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HomeMy WebLinkAboutNC0060321_Draft Factsheet_20231213NCDEQ / DWR / NPDES EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL NPDES Permit NCO060321 Sara Bassett / Compliance & Expedited Permitting Unit / sara.bassettkdeq.nc.gov / December 2023 FACILITY INFORMATION Applicant/Facility Name Edward Riggs Jr. / Manager and Owner First Craven Sanitary District Water Treatment Plant Mailing Address P.O. Box 608 Bridgeton, NC 28519 Facility Physical Address 560 NC Highway 55 East New Bern, NC 28560 Max, Monthly Avg Flow (MGD) 0.0614 MGD Type of Waste Backwash from greensand and reject from ion exchange Facility Class PC-1 County Craven Permit Status Renewal Regional Office WaRO STREAM CHARACTERISTICS Receiving Stream UT to Duck Creek Stream Classification SC; Swamp; NSW Stream Segment 27-103 Outfall Lat. 35.1228N 7Q10 - Summer (cfs) Tidal Outfall Long. 77.0033W 7Q 10 - Winter (cfs) Tidal Drainage basin Neuse 30Q2 (cfs) Tidal Subbasin 03-04-10 Average Flow (cfs) Tidal HUC 030202040404 IWC (%) 100% 303(d) List No FACILITY SUMMARY The First Craven Sanitary District WTP utilizes greensand iron filters and ion exchange water softeners with a design potable flow rate of 0.720 MGD that draws raw water from three wells. The treatment for raw water consists of two aerators, two detention tanks, four ion exchange water softeners, four greensand iron filtration, and declorination. The discharge produced from the treatment plant is backwash discharge from the greensand iron filters and water softeners. The existing treatment components at the water treatment plant are the following: • 4 greensand iron filters • 4 ion exchange water softeners • Dechlorination Chemical usage consists of - Potassium permanganate • Chlorine • OPO4 • Sulfur Dioxide Fact Sheet for Permit Renewal Dec 2023 - NPDES Permit NCO060321 - Page 1 RENEWAL SUMMARY This renewal contains the following changes: • The limits for Copper, Lead, and Zinc have been removed as the RPA did not show a reasonable potential to exceed water quality standards; quarterly monitoring has been implemented for these parameters. • Duration of Discharge monitoring has been added in Section A. (1) Effluent Table. The frequency and sample type were selected following the 2020 strategy guidelines. • Ammonia Nitrogen monitoring has been removed added in Section A. (1) Effluent Table as this facility has not reported use of chloramines. • Section A. (3) in the previous permit outlining the previous compliance schedule has been removed. • The Supplement to Cover Sheet has been updated with the with new max monthly average. • The facility grade has been added to Section A. (1). • Monitoring for Total Iron in Section A. (1) Effluent Table has been removed as there is no longer a water quality standard, per 2012 WTP guidance. • Section A. (3) has been updated regarding electronic submission of effluent data. Federal regulations require electronic submittal of all discharge monitoring reports (DMRs). COMPLIANCE HISTORY No violations or enforcements in the last permit cycle NCG59 GENERAL PERMIT ELIGIBILITY (FOR CONVENTIONAL & GREENSAND ONLY) • This plant utilizes ion exchange components as well as greensand • Conclusion: Ineligible for NCG59 General Permit. WHOLE EFFLUENT TOXICITY (WET) TESTING The current strategy recommends Acute 24-hr Pass/Fail with Mysid Shrimp [TGE3E] WET testing for this facility. However, Chronic, 7-day Pass/Fail with Mysid Shrimp at an effluent concentration of 90% [TGP3E] has been applied instead. This facility has not failed any toxicity tests in the last five years. From Previous factsheet (Brianna Young): "No evidence in file of why chronic test at 90% effluent pass/fail limit assigned. Spoke with Cindy Moore 9/29/17 for guidance, but she was unable to explain why chronic testing assigned over acute testing. She believes decision must have been made to assign the 90% chronic value and that the information is missing from the file. Renewing with updated chronic 90% pass/fail limit language." REASONABLE POTENTIAL ANALYSIS A reasonable potential analysis (RPA) was performed for a discharger going to a saltwater stream. A flow (Qw) of 0.061 MGD was used based on the maximum, monthly average flow between February 2019 and October 2023. Based on this analysis, the following permitting actions are proposed for this permit: Zinc — no reasonable potential to exceed water quality standards; removing limits from permit and applying quarterly monitoring Lead — no reasonable potential to exceed water quality standards; removing limits from permit and applying quarterly monitoring Copper — no reasonable potential to exceed water quality standards; removing limits from permit and applying quarterly monitoring Fact Sheet for Permit Renewal Dec 2023 - NPDES Permit NCO060321 - Page 2 COMMENTS ON DRAFT PERMIT Fact Sheet for Permit Renewal Dec 2023 - NPDES Permit NC0060321 - Page 3