HomeMy WebLinkAboutCOM 0035.001 2000-2002 HM o~ Depu~CHietiEn~eer
County of Hawaii 'G~~ C~~ 2? Fl~l 9 ?9
DEPARTMENT OF PUBLIC WORKS ~
25 Aupum Street, Roan 202 • Hlo, Hawaii 867204252 ; ~ t' ~ I
(806) 881-0321• Fax (BOB) 981-8630
December 15, 2000 Memo OOLH-180
Thomas E Arizumi, P E.
Chief, Environmental Management Division
State of Hawaii -Department of Health
P.O Box 3378
Honolulu, Hawaii 96801
Subiect Kulaimano Wastewater Treatment Plant
Operation and Maintenance Inspection, Year 2000 - EMDIWB 200971
Deficiencies Resulting in Unacceptable Rating;
1 Sludge continues to be stored in the abandoned effluent polishing pond. The
County has not provided a closure plan acceptable to the Department
As noted under "Status of Past Deficiencies" in the 08M Report, the County of
Hawaii submitted a proposed closure plan dated March 24, 2000 to the
Department of Health and the Clean Water Branch subsequently requested
clarification on a number of items relating to the proposed closure plan via a
letter dated May 18, 2000 (05080ELS.00).
Please note that the O&M report incorrectly indicated that the County of Hawaii
has not responded to the letter from the Clean Water Branch requesting
clarification on a number of items. The County of Hawaii provided clarification via
a letter dated May 31, 2000 (see attached) The County has been awaiting a
response from the Department of Health regarding the proposed closure plan
from the Clean Water Branch before finalizing the closure plan.
The County will proceed with the Final Closure Plan erg nding recent of
recommendations from the Department of Health regarding final closure of the
Effluent Polishing Pond as roposed in our letter dated March 24. 2000.
2 Discharging of non-chlonnated effluent into State Waters in January 2000.
As noted under "NPDES Permit Non-Compliance" in the 08M Report, the
Kulaimano Wastewater Treatment Plant bypassed approximately 15,000 gallons
of non-chlorinated effluent into State Waters due to failure of the Effluent Pump
Comm. Na.
Ftle No. s~W
Ref. Tot DEML
Date ~ 2 q 2000
Memo OOLH-180, Kulaimano W WTP -Year 2000 0&M Response
Page 2 of 4
Although aback-up Effluent Pump is installed, the original design of the
Treatment Plant did not include a control system to provide automatic initiation of
the back-up pump in the event of failure of the "lead" pump
The County Of Hawaii is currently in the process of modifying the control system
for the Effluent Pumps to initiate automatic start-up of the °lag" pump in the event
of failure of the "lead" pump
T~et Completion for modification of the control system is February 2001.
3. Exceeding of the effluent total residual chlorine requirement during the past year.
As noted under "NPDES Permit Non-Compliance" in the O8M Report, the
Kulaimano Wastewater Treatment Plant exceeded the Total Residual Chlorine
limits on August 30, 2000 and September 2, 2000.
Upon becoming aware that Total Residual Chlorine limitations had been
exceeded, the County of Hawau initiated corrective actions which included
checking of the both the Chlorine and Sulfur Dioxide systems for equipment
failures. Due to the fact that no equipment failures were found, the Suffer
Dioxide feed rate was increased to ensure adequate dechlorination. Initial
testing indicated that increasing of the feed rate for the Sulfur Dioxide resulted in
Total Residual Chlorine levels within the limitations specified in the NPDES
permit.
Due to the unusual nature of the problem, additional Total Residual Chlorine
samples were taken to confirm that Total Residual Chlorine levels did not exceed
permit limitations. Upon diswvering that the Total Residual Chlonne levels again
exceeded the permit limitations; the County contacted the vendor regarding the
possibility that we were not achieving adequate dechlonnation due to problems
with the Sulfur Dioxide The vendor indicated that they had not received any
similar inquiries and had never encountered similar problems in the past.
However, the vendor concurred that since no egwpment problems had been
found, switching of the Sulfur Dioxide cylinders should be performed since the
possibility exists
Upon exchange of the Sulfur Dioxide cylinder the Sulfur Dioxide feed rate was
returned to normal feed rates and testing confirmed that Total Residual Chlonne
levels were within NPDES requirements.
Due to unavailability of the test kit, the original cylinder was returned to the
vendor for testing and analysis To date, the County has not received the results
of the test from the vendor although the County has contacted the vendor on
several occasions requesting results of the testing
Corrective action for this item is considered as completed since the violation was
a result of an item beyond the control of the Counq~ of Hawau.
Mena OOLH-180, Kulalmarro W WTP -Year 2000 08M Response
Pege 3 of 4
4. Inconsistent flow readings between the influent and effluent flowmeters.
As indicated under "Observations" of the 08~M Report, the average effluent flow
exceeded the influent flow on a consistent basis within the reporting period.
The County of Hawau has addressed the "area of concern" regarding the
possibility that return flows from the effluent pumps are creating turbulence within
the Chlorine Contact Tank which may be affecting effluent flow readings by
extending the return line below the free surface in order to minimize turbulence
However, with regard to effluent flows being higher than influent flows, the
County of Hawaii notes the following•
• The Kulaimano WWTP had an average influent flow of 0.066 MGD during the
reporting period
• The facility has approximately 5,335 square feet of exposed surfaces within
the treatment process As such, effluent flows would be increased by 3,325
gallons for each inch of rainfall. This would result in average effluent flows of
approximately five percent (5%) over influent flows for each inch of rainfall
• The facility utilizes an average of 40,000 gallons per month (1,333 gallons per
day) of potable water for wash down operations, etc. As such, an average
effluent flow increa:.a of approximately 2 percent (2%) over the influent flow is
introduced on a daily basis.
• The influent and effluent flow meters are calibrated on a regular basis in
accordance with Section 3.c of the Standard NPDES Permit Conditions
With regard to average effluent flows exceeding ten percent (10%) of the influent
flows on several occasions, the County of Hawaii agrees that Section 3.b of the
Standard NPDES Permit Conditions requires that the flow meters have an
accuracy of plus or minus ten percent (10%) of the actual flow However,
the County notes that, based on the required accuracy of 10 percent (10%)
for each flow meter, the maximum allowable difference between the influent and
effluent flow meters would be twenty percent (20%) under Section 3 b of the
Standard NPDES Permit Conditions
Modification of the effluent pip return line is comoleted•
Other Deficiencies/Recommendations noted during the inspection:
1 Repair of the Turbine Aerator No 1 has not been completed
As noted in the 1999 08M response, this item was deferred in order to allow
addressing of higher pnonty items at other sites In addition two (2) separate
aeration streams are provided Only one (1) aeration stream is normally utilized
since existing flows to be plant are less than 20 percent of the Design Average
Flow.
Memo OOLH-180, Kulaimano W WTP -Year 2000 06M Response
Page 4 of 4
Turbine Aerator No. 1 will be repaired pnor to plaang the inactive stream on line.
Target Completion date is June 2001.
2. The battery terminals for the emergency generator shows signs of corrosion.
Regular cleaning is necessary to maintain good contact and prevent a voltage
drop which may result in failure of the generator to start.
The battery terminals were cleaned.
Completed.
3. The effluent pump retu,n water line should be relocated away from the flow
sensor to minimize turbulence in the Chlorine Contact Tank.
This item was addressed under paragraph 4 of "Defiaencies Resulting in
Unacceptable Rating" and modification is completed.
Comfit`
Should there be any comments or questions on the above please contact Mr. Peter
Boucher, P.E., Wastewater Division Chief, at 808-961-8338 or correspondence may
be sent via facsimile to 808-961-8644.
Sincerely,
~J A. Su ada
D uty Ch' f Engineer
cc Wastewater Division
County Counal Public Works Chairperson
WASTEWATER DIVISION
Dgwenw ~fPubGe Werks Mailing Ad~aa 27 Aupoot Street, Rm 102
IOi Raihoad Avemae • }ido, Hawes 96720 Hilo, Hawaii 96720272
(i0i)l61-i77i -Fu (i0i) 961-5644
MAY 31, 2000
THOMAS E. ARIZUMI, P.E., CHIEF
ENVIRONMENTAL MANAGEMENT DIVISION
DEPARTMENT OF HEALTH
919 ALA MOANA BOULEVARD, ROOM 301
HONOLULU, HAWAII 96814-4920
Re. Kulaimano WWTP
NPDES Permit No. HI 0020770
The following is in response to your May 18, 2000 letter (05080ELS.OD) regarding the
referenced facility abandoned waste stabilization pond:
1. How does the County propose to dewater the pond?
The County proposes to utilize a portable pump and temporary force main to
dewater the pond
2. Where will the dewatering effluent be discharged?
The County proposes to discharge the dewatering effluent at the Kulaimano
WWTP for treatment and disposal.
3. Who will determine when the restrictions on-site use are no longer
necessary and what criteria will they use?
The County is working to determine whether the residual sludge proposed for
land application meets the "Class B" requirements pursuant to 40 CFR 503.32(b)
Thereby, the criteria to determine when the restriction on-site use are no longer -
required will be pursuant to 40CFR503.32(b)(5) or as directed by your office
The details for meeting the federal requirements are being prepared and will be
forwarded to your office
PETER J BOUCHER, P E
Chief, Wastewater Division
Memo OOLH-180
ATTACHtiENT