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HomeMy WebLinkAboutWQCS00012_NOV-2020-DV-0081 Response_20200319M N= Cape Fear Public Utility Authority Stewardship. Sustalnabllity. Service. March 16, 2020 Tom Tharrington Asst. Regional Supervisor Water Quality Regional Operations Section Division of Water Resources, NCDEQ 127 Cardinal Drive Extension Wilmington, North Carolina 28405 Subject: Notice of Violation NOV-2020-DV-0081 Sanitary Sewer Overflows — December 2019 Dear Mr. Tharrington: Frank C. Styers, PE Assistant Executive Director 235 Government Center Drive Wilmington, NC 28403 910-332-6670 f ra n k.stvers@dpua. ora RECEIVED/NCDENR/DWR MAR 19 2020 Water Quality Regional Operations Section Wilmington yepional Office I am in receipt of your March 5, 2020 Notice of Violation (NOV) letter related to the sanitary sewage overflow (SSO) from the failure of the CFPUA Smith Creek Pump Station (Pump Station 10). The SSO occurred on December 17, 2019 and allowed approximately 2.44 million gallons of sewage to enter the receiving waters of Smith Creek. The cause of the failure appears to have been corrosion of the ductile iron discharge pipe directly outside of the pump station, likely due to the accumulation of hydrogen sulfide gas. CFPUA staff initiated its response on December 17th at 8:30 am immediately after being notified that an SSO was occurring at the pump station. When staff arrived and observed conditions at the station, CFPUA crews and our contractors worked around -the -clock on two important fronts — to limit the extent of the spill and to stop it. Within about an hour of the first report, CFPUA vactor trucks were at the scene, to be joined by others from a contractor. Pump and haul operations were conducted for the duration of the event. In total, about 500,000 gallons of wastewater were recovered from either upstream of the pump station site or the SSO site, minimizing the volume of untreated wastewater that was released. To stop the spill, crews initially attempted a bypass with standby equipment onsite. When that was unsuccessful, they constructed a 600-foot temporary bypass force main using high -density polyethylene pipe to route the wastewater from the failed pipe to a new force main that had March 16, 2020 Page Two recently been installed as part of our ongoing project to build a replacement for Pump Station 10. Just before 1:00 am on Thursday, December 19th, the temporary bypass was completed and successfully put into operation, stopping the SSO. Once the temporary bypass was operational, repair of the failed pipe began. The repair was completed late Sunday, December 20th, and the station was placed back into operation the following morning. The temporary bypass pumps and piping will remain onsite and available to the greatest extent possible until construction of the replacement pump station is complete. Additional system modifications are underway to prevent future SSO's from occurring. Our ongoing investment in our wastewater collection system includes the $8.9 million project underway near the SSO site to build a complete replacement for the current Pump Station 10. The replacement station is due to come online and be operational as early as August. CFPUA's 10-year Capital Improvement Plan (CIP) focuses on aging infrastructure and includes strategies to proactively investigate and prioritize the rehabilitation and/or replacement of aging infrastructure. An example is our "Find it, Fix it" program, which involves CCTV inspection and in -place lining of pipes in our collection system. The total capital investment in the approved 10-year CIP is $272,160,000, with the largest share — 73.2 percent or $199,230,000 — going toward rehabilitation and replacement of aging infrastructure. CFPUA also has an Odor and Corrosion Control program that provides for chemical treatment within the sewer collection system to prevent the formation of corrosive sewer gas within the system which will help avoid the recurrence of similar situations. The NOV also refers to the SSO that resulted from damage to a four -inch CFPUA sewer force main near 1422 Halcyon Lane. The SSO occurred on December 9, 2019 and allowed approximately 500 gallons of sewage to enter the receiving waters of the Intracoastal Waterway. The force main was struck and damaged by a contractor, Rainstorm Solutions, performing stormwater system modifications, likely on behalf of the development's Homeowner Association. CFPUA informs outside contractors of the location of underground utility lines through NC 811. Contractors engaging in excavation are required by law to contact NC 811 prior to working. Rainstorm Solutions did not properly contact NC 811 or CFPUA prior to the work. The sewer force main was not marked, and the contractor failed to investigate for existing utilities prior to excavation. March 16, 2020 Page Three Upon notification of the damage, CFPUA immediately turned off the pump station to stop wastewater from flowing to the broken force main. The SSO was stopped approximately 50 minutes from the time of first knowledge. CFPUA vactor trucks were mobilized to capture sewage that was escaping from the broken force main before it reached surface waters. This effort recovered approximately 400 gallons of sewage that had been released. CFPUA crews also repaired the force main and cleaned the area. CFPUA billed the contractor for reimbursement for damages and expenses incurred. CFPUA makes efforts to prevent the recurrence of similar situations by promoting and improving the effectiveness of its participation with NC 811. CFPUA typically attends regular monthly meetings of the Utilities Coordinating Committee of the Lower Cape Fear. The purpose of the committee is to bring together NC 811 representatives with utility owners and excavators. Meeting topics include review of NC 811 procedures, opportunities to improve coordination, and collaboration on specific projects. It is unfortunate that these SSOs occurred. The scale and intensity of our response speaks to the seriousness with which we take our role as stewards of the environment. CFPUA recognizes the seriousness of this violation. Based on the information presented in this letter, we respectfully request that CFPUA not be assessed a civil penalty for the NOV issued on March 5, 2020. I would be glad to meet with you to discuss this further or to provide additional information. Sincerely, Frank C. Styers, PE Deputy Executive Director