WQCS00025_NOI_NOV2021DV0381_Response_20210924

Water Resources Division
146 N Church Street
PO Box iio6
Asheboro, NC 27204-11o6
N O R T H C A R O L I N A
September 24, 2021
Mr. Lon T. Snider
NC Department of Environmental Quality
Division of Water Resources
450 Hanes Mill Rd
Suite 300
Winston-Salem, North Carolina 27105
Re: Response to Notice of Violation & Intent to Issue Civil Penalty
Tracking No.: NOV 2021-DV-0381
Dear Mr. Snider:
Tel: [phone] Ext. 258
Fax: [phone]
N C Department of
Environmental Quality
Received
SEP 2 7 2021
Winston-Salem
Regional Office
This letter is written in response to the above referenced letter of correspondence from your
office for the sanitary sewer overflows (SSO's) experienced on June 10 and 11, 2021. The City
of Asheboro experienced overflows at lift station numbers 2, 3, 4 & 6 due to heavy rainfall. Rain
gauges measured 3.2 inches of rain in a period of 1-2 hours. This intensity is between a 25 and
50 year storm. The area was under multiple flash flood warnings and some localized street
flooding did occur.
The SSO at Lift Station # 2 (Incident # 202101400) was due to an equipment failure. Lightning
from the storm tripped out the soft start for the lag pump. Logic in the control system called for
the lag pump to start but it couldn't. As soon as staff as was able to troubleshoot the problem,
they were able to reset the soft start and both pumps running quickly cleared the overflow. There
is currently no way for the logic to skip to the third pump in a situation like this. Two pumps
running would have handled the higher flow due to I & I in this event and prevented the SSO.
The SSO at Lift Station # 3 (Incident # 202101401) was due to I & I because of the heavy
rainfall. Maintenance staff responded to the alarm and evaluated the site to monitor the flow.
Laboratory sampling was conducted upstream and downstream of the site and no environmental
impact was measured. The City is in the planning/design stage for an upgrade to this station.
The City has been awarded funding from NCDEQ Division of Water Infrastructure and is
waiting for the Engineering Report approval to complete design plans. This basin and each sub
basin that flows into this station has been investigated to identify inflow/infiltration but no major
sources have been identified.
The SSO at Lift Station # 4 (Incident # 202101402) was also due to I & I because of the heavy
rainfall. The event was monitored and crews cleaned the site once the event stopped. Results of
laboratory analysis reveal no environmental impact to the stream. Flow metering and smoke
testing were utilized in a 2019 flow study in this drainage basin which identified some repairs to
gravity and service lines that were completed swiftly. However, these repairs don't appear to
have greatly decreased the amount of inflow/infiltration in the basin.
Home of the NC Zoological Park

Response to Notice of Violation & Intent to Issue Civil Penalty
9/24/2021
Page 2 of 2
The SSO at Lift Station # 6 (Incident # 202101403) was also due to I & I because of the heavy
rainfall. The event was monitored and crews cleaned the site once the event stopped. Results of
laboratory analysis reveal no environmental impact to the stream. The City did some flow
monitoring in the fall of 2020 that did not reveal any significant results. These meters have been
pulled to do monitoring throughout the system for our AIA study. We plan to get back to flow
monitoring in this basin when data collection for the AIA is complete.
Including these SSO's over the past two months, the overall performance of our system is
exemplary. The 2020 System Performance reveals that of the more than 1.5 billion gallons of
wastewater treated at the City of Asheboro W WTP, less than 0.05% was spilled at the plant or in
the collection system. Laboratory personnel sample after every SSO as soon as it is safe to do
so. None of the laboratory results from any SSO on these two dates revealed significant
environmental impact.
The City of Asheboro is committed to protecting the environment and improving wastewater
collection service to customers. We are working from many angles to address issues that will
improve the operation of our collection system. Staff is continuing flow monitoring and will be
aggressive in locating potential I & I sources and making repairs. The Capital Improvement Plan
provides future resources for studies, repairs and replacements to the wastewater collection and
treatment systems.
The City is currently utilizing a grant from NCDEQ Division of Water Infrastructure to complete
and Asset hiventory Assessment of our collection system. We have contracted with Freese &
Nichols to complete and assessment of the system and provide an updated Capital Improvement
Plan to prioritize future projects to eliminate SSO events.
Please take these efforts into consideration as you deliberate these matters. The City requests
NCDEQ refrain from taking enforcement action as a result of these incidents. The City of
Asheboro takes pride in being good stewards of the environment and is taking measures to
ensure water quality in our community. Thank you for your consideration in this matter. If you
have any questions, please contact me at [phone] ext. 258.
Sincerely,
Michael D. Rhoney, P.E.
Water Resources Director
ASHEBOfU
WATER RESOURCES