NC0076431_NOV-2021-LV-0578 Response_20210817

d"LMCarolina Water Service
Iltm of Noah Carolina"'
August 17, 2021
AUG 18 2021
Daniel Boss
Assistant Regional Supervisor
Water Quality Regional Operations Section
Asheville Regional Office
Division of Water Resources, NCDEQ
SUBJECT: NOV-2021-LV-0578 Response
Wolf Laurel WWTP: NCO076431
Carolina Water Service Inc. of North Carolina
Madison County
Dear Mr. Boss,
Water (.duality Regional Operatiors
Asheville Regional Office
On June 9, 2021, The North Carolina Division of Water Resources conducted an inspection of our Wolf
Laurel facility. During the inspection, it was noted that the sludge blanket in the clarifier was much
higher than they would expect. As per their request, the solids were pumped out to lower the percent
solids in the aeration. This did lower the sludge blanket but also severely impacted the treatment
process, specifically the ammonia levels.
In addition, a full investigation was performed internally to evaluate any other potential causes. A small
hole in one of the drop pipes was discovered. We have made repairs to the drop pipe to ensure proper
airflow into the treatment plant.
This treatment facility regularly meets or exceeds all compliance limits set forth, and we believe this rare
instance was caused by the abrupt treatment change. Going forward, major treatment changes, such as
lowering the sludge blanket, will be done slowly and methodically.
If you would like any additional information or have any questions, please do not hesitate to contact me.
Respectfully,
Neil Reece -
Ronnie "Neil' Reece
Area Manager
CC: Tony Konsul — Director of State Operations; CWSNC
Brent Milliron — Regulatory Compliance Manager; CWSNC
e 4944 Parkway Plaza Blvd. Suite 375 9 Charlotte, North Carolina 28217 •800-525-7990