NC0069523_NOV-2020-LV-0547_20200731

Department of Public Works
Water/Wastewater Division
4600 Goldmine Road
Monroe, INC 28110
T. 704-289-1434
F. 704-289-7395
www.unioncountync.gov
July 31, 2020
W. Corey Basinger,
Regional Supervisor
NCDEQ
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Dear Mr. Basinger,
WQ O
OORESVIL E REGIONAL OFFICE
This letter is in response to NOV-2020-LV-0547, outlining the exceedance in monthly flow that
was experienced at our Tallwood WRF in May 2020. This exceedance was a result of
I&I in the collections system.
In early May 2020, the WRF staff notified collections system staff of higher -than -normal flows
being experienced at the WRF. Collections staff began an investigation consisting of
smoke testing and manhole inspections. Findings included multiple defects which have since
been addressed. A list of repairs includes:
• Multiple broken clean -out caps replaced
• Repair of a man hole vent pipe that had broken off below grade
• Installation of sealed manhole lid in a critical location.
® Discovered and repaired major pipe defect., (22' below grade)
® Grouted leaking cone on a manhole.
• Injected grout around outfall pipe to stop I&I
Since these repairs were performed, WRF staff have seen a noticeable decrease in flows to the
plant. June ADF is down to 0.026, even with multiple rain events. For the last 12 months the
calculated annual ADF is 0.035.
We intend to continue our efforts finding and reducing the I&I in the Tallwood basin. If you have
any questions or concerns please contact me at 704-296-4215.
Sincerely,
� �J
Andrew Neff, PE
Water & Wastewater Division Director
Cc:
Hyong Yi, Public Works Administrator
Josh Brooks, Asst. Div. Director, Water & Wastewater
Bart Farmer, WRF Superintendent
Greg Morgan, Utility Services Superintendent
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