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HomeMy WebLinkAboutNC0063762_Response to Notice_20240125Metwater, Inc. 1000 Wooddhurst Drive Monroe NC 28110 1704.506.4255 dmetwater(@aol.com 12-15-23 Mr. Roberto Scheller Water Quality Regional Operations Center Division of Water Resources, NCDEQ 610 East Center Avenue, Ste. 301 Mooresville, NC 28115 Ref: NOV-2023-LV-0869 & Intent to Assess Civil Penalty Carolina Village WWTP NPDES# NC0063762 Dear Mr. Scheller, This letter is intended to address the NOV (Notice of Violation) letter addressed to Susan Gotshall of Carolina Village MHC, LLC, dated November 30th, 2023, wherein the monthly average Ammonia was exceeded. As you know, foaming issues are nothing new to the Carolina Village Wastewater Plant. Up until recently a small upset could be corrected with sludge wasting, chlorine sprayers and some lime. This is not the case anymore. I have never seen the foam and scum come on so fast and stay for so long. As we discussed, foam has the potential to contribute to poor settling and treatment leading to an array of non-compliance issues as we are seeing here. And unfortunately the first 2 weeks of November 2023 as BOD's were > 53 mg/1 and > 49 mg/l. However, the 3rd week of November shown improvements with BOD at 17mg/l, TSS at 7.8 mg/l, NH3N at 8.1 mg/l and a fecal of 10 colonies/100ml. We have been and continue to collect additional data and analytical results from our influent, EQ basin, aeration basin and effluent. We have found influent constituents to be at the high end of what should be 100% domestic, including CBOD's in the 300mg/1 range and source water (City) pH in the low to mid 7.0 S.U. We have also identified through mixed liquor microscopy that our microorganism predominance consist of manly filamentous bacteria with only a small population of desired organisms. We have been injecting chlorine into the RAS and are beginning to see a decline in filamentous bacteria and groupings of ciliates. Working with a consultant, we tried adding hydrated lime to reach the prescribed pH of 8 to 8.5 S.U. in the aeration basin. We went through a pallet of lime (45, 501b. bags) in couple weeks with little success. Then we switched to a 25% caustic drip into the EQ and although we are still tweaking the drip per minute setting, we are starting to see a consistent pH of 7.5 S.U. and above. We are currently on a path to: 1. Evaluating blower efficiency, amp draws, size of pulleys, calculating SUM as it relates to oxygen horsepower needed 2. Adding 25% caustic to increase and maintain pH of 8.5 +/- 0.2 S.U. 3. Evaluating condition of air headers and changing filters to wire mesh to increase air flow 4. Increase dissolved oxygen in aeration basin from its current 1.5 mg/1 to the desire 3.5 mg/1- 5.0 mg/1 5. Replacing all 8 diffusers in aeration basin 6. Evaluating need to have aeration basin emptied and any settleables removed off site 7. Continuing with the 12.5% Hypochlorite to RAS injection to control proliferation of filamentous bacteria. 8. Leaving one blower on 24 hrs. a day. Never turning off nor cycling blower run times. 9. We have also spoken to the manufacturer of NEWCO chlorine tablets (Sanitizer) to obtain a clear understanding of dosing requirements per gallons of water treated as the size of the tablets fluctuate and routinely only partially dissolve preventing the next tablet from dropping. In closing, we respectfully ask that your office consider the remedial actions taken thus far and our plan of action provided herein while in consideration of a civil penalty and chose not to move forward with any further enforcement. Should you need additional information or follow up please contact me directly by calling 704-506-4255 or emailing me at dmetwater@aol.com. Also thank you for the extension to reply. Sincerely, Dusty Metreyeon ORC, Carolina Village WWTP Metwater, Inc. 1000 Woodhurst Drive Monroe, NC 28110 CC: "tbivens@horizonlandco.com" <tbivens@horizonlandco.com>; "Emmett Conneely" <econneely@horizonlm.com>; "Jrusso" <jrusso@horizonlandco.com>; "Dluckinbill@horizonlm.com" <Dluckinbill@horizonlm.com>; "zgatica@horizonlm.com" <zgatica@horizonlm.com>; Page 2