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Home My WebLink AboutNC0074756_Notice of Violation_20220811DocuSign Envelope ID: 6FBE86BD-12AF-4369-BOOF-BF5A0452F378 August 10, 2022 MEMORANDUM DWR Division of Water Resources To: Corey Basinger Water Quality Regional Operations, MRO Through: Cindy A. Moore Olt Supervisor, Aquatic Toxicology Branch (ATB) DS From: Madison E. Myers Environmental Specialist I, Aquatic Toxicology Branch (ATB) Subject: Whole effluent toxicity test results Greater Badin Water & Sewer District NPDES Permit # NC0074756/001 Stanly County The aquatic toxicity test using flow -proportional composite samples of effluent discharged from the Greater Badin Water & Sewer District has been completed. Greater Badin Water & Sewer District has a permitted effluent discharge of 0.2 million gallons per day (MGD) entering Little Mountain Creek (7010 of 41.0 CFS). Whole effluent samples were collected on July 19 and July 21 by Roberto Scheller for use in a chronic Ceriodaphnia dubia pass -fail toxicity test. The test failed. Toxicity test information follows. Test Type Test Result Test Concentrations Control Survival Control Mean Reproduction Test Treatment Survival Treatment Mean Reproduction First Sample pH First Sample Conductivity First Sample Total Residual Chlorine Second Sample pH Second Sample Conductivity Second Sample Total Residual Chlorine 3-Brood Ceriodaphnia dubia chronic pass -fail Fail 83.4% 91.67% 31.42 neonates 0% 0.0 neonates 6.91 SU 249 micromhos/cm <0.1 mg/L 6.85 SU 262 micromhos/cm <0.1 mg/L Test results for the above samples indicate that the effluent would be predicted to have water quality impacts. These samples were split and tested by Meritech. The chronic Ceriodaphnia dubia pass/fail test performed by Meritech resulted in a pass. After reviewing the toxicity test documentation from both ATB lab and Meritech, Inc. lab, we see no obvious reason for the disagreeing lab results. ATB ended their monthly synthetic water Reference Toxicant Test on July 13, which did not indicate any issues with the in-house culture health. We had a discussion with the Regional Office staff member, Roberto Scheller. Each sample bottle was poured all at one time. We discussed doing another test next quarter; being sure to mix the effluent well and add 1/3 sample to each bottle and continue the well -mixed pour process until all bottles are filled. This would be a way to ensure each bottle receives the same level of effluent. Please DocuSign Envelope ID: 6FBE86BD-12AF-4369-BOOF-BF5A0452F378 DEC)-?,) DWR Division of Water Resources contact us if you have any questions or if further effluent toxicity monitoring is desired. We may be reached at cindy.a.moore@ncdenr.gov and madison.myers@ncdenr.gov. Basin: Yadkin -Pee Dee cc: Roberto Scheller (MRO)