NC0024881_NOI2022LV0319_Response_20220518

-lir. CITY OF
Reidsville
NORTH H `.t k(] 9.! j.J
Public Works Department
1100 Vance Street, Reidsville, North Carolina 27320
PHONE [phone]
FAX [phone]
RESPONSE TO NOV-2022-LV-0319 FOR PERMIT NUMBER NC0024881
Beginning in December 2021, lab analyses of the City of Reidsville's wastewater
treatment plant effluent revealed increasing concentrations of CBOD, ammonia, and
fecal coliform bacteria.
These concentrations continued building through January 2022 and eventually led to
non-compliance in all three parameters for February 2022.
The facility is also non -compliant for March and April 2022 for CBOD and ammonia.
May 2022 week one CBOD is 4.88 mg/L, and all ammonia results are below the
detection threshold. Fecal coliform bacteria's only excursion for in February.
The ultimate cause of these exceedances was an almost total kill of the facility's
biological treatment process. Contributing factors were:
• Equipment failures of both of the facility's primary wasting systems.
• Secondary wasting method inefficiency increased ammonia throughout the
facility due to excessive supernatant.
• Blockages in several diffusers significantly diminished air flow in the entry zone
of the aeration basin.
• Septicity throughout the entirety of the secondary treatment processes due to
significantly increased solids concentrations and age -related return pump
inefficiency.
• Excessive filamentous growth due to pumping septic liquid from an off-line
aeration basin into the active aeration basin.
The City of Reidsville has undertaken the following corrective actions:
• The primary wasting systems have been returned to service, and solids
concentrations have been drastically reduced.
• Lower solids concentrations have reduced the load on the return sludge train.
• A solid air flow has been re-established to the entry end of the aeration basin.
• Procured and incorporated biological compounds for short-term use to boost
treatment efficiency.

In plain language, the City of Reidsville lost the plant for approximately four to six weeks.
Recovery has been slow, however the facility is currently operating efficiently.