The frequent wetting and drying also
maintains the infiltration rate through the soil surface and minimizes soil clogging. This method of
land application is an effective treatment process for BOD5, TSS, trace organics, phosphorus, metals
and pathogen removal. Furthermore, removal of nitrogen can be significant when system is
managed for that objective.
4.5.1 Design
The slow-rate system site consists of a net area of approximately 5.5 acres. The 5.5 acres will be
divided into 4 small groves of native trees, so that water application will be rotated to a different
grove each day. An additional small grove will be utilized as an emergency (overflow) or reserve
when surface or distribution system maintenance is conducted. By using one groove per day the
wet/dry cycle will be 1-day wetting and 3-days drying.
The groves will be planted with native Hawaiian trees. Trees grown within the land application area
will need to be water tolerant. Table 4-9 lists potential native tree species.
Table4 9. PotentialLandApplicationSystemTreeSpecies
Common Name Genus Species Salt
Tolerance Water Requirements Rubbish and
Maintenance Preferred Elevation
Milo Thespesia populnea Very Dry to Wet Moderate Low to Medium
Loulu Pritchardia hillebrandii Very Dry to Wet Low Low
Aalii Dodonaea viscosa Very Dry to Medium Low Low to High
Kou Cordia subcordata Very Dry to Wet Moderate Low
Golden Loulu Pritchardia arecina Moderate Dry to Wet Low Low to Medium
Wiliwili Erythrina sandwicensis Moderate Dry to Medium Moderate Low
The distribution system will consist of gated piping located on the surface. The piping will have slots
to allow the applied wastewater to uniformly be distributed over the grove surface. A perimeter
fence will be installed to limit access. Access roads will surround each grove. Figure 4-11 reflects
the proposed land application schematic.
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JOB NO: 150440
LAND APPLICATION SYSTEM SCHEMATIC
PLAN
MAINTENANCE EXISTING
ROAD, TYP GRADE = 8%±
GROVE 1 GROVE 2 GROVE 3
GROVE 4
5'
A A'
H:V=3:1,
TYP
GROVE 1 GROVE 2 GROVE 3 GROVE 4
50'
TYP
3:1 MAX, TYP 2:1 MAX, TYP
SECTION A - A' 0 100 200
SCALE IN FEET
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.6 Ancillary Systems
4.6.1 Water
Potable water is not currently available at the site. The nearest potable water system is located
uphill in town. Table 4-10 provides an initial assessment of the potential water demands at the
WWTP. The water demands are either for process or potable uses. As shown in the table, the
process water demands are significantly greater than the potable demands.
Table4 10. PotentialWaterDemands
Description Flow Rate Type Priority
Screenings washer 20 gpm for 10 min/hour
4,800 gpd Process Mandatory with screen
Hose bibs 10 gpm for 20 min/day
200 gpd Process Desirable to maintain facility
Emergency eye wash / shower 20 gal per use Potable Mandatory
Restroom 20 gpd Potable Recommended
To supply water to the WWTP, it is recommended to construct approximately 2,000 linear feet of pipe
from the intersection of Huapala Street and Maile Street to the site and install a 1-inch water meter
with 1 ½-inch backflow preventer.
A plant water system will be supplied by the County water meter. The on-site water system will be
split into two branches, one for process water and one for potable water. The potable water will
service the restroom and emergency eye wash/shower. A second backflow preventer will separate
the process water uses from the potable connections.
4.6.2 Access Road
All weather access will be required to operate and maintain the WWTP. Access to the site will be
provided by connection to Maile Street. A paved driveway apron is proposed at Maile Street and an
all-weather driveway will extend into the site and provide access to and around the various WWTP
infrastructure. Additionally, a turn-around area large enough to accommodate a fire truck will be
provided.
Access road pavement options include aggregate base (AB) gravel, asphalt concrete (AC), or
concrete. AB is the lowest cost option, but requires the most maintenance. AC pavement is not
recommended for steep (greater than 12 percent) grades. Concrete is the highest cost option, but is
the most durable and requires the least maintenance.
The recommended driveway pavement section is 2-inches of AC over 6-inches of aggregate base
course. For portions of the driveway that exceed 12 percent slope, a concrete pavement section is
recommended.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.6.3 Stormwater Management
The overall goal of stormwater management is to mitigate the adverse impact of new construction on
the environment. Stormwater management can generally be separated into two areas:
1. Stormwater Quantity: management of the quantity to prevent increased flows and
volumes leaving the site on the downstream watercourses.
2. Stormwater Quality: management of the quality of stormwater runoff to prevent
contaminants such as silt, trash, hydrocarbons, heavy metals, and pesticides from
leaving the site through stormwater runoff.
4.6.4 Pre-development Stormwater Conditions
4.6.4.1 On-site
The majority of the proposed 42.5-acre site is currently utilized as macadamia nut orchards,
consisting of trees or unimproved agricultural roads. The parcel is bound on two sides by improved
county and state right-of-way and to the east by additional macadamia nut orchards.
The existing elevations range between 580 to 780 feet above mean sea level (MSL) and slopes in
the southerly direction at an average rate of 8 percent. The soils in this area are described as
Naalehu medial silty clay loam (NaC) by the Soils Conservation Service (SCS). These soils are
considered well drained with low runoff and slight erosion hazard.
On-site stormwater run-off generally sheet flows in a southerly direction to off-site swales along the
roadway frontages, Maile Street and Hawaiian Belt Road (also known as Mamalahoa Highway).
There is no known on-site drainage collection system, see Figure 4-12.
4.6.4.2 Off-site
Swales that run and collect along the roadway frontages of the property are conveyed through a box
culvert at the intersection of Maile Street and Hawaiian Belt Road and discharged makai. Similarly,
running along the north property line is an abandoned concrete flume, which was previously utilized
to discharge process water from the adjacent old sugar mill to agricultural land makai of Hawaiian
Belt Road. Figure 4-12 conceptualizes the existing drainage system.
4-21
HAWAII BELT ROADLOWER MAOULA ROADMAILE
S
T
R
E
E
T (MAMALAHOA HIGHWAY)780 800 760 740 720 580 660 640 680 620 700 TMK: (3) 9-6-002:016 TMK: (3) 9-6-002:044
(3) 9-6-002:024TMK: (3) 9-6-005:036 Path: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURESFile Name: 150440-FIG-ExistingDrainageSystem Plot Date: June 18, 2018 10:45 AM Cadd User: Richard Sellona OLD SUGAR
MILL FLUME
TMK: (3) 9-6-002:028
TMK: (3) 9-6-002:003
BISHOP ESTATES
(KAMEHAMEHA SCHOOLS)
TMK: (3) 9-6-002:018
TMK: (3) 9-6-002:04942.5 ACRES
TMK: (3) 9-6-005:054 EXISTING
ROADWAY EXISTINGGRASS SWALE ROADWAY
CULVERT
PROPERTY
LINE, TYP
EXISTING TMK: (3) 9-6-005:009 ROADWAY
GRASS SWALE
TMK: (3)
9-6-005:051
EXISTING
SHEET FLOW
TMK: (3) 9-6-002:021
600
0 200 400STREAM NOTE:
TOPOGRAPHICAL CONTOURS ARE APPROXIMATE AND SCALE IN FEETBASED ON PAHALA USGS TOPO QUADRANGLE.
PAHALA WASTEWATER TREATMENT PLANT FIGURESCALE: 1" = 200'
JOB NO: 150440 4-12EXISTING DRAINAGE SYSTEM
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.6.4.3 Flood Hazards
The subject property flood zone is designated Zone X, area of minimal flood hazard corresponding to
areas outside of the five-hundred-year flood plain, as indicated on the current September 29, 2017
Flood Insurance Rate Map (FIRM), Community Panel No. 1551661800F. Zone X designations are
not subject to the requirements of the Standards of Floodways, Chapter 27, Section 22 of the Hawaii
County Code. See Figure 4-13 for the Flood Insurance Rate Map.
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THIS IS AN OFFICIAL COPY OF A PORTION OF THE ABOVE
REFERENCED FLOOD MAP. IT WAS EXTRACTED USING F-MIT
ON-LINE. THIS MAP DOES NO REFLECT CHANGES OR
AMENDMENTS WHICH MAY HAVE BEEN MADE SUBSEQUENT
TO THE DATE ON THE TITLE BLOCK. FOR THE LATEST
PRODUCT INFORMATION ABOUT NATIONAL FLOOD
INSURANCE PROGRAM FLOOD MAPS CHECK THE FEMA
FLOOD MAP STORE AT WWW.MSC.FEMA.GOV.Path: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURES File Name: 150440-FIG-FIRM Plot Date: March 22, 2018 4:33 PM Cadd User: Richard Sellona PAHALA WASTEWATER TREATMENT PLANT FIGURESCALE: 1"=2,000'
JOB NO: 150440 FLOOD INSURANCE RATE MAP
SUBJECT PROPERTY:
ZONE X - AREAS OF MINIMAL FLOODING
BISHOP ESTATES
(KAMEHAMEHA SCHOOLS)
TMK:(3)9-6-002:018
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
4.6.4.4 Stormwater Quantity
The increase in peak flow and runoff volume is a function of the increase in impervious areas
associated with the proposed improvements.
All exposed (not enclosed) treatment processes will be sized to include free-board depth to
accommodate the 24-hour, 100-year storm event. Thus, no stormwater runoff from these areas is
anticipated.
A drainage system will be designed to address stormwater surface run-off caused by impervious
portions of the WWTP development. Per the Hawaii County Code, Chapter 27, Section 20, the site
drainage plan shall accommodate the run-off caused by the proposed development, within the site
boundaries, for a one-hour, ten-year storm event. The pre-development runoff (10-year, 1-hour
storm) is approximately 23 cubic feet per second (cfs). The post-development runoff is
approximated at 24.5 cfs, which is a net increase of 1.5 cfs.
To ensure that there is no adverse impact on adjacent or downstream properties due to post-
development flows, an on-site drainage system will collect runoff via grated inlets or swales. These
flows will be conveyed to on-site drainage detention systems, such as subsurface linear infiltration or
depressed detention basins, to detain flows and volumes to their pre-development condition.
Furthermore, landscape buffers with dirt berms will be constructed around most of the perimeter of
the property acting as secondary containment in the event of a large storm event.
A complete analysis of the pre and post development drainage condition will be completed during
the design phase.
4.6.4.5 Stormwater Quality
The quality of stormwater leaving the site is also a concern. Stormwater quality degrades with
development and increased impervious surfaces, because various pollutants are introduced into the
stormwater runoff.
The first half-inch of runoff during a storm is referred to as the Water Quality Volume (WQV) or the
“first-flush” volume. This portion of the runoff from a storm contains measurably more suspended
solids plus other contaminants per cubic foot than would be expected in runoff occurring later in the
storm.
To mitigate the quality of runoff, the drainage system will incorporate permanent Best Management
Practices (BMP’s). Recommended permanent BMP include scheduled good-housekeeping, which
will reduce litter and other constituents from being washed into the storm drain system, and
detention basins and underground infiltration facilities that prevent the release of sediment and
other pollutants to downstream waterways or adjacent properties. A full assessment of all available
BMP’s to optimize water quality will be provided during design of the project.
4.6.5 Electrical Systems
It will be necessary to bring electrical power to the WWTP site. It is anticipated that Hawaii Electric
Light Company (HELCO) will bring overhead power lines to the site and supply 480-volt, 3 phase
power to the WWTP via a pole-mounted transformer to a service panel with a meter.
The floating surface aerators will consume the majority of the electricity supplied to the site. An
electrical room will house the electrical gear, plant control equipment and the chlorination system.
Exterior lighting at the site will be limited to manually switched lights at the entrance to the electrical
building and at the headworks area.
A standby power system will be provided in the form of a pad-mounted diesel generator and above-
ground fuel tank with capacity to support three consecutive days of operation. In addition, the
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 4
electrical service panel will be equipped with a manual transfer switch and generator receptacle to
allow connection of a trailer-mounted generator in the event of emergency generator failure during
an extended power outage.
4.6.6 Telemetry Systems
A land-line telephone telemetry system with auto-dialer will be provided to provide Hilo-based
operation staff of alarm conditions and key operational parameters at the WWTP. Additionally, a cell
phone will be available for backup.
4.6.7 Operations Building
An operations building will be constructed to include the electrical room, chlorinator room, restroom,
and maintenance/storage room, as shown in Figure 4-14.
4.6.8 Site Fencing
The entire WWTP site, including the treatment systems and the land application system, will be
fenced (6-foot high chain link) and posted to prevent public access.
4-26
46'-8" 5'-0" 34'-8" 8"TYPPath: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURESFile Name: 150440-FIG-OpBldg Plot Date: June 12, 2018 2:56 PM Cadd User: Richard Sellona 6' MIN
6'-0" 6'-0"
0 1' 2' 3' 4' 8' 12'
SCALE: 3/16" = 1'-0"
PAHALA WASTEWATER TREATMENT PLANT FIGURESCALE: 3/16" = 1'-0"
JOB NO: 150440 OPERATIONS BUILDING PRELIMINARY FLOOR PLAN
SINK AND
COUNTER SPACE
MOTOR
CONTROL
CENTER
CHLORINATION ROOM
WITH VENTILATION
ELECTRICAL
CMU MAINTENANCE AND STORAGE ROOM
BLOCKS ROOM
EMERGENCY
SHOWER AND
EYE WASH DESK AND
WORK SPACE
TABLET
CHLORINATOR
12' WIDE ROLL-UP DOOR
4-14
Preliminary Design of
Improvements
The following is a summary of the preliminary design for the proposed Pahala WWTP.
5.1 Site Plan
The existing parcel is an active macadamia nut tree orchard. The prevailing grade is in the north to
south direction at 5 to 10 percent slope. Approximately 14.9 acres of the land will be cleared for the
construction of the proposed facility. Figure 5-1 presents a preliminary site plan for the WWTP.
5.2 Process Schematic
Figure 5-2 presents the recommended facilities process schematic.
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640780
600620660680700720740760 580800WSO/H ELEC (MAMALAHOA HIGHWAY)LOWER MAOULA ROADMAILE
S
T
R
E
E
T
LAGOON
1
LAGOON
3
LAGOON
4
LAGOON
2
W
E
T
L
A
N
D
HAWAII BELT ROAD900'± 200'±
850'± Path: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURESFile Name: 150440-FIG-PreliminarySitePlan_WithAerial_14.9acre_FullBuildAlternative Plot Date: June 18, 2018 1:46 PM Cadd User: Richard Sellona 1500'± 830±BISHOP ESTATES
(KAMEHAMEHA SCHOOLS)
TMK: (3) 9-6-002:018
42.5 ACRES
0 200 400NOTE:
TOPOGRAPHICAL CONTOURS ARE APPROXIMATE SCALE IN FEETAND BASED ON PAHALA USGS TOPO QUADRANGLE.
PAHALA WASTEWATER TREATMENT PLANT FIGURESCALE: 1" = 200'
JOB NO: 150440 5-1PRELIMINARY SITE PLAN
25' WIDE UTILITY
EASEMENT (0.94 ACRES)
1,000' WELL
SETBACK
8" INFLUENT
SEWER HEADWORKS
FIRE
HYDRANT
FIRE HYDRANT
6" DOUBLE CHECK
DETECTOR ASSEMBLY
FOR FIRELINE
1" WATER METER
FOR POTABLE
WATER
OPERATIONS
BUILDING
ODOR CONTROL
UNIT
FUTURE HEADWORKS
AND ODOR CONTROL
UNIT EXPANSION
25' SETBACK
LOT 1
(27.6 ACRES)
GROVE 2
50' SETBACK
EXISTING ACCESS VIA
KAMEHAMEHA SCHOOLS
FOR OTHERS TO REMAIN
(0.5 ACRES) GROVE 1
LOT 2
(14.9 ACRES)
GROVE 4
DISINFECTION
GROVE 3
PROPERTY
LINE, TYP 50' SETBACK
DRIVEWAY
ACCESS
FOR WWTP SLOW RATE LAND
APPLICATION
GROVE, TYP
UNNAMED
DRAINAGE WAY
Path: P:\Projects\Hawaii, County Of (HI)\150440 COH Pahala WWTP\_CAD\0-PROJECT\FIGURES File Name: 150440-FIG-LandAppPSys_Schem Plot Date: May 22, 2018 5:26 PM Cadd User: Richard Sellona PAHALA WASTEWATER TREATMENT PLANT FIGURESCALE: NONE
JOB NO: 150440 RECOMMENDED FACILITIES PROCESS SCHEMATIC
LEGEND
WW FLOW PATH
PARSHALL
FLUME WW ALTERNATIVE FLOW PATH
INFLUENT
INFLUENT FLOW METER AND
AUTOMATIC SAMPLER
BAR
RACK SLOW-RATE LAND
APPLICATION GROVES
TABLET
CHLORINATOR
AUTOMATIC
SCREEN AERATED LAGOONS CONSTRUCTED COVERED AUTOMATIC
WETLAND LAGOON SAMPLER
1 2 3 4
AUTOMATIC
SCREEN CHLORINE
CONTACT
TANK
FLOW METER
5-2
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
5.3 Design Criteria
Table 5-1 provides preliminary design criteria.
Table5 1. PreliminaryDesignCriteria
Description Value
Influent flows:
• Average dry weather 190,000 gpd
• Peak day wet weather 662,000 gpd
• Peak hour wet weather 630 gpm
Influent characteristics
• BOD5 300 mg/L
• TSS 300 mg/L
Odor control – granular activated carbon
• Airflow rate 500 cfm
• H2S Inlet concentration 1-10 ppm
• H2S removal efficiency 99%
• Media type High-capacity carbon
• Vessel diameter 3 feet
• Vessel height 6 feet
• Minimum carbon quantity 570 lbs
• Minimum bed depth 3 feet
• Fan motor 2 hp
• Nominal inlet size 8 inches
Mechanical screens
• Number of units 2
• Type In-channel cylindrical
• Screen opening size 0.25 inch (6 mm)
• Maximum flow rate capacity Greater than 625 gpm each
• Screening washing Integral
• Screening compaction Integral
• Screening wash water flow 20 gpm
• Screening wash water pressure 50 psi
Bypass screen
• Type Manually-cleaned bar rack
• Bar spacing 1 inch
• Rake Interlocking with bars
Screenings receptacle
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
Table 5 1. Preliminary Design Criteria continued
• Type 55-gallon drum or bags
• Screenings volume per million gallons treated 5 ft3/Mgal
• Estimated screenings quantity 1 ft3/day
• Disposal frequency 1/week
Influent flow metering
• Type Parshall flume
• Maximum flow capacity Greater than 630 gpm
• Minimum straight upstream channel section 20 times the throat width
Influent flow sampling Refrigerated automatic composite sampler
Lagoon cells
• Number of cells 4
• Maximum lagoon temperature 25ºC
• Minimum lagoon temperature 20ºC
• Freeboard 3 feet
• Working water depth 15 feet
• Allowance for sludge 3 feet
• Total water depth 18 feet
• Side slope 3(H) : 1(V)
• Working volume of lagoon 1 to 3 0.80 Mgal
• Working volume of lagoon 4 1.60 Mgal
Aerators
• Type Floating mechanical surface aerators
• Cell 1 aerators 30 hp (2 at 15 hp)
• Cell 2 aerator 15 hp
• Cell 3 aerator 10 hp
• Cell 4 aerator 5 hp aspirator style, floating ball cover for algae control
Constructed Wetland
• Water temperature 25 degrees C
• Aerated lagoon effluent nitrate-N concentration 19 mg/l
• Aerated lagoon effluent ammonia-N concentration 1 mg/l
• Constructed wetland effluent total N concentration 15.3 mg/l
• Total constructed wetland surface area 0.25 acres
• Flow path length 50 feet
• Hydraulic application width 200 feet
• Media depth 24 inches
• Media type Medium gravel, D10 = ¾ inch
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
Table 5 1. Preliminary Design Criteria continued
• Media porosity 38 percent
• Percolation prevention system 60 mil high density polyethylene (HDPE) liner
• Vegetation Native Hawaiian reeds and/or rushes, species to be
determined
Disinfection system
• Type Chlorine
• Form Calcium hypochlorite tablets
• Design chlorine dose 10 mg/L
• Chlorine contact time 15 minutes minimum
Effluent flow metering
• Type Magnetic
Effluent sampler
• Type Refrigerated automatic composite
Effluent quality
• BOD5
Less than 30 mg/L monthly average
Less than 60 mg/L peak
• TSS Less than 30 mg/L monthly average
Less than 60 mg/L peak
Effluent management system
• Type Slow-rate land application groves
• Number 4
• Minimum depth 5 feet
• Design percolation rate 0.0095 inches per minute
• Design application rate 8 percent of percolation rate
• Distribution system Gated pipe
• Stormwater containment 100-year, 24-hour storm event
• Vegetation Native Hawaiian trees
Stormwater site management 10-year, 1-hour storm
5.4 Environmental Benefits
A well-designed and managed land treatment system limits wastewater application to rates to
minimize adverse impact to groundwater quality. The deep percolate from the SR land treatment
system is expected to contain less than 1 mg/L of BOD5 and TSS. While the State of Hawaii has not
adopted formal groundwater quality standards, the drinking water standard for nitrate (10 mg/L as
N) in the annual average deep percolate below the land treatment system was used as a
performance target to design the land treatment site. Phosphorus adsorption is excellent in SR land
treatment systems, and 99 percent or greater phosphorus removal is anticipated. Table 5-2
compares the current loads to the environment via the LCCs and the loads to the environment after
the proposed project is implemented via the deep percolate from the land treatment system. Figure
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
5-3 provides a graphical representation of the environmental benefits of the proposed project
compared to the status quo.
Table5 2. EnvironmentalBenefitsofProposedProject
Parameter Current Annual Load to
Environment via LCCs
Annual Load to Environment
via Proposed Land Treatment
System Deep Percolate
Reduction
BOD5 174,000 lbs./year 600 lbs./year >99%
TSS 174,000 lbs./year 600 lbs./year >99%
Nitrogen 23,000 lbs./year 4,100 lbs./year 83%
Phosphorus 4,000 lbs./year 40 lbs./year >99%
Figure 5-3. Environmental Benefits of Proposed Project
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
5.5 Cost Estimates
An order of magnitude probable construction is summarized in Table 5-3. The estimate includes a
25 percent estimating contingency. The detailed cost estimate is included as Appendix A.
Table5 3. PahalaWWTPOrderofMagnitudeConstructionCostEstimate
Description Estimated Construction Cost
Electrical and instrumentation $1,976,000
Headworks $906,000
Odor Control $412,000
Lagoons $2,222,000
Constructed Wetland $611,000
Land Application $925,000
On-site improvements $6,325,000
Off-site improvements $1,223,000
Total Estimated Construction Cost $14,600,000
5.6 Future Expansion
5.6.1 Full Buildout Flows
Full buildout wastewater flow projections were developed using the Draft Ka’u Community
Development Plan (March 2015) and the CCH’s current (2017) wastewater standards. Table 5-4
summarizes the projected full buildout flows for the community, and Figure 2-1 shows the WWTP full
buildout service area.
Table5 4. PahalaWWTPFullBuildoutFlowProjections
Description Value Peaking Factor
Average dry weather flow 360,000 gallons per day 1.0
Peak day wet weather flow 1,260,000 gallons per day 3.5
Peak hour wet weather flow 1,200 gallons per minute 4.8
5.6.2 Improvements
To accommodate the flow increase anticipated from the full buildout of the Pahala wastewater
collection system, the WWTP will require facility upgrades. The recommended upgrades include
headworks and odor control expansion within the 14.9-acre site.
Additionally, the lagoon system will require modifications. Lagoon 1 will be converted to a complete
mix aerated lagoon environment to accommodate wastewater treatment needs. In a complete mix
aerated lagoon, sufficient mixing energy is provided to maintain the lagoon solids in suspension
always. A completely mixed aerated lagoon system performs as an activated sludge process without
solids recycle. The higher mixing energy, as compared to a partial mix lagoon, creates greater
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 5
opportunity for contact between the naturally-occurring micro-organisms in the lagoon and dissolved
organic matter. As a result, complete mix lagoons provide greater levels of treatment within a
smaller volume than partial mix lagoons. However, facilities must be provided downstream of
complete mixed lagoons to allow removal of settleable solids from the water column. To provide a
place for solids settling, lagoons 2 through 4 will continue to act as partial mix aerated lagoons
downstream of the complete mix lagoon 1. Lagoon 4 will require no aeration and will continue to be
covered to deprive algae of sunlight and allow suspended solids to settle out of the system effluent.
Utilizing this lagoon system approach, the Pahala WWTP will require modifications at full buildout
flows, but is not anticipated to expand beyond the initial build 14.9 acres.
5-9
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Implementation
Table 6-1 provides the implementation schedule for the WWTP. The LCCs will be closed following
connection of the existing sewer system to the WWTP.
Table6 1. ImplementationSchedule
Description Milestone
Complete design of WWTP September 18, 2019
Complete construction of WWTP May 20, 2021
Connect existing collection system to WWTP June 30, 2021
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Alternative Treatment Options
Evaluation
Several other treatment alternatives were considered for the Pahala WWTP, as summarized below.
7.1 Option Descriptions
7.1.1 Option 1: Aerated Lagoons/Constructed Wetland/Land Application
Option 1 consists of an aerated lagoon treatment system with a constructed wetland and
disinfection, followed by land application for effluent management, as described previously
throughout this report. Figure 7-1 is a schematic diagram for Option 1.
Figure 7-1. Option 1 Schematic Diagram
7.1.2 Option 2: R-1 Treatment/Land Application
Option 2 consists of constructing a membrane bioreactor (MBR) or an activated sludge treatment
process followed by cloth media filtration, followed by UV disinfection, to produce recycled water that
meets DOH R-1 recycled water criteria. R-1 recycled water is effluent that has undergone oxidation,
filtration, and disinfection. R-1 is considered the highest grade of recycled water and can be used for
irrigation of golf courses, parks, schools, and all types of agricultural crops. The R-1 treatment
system would be followed by land application as per Option 1. Figure 7-2 is a schematic diagram for
Option 2.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
Figure 7-2. Option 2 Schematic Diagram
7.1.3 Option 3: R-1 Treatment/Seasonal Water Recycling
Option 3 consists of a treatment system similar to Option 2 to produce R-1 recycled water. The
recycled water would be used to irrigate nearby macadamia nut orchards. Figure 7-3 provides a
schematic diagram of Option 3.
Figure 7-3. Option 3 Schematic Diagram
A water recycling analysis was prepared to assess the potential seasonal demand for recycled water
produced by the WWTP. Figure 7-4 is an irrigation demand assessment for the Pahala area based
on published climate data. The graph shows precipitation, estimated evapotranspiration, and the
irrigation demand for each month of the year. As shown in the figure, irrigation is typically needed
from April through September, reaching a peak demand in June. The graph shows that no irrigation
is typically needed between October and March, because precipitation exceeds evaporation during
those months.
7-2
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
8
7 Inches of Water 6
5
4
3
2
1
0
Month
Precipitation Evapotranspiration Irrigation Requirement
Figure 7-4. Irrigation Demand Assessment
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
The potential demand for recycled water produced by the Pahala WWTP was assessed, as shown in
Figure 7-5. The WWTP could potentially provide irrigation water for approximately 62 acres, based
on the peak month irrigation demand in June. During June, all the recycled water produced by the
WWTP would be used on the 62 acres. During all other months the supply of recycled water will
typically exceed the demand, and the excess water would be land applied on the WWTP property as
per the previous alternatives.
7.0
6.0 Million Gallons 5.0
4.0
3.0
2.0
1.0
0.0
Month
Recycled Water Use Effluent Disposal
Figure 7-5. Option 3 Recycled Water Demand Assessment
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
The Pahala climate makes it possible to only recycle only about 25 percent of the annual flow in this
scenario, due to the long wet season and relatively low evapotranspiration rate during the dry
season. This is in stark contrast to the Kailua-Kona area on the leeward side of the island, where the
climate will allow approximately 88 percent of the recycled water produced at the Kealakehe WWTP
7-3
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
throughout the year to be recycled. Figure 7-6 provides a comparison of the irrigation demand in
Pahala with the irrigation demand at Kealakehe.
10,000
6,000
5,000
4,000
3,000
2,000
1,000
0
Month
Kealakehe (Parks and Golf Course) Pahala (Macadamia Nuts)
Figure 7-6. Comparison of Irrigation Demands at Pahala and Kealakehe
7.1.4 Option 4: R-1 Treatment and Storage for 100% Water Recycling
Option 4 adds a seasonal storage reservoir, as shown schematically in Figure 7-7.
7,000
8,000
9,000 Unit Irrigation Demand (gpd/acre) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
7-4
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
Figure 7-7. Option 4 Schematic Diagram
Implementation of a seasonal storage reservoir would make it possible to recycle 100 percent of the
R-1 water produced by the Pahala WWTP in a typical year. The seasonal storage reservoir would
make it possible to save recycled water produced during the wet season for use during the dry
season. An annual water balance was prepared to assess the seasonal storage reservoir needs for
the Pahala WWTP. Figure 7-8 provides a summary of the evaluation, and shows recycled water
supply, use, and storage throughout a typical year. As shown in the graph, peak storage of
approximately 40 million gallons (Mgal) would occur during April, and by August the storage reservoir
would be dry and ready for another wet season. Under this scenario it would be possible to irrigate
approximately 253 acres of macadamia nut trees. The lined, 20-foot-deep storage reservoir would
have a water surface area of approximately 7 acres.
Storage of recycled water is not without its challenges. Recycled water contains nutrients that allow
algae to grow. The algae can cause odors if stagnant water conditions are allowed to develop.
Recycled water that is stored in open reservoirs must often be re-treated to improve the water quality
characteristics. Recycled water reservoirs can be equipped with mixers to prevent stagnant water
conditions, and/or be equipped with floating covers to block the sunlight that fosters algal growth.
7-5
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7 Million Gallons 45
40
35
30
25
20
15
10
5
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Recycled Water Supply Recycled Water Use Storage Volume
Figure 7-8. Seasonal Storage Reservoir Analysis
Implementation of a seasonal storage reservoir and recycling program would not eliminate the need
for a land application system at the WWTP, as described previously. HAR 11-62 requires a disposal
system for all recycled water system, to provide a means for disposal of water that does not meet R-
1 standards or disposal of excess water should the seasonal storage reservoir capacity be exceeded
during an exceptionally wet year.
7.1.5 Option 5: Maximum Practical Treatment
Option 5 consist of implementing advanced wastewater treatment processes that represent
maximum practical treatment. The option is illustrated schematically in Figure 7-9. The process
treatment train consists of a 5-stage Bardenpho activated sludge treatment process, followed by
chemical addition and denitrifying filters to reliably reduce total nitrogen to less than 4 mg/L and
total phosphorus to less than 0.1 mg/L. The treatment processes would be followed by a
disinfection process to create R-1 recycled water. The recycled water produced would be used to
irrigate macadamia nut trees as per Option 3. A seasonal storage reservoir could also be
implemented at additional cost. A land application system would be required as per the previous
Options.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
Figure 7-9. Option 5 Schematic Diagram
7.2 Cost Comparisons
Planning-level cost estimates were prepared for the five options, as described below.
7.2.1 Capital Costs
Table 7-1 summarizes the capital costs associated with the options described above. Additional
detail can be found in Appendix A. The capital costs shown in the table do not include costs
associated with collection system improvements or closure of the existing LCCs.
Table7 1. SummaryofCapitalCostEstimates
Option Name Estimated Capital Cost
1 Aerated lagoons/constructed wetland/land application $14.6 million
2 R-1 treatment/land application $18.4 million
3 R-1 treatment/seasonal water recycling $20.2 million
4 R-1 treatment and storage for 100% water recycling $30.4 million
5 Maximum practical treatment $26.0 million
Comparison of options 1 and 2 shows that providing R-1 treatment instead of the aerated lagoon
and wetland natural treatment system will increase the capital cost by approximately $3.8 million.
Option 3 shows that addition of water recycling to reuse approximately 25 percent of the annual flow
would add an additional $1.8 million in capital costs. Option 4 shows that constructing a seasonal
storage reservoir to recycle 100 percent of the flow would add an additional $10 million in capital
costs. Comparison of options 3 and 5 shows that providing maximum practical treatment instead of
normal R-1 treatment would add $5.8 million in capital costs.
7.2.2 Operation and Maintenance Costs
Operation and maintenance (O&M) costs include labor, electricity, chemicals, spare parts, sludge
management, and other costs required to operate and maintain the facility. Table 7-2 provides a
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
summary of the O&M cost estimates developed for the options. Additional details can be found in
Appendix A.
Table7 2. SummaryofO&MCostEstimates
Option Name Estimated Annual O&M Cost
1 Aerated lagoons/constructed wetland/land application $236,000
2 R-1 treatment/land application $1,052,000
3 R-1 treatment/seasonal water recycling $1,055,000
4 R-1 treatment and storage for 100% water recycling $1,063,000
5 Maximum practical treatment $1,421,000
As shown in the table, option 1 incurs significantly lower O&M costs than the other options. The
significant cost differential is due to the simple aerated lagoon natural treatment system that
requires less labor, electricity, chemical, and maintenance that the other options.
7.2.3 Recycled Water Sale Proceeds
Options 3, 4, and 5 will produce a marketable product in the form of R-1 recycled water that could be
sold to users for irrigation purposes. The value of recycled water is a function of the value of the
water that it replaces. In general, recycled water is sold to users at a fraction of the price of the
water that is being replaced to provide a financial incentive to use the product. The typical recycled
water price is 25 percent to 90 percent of the water it replaces.
The Pahala WWTP will be located at elevation 750 feet MSL. The cost to pump groundwater from
the basal lens to the ground surface at the WWTP is approximately $1,078 per million gallons. Table
7-3 provides a summary of a recycled water sales assessment of each option, assuming the recycled
water is sold for 90 percent of the cost of the irrigation water it would replace. Additional detail is
provided in Appendix A.
Table7 3. SummaryofAnnualRecycledWaterSaleProceeds
Option Name Annual Volume Recycled
(Mgal)
Maximum Annual
Sales Proceeds
1 Aerated lagoons/constructed wetland/land application 0 $0
2 R-1 treatment/land application 0 $0
3 R-1 treatment/seasonal water recycling 17 $17,000
4 R-1 treatment and storage for 100% water recycling 70 $68,000
5 Maximum practical treatment 17 $17,000
7.2.4 Life-Cycle Costs
Life-cycle costs represent the total costs to the community to construct and operate the wastewater
treatment system over a 30-year period. The life-cycle cost evaluation includes capital and O&M
costs, and recycled water sales proceeds as described above. In addition, equipment replacement
allowances are included after 20-years of operation. The life-cycle cost evaluation includes an
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
inflationary factor to account for long-term changes in the value of money. The life-cycle costs are
expressed as the Net Present Value (NPV). The NPV represents the amount of money that the
County would need to set aside now in an interest-bearing account to cover all of the costs over the
defined life-cycle. Table 7-4 provide a summary of the life-cycle cost evaluation. Additional detail
can be found in Appendix A.
Table7 4. SummaryofLife CycleCostEstimates
Option Name Estimated Life-Cycle Cost
1 Aerated lagoons/constructed wetland/land application $21.2 million
2 R-1 treatment/land application $43.0 million
3 R-1 treatment/seasonal water recycling $44.5 million
4 R-1 treatment and storage for 100% water recycling $54.0 million
5 Maximum practical treatment $59.0 million
As shown in the table, option 1 incurs the lowest life-cycle costs, and the other options would all
incur over double to nearly triple the cost over the 30-year life-cycle. The life-cycle cost estimates are
shown graphically in Figure 7-10. The operating costs shown in the figure include benefits (i.e., cost
reductions) from recycled water sales where applicable. 30-Year Life-Cycle Cost ($ million) 60
50
40
30
20
10
0
1 2 3 4 5
Option
Capital Costs Operating Costs
Figure 7-10. Life-Cycle Costs of Options
As shown in the graph, the operating cost differential between option 1 and the other options is the
leading contributor to the lower life-cycle cost of option 1. The major operating cost differences are
discussed below.
7.3 Non-Economic Discussion
The options are discussed on a non-economic basis below.
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
7.3.1 Labor Requirements
The Pahala WWTP will be operated by the COH DEM, Wastewater Division that is based in Hilo. The
Hilo-based WWTP operators will regularly visit to facility to check the system status, make
operational adjustments, and draw samples for required laboratory testing. In addition,
maintenance personnel will visit the WWTP as needed to conduct equipment and electrical system
repairs.
A major difference between option 1 and the other options is the frequency of routine operator visits
required, and the number of personnel routinely required. Option 1 will require a single operator to
normally visit the site once per week. The other options will require daily operator visits to conduct
sampling that is required for R-1 compliance. In addition, options 2 through 5 consist of mechanical
treatment technology that required more operator attention than option 1. Table 7-5 compares the
operational labor differences for the options, as expressed as full-time equivalents (FTEs).
Table7 5. ComparisonofOperationalLaborRequirements
Option Name Estimated Operational Labor
Requirement (FTEs)
1 Aerated lagoons/constructed wetland/land application 0.3
2 R-1 treatment/land application 3.7
3 R-1 treatment/seasonal water recycling 3.7
4 R-1 treatment and storage for 100% water recycling 3.7
5 Maximum practical treatment 5.6
7.3.2 Operational Complexity
HAR 11-61 establishes operator certification requirements for WWTPs. The DOH requires that
certified operators operate municipal WWTPs. The larger and/or more complex the wastewater
treatment process, the higher grade of operator required at the facility. Options 1 through 5 were
evaluated for operator certification requirements based on the criteria established in HAR 11-61.
Table 7-6 summarizes the results of the evaluation. As shown in the table, option 1 would require a
Grade I operator, while the other options would require a Grade IV operator (the highest grade). The
higher requirements for options 2 through 5 are due to the complexity of the treatment processes
compared to option 1. In general, the County has difficulty attracting and retaining Grade IV
operators.
Table7 6. ComparisonofOperatorCertificationRequirementsperHAR11 61
Option Name Operator Certification Level Requirement
1 Aerated lagoons/constructed wetland/land application I
2 R-1 treatment/land application IV
3 R-1 treatment/seasonal water recycling IV
4 R-1 treatment and storage for 100% water recycling IV
5 Maximum practical treatment IV
7-10
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
7.3.3 Energy Consumption
Figure 7-11 provides a comparison of the electrical energy requirements of the five options. As
shown in the graph, option 1 will require significantly less electrical energy to operate, due to the use
of natural treatment systems (aerated lagoons) instead of mechanical treatment processes that
require more aeration and process pumping.
1,200,000
1,000,000
800,000
600,000
400,000
200,000
0
Option
Figure 7-11. Comparison of Electrical Energy Requirements
7.3.4 Sludge Management
Sludge management for Option 1 is significantly different than the other options. The partial-mix
aerated lagoon treatment system allows wastewater solids to accumulate at the bottom of the
lagoon, forming a sludge blanket that slowly anaerobically digests. Sludge removal is infrequent,
typically on the order once every 15 to 20 years. The resulting solids are well-digested and
inoffensive due to the long retention time in the lagoons.
Options 2 through 5 would require an aerobic digester to stabilize and store waste solids from the
activated sludge treatment process. The solids would need to be dewatered and trucked to a landfill
on a weekly basis.
7.4 Living Machine®
Living Machine® technology was suggested during community outreach meetings. Living Machine®
is a proprietary technology by Worrell Water Technologies that incorporates aerated tanks planted
with vegetation to provide an attractive wastewater treatment process. In colder climates the
aerated tanks are housed in a greenhouse for protection. In addition, subsurface flow wetlands with
continuous and/or batch flow can be included in the process to provide desired treatment.
The Living Machine® technology has been implemented in “green” buildings like the San Francisco
Public Utilities Commission building, the Port of Portland Headquarters, and others. Review of the
company’s website did not reveal any municipal projects completed on the scale of what would be
needed for Pahala. Therefore, the technology is considered to be not feasible. Electricity Requirement (kWh/year) 1 2 3 4 5
7-11
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
It should be noted that the proposed non-proprietary treatment system (aerated lagoons and
subsurface flow wetland) uses essentially the same natural treatment processes as the Living
Machine®, but on a municipal scale.
7.5 Septic Tank Alternatives
A previous assessment recommended installation of a community septic tank and repurposing one
of the existing LCCs to serve as a seepage pit (SSFM, July 2007), in accordance with Alternative 1
proposed to the community by the County in 2004 (County of Hawaii, November 5, 2004). This and
other options that have been raised during the community outreach process that incorporate septic
tank technology are discussed below.
7.5.1 Community Septic Tank
The effectiveness of a septic tank is directly related to the amount of hydraulic detention time
provided by the tank volume. The previous study (SSFM, July 2007) suggested a 24-hour detention
time would be adequate. Applying the current flow projections for the project indicate a 190,000-
gallon tank would be appropriate if this criterion is used. However, for large community septic tanks
it has been found that longer detention times are needed to optimize treatment performance, avoid
the need for frequent septage pumping, and to account for peak flow rates that are developed by
community wastewater collection systems. Applying appropriate design criteria (Crites and
Tchobanoglous, 1998), to the project results in the need for an 800,000-gallon tank, which would
require pumping on a 3-year interval. The area required for an appropriately-sized community septic
tank would be approximately ¼ acre.
The use of a community septic tank would require the DOH to issue a variance to HAR 11-62-23.1,
which requires WWTPs with design capacities greater than 100,000 gallons per day to produce
effluent containing less than 30 mg/L of both BOD5 and TSS – septic tanks are not able to produce
effluent of this quality. A secondary treatment process is needed to comply with the effluent quality
requirements contained in the DOH regulations. The County would need to reapply for the variance
every 5-years, and if not renewed then secondary treatment would need to be provided.
Additionally, odors from a community septic tank present a significant concern. A septic tank is an
anaerobic treatment process that produces hydrogen sulfide, reduced sulfur compounds, and other
odorous gases. Odors emanating from septic tanks at individual residences are typically dispersed
to the atmosphere throughout the community via the household plumbing roof vents. A community
septic tank would concentrate the community’s emissions to a single point source that would require
foul air collection and treatment to avoid nuisance odor conditions. A dual-stage scrubber capable of
treating approximately 3,600 cubic feet per minute of foul air would be required to avoid nuisance
odor conditions. The dual-stage scrubber would consist of a biotrickling filter, followed by a granular
activated scrubber.
7.5.2 Converting LCC to Seepage Pit
A previous study (SSFM, July 2007) suggested that the existing LCC located on the County-owned
parcel TMK 9-6-002:024 could be converted to a seepage pit that would be regulated by DOH as an
injection well. HAR 11-23-07 allows injection wells located mauka of the UIC line that were in
existence prior to July 6, 1984 to continue to operate. However, the flow to the wells cannot
increase, nor can a new well be constructed. Therefore, the earlier plan to convert the existing LCC
to a seepage pit is not feasible for the following reasons:
• Closing LCC No. 2 that is located on private property would not be allowed, as it would
increase the flow to LCC No. 1 (converted to a seepage pit that is regulated as an injection
well) that is located on County property.
7-12
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
• The capacity, structure, and condition of the existing LCC No. 1 is not known. The LCC could
either be a lava tube or a large conventional cesspool. A geotechnical investigation
conducted on the site to depths of 30 to 35 feet did not reveal the presence of lava tubes
(Masa Fujioka & Associates, January 9, 2007), therefore it is likely a large conventional
cesspool. The County attempted to determine the structure and condition of the LCC via
closed circuit TV inspection, but could not ascertain either due to technological limitations. It
is not known if the LCC could accommodate the flow from the existing service area if LCC No.
2 is closed.
• HAR 11-62-25 requires new and proposed effluent disposal systems to have a backup
disposal system capable of handling the peak flow. A second seepage pit cannot be
constructed to comply with the regulatory requirement because the site is located mauka of
the UIC line. If the existing seepage pit were to fail then a replacement cannot be
constructed.
• The Kau Community Development Plan requires the County to provide for eventual
construction of sewers throughout the community. Providing sewers for the entire
community will increase wastewater flows considerably, as presented in Section 5.
Increasing flow to the existing LCC (converted to a seepage pit) would not be allowed.
Therefore, the use of the existing LCC as a disposal system could prevent the County from
providing the community’s desired future wastewater needs.
For these reasons, converting the existing LCC to a seepage pit is considered to be not feasible.
7.5.3 Leachfield Disposal
Leachfields are effluent disposal systems consisting of buried gravel-filled absorption trenches.
Significant treatment occurs as septic tank effluent percolates through the soil surrounding the
leachfield trenches. Leachfields are an integral part of residential septic systems, and DOH has
established trench design criteria applicable to both residential and municipal-scale leachfields. In
particular, HAR 11-62-34 requires trenches to be sized based on bottom area only. Application of
the DOH criteria to the project yields a need for at least 30 acres of land to satisfy DOH hydraulic
loading rate and redundancy requirements. Achieving even distribution of effluent over a leachfield
of this size would be challenging at best. Therefore, leachfield disposal for the project is considered
to be not feasible.
7.5.4 Conversion to Individual Wastewater Systems
The concept of a community wastewater system could be abandoned and all houses be required to
construct individual wastewater systems comprised of a septic tank and leachfield. However, many
of the lots in the community are small (less than 10,000 square feet) and significantly improved,
making the feasibility of constructing individual wastewater systems on every lot uncertain. HAR 11-
62-34 allows construction of seepage pits where there is insufficient land area to install absorption
trenches (i.e., a leachfield), but prohibits construction in soils having percolation rates slower than
10 minutes per inch or where rapid percolation through such soils may result in contamination of
water-bearing formations. The soils in the community are classified as Puueo-Naalehu complex, 3 to
10 percent slopes in the National Resource Conservation Service soil survey. This soil type consists
of approximately 18 inches of extremely cobbly medial silt loam over cobbles and bedrock. This soil
profile is too thin for conventional soil absorption trenches, so residents with sufficient space would
be required to import fill soil to create elevated mound systems in accordance with HAR 11-62-34 to
achieve adequate soil depth. Residents without sufficient space could potentially install seepage
pits if suitable subsurface geology could be located. However, previous subsurface investigations in
the community (Masa Fujioka & Associates, January 9, 2007, and Geolabs-Hawaii, September 23,
7-13
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 7
1998) revealed extremely permeable clinker layers and numerous lava tubes, both of which would
not meet HAR 11-62-34 requirements for seepage pits. For these reasons, conversion to individual
wastewater systems is considered to be not feasible.
7-14
Alternative Site Evaluation
Nine sites were evaluated as potential locations for the Pahala WWTP. Each site was assessed for
twenty-one criteria, in four broad categories: environmental, social and cultural; location and site;
land use and availability; and collection system and service area.
8.1 Methodology
The site evaluation was performed according to the following process:
1. Potential sites for the Pahala WWTP were initially identified by the Department of
Environmental Management. Additional sites were identified based on feedback from the
Pahala community obtained during Community Outreach meetings that took place in
December 2017.
2. Four general categories and twenty-one criteria were established and defined for the
analysis.
3. Six “fatal flaw” conditions were identified. Sites with a fatal flaw were eliminated from
further consideration.
4. Relative weighting factors were established for each category and criteria.
5. Sites were mapped using GIS. Data such as soil type, location of subsurface and surface
water, topography, zoning and prevailing wind direction were determined.
6. Each site was evaluated and scored for the twenty-one criteria.
7. A weighted ranking was determined for each site, based on the weighting factors established
in Step 4.
8. A preferred site was identified, based on the weighted high score.
8.2 Site Locations
Ownership, location, and proximity to the existing LCCs for all siting alternatives considered is
illustrated in Figure 8-1.
8-1
This page intentionally left blank.
MoaulaGlP unaluuGlHionamoaGlPunaluuGlHi
onamo
a
GlWaloalHionamoaGl
ID No. Land Owner TMK 1 County of Hawaii 9-6-002:024 2 PMK Capital Partners LLC 9-6-002:016 3 Hawaii Electric 9-6-002:043 4 Mauna Loa Macadamia Orchards LP 9-6-002:048 5 State of Hawaii 9-6-002:005 6 State of Hawaii 9-6-002:013 7 Kamehameha Schools 9-6-002:018 8 Kamehameha Schools 9-6-002:021 9 Kamehameha Schools 9-6-002:049
LEGEND
!
#
Streams
( Non-Potable Water Well
"
* Potable Water Well
) Existing Large Capacity Cesspool (LCC)
Pahala WWTP Alternative Sites
")
")
!(
!(
!(
#*
PunaluuGl
MoaulaGl
W al oala Waloala
Waloala
H ionam oaGl Waloala
W
al
o
a
l
a
Moaula G l
Moaula Gl Hionam oa Gl
W
alo
a
l
a
Mo
a
ul
aGl a Wal o ala
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o
n
am
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l
Waloala
Moaula
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Waloala HionamoaGl
W
aloala
Waloala
MoaulaGl
Hionam
oa
Gl
3,000 1,500
Feet
±
0
Kauhuhu'ulaGulch
Ka'ala'alaGulch
Keaiwa
Gulch
Pa'au'au
Gulch
Water Well #1 with
1,000ft Radius
Water Well #2 with
1,000ft Radius
Water Well #3 with
1,000ft Radius
Water Well #4 with
1,000ft Radius
1
2
3
4
5
6
9
8
7
PREVAILING WIND
N
W E
S
FIGURE SCALE AS SHOWN PAHALA WASTEWATER TREATMENT PLANT
JOB NO.: 150440 Pahala Site Alternatives 8-1
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
8.3 Criteria
The criteria used for the analysis are presented for each of four categories in Tables 8-1, 8-2, 8-3
and 8-4. A score was assigned to each criterion based on definitions included in the tables. A score
of five represents a preferred or positive condition, and a score of one a less preferred or negative
condition. A score of zero indicates a fatal flaw; six fatal flaw conditions were identified during the
analysis are identified in the corresponding table.
Table 8-1 outlines the environmental, social, and cultural criteria considered in the analysis.
Table8 1. Environmental,SocialandCulturalCriteria
Criteria Scoring and Definitions
5 4 3 2 1 0 = Fatal Flaw
Presence of or proximity to
archaeological/cultural
sites
No known or
suspected sites
Confirmed or
suspected sites
and mitigatable
No information
available
Confirmed or
suspected sites
and mitigation
ability unknown
Confirmed sites
and mitigation
ability unknown
Confirmed sites
and
unmitigatable
Proximity of treatment More than 1000 Between 50 and Between 50 and Less than 50 ft
units to existing occupied ft. from any 1000 ft. from 1000 ft. of from any
buildings occupied
building
non-school
building
school occupied
building
Prevailing wind direction Site is downwind
of most of the
community
Site is central Site is upwind of
most of the
community
Biology Endangered or
threatened
species not
present
Presence of
endangered or
threatened
species unknown
Endangered or
threatened
species known to
be present
Endangered or
threatened
species known to
be present and
unmitigatable
Visual impact Natural visual
mitigation (hill,
berm,
vegetation,
remoteness)
exists
Visible location,
mitigatable with
trees or other
engineered
buffers
Visible location,
unmitigatable
Contamination from prior
land use
No suspected
industry-related
contamination
issues
Presence of
contamination
unknown
Suspected or
confirmed
contamination
issues
Previously disturbed or
developed
Yes Partial No previous
development or
disturbance
The circumstance where a cultural or historical site is known to exist within the treatment facility
footprint and mitigation to relocate, protect, or preserve that site is not possible, was identified as a
fatal flaw condition.
From an environmental perspective, the presence of endangered or threatened species was
considered negative. A site previously disturbed or developed was viewed as positive, unless
contamination from a previous land use was suspected.
Considerations specific to social impact include proximity to occupied buildings (including
residences, school, commercial establishments and others), prevailing wind direction, and visual
impact.
8-3
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
Table 8-2 outlines the location and site characteristics considered in the analysis.
Table8 2. LocationandSiteCharacteristics
Criteria Scoring and Definitions
5 4 3 2 1 0 = Fatal Flaw
Parcel size More than 14.9
acres
Less than 14.9
acres
Soils type Good soil and in
sufficient
amounts in area
of parcel useable
for disposal
Good soil but
over limited area
and disposal
modification
required
Marginal soil in
area of parcel
useable for
disposal
No soil in area of
parcel useable
for disposal
Topography Gentle slopes
(less than 8%)
Moderate slopes
(8% -18%) or
localized
high/low points
Steep slopes
(18% -20%) Extreme slopes
(greater than
20%)
Proximity to water well Outside of both
1000 ft. radius
and upgradient
influence zone of
any well
Outside of 1000
ft. but suspected
within
upgradient
influence zone of
non-potable well
Within 1000 ft.
or within
upgradient
influence zone of
non-potable well
Within 1000 ft.
or within
upgradient
influence zone of
potable well
Presence of lava tubes None Possible or
unknown
Known
Proximity to surface water, Treatment and Treatment and Treatment and
intermittent stream or disposal more disposal disposal less
coast line than 500 ft.
away
between 50 to
500 ft.
than 50 ft. away
Flood control / drainage No risk of
flooding
Flood risk
unknown
Prone to flooding
or within flood
zone
Vehicle access Vehicle access
currently exists
Existing
easement, but
new road or
significant road
upgrades
required in or via
county/private
right if way
Existing
easement, but
new road or
significant road
upgrades
required in or via
state right-of-
way
No current
vehicle access or
easement,
access legally
restricted, or
significant
obstruction to
access
Power and potable water Utilities currently Utilities Potable water
availability available at available within and/or power
property line and 400 yds. of not currently
within 400 ft. of property or available within
site, no new unknown 400 yds. of
easement property and/or
required, no significant
known obstruction to
significant utility
obstructions (i.e. construction
-culverts,
streams, cultural
sites)
8-4
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
Three fatal flaw conditions were identified for the location and site characteristics category in Table
8-2:
• Sites less than 14.9 acres in size, which is the least amount of land needed for treatment,
disposal, and future growth.
• Average slopes greater than 20 percent, which significantly increase the cost of construction
and limit design options.
• Location within a 1000-foot radius surrounding a potable water well, which is prohibited by
HAR 11-62 for the protection of drinking water in the State of Hawaii.
Table 8-3 outlines the collection system and service area characteristics considered in the analysis.
Table8 3. CollectionSystemandServiceAreaCriteria
Criteria Scoring and Definitions
5 4 3 2 1
Distance from LCC collection
area
Parcel is adjacent
to existing LCC or
less than 0.25
miles away
Parcel is 0.25-0.5
mile away from
existing LCC
Parcel is 0.5-1.0
miles away from
existing LCC
Parcel is 1.0 – 1.5
miles away from
existing LCC
Parcel is more than
1.5 miles away from
existing LCC
Gravity flow possible or
pumping required
Gravity flow
possible
Pumping required
for wastewater
transmission from
collection area to
site
Number of properties newly
accessible
Commercial areas
become accessible
Additional
individual
residential
properties become
accessible outside
of LCC service area
No additional
properties become
accessible
A site location requiring large transmission distances of more than two miles are less preferable due
to both initial capital cost and future operations and maintenance requirements. Similarly, sites
where wastewater can flow via gravity from the collection area are preferable to those requiring a
pump station.
Newly accessible refers to properties within the service area that are not currently connected to the
LCC, but will become accessible to the County-owned sewer system when the collection lines are
relocated into the roadways fronting the property. Hawaii County Code requires connection of these
properties once the new collection system is constructed, and their individual wastewater systems
(cesspools or septic tanks) properly removed from service. All individual cesspools in the State of
Hawaii must be converted or closed by the year 2050.
8-5
-
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
Table 8-4 outlines the land use and availability characteristics considered in the analysis.
Table8 4. LandUseandAvailabilityCriteria
Criteria Scoring and Definitions
5 4 3 2 1
Current zoning and land use WWTP currently
permitted in zoning
without Special
Permit
WWTP possible
onsite Special
Permit required
WWTP not
recommended on
site
Land availability Owner willing and
able to sell or land
currently
government (state,
county) owned
Subdivision
required or friendly
condemnation
required
Difficult or lengthy
approval process
expected or owner
willingness to sell
unknown
Owner unwilling to
sell or unfriendly
condemnation of
land required
(private corporate
owner)
Owner unwilling to
sell or unfriendly
condemnation
required (private
family owner)
Although public facilities are permitted in any zoning in the County of Hawaii, construction of a
wastewater treatment facility requires a Special Permit within some zones. No fatal flaws were
identified for the land use and availability category.
8-6
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
8.4 Criteria Weighting Factors
To consider the relative importance to the categories and criteria, each was assigned a weighting
factor for the analysis. Weighting allows for appropriate consideration of all factors - both the
technical and non-technical - associated with siting. Relative weighting is summarized in Table 8-5.
Table8 5. RelativeWeightingFactors
Category Category Weight Criteria Criteria Weight
Environmental, social and cultural 35% Presence of and/or proximity to archaeological/cultural sites 25%
Proximity of treatment units to existing occupied buildings 25%
Prevailing wind direction 25%
Biology 10%
Visual impact 5%
Contamination from prior land use 5%
Previously disturbed or developed 5%
100%
Location and site characteristics 35% Parcel size 25%
Soils type 25%
Topography 15%
Proximity to water well 10%
Presence of lava tubes 8%
Proximity to surface water, intermittent stream or coast line 6%
Flood control / drainage 5%
Existing vehicle access 3%
Power and potable water availability 3%
100%
Collection system and service area 20% Distance from LCC collection area 50%
Gravity flow possible or pumping required 30%
Number of properties newly accessible 20%
100%
Land use and availability 10% Current ownership 55%
Current zoning and land use 45%
100%
8-7
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
8.5 Raw Scores
For the nine sites identified in Figure 8-1, raw scores were assigned for each of the twenty-one
criteria according to the definitions in Section 8.3. The results are presented in Table 8-6.
Table 8-6. Alternatives Analysis – Raw Scores
Site Raw Score Category Criteria 1 2 3 4 5 6 7 8 9
Presence of and/or proximity to archaeological/cultural sites 5 1 2 3 3 3 4 3 3
Proximity of treatment units to existing occupied buildings 3 3 5 5 5 5 5 5 5
Prevailing wind direction 5 5 5 5 5 5 5 5 5
Environmental, social
and cultural Biology 3 3 3 3 3 3 3 3 3
Visual impact 3 3 3 5 5 5 3 3 3
Contamination from prior land use 3 1 3 1 3 3 3 3 3
Previously disturbed or developed 5 5 5 3 3 3 5 5 5
Parcel sizea 0 5 0 5 5 5 5 5 5
Soils type 5 1 1 3 5 1 5 5 5
Topography 3 5 3 5 3 5 3 3 5
Proximity to water wellb 0 5 5 3 5 5 5 5 5
Location and site
characteristics Presence of lava tubes 1 1 3 3 3 3 3 3 3
Proximity tosurface water, intermittent stream or coast line 5 5 5 5 3 5 5 1 5
Flood control / drainage 3 3 3 3 3 1 3 3 3
Existing vehicle access 5 5 2 2 2 5 5 5 2
Power and potable water availability 3 3 3 1 1 1 3 3 1
Distance from LCC collection area 5 5 4 3 3 2 5 4 3
Collection system and
service area Gravity flow possible or pumping required 5 5 5 5 1 1 5 5 5
Number of properties newly accessible 3 3 3 3 3 3 3 3 3
Current zoning and land use 3 3 3 3 3 3 3 3 3
Land use and availability
Current ownership 5 5 3 3 5 5 4 4 4
Raw score totals (maximum possible = 105) FF 75 FF 72 72 72 85 79 79
a Fatal flaw condition for Sites 1 and 3.
b Fatal flaw condition for Site 1.
As indicated in Table 8-6, fatal flaw conditions were identified for Site 1 (due to both parcel size and
proximity to a drinking water well) and Site 3 (due to parcel size). These two sites were removed
from further analysis.
8-8
Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
8.6 Weighted Analysis
The weighted analysis is presented in Table 8-7.
Table 8-7. Alternatives Analysis – Weighted Scoring
Site Weighted Score Category Criteria 1 2 3 4 5 6 7 8 9
Presence of and/or proximity to archaeological/cultural sites 0.25 0.75 0.75 0.75 1.00 0.75 0.75
Proximity of treatment units to existing occupied buildings 0.75 1.25 1.25 1.25 1.25 1.25 1.25
Prevailing wind direction 1.25 1.25 1.25 1.25 1.25 1.25 1.25 Environmental,
social and Biology 0.30 0.30 0.30 0.30 0.30 0.30 0.30
cultural Visual impact 0.15 0.25 0.25 0.25 0.15 0.15 0.15
Contamination from prior land use 0.05 0.05 0.15 0.15 0.15 0.15 0.15
Previously disturbed or developed 0.25 0.15 0.15 0.15 0.25 0.25 0.25
Parcel size a 1.25 1.25 1.25 1.25 1.25 1.25 1.25
Soils type 0.25 0.75 1.25 0.25 1.25 1.25 1.25
Topography 0.75 0.75 0.45 0.75 0.45 0.45 0.75
Proximity to water well b 0.50 0.30 0.50 0.50 0.50 0.50 0.50
Location and site Presence of lava tubes 0.08 0.24 0.24 0.24 0.24 0.24 0.24characteristics
Proximity to surface water, intermittent stream or coast line 0.30 0.30 0.18 0.30 0.30 0.18 0.30
Flood control / drainage 0.15 0.15 0.15 0.05 0.15 0.15 0.15
Existing vehicle access 0.15 0.06 0.06 0.15 0.15 0.15 0.06
Power and potable water availability 0.09 0.03 0.03 0.03 0.09 0.09 0.03
Distance from LCC collection area 2.50 1.50 1.50 1.00 2.50 2.00 1.50 Collection
system and Gravity flow possible or pumping required 1.50 1.50 0.30 0.30 1.50 1.50 1.50
service area Number of properties newly accessible 0.60 0.60 0.60 0.60 0.60 0.60 0.60
Current zoningand land use 1.35 1.35 1.35 1.35 1.35 1.35 1.35Land use and
availability Current ownership 2.75 1.65 2.75 2.75 2.20 2.20 2.20
Overall weighted totals (maximum possible = 5) FF 3.61 FF 3.76 3.76 3.46 4.33 4.06 4.10
a Fatal flaw condition for Sites 1 and 3.
b Fatal flaw condition for Site 1.
8-9
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Pahala Wastewater Treatment Plant Preliminary Engineering Report Section 8
8.7 Results
The results of the analysis are presented in Table 8-8. Two sites were identified as having fatal flaws
and the remaining seven were ranked in accordance with the overall weighted score.
Table8 8. AlternativeSiteRanking
Rank Site
1 7
2 9
3 8
4 5
5 4
6 2
7 6
FF 1
FF 3
The top three sites for the Pahala WWTP are:
1. Site 7 (TMK 9-6-002:18)
2. Site 9 (TMK 9-6-002:49)
3. Site 8 (TMK 9-6-002:21)
Site 7 is preferred to the second and third ranked sites for the following reasons:
• A preliminary Archaeological Inventory Survey has been performed for Site 7, indicating no
unmitigable cultural sites on the property.
• Site 8 is bisected by an intermittent stream bed, and a steep gulch borders the property to
the west.
• Site 7 is closer to the existing collection area than both Site 8 and Site 9.
• Power and potable water are more readily available to Site 7. Site 9 will require the utilities
to cross the highway.
8.8 Conclusion
Based on the analysis, Site 7 (TMK 9-6-002:18) was selected as the preferred location for the
Pahala WWTP.
8-10
References
CH2MHILL. Kau High School and Pahala Elementary School Connection to County Sewer. July 2017.
County of Hawaii. Letter to Community Homeowners, signed by Mayor Harry Kim. November 5, 2004.
Crites, Ron, and George Tchobanoglous. Small and Decentralized Wastewater Management Systems. WCB McGraw-
Hill, 1998.
Crites, Ronald W., E. Joe Middlebrooks, Robert K. Bastian, and Sherwood C. Reed. “Natural Wastewater Treatment
Systems, Second Edition”. CRC Press, 2014.
Crites, Ronald W., E. Joe Middlebrooks, Sherwood C. Reed. Natural Wastewater Treatment Systems. CRC Taylor &
Francis, 2006.
Crites, Ronald W., Sherwood C. Reed, and Robert K. Bastian. “Land Treatment Systems for Municipal and Industrial
Wastes”. McGraw-Hill, 2000.
Department of Planning, County of Hawaii. Kau Community Development Plan. October 2017.
Department of Wastewater Management, City and County of Honolulu, State of Hawaii. Design Standards of the
Department of Wastewater Management, Volume 1 and 2. July 2017.
Great Lakes – Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers.
Recommended Standards for Wastewater Facilities. 1997.
Hawaii Administrative Rules (HAR), Title 11, Department of Health Administrative Rules.
Masa Fujioka & Associates. Letter Report, Probing for Large Cavities (Lava Tubes), Naalehu and Pahala Large
Capacity Cesspool Sewerage System. January 9, 2007.
M&E Pacific, Inc. Kau Sewer System Evaluation, Kau, Island of Hawaii, Hawaii. December 2004.
Reed, Sherwood C., Ronald W. Crites, E. Joe Middlebrooks. Natural Systems for Waste Management and Treatment.
McGraw-Hill, Inc. 1995.
Rich, Linvil G. High Performance Aerated Lagoon Systems. American Academy of Environmental Engineers, 1999.
SSFM International, Inc. Final Preliminary Engineering Report for Naalehu and Pahala Large Capacity Cesspool
Conversion Projects, July 2007.
USEPA. “Process Design Manual, Land Treatment of Municipal Wastewater Effluents”. EPA/625/R-06/016.
September 2006.
Water Environment Federation. Wastewater Disinfection, Manual of Practice FD-10. Water Environment Federation,
1996.
Water Pollution Control Federation. Aeration, Manual of Practice FD-13. 1988.
White, George Clifford,Handbook of Chlorination and Alternative Disinfectants, John Wiley & Sons Inc., New York,
1999.
9-1
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Pahala Wastewater Treatment Plant Preliminary Engineering Report
Appendix A: Cost Estimates
A-1
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County of Hawaii Department of Environmental Management
Pahala WWTP
Preliminary Design - Order of Magnitude Construction Cost
Electrical and instrumentation
Headworks
Odor Control
Lagoons
Wetland
Land Application
On-site improvements
Off-site improvements
Total Estimated Construction Cost
$ 1,976,000
$ 906,000
$ 412,000
$ 2,222,000
$ 611,000
$ 925,000
$ 6,325,000
$ 1,223,000
$ 14,600,000
Description Quantity Units Unit Cost Extension
Clear and grub
BMP's
Archaeological Monitoring
Earthwork
Sewerline extension
Operations building
Generator and tank
Fencing
Paving
Off-site waterline
On-site waterline
On-site fireline
Off-site overhead electrical
Trees (landscaping & Irrigation)
Headworks
Odor control unit
Lagoons
Constructed Wetland
Chlorine contact tank
Chlorine feed system
Land Application piping
Land Application trees/ground cover
Effluent flow meter and sampler
18.0
18.0
18
52,000
700
1,500
1
3,200
38,000
2,500
900
750
1
10
1
1
1
1
1
1
2,700
5.5
1
AC
AC
AC
CY
LF
SF
LS
LF
SY
LF
LF
LF
LS
EA
EA
EA
LS
LS
LS
LS
LF
AC
LS
$5,995
$13,080
$2,507
$25
$218
$500
$250,000
$164
$55
$327
$164
$218
$50,000
$2,500
$501,339
$329,797
$1,816,902
$489,000
$150,000
$26,577
$125
$5,000
$154,780
$107,910
$235,440
$45,126
$1,300,000
$152,600
$750,000
$250,000
$523,200
$2,071,000
$817,500
$147,150
$163,500
$50,000
$25,000
$501,339
$329,797
$1,816,902
$489,000
$150,000
$26,577
$337,500
$27,500
$154,780
Subtotal
On-site electrical 15%
Mobilization/Demoblization 1.0%
$10,472,000
$1,570,800
$104,720
Total
Contingency 20%
$12,148,000
$2,430,000
TOTAL ORDER OF MAGNITUDE CONSTRUCTION COST $14,600,000.00
A-2
A-3
A-4County of Hawaii Department of Environmental Management Pahala WWTP Options Assessment Cost Summary Capital Costs Option No. Treatment Disposal Recycling Capital Cost ($M) Total ($M)Lagoons R-1 Limit of TT Disposal Reservoir Diurnal Tank R-1 Pumps R-1 Pipelines 1 2 3 4 5 Aerated lagoons/wetland/disinfection MBR (R-1) MBR (R-1) MBR (R-1) Limit of treatment technology Land application Land application Land application Land application Land application None None Seasonal (25% of total annual flow) Annual storage reservoir (100% of flow) Seasonal (25% of total annual flow) 10.8 14.6 14.6 14.6 20.4 3.8 3.8 3.8 3.8 3.8 6.1 0.8 3.5 0.8 0.5 1.0 0.5 0.5 1.5 0.5 14.6 18.4 20.2 30.4 26.0 Annual O&M Costs No. Treatment Disposal Recycling Annual O&M Costs ($) Labor Electricity Chemicals Maintenance Sludge Mgmt Total 1 2 3 4 5 Aerated lagoons/wetland/disinfection MBR (R-1) MBR (R-1) MBR (R-1) Limit of treatment technology Land application Land application Land application Land application Land application None None Seasonal (25% of total annual flow) Annual storage reservoir (100% of flow) Seasonal (25% of total annual flow) $42,000 $582,000 $582,000 $582,000 $874,000 $118,000 $345,000 $348,000 $356,000 $348,000 $12,000 $10,000 $10,000 $10,000 $35,000 $54,000 $73,000 $73,000 $73,000 $102,000 $10,000 $42,000 $42,000 $42,000 $62,000 $236,000 $1,052,000 $1,055,000 $1,063,000 $1,421,000 Annual Recycled Water Sales No. Treatment Disposal Recycling Annual R-1 Water Sales High Price Low Price 1 2 3 4 5 Aerated lagoons/wetland/disinfection MBR (R-1) MBR (R-1) MBR (R-1) Limit of treatment technology Land application Land application Land application Land application Land application None None Seasonal (25% of total annual flow) Annual storage reservoir (100% of flow) Seasonal (25% of total annual flow) $0 $0 $17,000 $68,000 $17,000 $0 $0 $9,000 $38,000 $9,000 Equipment Replacement at 20-Years No. Treatment Disposal Recycling Equipment Replacement 1 2 3 4 5 Aerated lagoons/wetland/disinfection MBR (R-1) MBR (R-1) MBR (R-1) Limit of treatment technology Land application Land application Land application Land application Land application None None Seasonal (25% of total annual flow) Annual storage reservoir (100% of flow) Seasonal (25% of total annual flow) $2,693,000 $3,653,000 $3,653,000 $3,653,000 $5,097,000
County of Hawaii Department of Environmental Management
Pahala WWTP
Preliminary Options Assessment - Capital Costs
Common Capital Inputs
Current ENRCCI:
Area markup factor:
Contingency factor:
Project soft costs factor:
10870
30%
20%
25%
Lagoon-Wetland Treatment
Description Quantity Units Unit Cost Extension
Clear and grub 8 AC $15,000 $120,000
BMPs 8 AC $13,000 $104,000
Earthwork 9,500 CY $25 $237,500
Sewer extension 700 LF $160 $112,000
Headworks 1 EA $500,000 $500,000
Lagoons 1 LS $1,800,000 $1,800,000
Wetlands 1 LS $350,000 $350,000
Chlorine contact tank 1 LS $100,000 $100,000
Chlorine feed system 1 LS $30,000 $30,000
Operations building 1,500 SF $500 $750,000
Generator and tank 1 LS $250,000 $250,000
Fencing 1,500 LF $100 $150,000
Paving 15,000 SY $55 $825,000
Water line extension 1,500 LF $160 $240,000
Yard piping 1 LS $200,000 $200,000
Miscellaneous site work 1 LS 100,000 $100,000
HELCO power 1 LS 50,000 $50,000
Hawaiian Telcom 1 LS 20,000 $20,000
Archeological monitoring 8 AC 2,500 $20,000
Visual buffer trees and irrigation 10 EA 2,500 $25,000
Subtotal
Electrical and instrumentation
Total construction
Contingency
Total construction
Project soft costs
Total project cost:
20%
$5,983,500
$1,196,700
$7,180,200
$1,436,040
$8,616,240
$2,154,060
$10.770 million
Land Application
Description Quantity Units Unit Cost Extension
Clear and grub
BMPs
Earthwork
Fencing
Paving
Yard piping
Planting
Effluent flow meter and sampler
Archeological monitoring
6
6
33,500
1,700
23,000
3,500
6
1
6
AC
AC
CY
LF
SY
LF
AC
LS
AC
$15,000
$13,000
$25
$100
$30
$160
10,000
50,000
2,500
$82,500
$71,500
$837,500
$170,000
$690,000
$560,000
$60,000
$50,000
$15,000
Subtotal $2,536,500
Electrical and instrumentation 0% $0
Total construction $2,536,500
Contingency $507,300
Total construction $3,043,800
Project soft costs $760,950
Total project cost: $3.805 million
A-5
R-1 Treatment
Capacity: 0.19 mgd
Mainland cost at current ENRCCI: $39.44 /gpd
Local construction cost: $51.27 /gpd
Construction estimate: $9.7 million
Contingency: $1.9 million
Total construction cost: $11.7 million
Project soft costs: $2.9 million
Total project cost: $14.6 million
Limit of Treatment Technology
ENRCCI of estimate: 8952
10 mgd WWTP cost: $13.80 /gpd
10 mgd WWTP cost at current ENRCCI: $16.76 /gpd
Local 10 mgd WWTP cost: $21.78 /gpd
Small flow escalation: $71.54 /gpd
Construction estimate: $13.6 million
Contingency: $2.7 million
Total construction cost: $16.3 million
Project soft costs: $4.1 million
Total project cost: $20.4 million
Seasonal Storage Reservoir
Volume: 124 ac-ft
Mainland construction cost: $25,000 /ac-ft
Subtotal: $3.1 million
Local construction cost: $4.0 million
Contingency: $0.8 million
Total construction cost: $4.8 million
Project soft costs: $1.2 million
Total project cost: $6.1 million
Diurnal R-1 Tank - Seasonal Program
Volume: 0.19 mgal
Local construction cost: $3.00 /gallon
Subtotal: $0.6 million
Contingency: $0.1 million
Total construction cost: $0.7 million
Project soft costs: $0.1 million
Total project cost: $0.8 million
Diurnal R-1 Tank - Reservoir Program
Volume: 0.77 mgal
Local construction cost: $3.00 /gallon
Subtotal: $2.3 million
Contingency: $0.5 million
Total construction cost: $2.8 million
Project soft costs: $0.69 million
Total project cost: $3.5 million
from R-1 WWRF capital regression. y=24.003*(x^-0.299)
y=43.47x^-0.3 Per WERF analysis. BNR + advanced nutrient removal
1 peak day
1 peak day
A-6
R-1 Delivery Pumps - Seasonal Program
Peak day flow
Delivery time:
Pumping capacity:
Mainland construction cost @ ENRCCI 4500:
Current mainland construction cost:
Local construction cost:
Contingency:
Total construction cost:
Project soft costs:
Total project cost:
R-1 Delivery Pumps - Reservoir Storage
Peak day flow
Delivery time:
Pumping capacity:
Mainland construction cost @ ENRCCI 4500:
Current mainland construction cost:
Local construction cost:
Contingency:
Total construction cost:
Project soft costs:
Total project cost:
R-1 Pipelines - Seasonal Program
Peak delivery rate:
Pipeline diameter:
Hawaii construction cost:
Estimated length:
Local construction cost:
Contingency:
Total construction cost:
Project soft costs:
Total project cost:
R-1 Pipelines - Reservoir Storage
Peak delivery rate:
Pipeline diameter:
Hawaii construction cost:
Estimated length:
Local construction cost:
Contingency:
Total construction cost:
Project soft costs:
Total project cost:
0.19 mgal
8 hours
396 gpm
$100,000
$242,000
$315,000
$63,000
$378,000
$94,500
$0.5 million
0.77 mgal
8 hours
1604 gpm
$200,000
$483,000
$628,000
$125,600
$753,600
$188,400
$1.0 million
396 gpm
6
$25
2000
inches
/in-ft
feet
$300,000
$60,000
$360,000
$90,000
$0.5 million
1604 gpm
10
$25
4000
inches
/in-ft
feet
$1,000,000
$200,000
$1,200,000
$300,000
$1.5 million
A-7
County of Hawaii Department of Environmental Management
Pahala WWTP
Preliminary Options Assessment
O&M Costs
Common O&M Inputs
Labor cost: $100
1,560
$4
$2
$0.35
2%
$1,500
/hr (loaded)
FTE effective labor: hours/year
Chlorine tab cost: /lb
Alum cost: /lb
Electricity cost: /kWh
Maintenance cost: /year of equipment capital
Sludge management cost: /dry ton, dewatering, hauling, tip fee
Average flow: 0.19 mgd
Lagoon Treatment/Wetlands/Disinfection
Labor
Normal requirement: 1
1
8
visit/week
Operators/visit:
Time per visit: hours/visit
Weekly labor hours: 8 hours/week
Annual labor hours: 416 hours/year
FTEs: 0.3 FTEs
Annual labor cost: $41,600 /yr
Electricity
Load Equiv hp Percent kWhr/mo $/month
Aerators
Screens
Chlorine pumps
Effluent pumps
50
2
0.5
2
100%
10%
30%
100%
26,845
107
81
1,074
$9,396
$38
$28
$376
Totals $9,837
Annual power cost: $118,049
Annual power consumption: 337283 kWh/yr
Chemicals
Chlorine dose: 5 mg/L
Daily use: 8 lbs/d
Annual use: 2892 lbs/d
Annual cost: $11,568 /yr
Maintenance
Equipment cost: $2,692,575 (assume 25% of capital cost)
Annual maintenance: $53,852 /yr
Sludge Management
Production rate: 0.1 dry tons/mgal
Annual production: 6.935 /dry tons
Sludge management cost: $10,403 /year (deferred for 20 years)
R-1 Treatment
Labor
Normal requirement: 7
2
8
visits/week
Operators/visit:
Time per visit: hours/visit
Weekly labor hours: 112 hours/week
Annual labor hours: 5824 hours/year
FTEs: 3.7 FTEs
Annual labor cost: $582,400
A-8
Electricity
Daily power use: 2,700 kWh/d
Annual power use: 985,500 kWh/yr
Annual power cost: $344,925 /yr
Chemicals
Annual chemical cost: $10,000
Maintenance
Equipment cost: $3,652,973 (assume 25% of capital cost)
Annual maintenance: $73,059 /yr
Sludge Management
Sludge production: 0.4 dry tons/mgal
Annual production: 28 /dry tons
Sludge management cost: $41,610 /year
Limit of Treatment Technology
Labor
Normal requirement: 7
3
8
visits/week
Operators/visit:
Time per visit: hours/visit
Weekly labor hours:
Annual labor hours:
FTEs:
Annual labor cost:
168 hours/week
8736 hours/year
5.6 FTEs
$873,600
Electricity
Daily power use:
Annual power use:
Annual power cost:
2,700 kWh/d
985,500 kWh/yr
$344,925 /yr
Chemicals
Alum dose
Alum use:
Alum cost:
30 mg/L
48 lbs/d
$34,703 /yr
Maintenance
Equipment cost:
Annual maintenance:
$5,097,397 (assume 25% of capital cost)
$101,948 /yr
Sludge Management
Sludge production:
Annual production:
Sludge management cost:
0.6 dry tons/mgal
42 /dry tons
$62,415 /year
Seasonal Water Recycling (25%)
Load Equiv hp Percent kWhr/mo $/month
R-1 delivery pumps 5 25% 671 $235
Totals $235
Annual power cost: $2,819
Annual power consumption: 8054 kWh/yr
Annual Water Recycling (100%)
Load Equiv hp Percent kWhr/mo $/month
R-1 delivery pumps 5 100% 2,685 $940
Totals $940
Annual power cost: $11,275
Annual power consumption: 32214 kWh/yr
A-9
County of Hawaii Department of Environmental Management
Pahala WWTP
R-1 Sales Assessment
Avoided Cost of Pumping Irrigation Water
Assume pumping from basal lens
Elevation at WWTP: feet MSL
Flow rate: gpm
750
1000
2.2 cfs
Pump efficiency:
Motor efficiency:
85%
90%
Power cost: $0.35 /kWh
BHP: 223 hp
Motor draw: 185 kW
Unit volume: 1 mgal
Time to pump unit vol: 16.7 hours
Power to pump unit vol: 3080 kWh
Cost to pump unit vol: $1,078
Recycled Water Pricing
High price: 90%
50%
of avoided cost
Low price: of avoided cost
Recycled Water Sales
High price:
Low price:
$970 /mgal
$539 /mgal
Seasonal Recycling Sales
Annual reuse volume:
High price sales:
Low price sales:
17 mgal
$16,661 /year
$9,256 /year
100% Recycling Sales
Annual reuse volume:
High price sales:
Low price sales:
70 mgal
$67,987 /year
$37,770 /year
A-10
A-11County of Hawaii, DEM Pahala WWTP Options Assessment Alternatives Net Present Value Analysis County of Hawaii, DEM Sensitivity Adjustments (%) Results Risk Capital Other 30-year Benefit over Benefits Capital Cost Pahala WWTP Options Assessment Premium Costs Costs NPV Status Quo Lagoons / wetlands/ disinfection / land application $14,600,000 ($21,196,947) R-1 treatment / land application $18,400,000 ($42,993,152) ($21,796,205) R-1 treatment / seasonal recycling (25%) $20,200,000 ($44,496,467) ($23,299,520) R-1 treatment / annual storage res (100%) $30,400,000 ($53,785,222) ($32,588,276) Limit of treatment technology / 25% recycle $26,000,000 ($58,961,593) ($37,764,647) Select one 2017 Note: "Status quo" refers to All entries in dollars 3.20% Alternative 1 All entries in thousands of dollars 5.50% Make entries in yellow cells only Agency: Project/Problem: Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6 Alternative 7 Alternative 8 Alternative 9 Alternative 10 Alternative 11 Alternative 12 Year of analysis: Escalation rate: Discount rate:
County of Hawaii Department of Environmental Management
Pahala WWTP
Preliminary Options Assessment
Operator Requirement Evaluation
No. Treatment Disposal Recycling
1
2
3
4
5
Aerated lagoons/disinfection
MBR (R-1)
MBR (R-1)
MBR (R-1)
Limit of treatment technology
Land application
Land application
Land application
Land application
Land application
None
None
Seasonal (25% of total annual flow)
Annual storage reservoir (100% of flow)
Seasonal (25% of total annual flow)
Criteria per HAR 11-61
Option
1 2 3 4 5
Population served 1 1 1 1 1
Design average flow 1 1 1 1 1
Effluent discharge 2 2 6 6 6
Variation on raw wastes 0 0 0 0 0
Pretreatment 5 10 10 10 10
Primary treatment 0 0 0 0 0
Secondary treatment 8 15 15 15 20
Advanced waste treatment 0 12 12 12 22
Additional treatment processes 7 7 7 7 7
Solids handling 0 19 19 19 19
Disinfection 5 10 10 10 10
Laboratory control bacteriological 0 0 0 0 0
Laboratory control chemical/physical 0 0 0 0 0
Total points 29 77 81 81 96
WWTP Classification per 11-61 I IV IV IV IV
A-12
County of Hawaii Department of Environmental Management Pahala WWTP Water Recycling Assessments Seasonal Recycling with Disposal Average flow: 0.19 mgd Irrigated acreage: 62 acres Month Days WW Flow (mgal) Irrig Demand Disposal (mgal)(gpd/ac) (mgal) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 31 28 31 30 31 30 31 31 30 31 30 31 5.9 5.3 5.9 5.7 5.9 5.7 5.9 5.9 5.7 5.9 5.7 5.9 0 0 0 644 2,244 3,043 1,348 1,452 334 0 0 0 0.0 0.0 0.0 1.2 4.3 5.7 2.6 2.8 0.6 0.0 0.0 0.0 5.9 5.3 5.9 4.5 1.6 0.0 3.3 3.1 5.1 5.9 5.7 5.9 Totals 365 69.35 17 52 A-13Recycling efficiency: 25% Recycling with Annual Storage Reservoir Average flow: 0.19 mgd Irrigated acreage: 253 6.4 0.7 acres Reservoir surface area: acres Reservoir pan coefficient: Reservoir Storage WW Flow Irrig Demand WW in Precipitation in Pan Evap Evap out Delta Storage Cumulative Storage Water Depth Month Days (mgal) (gpd/ac) (mgal) (mgal) (inches) (mgal) (inches) Inches (mgal) (mgal) (mgal) (ac-ft) (feet) Jan 31 5.9 0 0.0 5.9 5.98 1.0 4.55 3.2 0.6 6.4 28.1 86.3 13.5 Feb 28 5.3 0 0.0 5.3 3.77 0.7 4.54 3.2 0.6 5.4 33.5 102.9 16.1 Mar 31 5.9 0 0.0 5.9 5.45 0.9 4.97 3.5 0.6 6.2 39.8 122.0 19.1 Apr 30 5.7 644 4.9 0.8 3.23 0.6 5.4 3.8 0.7 0.7 40.5 124.2 19.4 May 31 5.9 2244 17.6 -11.7 1.94 0.3 5.6 3.9 0.7 -12.1 28.4 87.3 13.6 Jun 30 5.7 3043 23.1 -17.4 1.56 0.3 5.94 4.2 0.7 -17.8 10.6 32.5 5.1 Jul 31 5.9 1348 10.6 -4.7 3.27 0.6 6.37 4.5 0.8 -4.9 5.7 17.5 2.7 Aug 31 5.9 1452 11.4 -5.5 3.08 0.5 6.23 4.4 0.8 -5.7 0.0 0.0 0.0 Sep 30 5.7 334 2.5 3.2 3.6 0.6 5.55 3.9 0.7 3.1 3.1 9.6 1.5 Oct 31 5.9 0 0.0 5.9 3.98 0.7 5.05 3.5 0.6 6.0 9.1 27.9 4.4 Nov 30 5.7 0 0.0 5.7 6.7 1.2 4.49 3.1 0.5 6.3 15.4 47.3 7.4 Dec 31 5.9 0 0.0 5.9 5.82 1.0 4.62 3.2 0.6 6.3 21.7 66.7 10.4 Totals 365 69.35 70 48.4 8.4 63.3 7.7 0.0 Recycling efficiency: 101% Max Volume: 40 Mgal 124 ac ft Peak demand: 23.1 mgal/mo 0.77 mgd
District, Hawai‘i
September 2018
THIS PAGE INTENTIONALLY LEFT BLANK
District, Hawai‘i
September 2018
Appendix C
August 2018 Biological Survey Report
AECOS
Biological survey for the P hala Community
Large Capacity Cesspool Closure Project on lot
TMK: 96 002:018, Ka‘ District, Hawai i Island
AECOS,
Biological survey for the P hala Community
Large Capacity Cesspool Closure Project on lot
TMK: 96 002:018, Ka‘ District, Hawai i Island
Draft AECOS
Macadamia integrifolia
AECOS
AECOS
Megathyrsus maximus
Manual of the Flowering Plants of Hawai‘i
Hawai‘i’s Ferns and Fern Allies
A Tropical Garden Flora
AECOS
AOU Check List of North American Birds
Lasiurus cinereus
semotus ‘pe‘ape‘a
Synedrella
nodiflora
Grevelia
robustaMelaleuca quinquenervia
AECOS
‘uhaloa Waltheria indica
koali ‘awa Ipomoea indica
Nephrolepis multiflora
Pityrogramma calomelanos
Araucaria columnaris
Amaranthus spinosus
Carissa macrocarpa
Nerium oleander
Schefflera actinophylla
Ageratum conyzoides maile hohono
AECOS
Bidens pilosa ki
Calyptocarpus vialis
Conyza bonariensis
Crassocephalum crepidioides
Cyanthillium cinereum
Lactuca serriola
Synedrella nodiflora
Anredera cordifolia
Lepidium virginicum
Cleome gynandra
Ipomoea indica koali ‘awa Ind
Ipomoea obscura
Merremia tuberosa
Momordica charantia
Euphorbia heterophylla kaliko
Euphorbia hirta
Ricinus communis
Acacia confusa koa
Leucaena leucocephala koa haole
Macroptilium atropurpureum
Neonotonia wightii
Leonotis nepetifolia
Abutilon grandifolium
Malvastrum coromandelianum
Sida rhombifolia
AECOS
Sida spinosa
Waltheria indica ‘uhaloa Ind
Ficus microcarpa
Melaleuca quinquenervia
Syzygium cumini
Rivina humilis
Grevillea robusta
Macadamia integrifolia
Spermacoce assurgens
Commelina benghalensis honohono
Cyperus gracilis
Axonopus compressus
Cenchrus purpureus
Chloris barbata
Digiteria sp.
Eleusine indica
Megathyrsus maximus
Setaria verticillata
Ind
AECOS
Cardinalis cardinalis
Zosterops japonicus Ceithagra mozambica
Leiothrix lutea
ST RA
AECOS
ST RA
ST
RA
Sus scrofa
AECOS
‘uhaloa koali ‘awa
Justicia betonica
Araucaria columnaris
Pterodroma sandwichensis Puffinus newelli
AECOS
e
Mus musculus domesticus Rattus rattus
Rattus norvegicus Rattus exulans hawaiiensis
AECOS
Evolution, Ecology, Conservation, and Management of Hawaiian Birds: A
Vanishing Avifauna. Studies in Avian Biology No. 22
Check list of North American Birds
Check list of North American Birds The Auk
AECOS
. The Auk,
The
Auk,
The Auk,
The Auk,
The Auk
The Auk
The Auk
The Auk
The Auk
The Auk
AECOS
The Auk
The Auk
The Auk, Ornithological
Advances
The Auk, Ornithological Advances
The Auk,
Ornithological Advances
The Auk, Ornithological Advances
The Auk,
Ornithological Advances
Colonial Waterbirds
Colonial
Waterbirds
AECOS
Puffinus auricularis newelli The Auk,
Elepaio
in:
Evolution, Ecology, Conservation, and
Management of Hawaiian Birds: A Vanishing Avifauna
Bishop Museum Tech. Rept
Hawai`i’s Ferns and Fern Allies
AECOS
Colonial Waterbirds
The Auk
Pterodroma
phaeopygia In:
A Tropical Garden Flora. Plants Cultivated
in the Hawaiian Islands and other Tropical Places.
‘Elepaio
Wildlife Soc. Bull
.
AECOS
Manual of the Flowering
Plants of Hawai‘i: Volume I and II
Supplement to the Manual of the flowering plants of
Hawai‘i In:
AECOS
District, Hawai‘i
September 2018
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