NC0085812_4/24 mail Union Co NOV responses_20200424

Strickland, Bev
From: Pitner, Andrew
Sent: Friday, April 24, 2020 4:21 PM
To: Scheller, Roberto
Cc: Basinger, Corey
Subject: 4/24 mail Union Co NOV responses
Attachments: D00042420-04242020-004.pdf, D00042420-04242020-003.pdf
Roberto,
Ori scanned the mail for 4/24 and Union Co submitted the attached two responses to recent NOVs.
Andrew
Andrew Pitner, P.G.
Assistant Regional Supervisor
Water Quality Regional Operations Section
Mooresville Regional Office
Division of Water Resources
Department of Environmental Quality
704 235 2180 direct office
704 663 1699 MRO main line
704 663 6040 fax
DWR website: http://www.ncwater.org
610 East Center Avenue, Suite 301, Mooresville, NC 28115
Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed
to third parties.

Department of Public Works
Water/Wastewater Division
4600 Goldmine Road
Monroe, NC 28110
T. 704-289-1434
F. 704-289-7395
www.unioncountync.gov
April 22, 2020
W. Corey Basinger,
Regional Supervisor
NCDEQ
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Dear Mr. Basinger,
RECEIVEDAVCDENR/DWR
APR 2 4 2020
WQROS
MOORESVILLE REGIONAL OFFICE
This letter is in response to NOV-2020-LV-0272, outlining the exceedance in monthly flow that
was experienced at our Tallwood WRF in January 2020. This exceedance was a result of
damage in the collections system, as well as higher than normal rain flows (6.2").
In early February 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:
• Re -lining and grouting of the influent wet well to eliminate infiltration at joins and pipe
penetrations.
• Installing inflow collector dishes in low-lying manholes.
• Installation of sealed manhole lid in a critical location.
• Repair/replace four clean -out caps.
• Repair of broken stand pipe.
• Discovered and repaired major pipe defect.
• Grouted leaking cone on a manhole.
Since these repairs were performed, WRF staff have seen a noticeable decrease in flows to the
plant. March ADF is down to 0.048.
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,
Andrew Neff, PE
Water & Wastewater Division Director
Cc: Hyong Yi, Public Works Administrator
Josh Brooks, Asst. Div. Director, Water & Wastewater
N co Bart Farmer, WRF Superintendent
No
13421 �y�` Greg Morgan, Utility Services Superintendent
Spy cA�o�

Department of Public Works
Water/Wastewater Division
4600 Goldmine Road
Monroe, NC 28110
T. 704-289-1434
F. 704-289-7395
www.unioncountync.gov
April 22, 2020
W. Corey Basinger,
Regional Supervisor
NCDEQ
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Dear Mr. Basinger,
RECEIVErVNCDENR/DWR
APR 2 4 2020
WOROS
MOORESVILLE REGIONAL OFFICE
This letter is in response to NOV-2020-LV-0270, outlining the exceedance in monthly flow that
was experienced at our Grassy Branch WRF in February 2020. This exceedance was a result
of multiple rain events in the system (6.5" for the month) as well as the capacity issues we have
discussed in previous conversations.
In our meeting on 05/02/2019, we detailed our efforts in reducing the I&I that is entering the
Grassy Branch collection system. Since that meeting our Collections team has continued
working to improve the system. Such efforts include:
• Smoke testing
• Camera work and jetting
• Visual inspections during rain events
• Manhole rehab
• Installation of inflow collector dishes
As stated in our last response letter, we are also wrapping up a comprehensive flow monitoring
study by Frazier Engineering. This study will give us more than 12 months of data, including
both dry and wet season flow characteristics. Once we evaluate this data, we will then start
micro -monitoring to pinpoint areas in the system that could profit from future repair/rehab efforts.
Since that last response, we have submitted a task order to keep the six flow monitors in place
for an additional six months to further evaluate the system.
In addition to the I&I reduction, we are in the process of obtaining a SOC agreement with
NCDEQ and Union County in order to expand the plant. This will allow us to better address the
capacity of the WRF to treat the flows.

We intend to continue our efforts finding and reducing the I&I in the Grassy Branch basin even
as we address the treatment/capacity issues at the Grassy Branch WRF. If you have any
questions or concerns please contact me at 704-296-4215.
Sincerely,
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
Page 2