NC0026646_Speculative Limits_19861118

NPDES DOCUMENT SCANHIN` COVER SHEET
NPDES Permit:
NC0026646
Pilot Mountain WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
✓Speculative Limits
Environmental Assessment (EA)
Document Date:
November 18, 1986
This document is printed on remise paper - ignore any
content on the re v ei a side

DIVISION OF ENVIRONMENTAL MANAGEMENT
November 18, 1986
MEMORANDUM
TO: Dale Overcash
FROM: Steve Zoufaly 6Z-
THROUGH: Meg Kerr '--
Steve W. Tedder
SUBJECT: Town of Pilot Mountain
With regards to the letter to Mr. R. Paul Wilms dated October 29,
1986 from Mr. Billy Pell, Town Manager of Pilot Mountain, the limits
they request of BOD5 30 mg/1 and NH3 14 mg/1 in item #1 are acceptable.
The BOD ultimate for these limits is 86 mg/1; BODu = 30 mg/1(1) +
14 mg/1(4). The level B model predicts a BODu of 85 mg/1. With the
normal disaggregation the resulting limits are BOD5 21 mg/1 and NH3
16 mg/1; BODu = 21 mg/1(1) + 16 mg/1(4).
The facility has been having trouble meeting its limits. For the
period of 7/85-6/86 the facility was averaging BOD5 44.97 mg/1 and
NH3 18.12 mg/1. They have also been experiencing toxicity and temperature
violations. The Winston-Salem Regional Office has requested an SOC for
Pilot Mountain and the in -stream assessment has been completed.
There is not a significant difference between the two BOD ultimates.
The facility would have an easier time of meeting the limits they requested
and without additional impact to the receiving stream. Therefore, I
recommend the facility be granted the disaggregation of BODu 85 mg/1
with limits of BOD5 30 mg/1 and NH3 14 mg/1.
SZ:ps

show THE OFFICE OF
Town Manager
RECEIVED
TOWN OF PILOT MOUNTAIN
P.O. DRAWER AA NOV 3 nee
PILOT MOUNTAIN, N. C. 27041
Mr. R. Paul Wilms
Director
Division of Environmental Management
P. 0. Box 27687
Raleigh, N. C. 27611-7687
Div. lei
PHONE [phone]
: iv.r onmental Mgt.
N..C. .
October 29, 1986
NOiV 4 1986
i' " ITS 4 I-Na i-4S
Dear Mr. Wilms,
This correspondence is in reference to the draft NPDES Permit
(NPDES Permit No. NC00266116) proposed for the Town of Pilot
Mountain, North Carolina. With this letter, we are formally
requesting relief from several of the stipulations set forth in
the draft permit.
Specifically, the Town of Pilot Mountain requests amendment
and/or modifications to the permit in the following areas:
1. The existing permit establishes the Summer limitations
for BOD and Ammonia -Nitrogen at 30 mg/1 and 14 mg/1,
respectively. The draft permit proposes limits of BOD
of 21 mg/1 and Ammonia -Nitrogen of 16 ag/l. It is our
understanding that these limitations are based on the
ultimate BOD level that the receiving stream can
accommodate and that there are several combinations of
BOD and Ammonia -Nitrogen values that are acceptable.
We request that the BOD and Ammonia -Nitrogen limits
remain as they are presently, for the summer months, at
BOD of 30 mg/1 and Ammonia -Nitrogen of 14 mg/1.
2. The Pilot Mountain Wastewater Treatment Plant cannot,
without significant upgrade comply with the 85 percent
removal stipulation of the -influent suspended solids.
This is because most of the flow received is from
industrial sources and has very little suspended solids
associated with it. The average annual suspended
_ solids values for 1982, 1983, 1984 and 1985 were 65
' mg/1, 74 mg/1, 78 mg/1 and 76 mg/1, respectively. An
85 percent removal would dictate an effluent suspended
solids level of less than 12 mg/1, consistently.. Past
operating history indicates this is not possible with
this plant and with such a highly industrialized
fraction of flow.
3. We respectfu:ly request that the weekly monitoring
requirement for copper and zinc not be restricted to
sampling only on Wednesdays, Thursdays, or Fridays.

Mr. R. Paul Wilms
October 29, 1986
Page 2.
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Time, personnel and laboratory constraints may dictate
other sampling days. Additionally, by limiting
sampling to only those three days, we may not be able
to accurately correlate plant performance with specific
industrial discharges.
With respect to temperature in the receiving stream, we
have, in previous correspondence, requested a variance
of the limitations of 2.8°C increase in the temperature
of the receiving stream. We also request that the
requirement that the ambient water temperature in the
receiving stream not exceed 29°C be deleted. A maximum
stream temperature standard does not ac
upstream temperatures. It is ossibl at the plant
could comply to the stipula on hat the stream
temperature not be raised more that 2.8°C and be in
violation of the maximum stream temperature of 29°C.
This facility was not designed for, nor intended to,
remove metals from the wastestream. The limitations
proposed for copper a nc will be difficult, if not
imp— s ibTe �o comply with. dditionally, some very
limited data, collected by Town personnel, indicates,
that the copper concentration in Pilot Mountains
drinking water is significantly higher than the
proposed standard for copper of 0.016 mg/1. This may
indicate that even if all industrial sources of copper
were eliminated, the plant would still be in violation
of the standard. We are requesting that both the
copper and zinc limitations be held in abeyance until
such time that it can be established that the plant can
or cannot meet these limits.
Your immediate attention to this matter will be greatly
appreciated. If you have any questions or if I may be of
assistance, please contact me at your convenience.
Sincerely,
TOWN OF PILOT MOUNTAIN
Billy Pell
Town Manager
CC: Mr. C. D. Malone
Mr. Billy Windham
SENT BY CERTIFIED MAIL
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