WQCS00009_NOV-2020-DV-0452 Response_20201102

WSACC
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IS01WOt2G01 • N013 Pu61th(ta • OHSAS180011001
November 25 2020
W. Corey Basinger, Regional Supervisor
Water Quality Regional Operations Section
Division of Water Resources, NCDEQ, MRO
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Re: NOV-2020-DV-0452, Collection System Permit No. WQCS0009
Water and Sewer Authority of Cabarrus Co Collection System
Cabarrus County
Dear Mr. Basinger:
WATER & SEWER AUTHORITY
OF CABARRUS COUNTY
Off ce: 232 Davidson Hwy,
Concord, NC 28027
704.786,1783 ♦ 704,795.1564 Fax
www.wsacc.org
WSACC is in receipt of the NOV for a Sanitary Sewer Overflow near 2001 Mount Pleasant Road South, Mount Pleasant,
NC. Below is a summary of background information and steps taken as a result of the overflow:
2001 Mount Pleasant Road South Force Main Failure and Spill
- The wastewater spill occurred due to the failure of an 8" PVC force main just downstream of the Mt. Pleasant
Pump Station # 1. The referenced pump station was upgraded in 2018. The force main was installed in 1981
and has been in continuous operation over the past 39 years.
The spill was discovered by a WSACC employee during a routine pump station inspection at approximately
2:30 pm on 9/30/2020. WSACC deployed a crew to the scene, but was unable to excavate to the line
immediately due to the depth of the line. WSACC contacted BRS that afternoon for assistance, and BRS
committed to be on -site to review the problem on the morning of 10/1/2020.
BRS visited the site on the morning of 10/1/2020 and reviewed the problem with WSACC personnel. BRS
established that their first availability to excavate and repair the line would be on 10/5/2020, and WSACC
requested that BRS move forward with mobilizing personnel and equipment to the site for the repair as soon
as possible. WSACC personnel also checked with other local contractors, but were unable to locate a
contractor with faster availability to make the repair.
WSACC personnel set up a bypass pump at the site on 10/1/2020 and rented and assembled associated high-
pressure bypass piping, stopping the source of the leak while still conveying flow from affected portions of
the collection system. WSACC operated the bypass pump throughout the duration of the repair.
BRS mobilized to the site starting on 10/5/2020, and excavated and identified the failed section of line. BRS
subsequently removed and replaced the failed section of line. WSACC and BRS observed that the failed
connection on the line had a bind from installation. WSACC believes that this bind contributed to the failure.
WSACC restarted the pump station on 10/8/2020, and, following confirmation of no leakage from the repair
area, shut down and disassembled the bypass pump and associated piping on the same day.
WSACC monitors this line on a regular basis and will continue to be proactive in watching for any leaks or
needed repairs.
WSACC will continue to monitor this area along with other areas throughout our system. WSACC will also continue to be
proactive to protect our facilities and to take all steps possible to prevent future spills. Please let me know if you have any
questions.
Sincerely,
Water and Sewer Authority of Cabarrus County
J
Thomas Hahn, PE
Assistant Engineering Director
cc: Mr. Chad VonCannon, Engineering Director
Mr. Wayne Lyles, Interceptor Supervisor