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HomeMy WebLinkAboutNC0021881_Instream Assessment_19940422NPDES DOCUHENT SCANNING COVER SHEET NC0021881 Lake Waccamaw WWTP NPDES Permit: Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Engineering Alternatives (EAA) Correspondence '-i...:F•f._'::.:_v.N'f:.i=ff.+.:tY..fN:r..'h.tiw.�ptyYd+ruL.ew. Instream Assessment (67b) Speculative Limits Environmental Assessment (EA) Document Date: April 22, 1994 This document is prizited on reuse paper - ignore any content on the rezterse side Note for Carla Sanderson From: Carla Sanderson Date: Fri, Apr 22, 1994 10:59 AM Subject: RE: Lake Waccamaw WWTP exp. To: Alan Clark Page 1 Alan - sorry it has taken me so long to get back to you on this. (You're sounded g- really covered alot of territory. It sounds like you explored not only natura beauty but rthe significant landmarks as well. Sometime I will bring in pictures and show them to you.) About the issue with Lake Waccamaw - the expansion in the order is not a permitted expansion. The existing permitted flow is 0.4 MGD and they should not be exceeding that because we have not seen a request for modification/expansion. For that matter we also did not see a request for SOC. According to the SOC write-up an instream assessment was not necessary. The additional flow will be after the Town takes care of current I/I problems and other treatment inadequacies. So really (as the region puts it - I talked to Dave A.) the wasteflow to the system will not change. I thought we covered the issue of expansions and new facilities in 030756-030758 in Table 6.2 of the Lumber River Plan. The allowance of an expansion will involve no increase in loading and therefore in some ca.cPs additional treatment will be necessary. Do you think this will satisfy the US Fish & Wildlife's concerns? Or do they want to possibly request enhanced treatment in the future for existing facilities Page 1 Note for Carla Sanderson From: Alan Clark Date: Tue, Apr 12, 1994 2:58 PM Subject: Lake Waccamaw WWTP exp. To: Carla Sanderson Sometime I'd love to talk to you about Puerto Rico. We saw El Yonque (the rain forest), the town of Ponce and its famous black and red -striped firehouse, the caves and giant sinkhole near Areciebo, and supposedly the oldest church in the new world in a small town near St. German. We also went snorkling at Rincon and along the west shore south of Mayaguez, went swimming at Boqueron, saw the phosphorescent bay (unfortunately under a full moon), went to a street festival at La Paguera, visted the Cobo Rojo lighthouse and saw lots of sights in between. I also drank a lot more rum than usual. What did you think of the drivers down there? But back to business. Do you know anything about the Lake Waccamaw WWTP being under an SOC and expanding, and discharging into a stream with 7Q10 and 30Q2 of zero? US Fish and Wildlife Service has suggested that we revise section 6.3.3 under the Subbasin 03-07-56 discussion to note that enhanced treatment for BOD and NH3 may be required as is proposed for new facilities in the Waccamaw watershed. )44 i STAFF REPORT FOR TOWN OF LAKE WACCAMAW SOC EMC NO. 93-08 COLUMBUS COUNTY I. Discussion i NOV 1 0 1993 l�/�Y,�ft�:r'iL ts;is i+�aij t9: "7Ale., i'i.i;.•ii The Town has submitted an application for an SOC to address the problem of periodic sewer collection system overflows. The SOC application requests an additional 100,000 gpd flow volume. Additional information was requested from the Town that specifically accounted for the 100,000 gpd additional flow volume. This information resulted in lowering the flow request to 60,000 gpd. The Town operates a 0.40 MGD wastewater treatment facility and holds NPDES Permit No. NC0021881. There is a repeated history of sewer collection system overflows caused by many conditions, including infiltration/inflow into the sewer collection system. There have been no violations of permitted monthly average flow volumes over the past year. II. Additional Information a. Current MP screen - The current MP screen is attached. The Permittee's monitoring report file was checked for DMR's generated from June 1992 thru May 1993. There were cases of noncompliance due to fecal coliform bacteria, ammonia nitrogen and some marginally low dissolved oxygen readings. The high fecal counts may have been caused by excessive flow volumes. The high ammonia readings may have been attributed to sludge accumulations within the polishing ponds producing ammonia gas. b. Funding source - The Town has indicated that local tax revenues, utility system revenues, and other funds may be used to finance the proposed sewer system rehabilitation program. c. Instream assessment - not required d. Additional flows - The Town has requested an additional 60,000 gpd to add to the permitted 400,000 gpd. The SOC is worded to allow additional flow volumes upon removing a like amount of flow volume from I/I sources. e. Facility improvements required by this Order - To perform modifications for improved performance of pumping scations and sewer collection system conduits. The pumping station improvements should concern reducing the frequency of pumping station overflows. Three (3) miles of sewer collection system conduit will be treated for infiltration/inflow. In addition, the SOC compliance schedule contains milestone dates for the construction of residual solids treatment/holding facilities at the treatment plant. f. Is facility monitored according to current NPDES Permit or SOC? The facility will be monitored according to the conditions specified within the NPDES permit. g. Does toxicity need to be included? Toxicity is included as a current requirement within the permit. h. Does pretreatment need to be addressed? No, the current waste stream is of domestic origin. i. Facility type and design flow? The wastewater treatment plant is an activated sludge extended aeration facility with two polishing ponds and chlorine treatment following the clarifier. The current permitted flow is 0.400 MGD. The design flow of this existing plant is hot known but is assumed to be limited by the aeration basin and clarifier. Exceeding the design flow may result in solids washing into the polishing ponds from the clarifier, but should have little effect on effluent water quality for infrequent occurrences. j. Is facility properly operated and maintained? No, the facility is not properly operated. The plant does not presently have a sludge treatment/holding unit. The Town has a permit to land apply sludge, but has been informed that unstabilized sludge can not be land applied. The Town has been allowing solids to wash thru the clarifier and accumulate within the polishing ponds. This is not proper operational technique. The Town has requested an Authorization to Construct sludge treatment facilities and construction activities have begun. k. Is NPDES Permit under adjudication? No 1. Are there special circumstances concerning issuance of the SOC? The SOC is being requested to address frequent sewer system over:lows relating to increased flow within the sewer collection system from infiltration/inflow. The Town will be required to perform improvements/modifications to the sewer collection system to achieve compliance with permit requirements and reduce the frequency of sewer system overflows. m. The date to achieve permit compliance is December 31, 1996, as listed on Attachments A and B of the Special Order. n. Are current NPDES parameters listed on the SOC limits/monitoring page? Yes o. Discuss downstream water quality impacts. The collection system overflows into adjacent surface waters can decrease oxygen levels to the extent of causing fish kills and pose a health hazard to swimmers. There are no water quality impacts predicted to occur downstream of the wastewater plant discharge point. p. Explain mechanisms for arriving at interim limits and compliance schedule. There are no interim limits associated with the Special Order. The request for additional flow volume and the compliance schedule was submitted by the Town based on recommendations from their consultant, McDavid and Associates, Incorporated. Additional information was submitted by the Town concerning specific flow volume allocations predicted Ito occur during the SOC period. The completion of the sewer system rehabilitation study, and a proposed schedule for completing improvements to Pumping Station 11 and for treating excessive I/I in three miles of sanitary sewers has been presented. The compliance schedule, as submitted, is reasonable. The anticipated additional flow volume is itemized below. 25,000 gpd - Annexation of Waccamaw Shores, Bella Coola, and Shawnee Acres 16,000 gpd - Proposed build schedule based on a historical average of 14 homes per year 19,000 gpd - Unspecified flow allocations III. Recommendations This report has been prepared based on a request by the Town of Lake Waccamaw to enter into a Special Order by Consent with the Commission for making sewer collection system improvements necessary to eliminate overflow conditions. The Town has submitted an application for Special Order by Consent and related information which shows the necessity of sewer collection system improvements. A request for an additional 60,000 gpd flow volume has been made to account for sewer system expansions during the SOC period. However, the Special Order is worded to allow the 60,000 gpd additional flow upon removing a like amount of flow volume caused by I/I with no additional permit limits modifications. The average flow taken over the period of July 1992 thru June 1993 was 0.25 MGD which is well below the NPDES permit limit if 0.40 MGD. miwo+ rv\mAkiAli D. 3B 58 The Town has presented a general plan within this application which concerns the performance of a sewer system study, Pumping Station 11 improvements, and treating three miles of sanitary sewers for excessive I/I. The application lists several recent sewer overflows which were caused by electrical problems in addition to I/I problems. The writer has made contact with the Town's Administrator and it's consultant engineer to address concerns over the frequency of overflows created by electrical problems. Based on this conversation, adequate safeguards are available at the problematic pumping stations which include portable or fixed auxiliary power generators and autodialing telemetry systems. The autodialers were installed at the beginning of this year. It is recommended that Special Order By Consent EMC WQ No. 93-08 be presented at public notice, and if no significant adverse public comment is received, the Order be should executed. ort epare =y er Qua i y Regional Supervisor JB:LAKEWAC3.893 cc: Steve Long Wilmington Office Files Central Files Technical Support Branch Oti S', M-3 Date ritilb1/50( 1951.3 Date North Carolina Division of Environmental Management Water Quality Section/Rapid Assessment Group September 25, 1992 MEMORANDUM To: Coleen Sullins Through: Carla Sanderson From: Susan A. Wilson V( Subject: Town of Lake Waccamaw NPDES No. NC0021881 Columbus County 030756 Mike Williams of the Wilmington Regional Office has informed me that this facility is currently monitoring for toxicity as required in an Administrative Letter. He requested that a toxicity testing requirement be placed in the permit for Lake Waccamaw WWTP. The Technical Support Branch agrees with this request and is recommending that a chronic bioassay test with a pass/fail limit of 90% be included in this permit before going to public notice - see attached. cc: Melissa Rosebrock Mike Williams racility Name LAKE (NA Cc47 Permit # n►G oo y t OS Pipe # CHRONIC TOXICITY PASS/FAIL PERMIT L The effluent discharge shall at no time exhibit chronic toxicity using LIMIT (QRTRLY) test procedures outlined in: 1.) The North Carolina Ce=Dia chronic effluent bioassay Procedure - Revised *September 1989) or subsequent versions. procedure (North Carolina Chronic Bioassay The effluent concentration at which there may be no observable inhibition of is qo % (defined as treatment two in the North Carolina reproduction or si n % (defined usingatthis procedure document). The I ficant mortality procedure to establish compliance with the permit holder shalle perform performed SeP after thirty days from the effective date of thisPermit condition. The first test will be Pr� '1''`� .Effluent samplingpermit during the months of permitted final effluent discharge below all treatment for this testing Shall be performed at the NPDES g processes. All toxicity testing results required as part of this MonitoringForm month in which it was permit conditionrwill entered on the Effluent Discharge Additionay, DEM (MR -1) (original) s to be sent to the fo llowing using the parameter code TGP3B. g address: . Attention: Environmental Sciences Branch North Carolina Division of Environmental Management 4401 Reedy Creek Road Raleigh, N.C. 27607 Test data shall be complete and accurate and include all supporting chemical/ h association with the toxicity tests, as well as all doseFiesponse data. Total residual chlorine of the effluent sample must be measured and reported1? yslcal measurements performed in if chlorine is employed for disinfection of the waste stream. toxicity Should any single quarterly monitoring indicate a failure to meet specified limits, then monthlymonitoring begin immediately until such time that a single test is passed. Upon passing, this monthly tesrequirement will revert to quarterly in the months specified above. r'e9 will Should any test data from this monitoring requirement or tests performed by the North Carolina Division of Environmental Management indicate potential impacts to the receiving stream, this permit may be re -opened modified to include alternate monitoring requirements or limits. and NOTE: Failure to achieve test conditions as specified in the cited document, such as minim survival and appropriate environmental controls, shall cons um rol organism retesting(within 30 days of initial monitoring event). t±tut„ an invalid test and will require immediate noncompliance with monitorin requirements. Failure to submit suitable test results will �, pj�*�'te g equire.*�nts. 7Q10 b . 0 cfs Permitted Flow O. MGD IWC Jco. o % Basin & Sub -basin 030 56, Receiving Stream _ uT Bo Ev- County __Cal_ m8u5 QCL PIF Version 9/91 Recommended by: Date �zs fq Z c6s-71/4-