NC0024392_Modification of Permit_20170804

Wa ter Resources
ENVIRONMENTAL QUALITY
ROY COOPER
Corel nor
MICHAEL S REGAN
Seci etap
S JAY ZIMMERMAN
Da ectoi
August 4, 2017
Mr Steven D. Capps
Duke Energy Carolinas, LLC
McGuire Nuclear Station
12700 Hagers Ferry Rd
Huntersville, NC 28078
Subject Modification of NPDES Permit NCO024392
McGuire Nuclear Station
Mecklenburg County
Dear Mr Capps:
The Division has received and reviewed your request to modify the subject permit The Division does not object 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) Insert the attached page into your permit and discard the old page.
The permit issued on May 6, 2016 included a footnote allowing for a permit modification if data collected for
thallium for the period of one year did not show reasonable potential. The Division revised thallium data for Outfall 001 and
determined that there is no reasonable potential to exceed the water quality criteria. Your permit was modified to eliminate
the limit and monitoring for thallium at outfall 001. Enclosed is the modified page 3 of the permit. Please insert the attached
page into your permit and discard the old page
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 Tlus permit does not affect the legal requirements to obtain other permits which
may be required by any other Federal, State, or Local governmental regulation. If you have any questions concerning this
matter, please contact Teresa Rodriguez [phone] or via e-mail [teresa [e-mail]]
Sincerely,
ay Zimin n, n ector
` ivision of Water Resources
CC' Central Files
NPDES Unit
DWR/Mooresville Regional Office/Water Quality
Ecopy USEPA Region 4
DWR/Aquatic Toxicology Branch/Susan Meadows
DWR/Mooresville Regional Office/Public Water Supply
Mecklenburg County/Richard Farmer
State of North Carolina I Environmental Quality I Water Resources
1617 Mail Service Center I Raleigh, NC 27699-1617
919 807 6300 919-807-6389 FAX

Pexnut NCO024392
PART I
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 001)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration, the
Permittee is authorized to discharge from Outfall 001. Such discharges shall be limited and
monitored' by the Permittee as specified below:
PARAMETER
DISCHARGE
LIMITATIONS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample Type
Sample
Location
Intake Flow (MGD)
Daily
Pump Los
I
Temperature3
(October - June)
95 OF
(35°C
Daily
Recorder
DCB
Temperature3
(July -September
990F
37 2°C_
Daily
Recorder
DCB
pH4
Quarter!y
Grab
_ DCB
Acute Toxicity5
_
Quarterly_
Composite __DCB
DS
Free Available Chlorine6
0 20 mg/L_
0 50 mg/L
Weekly
Multiple Grab?
Time of Chlorme Addition
I Footnote 8
NOTES:
1 Effective December 21, 2016, begin submitting discharge monitoring reports electronically using NC
DWR's eDMR application system See Special Condition A (23)
2 I• Intake DCB- Discharge canal bridge DS: Discharge structure corresponding to an individual unit
3. Temperature limits are based on Clean Water Act Section 316(a) thermal variance [see Special
Condition A (6)] A temperature mixing zone is defined in Special Condition A (17)
4 The pH shall not be less than 6 0 standard units or greater than 9.0 standard units
5 Acute Toxicity (Ceriodaphnia 24 hour), No significant mortality at 90% with a composite sample of
equal volumes collected at one-hour intervals during a 24-hour period. Toxicity samples will be
collected in February, May, August, and November. See Special Condition A (7)
6 Monitoring for free available chlorine is required during and subsequent to chlorination Monitoring
shall begin immediately upon start-up of chlorination and shall discontinue when free available
chlorine is no longer detected. Neither free available chlorine nor total residual chlorine may be
discharged from any single generating unit for more than two hours per day unless the discharger
demonstrates to the State that discharge for more than two hours is required for macroinvertebrate
control
7. Multiple grab samples shall consist of grab samples collected at the approximate beginning of Free
Available Chlorine discharge and once every 15 minutes thereafter until FAC is no longer detected
"Daily Maximum" FAC is the instantaneous maximum of any single grab
8 The Permittee shall maintain a log of all chlorination events within each unit The log shall be
maintained on file at the plant and shall be available for review or submitted to the Division upon
request by any of its representatives. For each chlorination event, the log shall list- (1) each system that
is chlorinated, (2) the volume of the system (gpm), (3) the chlorination begin and end time, and (4) the
total time of the chlorination event (minutes)
DISCHARGE OF ANY PRODUCT REGISTERED UNDER THE FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE ACT IS
PROHIBITED UNLESS SPECIFICALLY AUTHORIZED ELSEWHERE IN THIS PERMIT
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN TRACE AMOUNTS.
Page 3 of 16

Pemut NCO024392
NOTE. TREATMENT OF THE NUCLEAR SERVICE WATER WITH HYDROGEN PEROXIDE TO ADDRESS FOULING OF THE REACTOR
COOLANT PUMP HEAT EXCHANGER IS PERMITTED
A. (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of the permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 002 (Conventional Wastewater Treatment
Facility). Such discharges shall be limited and monitored' by the Permittee as specified below:
PARAMETER
DISCHARGE
LIMITATIONS
MONITORING REQUIREMENTS
Monthly Daily
Average Maximum
Measurement Sample Type Sample
Frequency Location
Flow MGD
Daily
Instantaneous
E
Oil and Grease
15.0 m /L
20 0 m / L
Quarterly
Grab
E
Total Suspended Solids
30.0 m /L
100 0 m /L
Quarterly
Grab
E
Total Residual Chlorine
Monthly
Grab
E
H3
Monthly
Grab
E
Acute ToXiCity4
Quarterly
Grab
E
NOTFS-
1. Effective December 21, 2016, begin submitting discharge monitoring reports electronically using NC
DWR's eDMR application system See Special Condition A (23)
2. E: Effluent, with sampling performed prior to mixing with any other waste streams.
3. The pH shall not be less than 6.0 standard units or greater than 9.0 standard units
4. Acute Toxicity (Ceriodaphrua); LC5o at 80% with samples collected in February, May, August, and
November. See Special Condition A. (8).
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN TRACE AMOUNTS
Page 4 of 16