NC0021423_Pretreatment_STMP_Letter_20191213

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
NORTH CAROLINA
Environmental Quality
December 13, 2019
Via Electronic Mail ([e-mail])
Richard Canipe
Town Manager
Town of Spruce Pine
P.O. Box 189
Spruce Pine, NC 28777
Subject: Pretreatment Review of Short Term Monitoring Plan
Program: Town of Spruce Pine, NPDES #: NCO021423
Mitchell County
Dear Mr. Canipe:
The PERCS Unit of the Division of Water Resources has reviewed the Short Term Monitoring Plan
(STMP) submitted by the Town of Spruce Pine. The submission was received by the Division on
September 16, 2019.
The review indicates that with the following corrections, the STMP is adequate and meet the
requirements needed to establish a site -specific Headworks Analysis (HWA). The updated STMP
was attached. Proper implementation of a STMP is also required by your NPDES permit. Please
refer to the Comprehensive Guidance for North Carolina Pretreatment Programs (Comprehensive
Guide) for additional information and examples.
1. Section A Sampling points:
a. "prior to mixing with side streams" was added for influent. It is critical for the
removal rate calculations that influent samples are taken before any recycle
streams such as return sludge, waste sludge, sludge dewatering and filter
backwash. Please add the recycle streams in Figure 1 so the influent sampling
point can be confirmed to be prior to any side streams.
b. Activated sludge basin description has been revised to "grab sample from the
oxidation ditch" as there are no multiple activated sludge basins.
c. Uncontrollable sample point is optional. From the email communications, the
PERCS unit understands that the Town does not wish to keep uncontrollable
sampling on the STMP and this is acceptable. Please remember to include any
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North Carolina Department of Environmental Quality Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center Raleigh, North Carolina 27699-1617
919.707.9000

additional sampling data in the HWA submission even it is not required in the
approved STMP.
2. Section B POC: As, Hg, Mo, Se, TP, % solids, sludge to disposal flow and TN were removed
from Section B as they are not limited in your NPDES permit nor IUPs nor required by EPA.
3. Section C Flow: Sampling point number was corrected for SIUs. Sludge to disposal flow
statement was removed. It does not apply any longer since the sludge goes to the landfill.
4. Section D SIU Monitoring: Frequency for all POCs was updated to once every five years to
be consistent with Section E.
5. Section E STMP Sampling Frequency: Option 1 and 2 for full programs were deleted as
they don't apply to Spruce Pine. Uncontrollable sampling point was removed as a result
of comment #1.c.
6. Section F Sampling Plan: As, Hg, Mo, Se and % Solids were removed as a result of comment
#2. All pollutants are required to be sampled at influent, effluent and SIUs. Ammonia is
required to be sample at the aeration basin in addition to what was listed in the
submission.
7. Section G Detection Levels: As, Hg, Mo and Se was removed as a result of comment #2.
Cadmium was updated to 0.001 mg/L, lead was updated to 0.005 mg/L and silver was
updated to 0.001 mg/L, according to Deborah Gore's memo dated June 28, 2019.
Please response to this letter before January 31, 2020 to address the following concerns:
1. Update the diagram to include the recycle streams.
2. Update the PERCS unit whether the town would like to add uncontrollable sampling to
the STMP or not.
3. Any objections to this revision.
Thank you for your continued support of the Pretreatment Program. If you have any questions
or comments, please contact me at [phone] [email: [e-mail]].
vz/Spruce Pine.stmp.01
Ec: Central Files (LF)
PERCS Unit file
Linda Wiggs, ARC)
Darrell Graham, ORC
Russell Lankford, Site superintendent
Sincerely,
DocuSigned by:
ong, PERCS Unit
Vivien �h
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