NC0025445_Tech_Assist_Inspection_20180525

Water Resources
Environmental Quality
May 25, 2018
Michael Glass
City of Randleman
204 South Main Street
Randleman, NC 27317
Subject: Technical Assistance Visit
NPDES Permit NCO025445
Randleman WWTP
Randolph County
Dear Mr. Glass,
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
On Thursday, May 17, 2018, 1 met with you for a Technical Assistance visit at the Randleman
Wastewater Treatment Plant located at 3475 Applewood Road in Randleman. The visit was at
your request concerning some higher than normal ammonia results that you had experienced
during the last 5 months, starting in December 2017. My observations, and highlights of our
conversation are listed below for your review.
The entire aeration system in all four basins has now been upgraded. However, with two blowers
running the basins have trouble reaching a D.O. level of 1.0 mg/I. When a third blower is turned
on the basins develop a frothy foam in excessive amounts that carries over to the clarifiers. The
Town has reached out to several individual experts for technical assistance, but no one has been
able to pinpoint the problem.
Although nothing conclusive was found to be the cause of the foaming problems, the following
remedial actions were discussed:
1. The day of my visit the MLSS was 4880 mg/I in Plant #1, 7720 mg/I in Plant #2, 4730 mg/I
in Plant #3, and 2920 mg/I in Plant #4. You explained that holes had recently been
discovered in the splitter box that feeds the 4 aeration basins. A new splitter box was
being fabricated and would be immediately installed when it arrived at the plant.
2. Lowering the MLSS after balancing out the contents in each aeration basin. This might
reduce the dissolved oxygen demand and raise the D.O. to an acceptable range for
nitrification to occur.
3. While running the third blower with only fine air diffusers it might be possible that with the
lack of mixing, the aeration basins are turning into a type of dissolved air flotation unit. If
this is a possibility, perhaps adding some course air diffusers to improve mixing would
remedy this problem.
<�Nothtng Compares -,-
State State of North Carolina I Environmental Quality

Our office appreciates the effort that you and the City of Randleman puts into staying in
compliance with your NPDES permit by reaching out to the Winston-Salem Regional Office, as
well as other wastewater treatment professionals for technical assistance.
In closing I would like to thank you for the opportunity to visit the City of Randleman Wastewater
Treatment Plant, and try to help you with your plant problems. It was a pleasure getting to work
with you and tour the plant. If I can be of any more help, please don't hesitate to contact me at
Gary. Hudson(&ncdenr.gov or [phone].
Sincerely,
Gy Hudson
Regional Consultant
Water Quality Regional Operations
NC Division of Water Resources