HomeMy WebLinkAbout2021-09-22 EMC testimony - (09-19) - Demoruelle, Sandra - DEM July 23, 2021 Correspondence to EPA Attachment AMitchell D. Roth
Mayor
Lee Lord
Managing Director
County of Hawaii
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
345 Kekuanao'a Street, Suite 41 • Hilo, Hawai'i 96720
Ph: (808) 961-8083 • Fax: (808) 961-8086
Email: cohdem@hawaiicounty.gov
Attachment A
July 23, 2021
Mr. Jelani Shareem
EPA Region 9 Compliance Officer
75 Hawthorne Street
San Francisco, CA 94105-3901
(Via E-mail: shareem.jelani(a�epa.gov)
Ms. Kate Rao
EPA Region 9 LCC Project Coordinator
75 Hawthorne Street
San Francisco, CA 94105-3901
(Via E-mail: rao.katcLepa. oovv)
SUBJECT: Wastewater Treatment Plant - Design
Federal Administrative Order on Consent
EPA Docket No. SDWA-UIC-AOC-2017-0002
Pahala Large Capacity Cesspools (LCC)
Dear Mr. Shareem and Ms. Rao:
Ramzi I. Mansour
Director
Brenda lokepa-Moses
Deputy Director
The County of Hawaii Department of Environmental Management (County) is revisiting the
intended treatment processes at the Pahala Wastewater Treatment Plant (WWTP) from the
aerated lagoons and constructed wetland outlined in the preliminary engineering report (PER)
to a mechanical secondary treatment process. This report is intended to provide a preliminary
overview of the proposed changes and an initial comparison of environmental impacts to those
presented in the project's final environmental assessment (FEA) for discussion with the United
States Environmental Protection Agency Region 9 (EPA). This report is not intended or
adequate to file with the Office of Environmental Quality Control (OEQC) to support filing a
notice of determination in accordance with Hawaii Administrative Rules (HAR) 11-200.1.
Additional assessment effort will be required to support an OEQC filing.
Project History
On March 8, 2020, the Joint Final Environmental Assessment/Finding of No Significant
Impact (FEA/FONSI) for the Pahala Large Capacity Cesspool (LCC) Replacement Project
(EPA Grant XP-96942401) was published in the Office of Environmental Quality Control The
Mr. Jelani Shareem
Ms. Kate Rao
July 23, 2021
Environmental Notice. The FEA stated the purpose of the project was to provide an industry -
standard wastewater collection system and a secondary treatment and disposal facility and to
eliminate underground injection from large capacity cesspools (LCCs) operated by the County
to help protect underground drinking water sources. Further, the FEA indicated a new sewer
collection system would be constructed in the Pahala community and would replace the
existing system of substandard gravity lines that convey sewage to the two LCCs and connect
it to the proposed wastewater treatment and disposal facility. The new collection system
would be routed almost entirely within the public right of way (ROW) of eight public streets
in the Pahala community.
The Pahala LCC Replacement project was awarded a U.S. Environmental Protection Agency
(EPA) Special Appropriations Act Project (SAAP) grant. The FEA stated the project may also
be funded by the State of Hawaii Department of Health (DOH) Clean Water State Revolving
Fund (CWSRF) Program. Under the CWSRF program, the project consists of two parts: Pahala
Large Capacity Cesspool Conversion and Pahala Wastewater Collection System. The Pahala
LCC Replacement Project will be constructed by the County of Hawaii Department of
Environmental Management (DEM) using County funds.
Need for Change
Topographic survey information obtained after PER development has escalated the
construction cost for the aerated lagoons. More significantly, geophysical and geotechnical
investigations have identified and confirmed the presence of a potential network of lava tubes
under the intended WWTP location and identified a large void below one of the four lagoons.
With cultural resources known to exist in lava tubes elsewhere in Pahala, the lava tubes create
schedule and cost risks to the County project by introducing both unknown construction and
cultural mitigation measures to the construction project. In response, the County desires to
change the WWTP process to one that will reduce theseproject risks and provide similar or
greater benefits to the community while maintaining or reducing the environmental impacts of
the intended project.
Hawaii Administrative Rules §11-200 Considerations
Chapter 343, HRS establishes a system of environmental review at the state and county levels
which ensure that environmental concerns are given appropriate consideration in decision
making along with economic and technical considerations. HAR 11-200.1 Environmental
Impact Statement rules require state and local governmental agencies under -taking projects
utilizing state or county lands or funds to consider the potential environmental impacts of a
proposed project by preparing environmental review documentation.
HAR § 11-200.1-11 establishes rules for using a prior FONSI to satisfy Chapter 343
requirements:
§ 11-200.1-11 Use of prior exemptions, findings of no significant impact, or accepted
environmental impact statements to satisfy chapter 343, HRS, for proposed actions.
(a) When an agency is considering whether a prior exemption, FONSI, or an accepted EIS
satisfies Chapter 343, HRS, for a proposed action, the agency may determine that
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Mr. Jelani Shareem
Ms. Kate Rao
July 23, 2021
additional environmental review is not required because:
(1) The proposed action was a component of, or is substantially similar to, an action that
received an exemption, FONSI, or an accepted EIS (for example, a project that was
analyzed in a program EIS);
(2) The proposed action is anticipated to have direct, indirect, and cumulative effects similar
to those analyzed in a prior exemption, final EA, or accepted EIS; and
(3) In the case of a final EA or an accepted EIS, the proposed action was analyzed within
the range of alternatives.
(b) When an agency determines that a prior exemption, FONSI, or an accepted EIS satisfies
Chapter 343, HRS, for a proposed action, the agency may submit a brief written
determination explaining its rationale to the office for publication pursuant to section 1I-
200.1-4 and the proposed action may proceed without further chapter 343, HRS,
environmental review.
Summary of Project Changes
Project changes are briefly described below. A site plan for the project is attached which reflects
the proposed changes.
Project elements that will remain the same
The following is a discussion of project elements that will remain the same as outlined in the
FEA.
1. Collection system: The collection system will remain unchanged.
2. Large capacity cesspool (LCC) closure: The two LCCs will be closed as described in the
FEA.
3. WWTP site: The WWTP will be located on the same ±14.9-acre parcel. The location of the
WWTP process area will remain in the north corner of the parcel.
4. Capacity: The WWTP will be designed to provide the same capacity as described in the
FEA; however, see below for discussion of a phased implementation approach.
5. Effluent quality: The mechanical treatment processes will be designed to provide similar or
better effluent quality as the aerated lagoons and subsurface flow constructed wetland.
Specifically, 5-day biochemical oxygen demand (BODS) and total suspended solids (TSS)
will be 30 milligrams per liter (mg/L) or better, total nitrogen will be less than 10 mg/L.
The preferred MBR process will produce effluent of the highest quality, and in addition to
the above will consistently provide effluent turbidity values of less than 2 nephelometric
turbidity units (NTU).
6. Effluent disposal method: Effluent disposal will be accomplished via slow rate land
treatment within the ±14.9-acre parcel as described in the FEA. However, see below for
changes to the intended effluent distribution method and trees within the slow rate land
treatment system.
7. Emergency power: An emergency generator and bulk fuel tank will be provided as
described in the FEA.
8. Utility building: The WWTP will have a building to house the electrical and other
necessary systems as described in the FEA.
Project Elements that will Change
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Mr. Jelani Shareem
Ms. Kate Rao
July 23, 2021
The proposed approach will include the following minor changes.
1. Phased capacity implementation: The mechanical treatment approach will allow a phased
capacity implementation approach to reduce the initial capital cost. The initial capacity will
be sufficient to provide service to the developed parcels within the service area, and a
modest amount of growth. The initial WWTP capacity needs will be developed using
historic potable water use data from the developed parcels. The WWTP will be designed to
be readily expandable to the full capacity as described in the FEA (i.e., 190,000 gallons per
day average dry weather flow) when needed to accommodate additional community
connection or growth.
2. Preliminary treatment: Preliminary treatment within a headworks will be needed upstream of
the mechanical treatment processes, an additional grit removal process that is not required
upstream of aerated lagoons. The proposed headworks will have one fewer automatic screen
than described in the FEA to compensate for the footprint added by the grit removal process.
3. Secondary treatment: As described above, the preferred MBR process will produce a higher
quality effluent than the aerated lagoon/subsurface flow constructed wetland process
described in the FEA. A mechanical plant will have a significantly smaller footprint than
the aerated lagoon/subsurface flow constructed wetland, requiring less site footprint than
one of the aerated lagoons. The tanks will also be shallower than the aerated lagoons,
requiring less excavation. The net benefit of the change is significantly reduced risk of
construction delays and costs associated with subsurface voids and cultural resources that
may be contained within. In addition, it will allow more of the site to be used for effluent
disposal purposes. Mechanical treatment technology was evaluated in the PER for the
project, which was included in the final EA as an appendix.
4. Effluent disposal: While the method of effluent disposal will remain as slow rate land
treatment, the application method and intended vegetation will change. Subsurface drip
irrigation will be used to apply water to the existing macadamia nut orchard, rather than
grading the site into basins for surface irrigation of native trees. The benefit of this change
is significant reduction of the number of macadamia nut trees that will require removal for
the project, and significantly less ground disturbance as a result of the reduced need for
grading at the site.
Preliminary Comparison of Environmental Impact
Table 1 is a preliminary comparison of the environmental impacts of the proposed approach
compared to the project as defined in the FEA. As shown in the table, the minor project
changes are anticipated to result in reduced or similar environmental impacts to the project as
defined in the FEA, and no greater impacts. Additional environmental assessment will be
required to support a use of prior exemption filing with OEQC.
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Mr. Jelani Shareem
Ms. Kate Rao
July 23, 2021
Item
Fauna
FEA I Environmental Impact Comparison
Section
Less
Similar
Greater
3.1
✓
3.2
✓
3.3
✓
3.4
✓
3.5
✓
3.6
✓
3.7
✓
3.8
✓
3.9
✓
3.10
✓
3.11
✓
3.12
✓
3.13
✓
3.14
✓
3.15
✓
3.16
✓
3.17
✓
3.18
✓
3.19
✓
3.20
✓
3.21
✓
3.22
✓
3.23
✓
3.24
✓
4
✓
5
Notes
Reduced grading.
Reduced grading and excavation.
Significantly fewer macadamia nuttrees will be removed.
Reduced ground disturbance. Reduced clearing and grubbing
of existing macadamia nut trees.
Birds will not be attracted to the mechanical WWTP.
Reduced ground disturbance.
Reduced grading and excavation.
Mr. Jelani Shareem
Ms. Kate Rao
July 23, 2021
Final EA Alternatives
The FEA analyzed a total of three potential treatment and disposal site alternatives. The
proposed project will remain within the same 14.9-acre project site that the FEA ultimately
recommended as the preferred alternative.
HAR §11-200.1-11 Conclusions
Based on the above preliminary evaluations, we believe the proposed project changes will fit
within the provisions of HAR § 11-200.1-11 and a written determination for use of prior
exemption can be filed with OEQC to satisfy the HRS 343 environmental review requirements.
Additional effort will be required to prepare a more comprehensive justification for the OEQC
filing; this letter is a preliminary review only.
Section 7 Considerations
The FEA discussed the impacts on related species listed under the Endangered Species Act
(ESA). As required by Section 7 of the ESA, consultation was conducted with the US Fish and
Wildlife Service (FWS). At that time, there was concern that the lagoons and constructed
wetlands could attract various species of waterbirds, including the listed Hawaiian coot (Fulica
alai), the endemic subspecies of the Hawaiian stilt (Hinnantopus mexicanus knudseni), and
Hawaiian goose (Branta sandvicensis). The proposed treatment and disposal facility does not
include open lagoons and constructed wetlands. Thus, the potential impacts to the listed
waterbird species would no longer occur.
Section 106 Considerations
Since collection system work described in the FEA would remain with no changes, the findings
of the previous determination by the State Historic Preservation Division (SHPD) concurrence
to consultation under Section 106 of the National Historic Preservation Act would not change.
Similarly, the determination under Hawaii Revised Statutes Chapter 6E would remain with no
changes.
We hope that this information is helpful in explaining the County's current direction with this
Pahala LCC project. Please contact Eric Takamura (808) 961-8333
eric.takamurakhawaiicountygov or me at (808) 961-8099 ramzi.mansourkhawaiicounty.gov
should you have any questions.
Sincerely,
Ramzi Mansour, Director
CC: Brenda Iokepa-Moses, Deputy Director
Eric Takamura, Wastewater Division Deputy Chief
Malia Hall, Deputy Corporation Counsel
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