NC0024406_Draft Permit_20180626

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
Water Resources LINDA CULPEPPER
Environmental Quality Interim Director
June 26, 2018
Mr. Paul Draovitch, Senior Vice President
Environmental, Health and Safety
Duke Energy Progress, LLC
Mail Code EC 13K
P.O. Box 1006
Charlotte, North Carolina 28201-1006
Subject: Draft NPDES Permit
Permit NC0024406
Belews Creek Steam Station
Stokes County
Facility Class I
Dear Mr. Draovitch:
Enclosed with this letter is a copy of the draft permit for your facility. Please
review the draft very carefully to ensure thorough understanding of the conditions and
requirements it contains.
The draft permit contains the following significant changes from your
current permit:
• The following monitoring parameters were eliminated (Internal Outfall 002) to be
consistent with the latest update to 40 CFR 423: Chlorides and TSS.
• The Technology Based Effluent Limits for Total Arsenic, Total Mercury, Total
Selenium, and nitrate/nitrite as N were added to the permit (Internal Outfall
002) based on the requirements in 40 CFR 423.
• The Decanting Special Conditions were added to Outfall 003, please see A. (3.).
• Monitoring frequency for all parameters that were previously monitored
Quarterly were reduced to Monthly with an exception of Toxicity (Outfall 003 -
normal operations/decanting), please see A. (3.).
• Instream Waste Concentration for Outfall 003 (normal operations/decanting)
was increased to 90% from 19% based on the re-consideration of the effluent
channel status.
• The compliance dates for fly ash transport water (November 1, 2018) and bottom
ash transport water (May 31, 2021) were added to Outfall 003 in accordance
with 40 CFR 423.
!'Nothing Compares=.f
State of North Carolina I Environmental Quality
1611 Mail Service Center I Raleigh,North Carolina 27699-1611
919-707-9000

• The compliance date of November 1, 2020 for Technology Based Effluent Limits
was added to Internal Outfall 002 in accordance with 40 CFR 423.
• The Water Quality Based Effluent Limits for Chlorides, Total Copper, Total
Aluminum, Total Cadmium, Total Selenium, Total Lead, Ammonia, and Total
Thallium were added to the permit based on the results of Reasonable Potential
Analysis (Outfall 003 - normal operations/decanting).
• A separate effluent page for the dewatering of the ash pond (Outfall 003) was
added to the permit. Please see Condition A. (4.).
• A separate effluent page for the new Retention Basin (Outfall 003A) was added to
the permit. Please see Condition A. (5.).
• A new Outfall for the new Retention Basin (Outfall 006) was added to the permit.
• The Instream Monitoring Special Condition was added to the permit to monitor
the impact of the facility on the receiving stream. Please see Special Condition A.
(22.).
• A new Outfall for the Toe Drain discharge (Outfall 111) was added to the permit.
• Federal regulations require electronic submittal of all discharge monitoring
reports (DMRs) and program reports. The final NPDES Electronic Reporting Rule
was adopted and became effective on December 21, 2015. The requirement to
begin reporting discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report (eDMR) internet application has been
added to your final NPDES permit. [See Special Condition A. (23.)]
For information on eDMR, registering for eDMR and obtaining an eDMR user
account, please visit the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr.
For more information on EPA's final NPDES Electronic Reporting Rule, please
visit the following web site:
https://www.federalregister.gov/documents/2015/10/22/2015-
24954/national-pollutant-discharge-elimination-system-npdes-electronic-
reporting-rule
• The turbidity limit was added to the permit (Outfall 003) to meet the state
turbidity standard per 15A NCAC 2B .0211(3) (k).
• Thermal Variance/Clean Water Act Section 316(b) special condition was updated
(Please see A. (16.)).
• A new outfall was added to the permit (Outfall 005). This is a former stormwater
outfall SW002, it consists of once through non-contact chiller water and
stormwater.
• A new internal outfall was added to the permit (Outfall 009) for the discharge of
domestic wastewater.
• A new outfall was added to the permit (Outfall 007) for the emergency spillway
discharge from the South Coal Basin.
• The Compliance Boundary special condition was added to the permit, please see
A. (25.). This special condition replaces Groundwater Well Construction and
Sampling special condition.
• An Applicable State Law special condition was added to the permit, please see A.
(26.).

Please provide any comments you have regarding the draft permit to this
office by July 26, 2018. At this time, the Division is also publishing a notice in the
newspapers of general circulation in Stokes County, inviting public comment on the draft
permit. Following the 30-day comment period, we will review all pertinent comments
received and take appropriate action on the permit renewal.
If you have any questions about the NPDES permit process, please contact me at
the following e-mail address: sergei.chernikovAncdenr.gov, or telephone number: 919-
807-6386.
Sincerely, /
(S,I_,%._
/
Sergei Chernikov, Ph.D.
Environmental Engineer II
Complex NPDES Permitting Unit
cc: Central Files
NPDES Files
EPA Region IV (e-copy)
Winston-Salem Regional Office/Water Quality (e-copy)
Winston-Salem Regional Office/PWS (e-copy)
WSS/Aquatic Toxicology Unit(e-copy)

Permit NC0024406
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
Draft PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful
standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended,
Duke Energy Carolinas, LLC
is hereby authorized to discharge wastewater from a facility located at the
Belews Creek Steam Station
3195 Pine Hall Road (NCSR 1908)
Belews Creek
Stokes County
to receiving waters designated as the West Belews Creek/Belews Lake (outfalls 001,
005, and 007), unnamed tributary to the Dan River (outfall 003 and Outfall 003A),
and Dan River (outfall 006) in the Roanoke River Basin
in accordance with effluent limitations, monitoring requirements, and other
applicable conditions set forth in Parts I, II, and III hereof.
This permit shall become effective
This permit and authorization to discharge shall expire at midnight on
Signed this day
DRAFT
Linda Culpepper, Interim Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 23

Permit NC0024406
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of
this permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the
exclusive authority to operate and discharge from this facility arises under the permit conditions, requirements,
terms, and provisions included herein.
Duke Energy Carolinas, LLC is hereby authorized to:
1. Continue to discharge:
• Outfall 001: once through cooling water consisting of intake screen backwash,
recirculating cooling water, station equipment cooling water and once-through
cooling water. This outfall discharges to Belews Lake.
• Outfall 003: ash basin discharge consisting of waste streams from the power
house and yard holding sumps, ash contact water, chemical holding pond, coal
yard sumps, stormwater, treated domestic wastewater, remediated groundwater,
coal pile collection basins (collecting contact stormwater from coal piles),
emergency release of anhydrous ammonia, release of ammonia during quarterly
testing, seepage from coal ash pond, emergency overflows from the existing
effluent channels, emergency overflow from the retention basin, and treated FGD
wastewater from internal outfall 002. This outfall discharges to Unnamed
Tributary (UT) to Dan River.
• Internal Outfall 002: FGD wastewater (discharging to ash pond)
• Outfall 003A/006. Upon completion of construction, discharge from the new lined
retention basin. Basin will accept wastes from holding basin, ash contact water,
various sumps, coal pile runoff, stormwater runoff, cooling tower blowdown, FGD
wastewater, and various low volume wastes such as boiler blowdown, oily waste
treatment, wastes/backwash from the water treatment processes, coal pile
collection basins (collecting contact stormwater from coal piles), plant area wash
down water, cooling tower blowdown, equipment heat exchanger water,
remediated groundwater, emergency overflow (rain in excess of designed storm
event), toe drain (potential discharge to outfall 006 only), emergency release of
anhydrous ammonia, release of ammonia during quarterly testing, and treated
domestic wastewater. This outfall discharges to UT to Dan River via the Outfall
003. Upon completion of construction all waste streams previously discharged to
ash basin, will be re-routed to the new retention basin. During the transition
period, wastewater from the ash pond can also be discharged. New Outfall 006
will be constructed for the lined retention basin within 3 years to replace Outfall
003A. This outfall (Outfall 006) will discharge to Dan River.
• Outfall 005. This is a former stormwater outfall SW002, consists of once through
non-contact chiller water and stormwater. This outfall discharges to Belews Lake.
• Outfall 007 (lat. - 36016'51.604"; long. 80°03'52.995"). This is an emergency
spillway for South Coal Basin. This outfall discharges to Belews Lake. The
spillway is designed for a flood greater than 100-year event. Sampling of this
spillway is waived due to an unsafe conditions associated with sampling during
an overflow event.
• Internal Outfall 009. Domestic wastewater plant. The wastewater from this outfall
discharges to UT to Dan River via Outfall 003 or to Dan River via Outfall 006.
• Toe Drain Outfall 111 (lat. - 36017'54.94"; long. - 80.04'32.57")- potentially
contaminated toe drain. This outfall discharges to UT to Dan River.
Page 2 of 23

Permit NC0024406
From a facility located at Belews Creek Station, 3195 Pine Hall Road (NCSR 1908),
Belews Creek in Stokes County, and
2. Discharge wastewater from said treatment works at the location specified on the
attached map into Belews Lake, and the UT Dan River/Dan River, which are
classified C and WS-IV waters, respectively, in the Roanoke River Basin.
Page 3 of 23

Permit NC0024406
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 this permit and lasting until expiration, the
Permittee is authorized to discharge once-through cooling water and intake screen backwash from
outfall 001. Such discharges shall be limited and monitored3 by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Daily Average Daily Measurement Sample Type Sample Location1
Maximum Frequency
Flow Continuous Pump Logs Effluent
Temperature 0C Daily Recorder/Grab Upstream
Temperature°C 2 Daily Recorder/Grab Downstream 1
Temperature°C 2 320C Daily Recorder/Grab Downstream 2
Temperature 0C Daily Recorder/Grab Effluent
Notes:
1. Sampling locations: Upstream - Upstream at Southern Railroad crossing of Belews Creek OR
East Belews Creek (site 405 or site 419), Downstream - Downstream at the discharge from the
Dam, approximately 5.3 miles from the outfall (Downstream 2), and approximately 0.5 miles
downstream of Outfall 001 (Downstream 1). Upstream and downstream temperature samples are
to be measured one foot below the surface.
2. In no case shall the ambient temperature exceed 32°C as a result of Belews Creek Steam
Station operations. The ambient temperature shall be defined as the daily average downstream
(Downstream 2) discharge water temperature. In cases where the Permittee experiences
equipment problems and is unable to obtain daily temperatures from the existing temperature
monitoring system, monitoring must be reestablished within five working days. The temperature
monitoring is required only when the discharge from the Lake Dam occurs.
3. Please See Special Condition A. (23.).
Chlorination of the once through condenser cooling water and/or auxiliary cooling water,
discharged through outfall 001, is not allowed under this permit. Should Duke Energy wish to
chlorinate its condenser cooling water, a permit modification must be requested and received
prior to commencing chlorination.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 4 of 23

Permit NC0024406
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Internal
Outfall 002)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from Internal Outfall 002 (treated FGD wet scrubber
wastewater to ash settling basin). Such discharges shall be limited and monitored' by the Permittee
as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Type Sample Location
Average Maximum Frequency
Flow. MGD Weekly Pump Logs or similar Effluent
readings
Total Arsenic 8.0 pg/L2 11.0 pg/L2 Quarterly Grab Effluent
Total Mercury3 356.0 ng/L2 788.0 ng/L2 Quarterly Grab Effluent
Total Selenium 12.0 pg/L2 23.0 pg/L2 Quarterly Grab Effluent
Nitrate/nitrite as N 4.4 mg/L2 17.0 mg/L2 Quarterly Grab Effluent
Oil and Grease 15.0 mg/L 20.0 mg/L Quarterly Grab Effluent
Total Suspended Solids 30.0 mg/L 50.0 mg/L Quarterly Grab Effluent
Notes:
1. Please See Special Condition A. (23.).
2. In accord with the Steam Electric Effluent Limitations Guidelines for FGD wastewater (40 C.F.R.
423), these limits shall become effective on November 1, 2020. This permit may be reopened and
modified if changes are made to 40 C.F.R. 423.
3. The facility shall use EPA method 1631E.
All flows shall be reported on monthly DMRs, should no flow occur during a given month, the words
"No Flow" shall be clearly written on the front of the DMR. All samples shall be of a representative
discharge.
Page 5 of 23

Permit NC0024406
A. (3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
003 - normal operations/decanting)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 003 Ash settling basin (decanting the free water
above the settled ash layer that does not involve mechanical disturbance of the ash). Such
discharges shall be limited and monitored5 by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Type Sample Location
Average Maximum Frequency
Flow, MGD Weekly Pump logs or Effluent
estimate
Oil and Grease' 15.0 mg/L 20.0 mg/L Monthly Grab Effluent
Total Suspended Solids'' 30.0 mg/L 50.0 mg/L Monthly Grab Effluent
Total Arsenic, pg/L Weekly Grab Effluent
Chlorides 250.0 mg/L 250.0 mg/L Monthly Grab Effluent
Sulfates 250.0 mg/L 250.0 mg/L Monthly Grab Effluent
Total Irony 1.0 mg/L 1.0 mg/L Monthly Grab Effluent
Total Copper 7.88 pg/L 10.47 pg/L Monthly Grab Effluent
Total Aluminum 6.5 mg/L 6.5 mg/L Monthly Grab Effluent
Total Cadmium 0.59 pg/L 3.24 pg/L Monthly Grab Effluent
Total Selenium 5.0 pg/L 56.0 pg/L Weekly Grab Effluent
Total Zinc, pg/L Monthly Grab Effluent
Total Chromium, pg/L Monthly Grab Effluent
Total Dissolved Solids,mg/L Monthly Grab Effluent
Total Silver, pg/L Weekly Grab Effluent
Fluoride, mg/L Monthly Grab Effluent
Total Phosphorus, mg/L Monthly Grab Effluent
Total Nitrogen(NO2+NO3+TKN),mg/L Monthly Grab Effluent
Chronic Toxicity2 Quarterly Grab Effluent
pH3.8 2/Month Grab Effluent
Bromides,mg/L Monthly Grab Effluent
Total Lead 2.94 pg/L 75.48 pg/L Monthly Grab Effluent
Total Thallium 2.0 pg/L 2.0 pg/L Monthly Grab Effluent
Total Mercury'',ng/L Weekly Grab Effluent
Turbiditys, NTU Weekly Grab Effluent
Total Hardness,mg/L Monthly Grab Effluent
Ammonias 1.0 mg/L 5.0 mg/L Variable Grab Effluent
Notes:
1. Monitoring for TSS, oil and grease and all toxicants shall be performed concurrently with the
Chronic Toxicity test.
2. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 90%. See
Condition A. (14.) for details.
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall employ method 1631E.
5. Please See Special Condition A. (23.).
6. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50
NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the
discharge cannot cause turbidity to increase in the receiving stream. Therefore, if the effluent
measurement exceeds 50 NTU, the Permittee shall sample upstream and downstream turbidity in
the receiving waterbody, within 24 hours, to demonstrate the existing turbidity level in the
receiving waterbody was not increased. All data shall be reported on the DMRs. (See 15A NCAC
2B .0211 (21)).
Page 6 of 23

Permit NC0024406
NTU - Nephelometric Turbidity Unit.
7. The facility shall continuously monitor TSS concentration when the decanting process
commences and the decanting pump shall be shutoff automatically when one half of the Daily
Maximum limit (15 minutes average) is exceeded. Pumping will be allowed to continue if
interruption might result in a dam failure or damage. The continuous TSS monitoring only
required when the pumps are employed for decanting.
8. The facility shall continuously monitor pH when the decanting process commences and the
decanting pump shall be shutoff automatically when the 15 minutes running average pH falls
below 6.1 standard units or rises above 8.9 standard units. Pumping will be allowed to continue
if interruption might result in a dam failure or damage. The continuous pH monitoring is only
required when the pumps are employed for decanting.
9. Ammonia limit and monitoring is only applicable in the event of the emergency release of
anhydrous ammonia. The sampling should be commenced as soon as possible after the release
considering personnel safety and every hour thereafter until the sampling indicate no discharge
of ammonia.
10. The limit applies onlywhen the chemical metal cleaningwaste is beingdischarged to the basin.
� PP g
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Outfall sampling shall be conducting prior to the commingling with wastewater from Outfall
003A.
The facility is allowed to drawdown the wastewater in the ash pond to no less than three feet
above the ash. The rate for lowering the liquid level in a coal ash pond shall not exceed one (1)
foot per day unless a higher rate is supported to the satisfaction of DEMLR and in accordance
with NCAC, Title 15A, Subchapter 2K.
The facility shall use a floating pump suction pipe with free water skimmed from the basin
surface using an adjustable weir. The limits and conditions in Section A. (4.) of the permit
apply when water in the ash settling basin is lowered below the three feet trigger mark.
By November 1, 2018 there shall be no discharge of pollutants in fly ash transport water. This
requirement only applies to fly ash transport water generated after November 1, 2018.
By May 31, 2021 there shall be no discharge of pollutants in bottom ash transport water. This
requirement only applies to bottom ash transport water generated after May 31, 2021.
The facility shall notify via e-mail DWR Complex NPDES Permitting Unit and DWR Winston-
Salem Regional Office seven calendar days prior to the commencement of the decanting.
In accordance with the N.C.G.S. § 130A-309.210, by December 31, 2019, the facility shall
convert to the disposal of dry bottom ash, as defined in the Coal Ash Management Act
("CAMA").
When the facility commences the ash pond/ponds decanting, the facility shall treat the
wastewater discharged from the ash pond/ponds using physical-chemical treatment, if
necessary to, to assure state Water Quality Standards are not contravened in the receiving
stream unless specific interim action levels are granted in a separate order. Duke Energy shall
notify DWR NPDES Permitting and DWR Winston-Salem Regional Office, in writing, within
seven calendar days of installing additional physical-chemical treatment at this Outfall.
If one of the pollutants (As, Se, Hg, Ni, and Pb) reaches 85% of the allowable level during the
decanting/dewatering, the facility shall immediately discontinue discharge of the wastewater
and report it to the Regional Office and Complex NPDES Permitting Branch via telephone and
e-mail.
Page 7 of 23

Permit NC0024406
A. (4.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
003 - dewate ring)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the commencement of dewatering and lasting until expiration of
the permit, the Permittee is authorized to discharge from outfall 003 Ash settling basin (Dewatering
- removing the interstitial water). Such discharges shall be limited and monitoreds by the
Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Type Sample Location
Average Maximum Frequency
Flow 2.0 MGD" Daily Pump logs or Effluent
estimate
Oil and Grease' 15.0 mg/L 20.0 mg/L Weekly Grab Effluent
Total Suspended Solidst7 30.0 mg/L 50.0 mg/L Weekly Grab Effluent
Total Arsenic 10.0 pg/L 340.0 pg/L Weekly Grab Effluent
Chlorides 250.0 mg/L 250.0 mg/L Weekly Grab Effluent
Total Iron, mg/L'° 1.0 mg/L 1.0 mg/L Weekly Grab Effluent
Total Copper 7.88 pg/L 10.47 pg/L Weekly Grab Effluent
Total Selenium 5.0 pg/L 56.0 pg/L Weekly Grab Effluent
Total Molybdenum 160.0 pg/L 160.0 pg/L Weekly Grab Effluent
Total Aluminum 6.5 mg/L 6.5 mg/L Weekly Grab Effluent
Fluoride 1.8 mg/L 1.8 mg/L Weekly Grab Effluent
Chromium III 117.7 pg/L 905.1 pg/L Weekly Grab Effluent
Chromium VI 11.0 pg/L 16.0pg/L Weekly Grab Effluent
Total Cadmium, pg/L Weekly Grab Effluent
Total Zinc 125.7 pg/L 125.7 pg/L Weekly Grab Effluent
Total Nickel 25.0 pg/L 335.2 pg/L Weekly Grab Effluent
Total Dissolved Solids,mg/L Weekly Grab Effluent
Total Phosphorus,mg/L Monthly Grab Effluent
Total Nitrogen(NO2+NO3+TKN),mg/L Monthly Grab Effluent
Chronic Toxicity2 Monthly Grab Effluent
pH3'8 Weekly Grab Effluent
Bromides, mg/L Weekly Grab Effluent
Total Lead 2.94 pg/L 75.48 pg/L Weekly Grab Effluent
Total Thallium 2.0 pg/L 2.0 pg/L Weekly Grab Effluent
Total Barium 1.0 mg/L 1.0 mg/L Weekly Grab Effluent
Sulfates 250.0 mg/L 250.0 mg/L Weekly Grab Effluent
Total Antimony 5.6 pg/L 5.6 pg/L Weekly Grab Effluent
Total Mercury4,ng/L Weekly Grab Effluent
Turbidity6,NTU Weekly Grab Effluent
Total Hardness, mg/L Weekly Grab Effluent
Ammonia9 1.0 mg/L 5.0 mg/L Variable Grab Effluent
Notes:
1. Monitoring for TSS, oil and grease and all toxicants shall be performed concurrently with the
Chronic Toxicity test.
2. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 90%. See
Condition A. (14.) for details.
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall employ method 1631E.
5. Please See Special Condition A. (23.).
6. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50 NTU.
If the instream turbidity exceeds 50 NTU due to natural background conditions, the discharge
Page 8 of 23

Permit NC0024406
cannot cause turbidity to increase in the receiving stream. Therefore, if the effluent measurement
exceeds 50 NTU, the Permittee shall sample upstream and downstream turbidity in the receiving
waterbody, within 24 hours, to demonstrate the existing turbidity level in the receiving waterbody
was not increased. All data shall be reported on the DMRs. (See 15A NCAC 2B .0211 (21)).
NTU - Nephelometric Turbidity Unit.
7. The facility shall continuously monitor TSS concentration when the dewatering process
commences and the dewatering pump shall be shutoff automatically when the one half of the
Daily Maximum limit (15 minutes average) is exceeded. Pumping will be allowed to continue if
interruption might result in a dam failure or damage. The continuous TSS monitoring is only
required when the pumps are employed for dewatering.
8. The facility shall continuously monitor pH when the dewatering process commences and the
dewatering pump shall be shutoff automatically when the 15 minutes running average pH falls
below 6.1 standard units or rises above 8.9 standard units. Pumping will be allowed to continue if
interruption might result in a dam failure or damage. The continuous TSS monitoring is only
required when the pumps are employed for dewatering.
9. Ammonia limit and monitoring is only applicable in the event of the emergency release of
anhydrous ammonia. The sampling should be commenced as soon as possible after the release
considering personnel safety and every hour thereafter until the sampling indicate no discharge of
ammonia.
10. The limit applies only when the chemical metal cleaning waste is being discharged to the basin.
11. The limit is only applicable to interstitial water.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Outfall sampling shall be conducting prior to the commingling with wastewater from Outfall
003A.
The rate for lowering the liquid level in a coal ash pond shall not exceed one (1) foot per day
unless a higher rate is supported to the satisfaction of DEMLR and in accordance with NCAC,
Title 15A, Subchapter 2K.
The facility shall use a floating pump suction pipe with free water skimmed from the basin
surface using an adjustable weir. By November 1, 2018 there shall be no discharge of
pollutants in fly ash transport water. This requirement only applies to fly ash transport water
generated after November 1, 2018.
By May 31, 2021 there shall be no discharge of pollutants in bottom ash transport water. This
requirement only applies to bottom ash transport water generated after May 31, 2021.
The facility shall notify via e-mail DWR Complex NPDES Permitting Unit and DWR Winston-
Salem Regional Office seven calendar days prior to the commencement of the dewatering.
In accordance with the N.C.G.S. § 130A-309.210, by December 31, 2019, the facility shall
convert to the disposal of dry bottom ash, as defined in the Coal Ash Management Act
("CAMA").
When the facility commences the ash pond/ponds dewatering, the facility shall treat the
wastewater discharged from the ash pond/ponds using physical-chemical treatment, if
necessary, to assure the permit limits are not violated. Duke Energy shall notify DWR NPDES
Permitting and DWR Winston-Salem Regional Office, in writing, within seven calendar days of
installing additional physical-chemical treatment at this Outfall.
If one of the pollutants (As, Se, Hg, Ni, and Pb) reaches 85% of the allowable level during the
decanting/dewatering, the facility shall immediately discontinue discharge of the wastewater
and report it to the Regional Office and Complex NPDES Permitting Branch via telephone and
e-mail.
Page 9 of 23

Permit NC0024406
A. (5.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
003A)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning upon the commencement of operations of the new Retention Basin and
lasting until expiration, the Permittee is authorized to discharge from Outfall 003A (new lined
retention basin). Such discharges shall be limited and monitored2 by the Permittee as specified
below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location
Flow, MGD Weekly Instantaneous Effluent
Oil and Grease 15.0 mg/L 20.0 mg/L Quarterly Grab Effluent
Total Suspended Solids 30.0 mg/L 50.0 mg/L Quarterly Grab Effluent
pH3 Weekly Grab Effluent
Total Arsenic, pg/L Quarterly Grab Effluent
Total Mercuryl, ng/L Quarterly Grab Effluent
Total Selenium 5.0 pg/L 56.0 pg/L Monthly Grab Effluent
Nitrate/nitrite as N, mg/L Quarterly Grab Effluent
Chlorides 250.0 mg/L 250.0 mg/L Monthly Grab Effluent
Sulfates 250.0 mg/L 250.0 mg/L Monthly Grab Effluent
Total Nickel, pg/L Quarterly Grab Effluent
Sulfate, mg/L Quarterly Grab Effluent
Fluoride, pg/L Quarterly Grab Effluent
Total Barium, mg/L Quarterly Grab Effluent
Total Chromium, pg/L Quarterly Grab Effluent
Total Cadmium pg/L 0.59 pg/L 3.24 pg/L Monthly Grab Effluent
Total Hardness, mg/L Quarterly Grab Effluent
Total Copper 7.88 pg/L 10.47 pg/L Monthly Grab Effluent
Total Lead 2.94 pg/L 75.48 pg/L Monthly Grab Effluent
Total Thallium 2.0 pg/L 2.0 pg/L Monthly Grab Effluent
Chronic Toxicity4 Quarterly Grab Effluent
Ammonias 1.0 mg/L 5.0 mg/L Daily Grab Effluent
Total Iron6 1.0 mg/L 1.0 mg/L Quarterly Grab Effluent
Notes:
1. The facility shall use EPA method 1631E.
2. Please See Special Condition A. (23.).
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 90%. See
Condition A. (14.) for details.
5. Ammonia limit and monitoring is only applicable in the event of the emergency release of
anhydrous ammonia.
6. The limit applies when the chemical metal cleaning waste is being discharged to the basin.
The facility shall submit EPA Form 2C for this Outfall within 2 years of commencement of the
discharge.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Outfall sampling shall be conducting prior to the commingling with wastewater from Outfall
003.
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Permit NC0024406
A. (6.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
005)1
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge once-through non-contact chiller water and stormwater from
outfall 005. Such discharges shall be limited and monitored3 by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Daily Average Daily Measurement Sample Type Sample Location
Maximum Frequency
Flow Weekly Pump Logs or Effluent
Estimate
Temperature,0C Weekly Grab Effluent
TSS, mg/L Monthly Grab Effluent
Total Arsenic, pg/L Monthly Grab Effluent
Total Selenium, pg/L Monthly Grab Effluent
Total Hardness,mg/L Monthly Grab Effluent
Notes:
1. Please See Special Condition A. (23.).
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 11 of 23

Permit NC0024406
A. (7.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
006)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning upon the commencement of operations of the new Retention Basin and
lasting until expiration, the Permittee is authorized to discharge from Outfall 006 (new lined
retention basin). Such discharges shall be limited and monitored2 by the Permittee as specified
below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location
Flow, MGD Weekly Instantaneous Effluent
Oil and Grease 15.0 mg/L 20.0 mg/L Quarterly Grab Effluent
Total Suspended Solids 30.0 mg/L 50.0 mg/L Quarterly Grab Effluent
pH3 Weekly Grab Effluent
Total Arsenic, pg/L Quarterly Grab Effluent
Total Mercury1, ng/L Quarterly Grab Effluent
Total Selenium, pg/L Quarterly Grab Effluent
Nitrate/nitrite as N, mg/L Quarterly Grab Effluent
Chlorides,mg/L _ Quarterly Grab Effluent
Total Nickel, pg/L Quarterly Grab Effluent
Sulfates,mg/L Quarterly Grab Effluent
Fluoride, pg/L . Quarterly Grab Effluent
Total Barium,mg/L Quarterly Grab Effluent
Total Chromium, pg/L Quarterly Grab Effluent
Total Copper 29.75 pg/L 34.23 pg/L Monthly Grab Effluent
Total Lead 11.1 pg/L 246.7 pg/L _ Monthly Grab Effluent
Total Thallium Quarterly Grab Effluent
Total Hardness, mg/L Quarterly Grab Effluent
Chronic Toxicity4 Quarterly Grab Effluent
Ammonias 1.0 mg/L 5.0 mg/L Daily Grab Effluent
Total Iron6 1.0 mg/L 1.0 mg/L Quarterly Grab Effluent
Notes:
1. The facility shall use EPA method 1631E.
2. Please See Special Condition A. (23.).
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 10.9%. See
Condition A. (14.) for details.
5. Ammonia limit and monitoring is only applicable in the event of the emergency release of anhydrous
ammonia.
6. The limit applies when the chemical metal cleaning waste is being discharged to the basin.
The facility shall submit EPA Form 2C for this Outfall within 2 years of commencement of the
discharge.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
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Permit NC0024406
A. (8.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
007)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 007 — Emergency spillway of the South Coal Pile
Basin. Such discharges shall be limited and monitored by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Frequency Sample Sample
Average Maximum Type Location
Flow, MGD Waived Estimate Effluent
pH Waived Grab Effluent
TSS Waived Grab Effluent
Oil and Grease Waived Grab Effluent
The emergency spillway is designed for a flood greater than 100-year event in Stokes County.
Sampling of this spillway is waived due to unsafe conditions associated with sampling during
an overflow event.
Monitoring is required for any other rain event that might trigger a discharge.
A. (9.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Internal
Outfall 009)
[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 Internal Outfall 009 (domestic wastewater plant). Such
discharges shall be limited and monitored l by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location
Flow, MGD Weekly Instantaneous Effluent
BOD,5-day,20°C 30.0 mg/L 45.0 mg/L Weekly Grab Effluent
TSS 30.0 mg/L 45.0 mg/L Weekly Grab Effluent
Fecal Coliform(geo.mean) 200/100 mL 400/100 mL Weekly Grab Effluent
Notes:
1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's
eDMR application system. Please See Special Condition A. (23.).
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Permit NC0024406
A. (10.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
111)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 111 —Toe Drain Discharge. Such discharges shall
be limited and monitored' by the Permittee as specified below:
PARAMETER LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Sample
Average Maximum Fre•uenc 2 T •e Location _
Flow, MGD Monthly/Quarterly Estimate Effluent
pH3 Monthly/Quarterly Grab Effluent
TSS 30.0 mg/L 100.0 mg/L Monthly/Quarterly Grab Effluent
Oil and Grease 15.0 mg/L 20.0 mg/L Monthly/Quarterly Grab Effluent
Fluoride, mg/L Monthly/Quarterly Grab Effluent
Total Mercury4, ng/L 12.0 ng/L 12.0 ng/L Monthly/Quarterly Grab Effluent
Total Barium, mg/L Monthly/Quarterly Grab Effluent
Total Zinc, pg/L Monthly/Quarterly Grab Effluent
Total Arsenic 10.0 pg/L 340.0 pg/L Monthly/Quarterly Grab Effluent
Total Boron, pg/L Monthly/Quarterly Grab Effluent
Total Cadmium, pg/L 0.59 pg/L 3.24 pg/L Monthly/Quarterly Grab Effluent
Total Chromium, pg/L Monthly/Quarterly Grab Effluent
Total Copper, pg/L Monthly/Quarterly Grab Effluent
Total Thallium Monthly/Quarterly Grab Effluent
Total Lead, pg/L Monthly/Quarterly Grab Effluent
Total Nickel, pg/L Monthly/Quarterly Grab Effluent
Total Selenium 5.0 pg/L 56.0 pg/L Monthly/Quarterly Grab Effluent
Nitrate/nitrite as N, mg/L Monthly/Quarterly Grab Effluent
Sulfates, mg/L Monthly/Quarterly Grab Effluent
Chlorides 250.0 mg/L 250.0 mg/L Monthly/Quarterly Grab Effluent
TDS 500.0 mg/L 500.0 mg/L Monthly/Quarterly Grab Effluent
Total Hardness, mg/L Monthly/Quarterly Grab Effluent
Temperature,0C Monthly/Quarterly Grab Effluent
Conductivity, pmho/cm Monthly/Quarterly Grab Effluent
Notes:
1. Please See Special Condition A. (23.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly.
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If no discharge occurs during the reporting period or the Permittee is unable to obtain a
representative sample due to low-flow conditions at the seep, the Permittee shall submit its
DMR, as required, and indicate "No Flow" for the seep (15A NCAC 02B .0506(a)(1)(E)).
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 14 of 23

Permit NC0024406
A. (11.) ADDITIONAL CONDITIONS AND DEFINITIONS
[NCGS 143-215.3 (a) (2) and NCGS 143-215.66]
1. EPA methods 200.7 or 200.8 (or the most current versions) shall be used for analyses of all
metals except for total mercury (EPA Method 1631E).
2. All effluent samples for all external outfalls shall be taken at the most accessible location after
the final treatment but prior to discharge to waters of the U.S. (40 CFR 122.41(j)).
3. The term low volume waste sources mean wastewater from all sources except those for which
specific limitations are otherwise established in this part (40 CFR 423.11 (b)).
4. The term chemical metal cleaning waste means any wastewater resulting from cleaning any
metal process equipment with chemical compounds, including, but not limited to, boiler tube
cleaning (40 CFR 423.11 (c)).
5. The term metal cleaning waste means any wastewater resulting from cleaning [with or
without chemical cleaning compounds] any metal process equipment including, but not
limited to, boiler tube cleaning, boiler fireside cleaning, and air preheater cleaning (40 CFR
423.11 (d)).
6. For all outfalls where the flow measurement is to be "estimated" the estimate can be done by
using calibrated V-notch weir, stop-watch and graduated cylinder, or other method approved
by the Division.
7. The term "FGD wet scrubber wastewater" means wastewater resulting from the use of the flue-
gas desulfurization wet scrubber.
8. There shall be no discharge of polychlorinated biphenyl compounds.
9. The permittee shall report the presence of cenospheres observed in any samples on the DMRs
in the comment section.
10.The applicant is permitted to discharge chemical metal cleaning wastes to the ash basin.
11. Nothing contained in this permit shall be construed as a waiver by the permittee of any right
to a hearing it may have pursuant to State or Federal laws and regulations.
A. (12.) BOILER CLEANING WASTES
[40 CFR 423]
It has been demonstrated that under certain conditions it is possible to reduce the concentration of
metals in boiler cleaning wastes in the range of 92-99+ percent by treatment in ash ponds. Because
of dilution problems and the existence of boundary interface layers at the extremities of the plume, it
is difficult to prove beyond doubt that the quantity of iron and copper discharge will always be less
than one milligram per liter times the flow of metal cleaning when treated in this manner.
The application of physical/chemical methods of treating wastewater has also been demonstrated to
be effective in the treatment of metal cleaning wastes. However, the effectiveness of ash pond
treatment should be considered in relation to the small differences in effluent quality realized
between the two methods.
It has been demonstrated that the presence of ions of copper, iron, nickel and zinc in the ash pond
waters was not measurably increased during the ash pond equivalency demonstration at the Duke
Energy's Belews Creek Steam Station. Therefore, when the following conditions are implemented
during metal cleaning procedures, effective treatment for metals can be obtained at this facility:
1. Large ash basin providing potential reaction volumes in the ratio of 100 to 1.
2. Well-defined shallow ash delta near the ash basin influent.
3. Ash pond pHs of no less than 6.5 prior to metal cleaning waste addition.
4. Four days retention time in ash pond with effluent stopped.
5. Boiler volume less than 86,000 gallons.
6. Chemicals for cleaning to include only one or more of the following:
a. Copper removal step- sodium bromate (NaBr02), ammonium carbonate ((NH4)2CO3-H20,
and ammonium hydroxide (NH4OH).
Page 15 of 23

Permit NC0024406
b. Iron removal step- hydrochloric acid (HC1), ammonium bifluoride ((NH4)HF2 and
proprietary inhibitors.
7. Maximum dilution of wastewater before entering ash pond: 6 to 1.
8. If monitoring of basin effluents (as required by the permit) after treatment of metal cleaning
wastes reveals discharges exceed the limits of the permit, Permittee will:
1) re-close the basin discharge,
2) conduct such in-basin sampling as necessary to determine the cause of
nonconformance,
3) take appropriate corrective actions, and
4) file a report with EPA including all pertinent data.
A. (13.) SPECIAL CONDITION FOR ASH POND DISCHARGE
[40 CFR 423]
Beginning on the effective date of this permit and lasting until expiration, there shall be no discharge
of plant wastewater to the ash pond unless the Permittee provides and maintains at all times a
minimum free water volume (between the top of the sediment level and the minimum discharge
elevation) equivalent to the sum of the maximum 24-hour plant discharges plus all direct rainfall and
all runoff flows to the pond resulting from a 10-year, 24-hour rainfall event, when using a runoff
coefficient of 1.0. During the term of the permit, the Permittee shall remove settled material from the
ponds or otherwise enlarge the available storage capacities in order to maintain the required
minimum volumes at all times. The Permittee shall determine and report to the permit issuing
authority the following on an annual basis:
1) the actual free water volume of the ash pond,
2) physical measurements of the dimensions of the free water volume in sufficient detail to allow
validation of the calculated volume, and
3) a certification that the required volume is available with adequate safety factor to include all
solids expected to be deposited in the pond for the following year.
Present information indicates a needed volume of 86.2 acre-feet in addition to solids that will be
deposited to the ash pond; any change to plant operations affecting such certification shall be
reported to the Director within five days.
NOTE: In the event that adequate volume has been certified to exist for the term of the permit,
periodic certification is not needed.
A. (14.) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 90% for Outfall 003 and Outfall
003A, and 10.9% for Outfall 006.
The permit holder shall perform at a minimum, monthhi monitoring for Dewatering (Outfall 003) and
quarterly monitoring for Decanting/Normal operation (Outfalls 003/003A/006) using test procedures
outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised
December 2010, or subsequent versions or "North Carolina Phase II Chronic Whole Effluent Toxicity
Test Procedure" (Revised- December 2010) or subsequent versions. Effluent sampling for this testing
must be obtained during representative effluent discharge and shall be performed at the NPDES
permitted final effluent discharge below all treatment processes.
If the monthly/quarterly test procedure results in a failure or ChV below the permit limit,
then multiple-concentration testing shall be performed at a minimum, in each of the two
following months as described in "North Carolina Phase II Chronic Whole Effluent Toxicity
Test Procedure" (Revised-December 2010) or subsequent versions.
Page 16 of 23

Permit NC0024406
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the
parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally,
DWR Form AT-3 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than
30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and
all concentration/response data, and be certified by laboratory supervisor and ORC or approved
designate signature. Total residual chlorine of the effluent toxicity sample must be measured and
reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT)
test form indicating the facility name, permit number, pipe number, county, and the month/year of
the report with the notation of"No Flow" in the comment area of the form. The report shall be
submitted to the Water Sciences Section at the address cited above. Should the permittee fail to
monitor during a month in which toxicity monitoring is required, monitoring will be required during
the following month. Assessment of toxicity compliance is based on the toxicity testing month.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Resources indicate potential impacts to the receiving stream, this permit may be
re-opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival, minimum control organism reproduction, and appropriate environmental
controls, shall constitute an invalid test and will require immediate follow-up testing to be
completed no later than the last day of the month following the month of the initial monitoring.
A. (15.) BIOCIDE CONDITION
[NCGS 143-215.1]
The permittee shall not use any biocides except those approved in conjunction with the permit
application. The permittee shall notify the Director in writing not later than ninety (90) days prior to
instituting use of any additional biocide used in cooling systems which may be toxic to aquatic life
other than those previously reported to the Division of Water Resources. Such notification shall
include completion of Biocide Worksheet Form 101 and a map locating the discharge point and
receiving stream. Completion of Biocide Worksheet Form 101 is not necessary for those outfalls
containing toxicity testing. Division approval is not necessary for the introduction of new biocides into
outfalls currently tested for whole effluent toxicity.
A. (16.) CLEAN WATER ACT SECTION 316 (B)
[40 CFR 125.95]
The permittee shall comply with the Cooling Water Intake Structure Rule per 40 CFR 125.95. The
permittee shall submit all the materials required by the Rule 3.5 years from the effective date of the
permit.
Page 17 of 23

Permit NC0024406
Copies of all the study plans, study results, and any other applicable materials should be submitted
to:
1) Electronic Version Only (pdf and CD)
Division of Water Resources
WQ Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
2) Electronic Version (pdf and CD) and Hard Copy
Division of Water Resources
Water Sciences Section
1623 Mail Service Center
Raleigh, NC 27699-1623
A. (17.) STRUCTURAL INTEGRITY INSPECTIONS OF ASH POND DAMS
[15A NCAC 02K.0208]
The facility shall meet the dam design and dam safety requirements per 15A NCAC 2K.
A. (18.) FISH TISSUE MONITORING NEAR ASH POND DISCHARGE (Outfall
003/006)
[NCGS 143-215.3 (a) (2)]
The facility shall conduct fish tissue monitoring annually and submit the results with the NPDES
permit renewal application. The objective of this monitoring is to evaluate potential uptake of pollutants
by fish tissue near the ash pond discharge. The parameters analyzed in fish tissue shall include
arsenic, selenium, and mercury. The monitoring shall be conducted in accordance with the sampling
plan approved by the Division. The plan should be submitted to the Division within 180 days from the
effective date of the permit. Upon approval, the plan becomes an enforceable part of the permit.
Copies of all the study plans, study results, and any other applicable materials should be submitted
to:
1) Electronic Version Only (pdf and CD)
Division of Water Resources
WQ Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
2) Electronic Version (pdf and CD) and Hard Copy
Division of Water Resources
Water Sciences Section
1621 Mail Service Center
Raleigh, NC 27699-1621
A. (19.) PUMPING FROM DAN RIVER INTO BELEWS LAKE
[NCGS 143-215.1]
The Division recognizes the additional cooling water demand on Belews Lake associated with new
scrubbers. The operation of a permanent pump station and cooling water intake structure, receiving
water pumped from the Dan River to Belews Lake, is hereby authorized under the following
conditions:
Page 18 of 23

Permit NC0024406
• Pumping must not lower the flow in Dan River below 110 cfs, which is the Division of Water
Resources target flow recommendation for this site. River flow at the pumping location must
be checked at a newly installed USGS gauge station near the old USGS Pine Hall gauge
station prior to each daily pumping event.
• The Dan River pumps intake will be positioned above the river bottom and have an approach
velocity less than or equal to 0.5 feet/second at the inlet of the velocity caps and at the 2mm
fine mesh traveling screens to minimize fish entrainment and impingement.
• The withdrawal location will be near the confluence of the spillway channel below Belews
Lake Dam and the Dan River. This is a scoured bottom area that does not provide suitable
aquatic habitat.
• The facility will perform routine semi-annual lake monitoring to assess limnological
conditions in Belews Lake.
• Pumping may occur to a maximum water level in Belews Lake of 724.5 feet msl.
• Pumping must not occur from April 1 through June 30 of any year, in order to avoid the fish
spawning period.
• At least 80% of ambient flow as recorded at the new Pine Hall USGS gauge must be bypassed
(i.e., withdraw no more than 20% of flow).
This approval allows the operation of two 50 cfs velocity caps, a permanent settling pond with
approximately 6000 square feet of surface area, a 4-pump pumping station with a capacity not to
exceed 100 cfs, force main, an electrical substation with an access road, and a diffuser in Belews
Lake. Please note that this authorization does not affect the legal requirements to obtain other
permits or approvals which may be required for this activity by the Division of Water Resources or
other agencies, including the Division of Land Resources, or the US Army Corps of Engineers. The
Division reserves the right to reopen this permit in the event of unforeseen negative environmental
impacts due to this pumping operation.
A. (20.) BROMIDE REDUCTION EVALUATION
[NCGS 143-215.1]
Duke Energy shall investigate technical solutions to reduce bromide in the discharge from Outfall
003. Duke Energy shall submit semi-annual reports on the efforts it undertakes to reduce bromide
at the source as well as efforts at downstream water treatment plants to reduce formation of total
trihalomethanes (TTHM). Duke Energy shall continue to work with the downstream public water
supply systems to find a solution to the issue of the TTHM formation in the distribution system of the
downstream water systems. The semi-annual status reports (3 copies) shall be submitted to the
Division of Water Resources, Complex NPDES Permitting Unit.
In the event of a Maximum Contaminant Level (MCL) violation for Total Trihalomethanes (THMs) at
the Town of Madison, the City of Eden or any wholesale customers of those systems, Duke Energy
will within 14 days of the request provide the latest available bromide monitoring data that can be
incorporated into required Public Notices issued by the public water system(s).
A. (21.)DOMESTIC WASTEWATER TREATMENT PLANT
[NCGS 143-215.1]
The domestic wastewater treatment plant shall be properly operated and maintained to ensure
treatment of domestic wastewater to secondary levels.
Page 19 of 23

Permit NC0024406
A. (22.) INSTREAM MONITORING (Outfall 003)
[15A NCAC 02B.0500 ET SEQ.]
The facility shall conduct monthly instream monitoring (approximately 2.7 miles upstream at the
Highway 311 bridge and approximately 250 meters downstream of the ash pond discharge) for total
arsenic, total selenium, total mercury, total chromium, dissolved lead, dissolved cadmium, dissolved
copper, dissolved zinc, total bromide, total hardness (as CaCO3), temperature, turbidity, and total
dissolved solids (TDS). The monitoring results shall be reported on the facility's Discharge Monitoring
Reports and included with the NPDES permit renewal application.
A. (23.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and
program reports. The final NPDES Electronic Reporting Rule was adopted and became effective on
December 21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)1
The permittee shall report discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report (eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month
and submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. Until such time that the
state's eDMR application is compliant with EPA's Cross-Media Electronic Reporting Regulation
(CROMERR), permittees will be required to submit all discharge monitoring data to the state
electronically using eDMR and will be required to complete the eDMR submission by printing,
signing, and submitting one signed original and a copy of the computer printed eDMR to the
following address:
NC DENR / Division of Water Resources / Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the
facility being physically located in an area where less than 10 percent of the households have
broadband access, then a temporary waiver from the NPDES electronic reporting requirements
may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1,
1.1, 2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be
submitted to the mailing address above. See "How to Request a Waiver from Electronic
Reporting" section below.
Regardless of the submission method, the first DMR is due on the last day of the month following
the issuance of the permit or in the case of a new facility, on the last day of the month following
the commencement of discharge.
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Permit NC0024406
Starting on December 21, 2020, the permittee must electronically report the following
compliance monitoring data and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act (CWA) Section 316(b) Annual Reports.
The permittee may seek an electronic reporting waiver from the Division (see "How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the
time of each electronic submission. The permittee should use the EPA's website resources to
identify the initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity
(EPA or the state authorized by EPA to implement the NPDES program) that is the designated
entity for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and for each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at: http://www2.epa.gov/compliance/final-national-
pollutant-discharge-elimination-system-npdes-electronic-reporting-rule.
Electronic submissions must start by the dates listed in the "Reporting Requirements" section
above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request
to the Division. Requests for temporary electronic reporting waivers must be submitted in writing
to the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring
data and reports shall be submitted electronically to the Division unless the permittee re-applies
for and is granted a new temporary electronic reporting waiver by the Division. Approved
electronic reporting waivers are not transferrable. Only permittees with an approved reporting
waiver request may submit monitoring data and reports on paper to the Division for the period
that the approved reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found
on the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
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Permit NC0024406
4. Signatory Requirements [Supplements Section B. (11.1 (bl and Supersedes Section B. (11.1
Id11
All eDMRs submitted to the permit issuing authority shall be signed by a person described in
Part II, Section B. (11.)(a) or by a duly authorized representative of that person as described in
Part II, Section B. (11.)(b). A person, and not a position, must be delegated signatory authority
for eDMR reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall
make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION
WILL BE ACCEPTED:
"I certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate,
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
5. Records Retention [Supplements Section D. (6.11
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from
the date of the report. This period may be extended by request of the Director at any time [40
CFR 122.41].
A. (24.) THERMAL VARIANCE
[40 CFR 125, Subpart H]
In order to continue the Thermal Variance beyond the term of this permit the facility shall develop
and conduct comprehensive 316(a) studies. The 316(a) studies shall be performed in accordance with
the Division of Water Resources approved plan. The temperature analysis and the balanced and
indigenous study plan shall conform to the specifications outlined in 40 CFR 125 Subpart H and the
EPA's Draft 316(a) Guidance Manual, dated 1977, and the Region 4 letter to NCDENR, dated June 3,
2010.
The study shall be performed in accordance with the following schedule:
1) Effective date of the permit +60 days- submit the Draft Study Plan to the DEQ and EPA, the
DEQ will perform the Plan review and provide the comments to Duke within 30 days of the
Plan receipt.
2) Effective date of the permit +120 days- meet with the DEQ to provide responses to the
DEQ/EPA comments and discuss the Study Plan.
3) Effective date of the permit +150 days- submit the Final Study Plan to the DEQ and to the
EPA.
4) After obtaining an approval of the Study Plan, conduct 1 year of the monitoring.
5) 120 days after completing the monitoring, submit the study results and application to
continue the 316a variance to DEQ.
Page 22 of 23

Permit NC0024406
Copies of all the study plans, study results, and any other applicable materials should be submitted
to:
1) Electronic Version Only (pdf and CD)
Division of Water Resources
WQ Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
2) Electronic Version (pdf and CD) and Hard Copy
Division of Water Resources
Water Sciences Section
1621 Mail Service Center
Raleigh, NC 27699-1621
A. (25.) COMPLIANCE BOUNDARY
[15A NCAC 02L.0107]
The compliance boundary for the disposal system shall be specified in accordance with 15A NCAC
02L .0107(a) or (b) dependent upon the date permitted. An exceedance of groundwater standards at
or beyond the compliance boundary is subject to remediation action according to 15A NCAC 02L
.0106(c), (d), or (e) as well as enforcement actions in accordance with North Carolina General Statute
143-215.6A through 143-215.6C. The compliance boundary map for this facility is incorporated
herein and attached hereto as Attachment A.
A. (26.) APPLICABLE STATE LAW (State Enforceable Only)
[NCGS 143-215.1(b)]
This facility shall meet the General Statute requirements under NCGS § 130A-309.200 et seq. This
permit may be reopened to include new requirements imposed under these Statutes.
Page 23 of 23

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NC0024406 - Belews Creek Steam StationFacility X
Latitude(001): 36°16'49.5" Receiving Stream(001,005,007):Belews Lake,class C Location
Longitude(001): 80°03'39.8" Receiving Stream(003,1 l l):UT to Dan River,
Latitude(003): 36°18'22.0" Class WS-1V $-
Longitude(003): 80°04'50.7" Receiving Stream(006):Dan River,
Duke Enerp:-Belews Steam Station
Latitude(005): 36°17'50.3"Latitude(006): 36°18'34.8"
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Longitude(005): 80°3'29.7" Longitude(006): 80°04'36.1" North pnottNC002scale not to scale

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DEQ/DWR
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NC0024406
Facility Information
Applicant/Facility Duke Energy Carolinas, LLC- Belews Creek Steam Station
Name:
Applicant Address: 13339 Hagers Ferry Road; Huntersville, North Carolina 2807E
Facility Address: 3195 Pine Hall Road; Belews Creek, NC 27009
Permitted Flow N/A
Type of Waste: Industrial (-100%); Domestic (<1%)
Prim.SIC Code: 4911
Facility/Permit Class I /Active; Renewal
Status:
County: Stokes County
Miscellaneous
Receiving Stream: Belews Lake (001, Regional Office: Winston-Salem
005, 007), UT to (WSRO)
Dan River (003,
003A) , Dan River
(006)
Stream C (Belews Lake), State Grid / USGS B18SE/Belews
Classification: WS-IV (Dan Quad: Lake
River) _
303(d) Listed? No Permit Writer: Sergei Chernikov,
Ph.D.
Subbasin: 03-02-01 Date: 09/09/2016
Drainage Area (mi2): 501 (Dan River)
Summer 7Q10 (cfs) 80 (Dan River)
Winter 7Q10 (cfs): 160 (Dan River)
30Q2 (cfs) 195 (Dan River)
Average Flow (cfs): 576 (Dan River) 001: Lat. 36°16'49.5"N Long. 80°03'39.8"W
003: Lat. 36°18'22.0"N Long. 80°04'50.7"W
IWC (%): 26.5 006: Lat. 36°18'34.8"N Long. 80°04'36.1"W
BACKGROUND
Duke Energy's Belews Creek Steam Station is a coal fired steam electric plant in Stokes
County. The facility is subject to the federal effluent guidelines 40 CFR Part 423.
In addition to NPDES Permit NC0024406, the facility also holds the following permits:
01983R12 (air permit), NCD000856591 (Hazardous wastes), and 85-03 (industrial
landfill).
The Division revokes the Effluent Channel designation for Outfall 003 with this permit
renewal.
The facility operates the following outfalls:
• Outfall 001: once through cooling water consisting of intake screen
backwash, recirculating cooling water, station equipment cooling water and
once-through cooling water, this Outfall discharges to Belews Lake.
Page 1of13

I z
• Outfall 003: ash basin discharge consisting of waste streams from the power
house and yard holding sumps, ash sluice lines, chemical holding pond,
coal yard sumps, stormwater, coal pile collection basins (collecting contact
stormwater from coal piles), remediated groundwater, emergency release of
anhydrous ammonia, seepage from coal ash basin, emergency overflow from
the retention basin, emergency overflows from the existing effluent channels,
and treated FGD wastewater from internal outfall 002. The wastewater from
this outfall discharges to Unnamed Tributary (UT) to Dan River.
• Internal outfall 002: FGD wastewater (discharging to ash pond)
• Outfall 003A/006. Upon completion of construction, discharge from the new
lined retention basin. Basin will accept wastes from holding basin, various
sumps, coal pile runoff, stormwater runoff, cooling tower blowdown, FGD
wastewater, and various low volume wastes such as boiler blowdown, coal
pile collection basins (collecting contact stormwater from coal piles),oily
waste treatment, wastes/backwash from the water treatment processes,
plant area wash down water, cooling tower blowdown, equipment heat
exchanger water, remediated groundwater, treated domestic wastewater,
emergency release of anhydrous ammonia,and emergency overflow (rain in
excess of designed storm event). The wastewater from this outfall discharges
to UT to Dan River via the Outfall 003. New Outfall 006 will be constructed
for the lined retention basin within 3 years. This outfall will discharge to
Dan River.
• Outfall 005. This is a former stormwater outfall SW002, consists of once
through non-contact chiller water and stormwater. The wastewater from this
outfall discharges to Belews Lake.
• Outfall 007 (lat. - 36°16'51.604"; long. 80003'52.995"). This is an emergency
spillway for South Coal Basin. This outfall discharges to Belews Lake. The
spillway is designed for a flood greater than 100-year event. Sampling of this
spillway is waived due to unsafe conditions associated with sampling during
overflow event.
• Internal outfall 009. Domestic wastewater plant. The wastewater from this
outfall discharges to UT to Dan River via Outfall 003 or to Dan River via
Outfall 006.
• Toe Drain Outfall 111 (lat. - 36°17'54.94"; long. - 80.04'32.57")- potentially
contaminated toe drain. This outfall discharges to UT to Dan River.
TOE DRAIN-OUTFALL 1 1 1
The facility identified 1 unpermitted toe drain from the ash settling basin.
The location of the toe drain is identified below and are depicted on theattached
P map
to the permit.
Table 1. Discharge Coordinates and Assigned Outfall Numbers
Discharge ID Latitude Longitude Outfall number
S-11 36017'54.94" 80.04'32.57" 111
ASH POND DAMS
Seepage through earthen dams is common and is an expected consequence of
impounding water with an earthen embankment. Even the tightest, best-compacted
clays cannot prevent some water from seeping through them. Seepage is not
necessarily an indication that a dam has structural problems, but should be kept in
check through various engineering controls and regularly monitored for changes in
quantity or quality which, over time, may result in dam failure.
Page 2 of 13

i-
FGD TREATMENT
Currently the facility uses the following treatment train for FGD wastewater
1) addition of lime, ferric chloride, and polymer in the multiple reaction tanks
2) 2 clarifiers
3) 3 filters
4) 8 first stage bioreactors
5) 8 second-stage bioreactors
However, this treatment is insufficient to consistently meet the new FGD limits for
selenium. For example, on 01/29/2015 and on 02/25/2015 the selenium
concentration in the wastewater discharged from Outfall 002 was 32.2 µg/L and 37.9
µg/L, respectively. This is substantially higher than the 23 pg/L, which is a selenium
limit in a newly promulgated effluent guideline. Therefore, Duke is proposing to install
an additional membrane ultrafiltration treatment. Installation and optimization of this
system would require time, it has been determined that November 1, 2020 is an
appropriate effective date for complying with the new FGD limits.
It is important to emphasize that Duke Energy's proposed combination of treatment
technology (adding membrane ultrafiltration to the existing chemical precipitation and
biological treatment system) is more advanced treatment than the BAT technology
basis for the ELGs (chemical precipitation and biological treatment). This treatment
has the potential to remove significant amounts of the arsenic, mercury and selenium
that remains following BAT-level treatment. Such would not be the case if a facility
were to propose adding less effective technology (such as sand filtration, which is
already part of the BAT technology basis) to the BAT technology. Furthermore, this
facility will be the first full-scale implementation of membrane ultrafiltration for
treating FGD wastewater.
REASONABLE POTENTIAL ANALYSIS(RPA)-ASH POND AND TOE DRAIN
The Division conducted EPA-recommended analyses to determine the reasonable
potential for toxicants to be discharged at levels exceeding water quality
standards/EPA criteria by this facility. For the purposes of the RPA, the background
concentrations for all parameters were assumed to be below detections level. The RPA
uses 95% probability level and 95% confidence basis in accordance with the EPA
Guidance entitled "Technical Support Document for Water Quality-based Toxics
Control." The RPA included evaluation of dissolved metals' standards, utilizing a
default hardness value of 25 mg/L CaCO3 for hardness-dependent metals. The RPA
spreadsheets are attached to this Fact Sheet.
a) RPA for Decanting of Ash Pond (Outfall 003).
The RPA was conducted for decanting of Ash Pond, the calculations included: As,
Cd, Chlorides, Cr, Cu, F, Pb, Hg, Mo, Ni, Se, Zn, Ba, Sb, Sulfates, and Ti (please
see attached). The flow of 18.6 MGD was used for the analysis. The discharge
data on the EPA Form 2C, and DMR reports were used for the RPA, the data was
supplemented by the analysis of the free standing water in the ash pond. The
analysis indicates reasonable potential to violate the surface water quality
standards or EPA criteria for the following parameters: Cu, Pb, and Ti. The
appropriate limits were added to the permit. This analysis is also applicable for
Outfalls 003A and 006 since they will accommodate discharge from the same
facility with the same sources of wastewater.
A separate RPA was conducted based on the assumption of the discharge to the
zero-flow stream (current situation for Outfall 003 and Outfall 003A). The
analysis indicates reasonable potential to violate the surface water quality
Page 3 of 13

z
standards or EPA criteria for the following parameters: Sulfates, Chlorides, Cu,
Cd, Se, Pb, and Tl. The appropriate limits were added to the permit.
b) RPA for Dewatering of Ash pond (Outfall 003).
To meet the requirements of the Coal Ash Management Act of 2014, the facility
needs to dewater ash ponds by removing the interstitial water. The facility's
highest discharge rate from the dewatering process will be 2.0 MGD. The facility
submitted data for the standing surface water in the ash ponds, interstitial water
in the ash, and interstitial ash water that was treated by filters of various sizes.
To evaluate the impact of the dewatering on the receiving stream the RPA was
conducted for the wastewater that will be generated by the dewatering process.
To introduce a margin of safety, the highest measured concentration for a
particular parameter was used. The RPA was conducted for As, Cd, Chlorides,
Cr, Cu, F, Pb, Hg, Mo, Ni, Se, Zn, Ba, Sb, and Sulfates. The analysis indicates
reasonable potential to violate the surface water quality standards or EPA criteria
for the following parameters: As, Chlorides, Cu, Se, Mo, F, Cr (III), Cr (VI), Zn, Ni,
Pb, Tl, Ba, Sulfates, and Sb. The appropriate limits were added to the permit.
c) RPA for Toe Drain (Outfall 111).
The RPA calculations was conducted for Toe Drain, the calculations included: As,
Cd, Chlorides, Cr, Cu, F, Pb, Hg, Mo, Ni, Se, Zn, Ba, Sb, and Sulfates. The flow
volume for all seeps was measured at 0.2 MGD. However, the flow of 2.0 MGD
was used for RPA calculations to incorporate a safety factor, account for potential
new seeps that might emerge in the future or increase in flow volume at the
existing seeps. The analysis indicates reasonable potential to violate the surface
water quality standards or EPA criteria for the following parameters: Hg, As, Cd,
Tl, Se, and Chlorides. The appropriate limits were added to the permit.
d) RPA for Outfall 005.
The RPA was conducted for Outfall 005, the calculations included: As, Cd, Cr,
Cu, Pb, Hg, Mo, Ni, Se, Zn, Ba, Sb, and Tl (please see attached). The flow of 2.59
MGD was used for the analysis. The discharge data on the EPA Form 2C were
used for the RPA. The analysis indicates no reasonable potential to violate the
surface water quality standards or EPA criteria.
The proposed permit requires that EPA methods 200.7 or 200.8 (or the most current
versions) shall be used for analyses of all metals except for total mercury.
MERCURY EVALUATION-OUTFALL 003 (AsH POND)
The State of North Carolina has a state-wide mercury impairment. A TMDL has been
developed to address this issue in 2012. The TMDL included the implementation
strategy, both documents were approved by EPA in 2012. The mercury evaluation was
conducted in accordance with the Permitting Guidelines for Statewide Mercury TMDL.
Year 2011 2012 2013 2014 2015 2016
Annual 1.83 2.15 1.47 1.57 2.97 2.6
average
concentration
(ng/L)
Maximum 2.98 2.69 1.59 1.76 5.0 2.94
sampling
result (ng/L)
Number of 2 4 4 6 9 2
samples
Page 4 of 13

The allowable mercury concentration for this facility is 45.3 ng/L. All annual average
mercury concentrations are below the allowable level. All maximum sampling results
are below the TBEL of 47.0 ng/L. Based on the Permitting Guidelines for Statewide
Mercury TMDL, the limits are not required.
TEMPERATURE VARIANCE-OUTFALL 001
State of North Carolina (NC Board of Water and Air Resources) granted the facility a
temperature variance in 1970, which was prior to the 316(a) requirement of the CWA.
However, based on the biological study submitted in 2016, the Water Sciences Section
of the DWR concluded that the information provided in the latest report is insufficient
to determine existence of the Balanced and Indigenous population of fish and
macroinvertebrates in the receiving stream.
The facility will be provided a compliance schedule to develop and conduct a
comprehensive study of the Belews Lake and obtain a 316(a) Variance in accordance
with the 40 CFR 125 Subpart H and the EPA's Draft 316(a) Guidance Manual, dated
1977, and the Region 4 letter to NCDENR, dated June 3, 2010.
CWA SECTION 316(b)
The permittee shall comply with the Cooling Water Intake Structure Rule per 40 CFR
125.95. The Division approved the facility request for an alternative schedule in
accordance with 40 CFR 125.95(a)(2). The permittee shall submit all the materials
required by the Rule with the next renewal application. Duke is involved in a large
scale decommissioning of ash ponds, excavation of coal ash, landfilling of coal ash,
construction of new treatment systems for FGD wastewater and other wastes, and
conversion to zero liquid discharge for bottom ash. Under these circumstances, Duke
is unable to develop comprehensive documentation required by 316(b) rule during this
renewal.
INSTREAM MONITORING-OUTFALL 003/003A/006 (ASH POND)
In 2014, the facility provided instream sampling data for Oil 86 Grease, COD,
Chlorides, Fluoride, Sulfate, Mercury, Aluminum, Barium, Boron, Calcium, Hardness,
Iron, Magnesium, Manganese, Zinc, Antimony, Arsenic, Cadmium, Chromium,
Copper, Lead, Molybdenum, Nickel, Selenium, Thallium, TDS, TSS, pH, Temperature,
and Specific Conductance. The upstream monitoring station was located
approximately 6,000 ft. upstream of Outfall 003 and the downstream monitoring
station was located approximately 21,000 ft. downstream of the Outfall 003.
The following parameters were below detection level at both monitoring stations: Oil 86
Grease, COD, Fluoride, Mercury, Zinc, Antimony, Arsenic, Cadmium, Chromium,
Copper, Lead, Molybdenum, Nickel, Selenium, and Thallium. All parameters were well
below water quality standards/EPA criteria.
The proposed permit will require a monthly monitoring for total arsenic, total
selenium, total mercury, total chromium, dissolved lead, dissolved cadmium, dissolved
copper, dissolved zinc, total bromide, total hardness (as CaCO3), temperature,
turbidity, and total dissolved solids (TDS).
FISH TISSUE MONITORING-NEAR OUTFALL 003/003A/006
The permit required fish tissue monitoring for As, Se, and Hg near the ash pond
discharge once every 5 years. This frequency is consistent with EPA guidance. Golden
Redhorse and Redbreast Sunfish tissues were analyzed for these trace elements. The
data was collected from one locations upstream of the discharge and two locations
downstream of the discharge. The results were below NC human consumption
Page 5 of 13

advisory levels for Se and Hg (10.0 µg/g- Se, 0.40 µg/g- Hg, NC) and screening value
for As (1.20 - µg/g, EPA). Only one Golden Redhorse from one downstream location
had a mercury concentration of 0.40 µg/g, which is equal to NC human consumption
advisory level for Hg.
TOXICITY TESTING-OUTFALL 003 (AsH POND)
Type of Toxicity Test: Chronic P/F
Existing Limit: 003: Chronic P/F @ 19% (Ceriodaphnia dubia)
Recommended Limit: 003: Chronic P/F @ 90% (Ceriodaphnia dubia)
Recommended Limit: 006: Chronic P/F @ 10.9% (Ceriodaphnia dubia)
This facility has passed all toxicity tests (22 out of 22) during the previous permit cycle,
please see attached.
The Division will increase the Instream Waste Concentration from 19% to 90% due to
the reconsideration of the effluent channel status. For the purposes of the permitting,
the highest monthly average flow reported during the last 3 years in conjunction with
the 7Q 10 summer flow was used to calculate the percent effluent concentration to be
used for WET.
COMPLIANCE SUMMARY
During the last 5 years, the facility had 1 violations of the Copper limit (Outfall 003),
please see attached.
PERMIT LIMITS DEVELOPMENT
• The temperature limit in the permit (Outfall 001) is based on the North Carolina
water quality standards (15A NCAC 2B .0200).
• The limits for Oil and Grease and Total Suspended Solids (Outfall 003, Outfall
003A, Outfall 006, and Outfall 111) were established in accordance with the 40
CFR 423.
• The limits for BOD and Total Suspended Solids (Internal Outfall 009) were
established in accordance with the 40 CFR 133.102.
• The limit for Fecal Coliform (Internal Outfall 009) is based on the North
Carolina water quality standards (15A NCAC 2B .0200).
• The pH limits (Outfall 003, Outfall 003A, Outfall 006, and Outfall 111) in the
permit are based on the North Carolina water quality standards (15A NCAC 2B
.0200).
• The turbidity limit in the permit (Outfall 003) is based on the North Carolina
water quality standards (15A NCAC 2B .0200).
• The Whole Effluent Toxicity limit (Outfall 003, Outfall 003A, and Outfall 006) is
based on the requirements of 15A NCAC 2B .0500.
• The Technology Based Effluent Limits for Total Arsenic, Total Mercury, Total
Selenium, Nitrate/nitrite as N, Oil and Grease and Total Suspended Solids
(Internal Outfall 002) are based on the requirements of 40 CFR 423.
• The Technology Based Effluent Limit for Total Iron (Outfall 003, Outfall 003A,
and Outfall 006) are based on the requirements of 40 CFR 423.
• The Water Quality Based Effluent Limits for Chlorides, Sulfates, Total Copper,
Total Aluminum, Total Cadmium, Total Selenium, Total Lead, and Total
Thallium in the permit (Outfall 003 - normal operations/decanting) are based
on the North Carolina water quality standards (15A NCAC 2B .0200) and EPA
water quality criteria.
• The Water Quality Based Effluent Limits for Total Arsenic, Chlorides, Total
Aluminum, Total Copper, Total Molybdenum, Total Selenium, Total Lead,
Fluoride, Chromium III, Chromium VI, Total Zinc, Total Nickel, Total Barium,
Page 6 of 13

Sulfates, Total Antimony, and Total Thallium in the permit (Outfall 003 -
dewatering) are based on the North Carolina water quality standards (15A
NCAC 2B .0200) and EPA water quality criteria.
• The Water Quality Based Effluent Limits for Total Selenium, Chlorides,
Sulfates, Total Cadmium, Total Copper, Total Lead, and Total Thallium in the
permit (Outfall 003A) are based on the North Carolina water quality standards
(15A NCAC 2B .0200) and EPA water quality criteria.
• The Water Quality Based Effluent Limits for Total Copper and Total Lead in the
permit (Outfall 006) are based on the North Carolina water quality standards
(15A NCAC 2B .0200) and EPA water quality criteria.
• The Water Quality Based Effluent Limits for Total Mercury, Total Arsenic, Total
Cadmium, Total Selenium, TDS, and Chlorides (Outfall 111) are based on the
North Carolina water quality standards (15A NCAC 2B .0200) and EPA water
quality criteria.
• Ammonia limits in the permit (Outfall 003, Outfall 003A, and Outfall 006) are
based on the ammonia criteria (monthly average limit). The Division uses
ammonia criteria that were developed by EPA: 1 mg/L - summer; 1.8 mg/L -
winter.
PROPOSED CHANGES
• The following monitoring parameters were eliminated (Internal Outfall 002) to
be consistent with the latest update to 40 CFR 423: Chlorides and TSS.
• The Technology Based Effluent Limits for Total Arsenic, Total Mercury, Total
Selenium, and Nitrate/nitrite as N were added to the permit (Internal Outfall
002) based on the requirements in 40 CFR 423.
• The Decanting Special Conditions were added to Outfall 003, please see A. (3.).
• Monitoring frequency for all parameters that were previously monitored
Quarterly were reduced to Monthly with an exception of Toxicity (Outfall 003 -
normal operations/decanting), please see A. (3.).
• Instream Waste Concentration for Outfall 003 (normal operations/decanting)
0 19%
was increased to 90% from based on the re-consideration of the effluent
channel status.
• The compliance dates for fly ash transport water (November 1, 2018) and
bottom ash transport water (May 31, 2021) were added to Outfall 003 in
accordance with 40 CFR 423.
• The compliance date of November 1, 2020 for Technology Based Effluent Limits
was added to Internal Outfall 002 in accordance with 40 CFR 423.
• The Water Quality Based Effluent Limits for Chlorides, Total Copper, Total
Aluminum, Total Cadmium, Total Selenium, Total Lead, Ammonia, and Total
Thallium were added to the permit based on the results of Reasonable Potential
Analysis (Outfall 003 - normal operations/decanting).
• A separate effluent page for the dewatering of the ash pond (Outfall 003) was
added to the permit. Please see Condition A. (4.).
• A separate effluent page for the new Retention Basin (Outfall 003A) was added to
the permit. Please see Condition A. (5.).
• A new Outfall for the new Retention Basin (Outfall 006) was added to the permit.
• The Instream Monitoring Special Condition was added to the permit to monitor
the impact of the facility on the receiving stream. Please see Special Condition A.
(22.).
• A new Outfall for the Toe Drain discharge (Outfall 111) was added to the permit.
• Federal regulations require electronic submittal of all discharge monitoring
reports (DMRs) and program reports. The final NPDES Electronic Reporting
Rule was adopted and became effective on December 21, 2015. The requirement
to begin reporting discharge monitoring data electronically using the NC DWR's
Page 7 of 13

Electronic Discharge Monitoring Report (eDMR) internet application has been
added to your final NPDES permit. [See Special Condition A. (23.)]
For information on eDMR, registering for eDMR and obtaining an eDMR user
account, please visit the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr.
For more information on EPA's final NPDES Electronic Reporting Rule, please
visit the following web site:
https://www.federalregister.gov/documents/2015/10/22/2015-
24954/national-pollutant-discharge-elimination-system-npdes-electronic-
reporting-rule
• The turbidity limit was added to the permit (Outfall 003) to meet the state
turbidity standard per 15A NCAC 2B .0211(3) (k).
• Thermal Variance/Clean Water Act Section 316(b) special condition was
updated (Please see A. (16.)).
• A new outfall was added to the permit (Outfall 005). This is a former stormwater
outfall SW002, it consists of once through non-contact chiller water and
stormwater.
• A new internal outfall was added to the permit (Outfall 009) for the discharge of
domestic wastewater.
• A new outfall was added to the permit (Outfall 007) for the emergency spillway
discharge from the South Coal Basin.
• The Compliance Boundary special condition was added to the permit, please see
A. (25.). This special condition replaces Groundwater Well Construction and
Sampling special condition.
• An Applicable State Law special condition was added to the permit, please see A.
(26.).
PROPOSED SCHEDULE
Draft Permit to Public Notice: June 12, 2018
Permit Scheduled to Issue: July 31, 2018
STATE CONTACT
If you have any questions on any of the above information or on the attached permit,
please contact Sergei Chernikov at [phone] or [e-mail].
Page 8 of 13

NPDES Implementation of Instream Dissolved Metals Standards-Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13,2014. The US EPA
subsequently approved the WQS revisions on April 6,2016,with some exceptions.Therefore,metal
limits in draft permits out to public notice after April 6,2016 must be calculated to protect the new
standards -as approved.
Table 1. NC Dissolved Metals Water Quality Standards/Aquatic Life Protection
Parameter Acute FW,µg/1 Chronic FW, Acute SW,pg/1 Chronic SW,
(Dissolved) pg/1 (Dissolved) µg/1
(Dissolved) (Dissolved)
Arsenic 340 150 69 36
Beryllium 65 6.5
Cadmium Calculation Calculation 4() 8.8
Chromium III Calculation Calculation ---
Chromium VI 16 11 1100 50
Copper Calculation Calculation 4.8 3.1
Lead Calculation Calculation 210 8.1
Nickel Calculation Calculation 74 8.2
Silver Calculation 0.06 1.9 0.1
Zinc Calculation Calculation 90 81
Table 1 Notes:
1. FW= Freshwater,SW= Saltwater
2. Calculation = Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still
necessary to evaluate total recoverable aquatic life and human health standards listed in 15A
NCAC 2B.0200 (e.g.,arsenic at 10µg/1 for human health protection;cyanide at 5 pg/L and
fluoride at 1.8 mg/L for aquatic life protection).
Table 2. Dissolved Freshwater Standards for Hardness-Dependent Metals
The Water Effects Ratio (WER)is equal to one unless determined otherwise under
15A NCAC 02B .0211 Subparagraph (11)(d)
Metal NC Dissolved Standard,pg/1
Cadmium,Acute WER*{1.136672-[ln hardness](0.041838)} • e^{0.9151 [ln hardness]-
3.1485}
Cadmium, Acute Trout WER*{1.1366721/n hardness](0.041838)} • {0.9151[In hardness]-
waters 3.6236}
Cadmium, Chronic WER*{1.1016724/n hardness](0.041838)1 • e^{0.7998[In hardness]-
4.4451}
Chromium III,Acute WER*0.316 • e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic WER*0.860 • e^{0.8190[/n hardness]+0.6848}
Page 9 of 13

Copper,Acute WER*0.960 • e^{0.9422[In hardness]-1.700}
Copper,Chronic WER*0.960 • e^{0.8545[In hardness]-1.702}
Lead,Acute WER*{1.462034/n hardness](0.145712)) • e^{1.273[In hardness]-
1.460}
Lead, Chronic WER*{1.46203-[ln hardness](0.145712)) • e^(1.273[In hardness]-
'
4.705)
Nickel,Acute WER*0.998 • e^{0.8460[/n hardness]+2.255}
Nickel, Chronic WER*0.997 • e^{0.8460[In hardness]+0.0584}
Silver,Acute WER*0.85 • e^{1.72[In hardness]-6.59}
Silver,Chronic Not applicable
Zinc,Acute WER*0.978 • e^{0.8473[In hardness]+0.884}
Zinc,Chronic WER*0.986 • e^{0.8473[In hardness]+0.884}
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However,
application of the dissolved and hardness-dependent standards requires additional consideration in
order to establish the numeric standard for each metal of concern of each individual discharge.
The hardness-based standards require some knowledge of the effluent and instream (upstream)
hardness and so must be calculated case-by-case for each discharge.
Metals limits must be expressed as `total recoverable'metals in accordance with 40 CFR 122.45(c).
The discharge-specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on
that below),but it is also possible to consider case-specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WQBELs for Hardness-Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of
concern,based on recent effluent data,and calculate the allowable effluent concentrations,based on
applicable standards and the critical low-flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute),the
discharge has reasonable potential to exceed the standard,which warrants a permit limit in most
cases. If monitoring for a particular pollutant indicates that the pollutant is not present(i.e.
consistently below detection level), then the Division may remove the monitoring requirement in the
reissued permit.
1. To perform a RPA on the Freshwater hardness-dependent metals the Permit Writer
compiles the following information:
• Critical low flow of the receiving stream, 7Q10 (the spreadsheet automatically
calculates the 1Q10 using the formula 1Q10 = 0.843 (s7Q10, cfs) 0.993
• Effluent hardness and upstream hardness, site-specific data is preferred
• Permitted flow
• Receiving stream classification
Page 10 of 13

,1,
2. In order to establish the numeric standard for each hardness-dependent metal of concern
and for each individual discharge, the Permit Writer must first determine what effluent and
instream (upstream) hardness values to use in the equations.
The permit writer reviews DMR's,Effluent Pollutant Scans,and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for
instream hardness values,upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial evaluation
using a default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits
on the hardness value used for water quality calculations are 25 mg/L and 400 mg/L,
respectively.
If the use of a default hardness value results in a hardness-dependent metal showing
reasonable potential, the permit writer contacts the Permittee and requests 5 site-specific
effluent and upstream hardness samples over a period of one week. The RPA is rerun using
the new data.
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
= (Permitted Flow.cfs *Avg. Effluent Hardness.mg/L) + (s7Q10.cfs *Avg. Upstream Hardness,
mg/L)
(Permitted Flow,cfs + s7Q10,cfs)
The Combined Hardness for acute is the same but the calculation uses the 1Q10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total
recoverable metal,using the EPA Default Partition Coefficients (DPCs) or site-specific
translators,if any have been developed using federally approved methodology.
EPA default partition coefficients or the"Fraction Dissolved" converts the
value for dissolved metal at laboratory conditions to total recoverable metal
at in-stream ambient conditions. This factor is calculated using the linear
partition coefficients found in The Metals Translator: Guidance for
Calculating a Total Recoverable Permit Limit from a Dissolved Criterion
(EPA 823-B-96-007, June 1996) and the equation:
Cdiss = 1
Ctotal 1 + { [Kpo] [SS(1+1 [101 }
4. The Where:
ss=in-stream suspended solids concentration [mg/1],minimum of 10 mg/L
used, and
Kpo and a=constants that express the equilibrium relationship between
dissolved and adsorbed forms of metals. A list of constants used for each
hardness-dependent metal can also be found in the RPA program under a
numeric standard for each metal of concern is divided by the default partition coefficient (or
site-specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases,where an EPA default partition coefficient translator does not exist (ie.
silver),the dissolved numeric standard for each metal of concern is divided by the EPA
conversion factor to obtain a Total Recoverable Metal at ambient conditions.This method
presumes that the metal is dissolved to the same extent as it was during EPA's criteria
Page 11of13

development for metals. For more information on conversion factors see the June, 1996
EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable
concentration (permit limits) for each pollutant using the following equation:
Ca = (s7Q10 + Qw) (Cwqs) —(s7Q10) (Cb)
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (j.tg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3* (µg/L or
mg/L)
Qw = permitted effluent flow (cfs,match s7Q10)
s7Q10 = summer low flow used to protect aquatic life from chronic toxicity and human
health through the consumption of water, fish,and shellfish from noncarcinogens (cfs)
* Discussions are on-going with EPA on how best to address background
concentrations
Flows other than s7Q10 may be incorporated as applicable:
1Q10 = used in the equation to protect aquatic life from acute toxicity
QA = used in the equation to protect human health through the consumption of
water, fish,and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of
concern. Data entered must have been taken within four and one-half years prior to the
date of the permit application (40 CFR 122.21). The RPA spreadsheet estimates the
95th percentile upper concentration of each pollutant. The Predicted Max
concentrations are compared to the Total allowable concentrations to determine if a
permit limit is necessary. If the predicted max exceeds the acute or chronic Total
allowable concentrations, the discharge is considered to show reasonable potential to
violate the water Quality standard, and a permit limit (Total allowable concentration) is
included in the permit in accordance with the U.S. EPA Technical Support Document
for Water Quality-Based Toxics Control published in 1991.
7. When appropriate,permit writers develop facility specific compliance schedules in
accordance with the EPA Headquarters Memo dated May 10,2007 from James Hanlon to
Alexis Strauss on 40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards.As a cost savings measure,total chromium
data results may be used as a conservative surrogate in cases where there are no analytical
results based on chromium III or VI. In these cases, the projected maximum concentration
(95th%) for total chromium will be compared against water quality standards for chromium
III and chromium VI.
9. Effluent hardness sampling and instream hardness sampling,upstream of the discharge,are
inserted into all permits with facilities monitoring for hardness-dependent metals to ensure
the accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter Value Comments (Data Source)
Page 12 of 13

} + s
Average Effluent Hardness (mg/L) 25.0 Default value
[Total as, CaCO3 or(Ca+Mg)]
Average Upstream Hardness
(mg/L) 25.0 Default value
[Total as, CaCO3 or(Ca+Mg)]
7Q10 summer (cfs) 0 Lake or Tidal
1Q10 (cfs) 0 Lake or Tidal
Permitted Flow (MGD) 2.1 For dewatering
Page 13 of 13