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Home My WebLink AboutCOM 0634.000 1998-2000 i o `~JM. M1k' ~i,: tip,: Stephen K. Yamashiro I': Mayor - Jiro A. Sumada ~~+~+r oi:N'1~ Deputy Chief Engineer ~uixntg of ~tt£trt~ii DEPARTMENT OF PUBLIC WORKS 25 Aupuni Street, Room 202 • Hilo, Hawaii 967244252 (808)961-8321 • Fax (808)961-8630 January 13, 2000 Memo 99Lhf~,')~3 C Thomas E. Arizumi, P.E. - ~ Chief, Environmental Management Division State Department of Health P.O. Box 3378 ~ Honolulu, Hawaii 96801 Subject: Kulaimano Wastewater Treatment Plant Operation and Maintenance Inspection - EMDNVB 991059 References: (a) Dept. of Health, Clean Water Branch Ltr. 11068EAT.99 dated November 24, 1999 (b) County of Hawaii Ltr. 99LH-126 dated December 14, 1999 The County of Hawaii Wastewater Division has received the annual Operation and Maintenance Inspection Report for the Kulaimano Wastewater Treatment Plant and provides the following corrective action plan to address the deficiencies cited in the report. NPDES or Chapter 62 Violations: 1. The effluent polishing pond has been abandoned in place since the mid-1980's and the pond still contains sewage sludge. The County of Hawaii is currently in the process of evaluating alternatives for accomplishing final closure of the existing Waste Stabilization Pond. The Clean Water Branch informed the County of Hawaii of the apparent violation via reference (a). Reference (b) requested an extension of sixty (60) days to complete the evaluation of alternatives and submission of a compliance schedule for final closure of the existing Waste Stabilization Pond. A field survey of the Waste Stabilization Pond including sludge sampling and determination of the depth of the existing sludge is currently scheduled for January 20, 2000. Comm. No. ~ -1 Rile No. ~~~ti~ Ref. To: ~ PC Ref. Date JAN 2 1 2lDOQ Memo 99LH-133. Kulaimano 1999 08M Inspection Page 2 of 4 Since this item is considered as an NPDES Violation and since the Clean Water Branch has issued reference (a) citing the apparent violation, it is requested that the Wastewater Branch close this item as an Operation and Maintenance item. This would allow the County of Hawaii to work directly with the Clean Water Branch regarding final closure of the existing Waste Stabilization Pond. The County of Hawaii will keep the Wastewater Branch apprised of the progress regarding final closure of the existing Waste Stabilization Pond. 2. The influent sampling station was temporarily relocated downstream of the grit chamber after the barminutor became inoperable. The Clean Water Branch informed the County of Hawaii of the apparent violation via reference (a). Reference (b) clarified that temporary relocation of the Influent Sampling Station occurred on September 14, 1999 and was corrected on September 15, 1999. Sampling for NPDES Monitoring Requirements was conducted on September 16, 1999 therefore the NPDES samples were not affected by the temporary relocation of the Influent Sampling Station. Plant Operators were also advised of the requirement that sampling stations cannot be changed without prior notification and approval of the Director of Health. Deficiencies: 1. The barminutor at the headworks was inoperable. Repair of the barminutor was completed on September 22, 1999. 2. The suction from the headworks ventilation system was noticeably weak. The primary means for providing ventilation for the headworks area is via the louvered windows (13'4" x 5'7-1/2") which are left in the open position to provide constant air flow. The suction from the blower is an existing design condition. The sheaves and drive belts were replaced to allow the blower to operate at its maximum rated speed of 2500 rpm in order to obtain the maximum suction from the existing blower. 3. Aeration Turbine No. 1 was out of service due to an electrical tripping problem. Repair of the existing Aeration Turbine No. 1 will be deferred in order to allow addressing of higher priority items at other sites. Two (2) separate aeration streams are provided with three (3) each Aeration Turbines per stream. One (1) aeration stream is normally not utilized since existing flows to the plant are less than 20 percent of the Design Average Flow. Memo 99LH-133. Kulaimano 1999 O&M Inspection Page 3 of 4 A spare motor and gear box assembly is currently available. Turbine Aerator No. 1 will be repaired prior to placing the inactive aeration stream on line. 4. The baffle boards for Final Clarifier No. 1 needs replacement. Repair of the existing baffle boards for Final Clarifier No. 1 will be deferred in order to allow addressing of higher priority items at other sites. Two (2) separate Final Clarifiers are provided. Only one (1) each Final Clarifier is utilized at a time since existing flows to the plant are less than 20 percent of the Design Average Flow. The replacement baffles are located at the plant and will be installed prior to placing Final Clarifier No. 1 on line. 5. The isolation valves for the aerobic digester diffusers were defective. The aeration piping was modified to accommodate the addition of isolation valves. 6. The flow chart recorder for the aerobic digester records an airtlow even when the blowers are not in operation. The chart recorder is not utilized for process control purposes and will be deactivated. 7. The electronic board for the backup DCG unit was removed for use at the Papaikou WWTP and was never replaced. The electronic board had been replaced prior to the O&M inspection. Operators verified that the DCG unit is operational. 8. Blower No. 1 is inoperable. Four (4) blowers are currently installed. The plant currently operates at less than 20 percent of the Design Average Flow and no major developments in the area are expected in the near future. Only one (1) each Blower is utilized at a time since the blowers are over-sized for the existing flows. As such, the Wastewater Division intends to defer replacement of the existing blower until such time that blower redundancy is affected. The blower would be replaced with a lower capacity blower at that time to improve plant efficiency and reduce electricity bills. Memo 99LH-133. Kulaimano 1999 O&M Inspection Page 4 of 4 9. The facility's backflow preventer leaked water. The backflow preventer was repaired and tested in accordance with Chapter 21, Title 11, Administrative Rules requirements. The Wastewater Division currently has an annual contract for testing and repair of the existing backflow preventers. Recommendations: 1. The facility should consider re-implementing the anoxic zone in the aeration basin to minimize and control nitrification in the system. Operators attempted to re-implement the anoxic zone at the plant but found that process control becomes unstable due to shutdown of the blowers during evening hours therefore the use of the anoxic zone will not be utilized. 2. The influent sampler refrigeration was broken and the County had no plans to replace it. This is incorrect. The Wastewater Division always intended to replace the refrigerator but was having difficulty in obtaining the replacement refrigerator in a timely manner due to procurement requirements. Anew refrigerator is currently installed. 3. Sludge wasting is performed by a single Peabody Barnes positive displacement pump with no backup capability. Backup capability would be provided by a portable pump in the event of failure of the existing pump. Existing portable pumps are currently available at the Hilo Wastewater Treatment Plant and can be readily transported to the site in the event of failure of the existing Peabody Bames pump. Should there be any comments or questions on the above please contact Peter Boucher, Wastewater Division Chief, at 808-961-8338 or correspondence may be sent via facsimile to 808-961-8644. Sincerely, Jir A. Sum da De ty Chi f Engineer cc: Wastewater Division County Council Public Works Chairperson