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HomeMy WebLinkAboutNC0072702_Corrective Action Plan_20190412 (2)Town of Beaufort 701 Front St. • P.O. Box 390 • Beaufort, N.C. 28516 252-728-21410252-728-3982 fax www.beaufortnc.ore April 12, 2019 Mr. John Hennessy Division of Water Resources Water Quality Permitting Section — NPDES 1617 Mail Service Center Raleigh, NC 27699-1617 RE: Corrective Action Plan Glenda Drive Water Treatment Plant NPDES Permit NCo072702 Town of Beaufort, Carteret County, NC Dear Mr. Hennessy: RECEPdEUDEN R/DWR APR 2 3 2019 Water Resources Permiting Section Please find enclosed a single copy of a document titled "Corrective Action Plan." This plan is being provided in accordance with a requirement contained within the National Pollutant Discharge Elimination System permit issued for the discharge to an unnamed tributary of Turner Creek of water softener regeneration backwash from ion exchange units at the Glenda Drive Water Treatment Plant. An electronic copy of this plan was sent to you as an email attachment on April i5th. We ask that you advise us as to your Division's concurrence with the actions set forth by the plan as we intend to carry them out unless and until advised otherwise. Your cooperation in this matter is greatly appreciate. Please therefore, do not hesitate to contact us if you have questions or are in need of additional information. Sincerely, /< Al,,-`�� Gregory K. Meshaw, PE Town Engineer Encl. CC: Morella Sanchez -King, Environmental Program Supervisor III, DWR-WiRO Dean Hunkele, Senior Environmental Specialist, DWR-WiRO Mayor Everette S. (Rett) Newton Commissioner John Hagle • Commissioner Sharon Harker • Commissioner Marianna Hollinshed Commissioner Ann Carter • Commissioner Charles McDonald Town Manager John Day Town of Beaufort 701 Front St. • P.O. Box 390 • Beaufort, N.C.28516 252-728-2141•252-728-3982fax www.beaufortnc.ore Corrective Action Plan Location: Glenda Drive Water Treatment Plant NPDES Permit NCoo72702 Beaufort, Carteret County Date: March i, 2oi9 Town 5&K 12345 PE Background: A National Pollutant Discharge Elimination System (NPDES) permit with an effective date of March 1, 2oi8 was issued for the discharge of water softener regeneration backwash from ion exchange units. Among the thirteen (13) effluent characteristics to be limited and/or monitored included two metals withlimitations as follows: Monthly Average Limit Daily Maximum Limit Total Copper 1.85 µg/L 2.90 µg/L Total Zinc 42.8 µg/L 47.6 µg/L The permit called for compliance with the above limitations within five years of the effective date of the permit which will be 2023. To that end, the permit also required the submission of a Corrective Action Plan (CAP) to the Division of Water Resources (DWR) within the first year of the permit. The stated purpose of the CAP is to summarize the actions or strategy to be taken to achieve compliance with the total copper and total zinc limits. With issuance of the permit, once -a -month sampling for the regulated metals was begun by the Town. This sampling revealed the presence of zinc above its stipulated limits for the period between and including March 2018 through February 2019 only once when it was detected at 255 µg/l during August 2o18. On the other hand, copper has been detected above its stipulated limits five times. The concentrations detected ranged from 3 µg/1 to 16 µg/1 with four of the five results ranging between 7 µg/1 and 3 99/1. Given the single exceedance of the total zinc limit over the past year along with the multiple exceedances of the limits for total copper, the Town of Beaufort proposes to institute the actions described in the section below titled "Proposed Actions." Proposed Actions: The following are actions proposed by the Town of Beaufort to assure compliance with the permit limitations for total copper and total zinc by March 1, 2023. The Glenda Drive discharge was redirected to the Town's sanitary sewer collection system via a new service line installed subsequent to the sampling conducted during February 2019. This action was taken in response to difficulties over the past year in achieving compliance with the monthly average and daily maximum limits of io mg/1 and 15 mg/l, respectively for total suspended solids. Page i of 2 Mayor Everette S. (Rett) Newton Commissioner John Hagle • Commissioner Sharon Harker • Commissioner Marianna Hollinshed Commissioner Ann Carter • Commissioner Charles McDonald Town Manager John Day Although the discharge of water softener regeneration backwash from ion exchange units to an unnamed tributary to Turner Creek has ceased, the Town plans to continue gathering data from the backwash as it is discharged to the sewer collection system. The Town will also begin examining sampling data at its wastewater treatment facility. Both types of sampling are planned so that the technical and monetary feasib' 'ties of one or more treatment technologies designed to achieve compliance with the permit limits can be evaluated against continued redirection of the discharge to the Town's sanitary sewer collection system. Results for the metals, suspended solids, and other parameters as deemed appropriate will continue to be obtained and inventoried on a quarterly basis in an effort to better ascertain the range of concentrations that the Town could expect to see for each constituent if discharges were left untreated. The Town will also track the levels of copper and zinc in the sludge from the treatment process to see if any noticeable change in concentrations of these metals occurs pursuant to redirection of the backwash to the collection system. The Town proposes to continue this effort until March 1, 2021 whereupon the engineering alternatives analysis will be undertaken. The engineering alternatives analysis is expected to yield a recommendation of a preferred alternative for achieving compliance. Thereafter, DWR's concurrence regarding the preferred alternative will be sought. This will of course, be followed by implementation of corrective action to included related tasks such as design and permitting. The proposed timeline for monitoring, performing the alternatives analysis, and implementing corrective action is as follows: Date jT imeframe March 1, 2019 — February 29, 2021 March 1, 2021 — July 31, 2021 August 1, 2021 — February 28, 2022 March 1, 2022 — January 31, 2023 Task.U&tion Continue procurement, review, and inventorying of laboratory results for total copper, total zinc, total suspended solids, and other parameters as deemed appropriate. Conduct engineering analysis of alternatives that will result in compliance. Prepare plans and specifications and procure the necessary permit(s) thereafter for any alternative that involves treating the water softener regeneration backwash and reestablishing its discharge to the watercourse. Plans, specifications, and permit(s) will not be necessary if continued diversion to the Town's sewer collection system is deemed appropriate. Bid and award a contract to construct the treatment additions. Thereafter, construct, start-up, test and place into service the treatment unit(s) and reestablish discharge to the tributary. Alternatively, continue discharge to the collection system and do not apply for a NPDES permit renewal if discharge to the collection system is deemed the appropriate corrective action. Page 2 of 2 Mayor Everette S. (Rett) Newton Commissioner John Hagle * Commissioner Sharon Harker • Commissioner Marianna Hollinshed Commissioner Ann Carter• Commissioner Charles McDonald Town Manager John Day