NC0020761_PERMIT MODIFICATION_20121115

NPDES DOCUWEMT SCAMMIMO COVER $MEET
NPDES Permit:
NC0020761
North Wilkesboro WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification?
Complete File - Historical
Speculative Limits
Instream Assessment (67b)
Environmental Assessment (EA)
Permit
History
Document Date:
November 15, 2012
Timis document iB Printed on reuise paper -ignore ahy
content cbxx the reverme Bide

A�
NC®ENR
North Carolina Department of Environment and Natural Resources
Beverly Eaves Perdue
Governor
Mr. Bradley Bucy
Hobbs Upchurch Associates
9140 Arrowpoint Blvd / Ste 120
Charlotte, NC 28273
Dear Mr. Bucy:
Division of Water Quality
Charles Wakild, P.E.
Director
November 15,, 2012
Dee Freeman
Secretary
Subject: Modification of NPDES Permit NCO020761
Thurman Street WWTP
Wilkes County
The Division has reviewed the modification request you submitted on October 26, 2012,
The Division has no objection to your request. This modification is issued pursuant to the
requirements of North Carolina General Statute 143-215.1 and the Memorandum of Agreement
between North Carolina and the U.S. Environmental Protection Agency dated October 15, 2007
(or as subsequently amended).
This modified permit includes the following changes from your current permit:
➢ The list of installed components on the Supplement to Permit Cover Page limit has
been updated.
➢ The Total Residual Chlorine limit and associated monitoring requirements have been
made optional, effective only if chlorine is used for disinfection.
Insert the enclosed pages into your permit. You may discard the old pages. The changes in
this permit modification are effective November 1, 2012.
If any parts, measurement frequencies or sampling requirements contained in this
modification are unacceptable to you, you have the right to an adjudicatory-hearing upon written
request within thirty (30) days following receipt of this letter. This request must be in the form of
a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed
with the Office of Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina
27699-6714). Unless such demand is made, this decision shall be final and binding.
This permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the
legal requirements to obtain other permits which may be required by the Division or permits
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 One
512 North Salisbury Street, Raleigh, North Carolina 27604 NOi-ChC11'011lla
Phone: [phone] FAX [phone] / Internet: www,ncwaterqual'dy.org
An Equal Opportunity/Affirmative Action Employer — 50% Recycled110"/6 Post Consumer Paper Naturally

required by the Division of Land Resources, the Coastal Area Management Act or any other
Federal or Local governmental permit that may be required.
If you have any questions concerning this matter, please contact Charles H. Weaver at
[phone]. or via e-mail [[e-mail]].
Since ely,
A U
, r Charles akild, P.E.
cc: Central Files
Winston-Salem Regional Office / Surface Water Protection
�NPDES Unit)
Jimmy MG Rrtrtin [100 Thurman St, North Wilkesboro, NC 28659]

Permit NC0020761
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge, are hereby
revoked. [The exclusive authority to operate this facility arises under this permit. The authority
to operate the facility under previously issued permits bearing this number is no longer effective.]
The conditions, requirements, terms and provisions of this permit authorizing discharge under
the NPDES govern discharges from this facility.
Town of North Wilkesboro
is hereby authorized to:
1. Continue to operate an existing 2.0 MGD wastewater treatment facility
that includes the following components:
Mechanical bar screen and manual bypass bar screen
Grit chamber
Influent pump station
Influent flow measurement
Primary clarification
Dual aeration basins
Secondary clarification
UV disinfection
Flow measurement
Aerobic digestion
Sludge thickening
Sludge drying beds
Sludge storage
This facility is located at the Thurman Street WWTP (100 Thurman St,
North Wilkesboro) in Wilkes County.
2. Discharge from said treatment works at the location specified on the
attached map into the Yadkin River, currently classified C waters in
hydrologic unit 03040101 of the Yadkin -Pee Dee River Basin.

Permit NCO020761
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
Beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to
discharge treated wastewater from Outfall 001. Such discharges shall be limited and monitored by the
Permittee as specified below:
PARAMETER
EFFLUENT LIMITATIONS
MONITORING REQUIREMENTS
[PCS CODE]
Montldy Average
Weekly
Daily
Measurement
Sam Ie T e
Prequency yp
Sample
Average
Maximum.
F
Location I
now
2.0 MGD
Continuous
Recording
6
Influent or
[50050�
L'Efluent
B0135, 20°CZ
30.0 mg/L
45.0 mg/L
. 3/Week
Composite
Influent,
1003101
Effluent
Total Suspended Solidsc
30.0 mg/I.
45.0 mg/1.
3/\C�eck
Composite
Influent,
[00530�
Lffluent
NI f3 as N [00610]
(April I -October 31)
9.0 mg/L
27.0 mg/]:,
3/Week
Composite
Effluent
N143 as N [00610]
(November 1-March 31)
24.0 mg/I,
35.0 mg/1.,
3/Week
Composite
Effluent
Fccal Coliform
200/100 ml
400/100 nil
3/Week
Grab
Effluent
[3161 G1
hccal Colifonn
[31616]
3/Week
Grab
U & D
Total Residual Chlormc3
[SOOGO]
28 µg/L
3/Week
Grab
Effluent
Temperature, -C
[00010]
3/Week
Grab
Effluent
pl-I
> 6.0 and < 9.0 standard units at all times
3/Week
Grab
Effluent
[00400]
'total Nitrogen
[006001
Monthly
Composite
Effluent
Total Phosphorus
(00G65�
Monthly
Composite
Effluent
Chromc Toxiclty4
[TGP3B]
Quarterly
Composite
Effluent
Footnotes:
1. U: at least 100 yards upstream from the outfall. D: at least 100 yards downstream from the outfall. As a
member of the Yadkin -Pee Dee River Basin Association, the subject facility is not responsible for
conducting the instream monitoring requirements summarized above. Should your membership in the
Association be terminated, the Division shall be immediately notified and all instream monitoring
requirements will be immediately reinstated.
2. The monthly average effluent BOD5 and total suspended solids concentrations shall not exceed 15% of
their respective influent value (85% removal).
3. Limit and monitoring requirements apply only if chlorine is used for disinfection. The Permittee shall
report all effluent TRC values reported by a NC -certified laboratory [including field-certifred]. Effluent
values < 50 Ng/ L will be treated as zero for compliance purposes.
4. Chronic Toxicity (Cenodaphnia) P/F Q 1.5% with testing in January, April, July, and October [see A. (2) of
this permit].
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN TRACE AMOUNTS.

7� Hobbs Upchurch Associates
tin � ���� �„yiripering Punning I wrvaying
October 26, 2012
Charles Weaver
Winston Salem Regional Office
NCDENR
585 Waughtown Street
Winston Salem, NC 27107
Re: Town of North Wilkesboro — Thurman Street W WTP
NPDES #NC0020761
Administrative Revision to NPDES for UV Disinfection
Mr. Weaver:
The Town of North Wilkesboro has completed construction of a new dual bank UV
disinfection system capable of treating a peak flow of 5.0 MGD with 100% redundancy
and a 405 kW generator, in conformity with the project plans, specifications, and other
supporting data subsequently filed and approved by the Department of Environment and
Natural Resources under A to C No. 020761A02. The Engineer's Certification letter as
sent to NC DENR / D WQ Construction Grants and Loans is attached.
We request the subject NPDES #NC0020761 be updated to reflect the following
New UV disinfection system and generator as outlined above
Elimination of chlorine disinfection and sodium hisulfrte dechlorination
Removal of Total Residual Chlorine Monitoring requirements
'fhank you for your assistance. If you need any additional information, please contact me
at 704-342-3000.
Sincerely,
HOBBS, UPCHURCH & ASSOCIATES, P.A.
Bdlky H, ucy, PE
CC: Corey Basinger - Surface Water Protection Supervisor- NC DENR/WSRO
Jimmy Martin — Town of North Wilkesboro — Thurman Street W WTP
T: 704.342.3000I F: 704.342.3077 I 0 CHARLOTTE.
DESIGN 8273 I WVM.HOBBSUPCHURCH.COM
SUPERIOR PERFORMANCE THROUGH

Town of North Wilkesboro
A TO C No. 020761 A02
Issued January 20, 2011
Engineer's Certification
I, Bradley H. Bucy, as a duly registered Professional Engineer in the State of North
Carolina, having been authorized to observe (periodically/weekly/full time) the
construction of the modifications and improvements to the Thurman Street WWTP,
located on Thurman Street in Wilkes County for the Town of North Wilkesboro, hereby
state that, to the best of my abilities, due care and diligence was used in the observation
of the following construction:
Replacement of an existing gas chorine disinfection system with a new dual bank
UV disinfection system capable of treating a peak flow of 5.0 MGD with 100%
redundancy and a 405 kW generator, in conformity with the project plans,
specifications, and other supporting data subsequently filed and approved by the
Department of Environment and Natural Resources. A back-up tablet chlorine
disinfection and dechlorination system was not installed following discussions
with NC DENR / DWQ. With the incorporation of the new generator and dual
bank UV system, the facility has automatically activated stand-by power supply
for all on -site essential components and multiple component duality for
disinfection.
I certify that the construction of the above referenced project was observed to be built
Within substantial compliance and intent of the approved plans and specifications.
Signature Ije4 Registration No.24709
Date `i 6 t --
Send to: Construction Grants & Loans
DENR/DWQ
1633 Mail Service Center
Raleigh, NC 27699-1633
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