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HomeMy WebLinkAboutWQCS00011_Response to NOV-2020-DV-0311_20200727 (2)(9. ROCKY MOUNT WATER RESOURCES THE CENTER OF IT ALL July 27, 2020 Brenton Bent Director of Water Resources City of Rocky Mount 331 South Franklin Street Rocky Mount, NC 27804 Scott Vinson, Regional Supervisor Water Quality Regional Operations Section Raleigh Regional Office 13800 Barrett Drive, Raleigh, NC 27609 Subject: Notice of Violation & Intent to Issue Civil Penalty Tracking No.-NOV 2020-DV-0311 Collection System Permit No. WQCS00011 Dear Mr. Vinson, I received the Notice of Violation from the DWR dated July 13, 2020 regarding the sanitary sewer overflow (SSO) events that occurred between June 17, 2020 and June 28, 2020. The city of Rocky Mount takes these incidents very seriously and continues to take steps to minimize the potential for such overflows within our sewer collection system. Twenty-one (21) of the twenty-three (23) incidents occurred between June 17 and June 18. This was due to the saturated soil conditions and the roughly 7.53 inches of rain experienced locally over a six (6) day period, which caused the sewer collection system to become overwhelmed with heavily diluted wastewater. The other incidents occurred on June 22 and 28 resulted from severe natural conditions and debris in line respectively. The city has embarked on several capital projects with specific focus on increasing flow capacity to reduce inflow/infiltration across our entire sewer collection system. The actions detailed below reinforces the city's desire and total commitment towards resolving sanitary sewer overflows in a concerted and expeditious manner. • January 27, 2020- Purchase order was issued to AMLINER East in the amount of $2,358,958.70 to rehabilitate approximately 9,480 linear feet of the 27-inch Beech Branch sewer outfall from the Wastewater Treatment Plant to Seven Bridges Road. The existing (252) 972-1121 / 331 S. Franklin St., PO Box 1180, Rocky Mount, NC 27802-1180 / www.rockymountnc.gov coal tar epoxy corrugated metal gravity line has been a source of significant inflow/infiltration which reduces system capacity. The line will be rehabilitated using the cured in place method. Additional work includes rehabilitation or replacement of existing manholes. This outfall serves residential and industrial customers in the northern end of the city and accounts for approximately 30% of the flows to the Wastewater Treatment Plant. The relining of the pipe is currently in progress and is anticipated to be substantially completed in March 2021. It should also be noted that the city has allocated an additional $2,000,000 in fiscal year 2022 to address the second phase of this project which will include the remaining section of the line from Seven Bridges Road to Highway 301. October 30, 2019-Purchase Order was issued to Step Construction Inc. in the amount of $624,000 for the replacement of two screw pumps at the Highway 97 Lift Station. This lift station is downstream of Riverside Drive and receives approximately 65% of the flows to the Wastewater Treatment Plant. The pumps to be replaced were operating at a reduced pumping capacity of 2-3 million gallons per day. The new pumps are each rated at 10 million gallons per day and it is anticipated that this will significantly reduce incidents of sanitary sewer overflows at the River Side Drive location. The project is currently in progress and is anticipated to be substantially completed in September 2020. March 20, 2019- Frazier Engineering completed a flow monitoring report that investigated four (4) sites in the city's wastewater collection system. The purpose of the flow monitoring was to determine the average daily flow, diurnal peaking factors and wet weather responses within the Old Mill Road Pump Station Basin. This basin is upstream of Riverside Drive. City engineering staff continues to evaluate the report with the intention of addressing the noted infiltration concerns along the downstream portion of the Basin. The system geometry is also being evaluated for hydraulic improvement opportunities. April 29, 2019- The Wooten Company (TWC) completed a pump runtime analysis on 32 pump stations in the sewer system. The goal of the analysis was to provide a preliminary evaluation of the pump stations to determine issues based on pump runtimes and to determine how close pump stations are to reaching design capacity. As a result of this exercise, the city identified four (4) priority pump stations requiring rehabilitation work to improve pumping capacity. These stations are listed in the FY 21-25 Capital Improvement Plan (CIP) as follows: Pump Station Location Fiscal Year Cost allocated $ Johnson Street 2021 1,000,000 Old Mill Road 2022 1,500,000 Sharpsburg 2023 1,000,000 Arbor Lane 2023 1,000,000 Please be assured that the city of Rocky Mount is working with great care and perseverance to reduce the number of sanitary sewer overflows in the collection system and this effort will remain a top priority into the foreseeable future. As you can see, we are taking the necessary steps to address the integrity of our entire collection system and our hope is that the Division of �252) 972-1325 / 331 S. Franklin St., `0 Box 1180, Rocky Mount, NC 27802-1180 / www.rockymountnc.p2 Water Resources will favorably consider these efforts as you deliberate on any further actions regarding these incidents. If you have any questions, or require any additional information regarding our efforts, please do not hesitate to contact me at 252-972-1299 or email at Brenton.bent@rockmountnc.gov Sincerely, Brenton Bent, Director of Water Resources �252) 972-1325 / 331 S. Franklin St., PO Box 1180, Rocky Mount, NC 27802-1180 / www.rockymountnc.900