NC0072877_Technical Assistance_20000831

NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
FAYETTEVILLE REGIONAL OFFICE
August 31, 2000
The Honorable William Wilson
Mayor, Town of Newton Grove
PO Box 4
Newton Grove, NC 28366
SUBJECT: Technical Assistance Evaluation
Town of Newton Grove
Wastewater Treatment Plant
NPDES Permit No. NC0072877
Sampson County
Dear Mr. Wilson:
On August 15, 2000, I met with the Newton Grove Wastewater Treatment Plant
ORC, Mr. Jim Balance, to discuss the facility's NPDES permit compliance problems
regarding ammonia nitrogen limits. I was given a tour of the facility, which has a good
process appearance as well as a clear effluent.
I had numerous process control questions that could not be answered, because
Mr. Balance said the plant had operated so well, that he could not justify the expense for
the lab test needed. I explained that constant monitoring is the only way he would know
how to correct the process when there was a problem.
The following are the tests that I recommend be analyzed for process control:
MLSS, MLVSS, RAS — TSS, influent ammonia nitrogen and BOD, clarifier alkalinity
(analyze weekly) and oxidation ditch D.O.'s, pH (analyze daily).
The activated sludge settled not at all, so it was examined under the microscope
and filaments were found to be one of the causes for the settling problem. Filaments are
usually caused by one or a combination of the following: low f/m, high MCRT, and low
aeration D.O.. We checked the basin D.O. and found it to be low, 0.8 brush discharge,
0.5 at mid -point, and 0.1 before the brush.
I took a basin sample and sent it to Microbac Lab for solids analysis. The MLSS
was 3476, MLVSS was 2770, and RAS was 7256. The MCRT calculated to be 49 days
and the f/m was 0.03. As soon as the ammonia nitrogen is back under control, I
recommend that you increase the wasting to reduce the MCRT to 20 — 24 days, which
will lower the MLSS and increase the f/m. This should help with the filamentous bulking
in the activated sludge basin.
10191111011111111911
225 GREEN STREET, SUITE 714 / SYSTEL BLD. FAYETTEVILLE, NORTH CAROLINA 28301-5043
PHONE [phone] FAX [phone]
AN .EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/1 O% POST -CONSUMER PAPER

Mayor Wilson
Page 2
August 31, 2000
Mr. Balance told me of what appeared to be several Friday afternoon occurrences of
unidentifiable wastewater received at the plant causing a possible organic overload. He is going to collect
samples from the collection system to determine the source of the high strength discharge. In order to
meet the ammonia nitrogen limit, it is crucial for the plant not to be organically overloaded.
I am requesting that Mr. Balance fax me a summary of the weekly lab information, so that I can
follow the progress of the recovery of the facility's nitrification system.
Respectfully,
441
Don Register
Environmental Technician IV
/dr
cc: Jim Balance, Town of Newton Grove
Dwight Lancaster, Training & Certification
FRO File