NC0021211_202404Response_20240724

Tity of &a4am
P O. Drawer 357
201 South Main Street
Graham, North Carolina 27253
Tel: [phone] / Fax: [phone]
July 15, 2024
Certified Mail No. 7015 0640 0002 3551 9271
Lon T. Snider
NCDEQ\DWR
450 West Hanes Mill Rd., Suite #300
Winston-Salem, NC 27105
Dear Mr. Snider:
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Subject: Tracking No.: NOV-2024-LV-0567
Limit Exceedance Violations — April 2024
City of Graham
NPDES Permit # NCO021211
Alamance County
Winston;
Regis:...:'
The City of Graham received a notice of violation and intent to issue civil penalty for
Limit Exceedance violations of our permit in April 2024. The City of Graham requests that you
consider the following response in your decision process prior to taking enforcement action.
On the morning of Monday, April 8, 2024, the shaft on one of the two surface aerators in
our Extended Aeration basin became dislodged and fell into the basin. The City spent almost
$38,000 five years ago completely rehabbing this aerator. Included in this rehab was the
disassembling and cleaning of all parts in the motor and gearbox, the installation of new bearings,
shims, seals and a new shaft which was balanced and tested. In the past, when an aerator would
fall into an Aeration Basin, we would simply move operations over to our other Aeration Basin
until repairs could safely be made. Due to ongoing construction from our plant upgrade, the
other Aeration Basin was not available as it is being converted to BNR Process tanks. Because of
this, a floating aerator was placed into service in the basin later that same day. This process
change due to equipment failure was reported to Ron Boone at the Winston-Salem Regional
Office. Initially, the floating aerator seemed to be a suitable replacement. But as temperatures
increased during the month, the floating aerator struggled to provide adequate air in the basin.

As a result, Ammonia levels began to rise which led to the two weekly violations and eventually
a monthly violation. Prior to the equipment failure, weekly and monthly Ammonia results for the
plant had been in compliance.
Based on the information provided herein, the City of Graham request that enforcement
action not be taken for these Limit Exceedance violations. Thank you for your consideration in
this matter. Should you have any question please contact me via email at
tmann[[e-mail] or by phone at 336-570-6721.
Sincerely,
Tonya Mann
Utilities Director
Cc: Megan Garner, City Manager
Cris Routh, Wastewater Treatment Plant Superintendent