WQCS00054_NOV-2019-DV-0355 Response_20190913

Public Works
500 North Main Street
Suite # 600
Monroe, NC 28112
E S'1l. 1842
September 13, 2019
Mr. W. Corey Basinger
Regional Supervisor
Water Quality Regional Operations Section
Mooresville Regional Office
610 East Center Ave., Suite 301
Mooresville, NC 28115
Subject: Notice of Violation & Intent to Issue Civil Penalty
Tracking #: NOV-2019-DV-0355
Sanitary Sewer Overflows — August 2019
Collection System Permit — WQCS00054
Union County
Dear Mr. Basinger:
Union County has received the NOV referenced above for collection system overflows.
Explanations of the overflows were on the BIMS Overflow Reporting Forms submitted by Union
County Public Works (UCPW) to the NCDEQ. However, we have added a few additional facts
n the explanations below.
Incident # Date Location
201901354 8/13/2019 5012 Lydgate Drive
Response:
The sewer overflow was the result of construction debris accumulation in the pipes. The sanitary sewer overflow
occurred behind 5012 Lydgate Drive out of a sanitary sewer manhole. The overflow began at approximately 11:20 am
asting until 11:35 am on August 13, 2019, and is estimated at 150 gallons. There were no signs leading up to the
spill that would indicate a backup was to occur.
Incident # Date Location
201901430 8/23/2019 4015 Sardis Church Road
Response:
The SSO listed in this section were due to I&I introduction during heavy rains and flash flooding. The system
associated with this area was inundated with floodwaters and increased flows at CCWRF. The new CCWRF EQ
system was being utilized to attenuate peak flows experienced during storm events, however, during construction of
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the new gravity system an existing 8-inch gravity main located on the north side of Sardis Church
Road was thought to be abandoned and as such was not reconnected to the new gravity system.
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This line is connected to a 12-inch line on the south side of Sardis Church Road, however, without the parallel 8-inch
line available to convey flow the collection system experienced a severe hydraulic condition. The 8-inch line has been
connected to avoid this restriction in the future. Plans are being developed with our CIP team to resolve to improve
general hydraulics in this area. Also the Notice of Violation states a duration of 990 minutes which should be
corrected to 270 minutes.
Union County Public Works has underwent a comprehensive Master Plan (Black & Veatch) and improvements
strategy in efforts to better identify areas of improvement within the Crooked Creek basin. Efforts such as flow
monitoring studies (CDMSmith/Hydrostructures and Frazier Engineering) to identify areas of inflow and infiltration,
capacity assessments of the CCWRF and associated lift stations, lift station assessments to identify aging
nfrastructure, among others.
As a result of these studies, UCPW has developed a CIP plan to address certain areas of concern.
A significant plant upgrade at the Crooked Creek WRF was completed including new headworks, a 3MG EQ
basin, and process improvements. Total cost is $7.775M project also included a new 10.3 MGD influent PS,
new headworks containing new bar screens, compactor, and grit removal/dewatering, and relocation of
1200' of 18" gravity sewer.
&I flow studies have been conducted by CDMSmith/Hydrostructures and Frazier Engineering. These
studies have narrowed the basin into concentrated sub -basins to target I&I reduction. The intended
approach is a find -fix method to utilize funding efficiently and consistently. The first initial 2017 target area is
southwest of CCWRF in the Indian Trail area south of Hwy 74, west to the Union/Mecklenburg county line.
This I&I abatement work has been completed. Additional areas for I&I abatement are being evaluated.
UCPW also has an aggressive Capital Improvement Program throughout the next 5 years. The
projects include:
`r Crooked Creek Basin Improvements - $24,259,922.00
➢ Crooked Creek Interceptor Improvements Ph. 1 - $9591515C0.00
Suburban Estates PS and FM - $1,000,000.00
➢ WaxhawInterceptor —3,200,000.00
WW PS Improvements - $3,600,000.00
Collection System SSES & Rehab — $2,080,000 (not including $85k annually in
Operations)
➢ PS Upgrades - $300,000 annually
UCPW's current CIP projects are also ongoing with projects including:
`r Waxhaw Sewer Improvements - $295,000.00
➢ Blythe Creek Sewer Improvements - $3,083,200,00 _
➢ Forest Park PS Replacement & Interceptor Improvements - $2,540,000.00
➢ Crooked Creek I&I Study & Remediation - $2,538,300.00
Suburban Estates PS replacement-S933,000.00

Union County Public Works continues to invest in SSES work, capital improvements,
maintenance and operations to improve the wastewater collection system. If further information
or details regarding the CCWRF Improvements, as well as, the CIP projects listed above are
required, please feel free to contact Greg Morgan, Superintendent/ORC, at 704-289-3288 or
myself at 704-296-4215.
Thank you for your consideration on this issue.
Sincerely,
aulL
Andrew Neff, PE
Water/Wastewater Division Director
cc: Hyong Yi, Public Works Administrator
Josh Brooks, Assistant Director, WaterMastewater Operations
Greg Morgan, Utility Field Services Superintendent/ORC