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Home My WebLink AboutNC0031879_RESP_NOVNOI2020LV0465_20200616CITY OF MARION PUBLIC WORKS DEPARTMENT P.O. Drawer 700 Marion, NC 28752 June 16, 2020 Mr. G. Landon Davidson, P.G., Regional Supervisor Water Quality Regional Operations Section, NCDEQ Asheville Regional Office 2090 U.S. Hwy 70 Swannanoa, NC 28778 Dear Mr. Davidson, OFFICE OF THE PUBLIC WORKS DIRECTOR � If �- JUN 1. 3 2020 n;,a!iry ;regional Operations Astieville Regional Office Subject: Notice of Violation & Intent to Assess Civil Penalty Tracking #: NOV-2020-LV-0465 Permit NO. NCO031879 Corpening Creek WWTP McDowell County I am writing in response to your letter dated June 9, 2020 and received by the City of Marion on June 11, 2020, requesting, within 10 business days of the receipt of the letter, an explanation of violations occurring at the Corpening Creek WWTP during the month of May, 2020. The violations in question, as well as the causes for each violation and the corrective actions taken for each violation are listed in table below. Description of Violation Date Cause of Violation Corrective Measures Effluent pH — 5/21/20 Operator Error. The Lab Retraining was initiated Daily Technician that made the error is immediately upon discovery. minimum not new to the position. The The importance of proper reached violation was caused by the Lab sampling and testing protocol Tech's failure to allow the pH was reemphasized to the Lab meter to stabilize before taking Tech and her Supervisor. the reading. Insufficient training and an insufficient amount of observation by the trainer also contributed to the error. Effluent BOD 5/23/20 Severe Natural Conditions — Operators followed the SOP for — Weekly avg. Flood event 5/19/20 — 5/22/20. high flow operations, which exceeded The WWTP received 7.5" of entails measures aimed at rain in 3 days, with 4" of that retaining as many solids as amount accumulating in one day possible for treatment. The SOP (5/20/20) and 2.3" of that includes turning off the aerators amount accumulating the in the aeration basin when flow following day (5/21/20). Flows reaches 2.5 MGD. Flow and to the WWTP were 3.26 MGD, settle ability is closely monitored 3.72 MGD, and 1.87 MGD on and when the flow returns to a 5/20/20, 5/21/20, and 5/22/20, consistent 2 MGD, the aerators respectively. The high flows are restarted. caused solids to wash out with the effluent, which in turn reduced the plant's ability to reduce BOD. Effluent Nh3 5/23/20 Same as BOD above. High Operators followed the SOP for — Weekly avg. flows from flood event caused high flow operations. exceeded loss of solids, which negatively affected the plant's nitrification process and reduced its ability to reduce Nh3 levels. Effluent TSS 5/23/20 Same as BOD and Nh3 above. Operators followed the SOP for — Weekly High flows from flood event high flow operations. average caused loss of solids. exceeded Effluent DO — 5/26/20 Operator Error. The reason for Retraining was initiated Daily the reading being so low is immediately upon discovery. minimum not unknown. The Lab Technician The importance of proper reached should have retested sampling and testing protocol immediately when the unusual was reemphasized to the Lab reading was obtained. When the Tech and her Supervisor. unusual reading was noticed by the new employee's supervisor, the DO was retested and was found to be normal (above 5.0). Effluent pH — 5/26/20 Operator Error. The Lab Retraining was initiated Daily Technician that made the error is immediately upon discovery. minimum was new to the position. The The importance of proper not reached violation was caused by the Lab sampling and testing protocol Tech's failure to allow the pH was reemphasized to the Lab meter to stabilize before taking Tech and her Supervisor. In the reading. Insufficient training addition, the Supervisor was and an insufficient amount of reminded to review the results observation by the trainer also obtained by the new employee in contributed to the error. a timely manner. Had the pH result from 5/21/20 been reviewed sooner, the employee could have been confronted and retrained sooner, and the testing error that occurred on 5/26/20 could have been avoided. Effluent TSS 5/31/20 Same as the weekly violations Operators followed the SOP for — Monthly noted above. The TSS monthly high flow operations. average violation was a direct result of exceeded the same flood event. TSS results from the week ending 5/23/20 caused the monthly limit to be exceeded. In summary and as shown above, four of the violations were caused by severe natural conditions and three of the violations were caused by errors made by a new employee. Regarding the violations caused by severe natural conditions, W WTP staff responded immediately to the hydraulically upset plant and did everything possible to retain solids and avoid violations. Once the rains subsided and flows returned to a more manageable level, staff returned the plant to compliance quickly. The storm total rainfall amount for the City of Marion, as reported by the McDowell County Emergency Operations Center, was 8.03". The W WTP received 8.4" of rain during the month of May, with 89% (7.5") of that amount occurring from 5/19/20 — 5/22/20. Regarding the violations caused by operator error, the Superintendent/ORC has met with the new employee and the Lab Supervisor to reiterate the importance of following SOP and being cognizant of the results obtained. The Superintendent has also discussed the importance of proper training with the Lab Supervisor and has implemented measures to prevent the same mistakes from happening again. For the reasons cited above, the City would respectfully request that a civil penalty not be assessed for the violations in question. Four of the violations were caused by severe natural conditions that were out of the City's control. The other three violations were caused by human error and those errors have been swiftly and assertively addressed with the responsible employee and the employee's supervisor. As mentioned earlier, measures have been implemented to prevent these mistakes from happening again. If you have any questions or require additional information, please contact me at 828-652-4224 or W WTP Superintendent Tim Horton at 828- 652-8843. Thank you in advance for your time and consideration. Sincerely, /J. Brant Sikes Public Works Director cc: Bob Boyette, City Manager Tim Horton, WWTP Superintendent