NCS000606_Permit Modification_20231108

t STATE
ROY COOPER
Governor 0 - 2�01
ELIZABETH S.BISER
secretary
WILLIAM E.TOBY VINSON,JR NORTH CAROLINA
Interim Director Environmental Quality
November 8, 2023
Jessica Bednarcik, Senior Vice President
Duke Energy Progress, LLC
526 S Church Street
Mail Code Ec13k
Charlotte, NC 28201-1002
Subject: Minor Permit Modification
NPDES Permit NCS00606
Harris Nuclear Plant
Wake County
Dear Permittee:
The Division of Energy, Mineral, and Land Resource (the Division) acknowledges comments submitted
by Bob Wilson on behalf of Duke Energy Progress, LLC on October 25, 2023 concerning the
recently issued permit (June 14, 2023).
Accordingly, we hereby forward the modified permit pages to amend your permit changing outfall
descriptions and removing monitoring for outfall SW005. Please insert these change pages into
your existing permit and discard the old pages. We regret any inconvenience this causes your
organization. Additionally, please find attached responses to your additional questions.
Please note that this permit is not transferable except after notice to the Division, The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the
legal requirements to obtain other permits which may be required by the Division of Energy,
Mineral, and Land Resource or any other Federal, State, or Local governmental permits that may be
required.
If you have questions, or if we can be of further service, please contact Brianna Young at
[e-mail] or call 919-707-3647.
Sincerely,
Michael Lawyer, Stormwater Program Supervisor
Division of Energy, Mineral, and Land Resources
Attachments: NPDES Stormwater Permit NCS000606
cc: NPDES Stormwater Program Files (Laserfiche)
Raleigh Regional Office
Don Safrit, Lead Environmental Specialist, Duke Energy
Bob Wilson, Harris Nuclear Plant Site Environmental Field Professional, Duke Energy
�� )+forth Carolina Department of Environmental Quality I Division of Energy,Mineral and Land Resources
R 512 North Salisbury Street 1 1612 Mall Service Center I Raleigh.North Carolina 27699-1612
919.70T9200

QUESTIONS:
Is it possible to complete four(4) samples in a quicker timeframe for the purpose of
requesting Representative Outfall Status (ROS) if those samples meet the qualifying storm
event criteria and are separated by at least 30 days?
Taking one sample in each quarter allows the Stormwater Program to evaluate effect of different
seasons on stormwater discharge. One sample per quarter will need to be taken before ROS can be
requested.
Since the permit was issued September 27,2023,Duke Energy understands and interprets
observations (qualitative) and analytical(quantitative) obligations associated with NCS000606
do not go into effect until the first quarter of 2024. Please clarify if appropriate.
Correct, sampling is not required to begin before January 1, 2024 since the permit effective date is
in the middle of a sampling quarter.
Is the average monthly usage of new motor oil and hydraulic oil a running 12-month average?
Yes,the average monthly usage is based on a rolling 12 month average.
Part D,Table 2,footnote 3, bullet point 2 states: "Intermittently,the auxiliary boiler heat
exchanger and draining of filtered water and demineralized (msp)water storage tanks will be
pushed to the outfall." Duke Energy requests an explanation of how the water will be pushed
to the outfall. Duke Energy believes the more appropriate language would be: ... and
demineralized water storage tanks will be routed to the outfall.
This is language that was provided by Duke during the permit renewal and thus incorporated into
the permit; however,the word"pushed"will be updated to"routed".
REQUESTED CORRECTIONS:
A. In the summary of baseline sampling requirement tables throughout the permit, estimated
average monthly oil usage is listed a parameter for all outfalls. Since this is average is facility
wide,Duke Energy requests that this parameter be required for SW-006 only.
You are correct that this is a site-wide average, however,the reporting requirement will remain for
each outfall. You may add in the comments section of eDMR that the oil usage number being
reported is site-wide and does not represent the amount of oil used in each drainage area.
B. Table 2, Outfall SW-005 discharges into the Main Intake Canal and is then directed to the
process water for discharge through NPDES Outfalls. Duke Energy requests that the
monitoring requirements for SW-005 be removed from the permit because this outfall does

not discharge to the stormwater drainage system or to surface waters (reference Additional
Outfalls page 19).
This was not clear during the permit review and public notice processes. The permit will be updated
to reflect this change.
C. Part D,Table 2, footnote 3 references a service transformer. However, there are multiple
service transformers present.Duke Energy requests that footnote 3 be updated to reflect site
conditions. See corrected language below:
Outfall SW002: Drainage area includes Diesel Generator Building, northern portion of the cooling
tower, Major Projects Building, one (I) 6,500-gallon phosphoric acid tank three (3) 4,500-gallon
water treatment chemical tanks, service transformers, sewage lift station;gravel surfaced parking
areas, rail lines, and grassed yard areas.
This is not a significant distinction,therefore a permit modification is not needed. However, the
update will be made as other permit changes are being incorporated.
D.Part D,Table 2, footnote 3 references two Water Treatment Buildings. However,there is
only one of these buildings present. Duke Energy requests that footnote 3 be updated to reflect
site conditions. See corrected language below:
Outfall SW006: Drainage area includes one (1) Water Treatment Building, Paint Shop, Chemical
Warehouse, Mobile Equipment Area, a portion of the Service Building, a portion of the Bulk
Warehouse, the Neutralization Basin, the Settling Basin, gasoline storage tanks, diesel fuel storage
tanks, used oil storage tanks, oil/water separator and adjacent 1,000 gallon used oil collection tank;
service transformers, three (3) sewage lift stations, one (1) 8,315 gallon sulfuric acid storage tank,
solid waste compactor,paved roads, gravel-surfaced areas, external storage areas,parking areas,
and grassed areas. Intermittently, the auxiliary boiler heat exchanger and draining offrltered water
and decriminalized water storage tanks will be pushed to the outfall.
This information was not clarified during the permit review or public notice processes. The outfall
description can be updated to state: Drainage area includes one(1) Water Treatment Building, Paint
Shop, Chemical Warehouse, Mobile Equipment Area, a portion of the Service Building, a portion of
the Bulk Warehouse, a portion of the Waste Processing Building,the Neutralization Basin,the
Settling Basin, gasoline storage tanks, diesel fuel storage tanks, used oil storage tanks, oil/water
separator and adjacent 1,000 gallon used oil collection tank, service transformers, three (3) sewage
lift stations, one(1) 8,315 gallon sulfuric acid storage tank, a fueling area, a water treatment facility,
solid waste compactor,paved roads, gravel-surfaced areas,external storage areas, parking areas,
and grassed areas. Intermittently,the auxiliary boiler heat exchanger and draining of filtered water
and decriminalized water storage tanks will be routed to the outfall.
E. Part D, Table 3, footnote 3, bullet point 1 does not identify the transformers within Outfall
SW-003. Duke Energy requests that this item be updated to reflect site conditions. See
corrected language below:
Outfall SW003: Drainage area includes the southern portion of the Cooling Tower, one (1) 5,600-
gallon sodium hypochlorite tank other small water treatment chemical storage tanks, chemical

storage building, Cooling Tower circulating water pumps, transformer yard, transformers,paved
parking areas, and grassed yard areas.
The identification of the transformer yard indicates transformers are present in the area. This is not a
significant distinction, therefore a permit modification is not needed.
F. Part D, Table 4, footnote 3, bullet point 1 does not identify the transformers within Outfall
SW-004. Duke Energy requests that this item be updated to reflect site conditions. See
corrected language below:
Outfall SWO04: Drainage area includes gravel-surfaced switchyard, transformers,paved roads and
parking areas, and grassed yard areas.
The identification of the switchyard indicates transformers are present in the area. This is not a
significant distinction, therefore a permit modification is not needed.
G. On page 19 under "Additional Outfalls," SW-007 and Drainage Area 10 are said to
discharge to the Emergency Service Water Intake Canal. However, SW-005 also discharges to
the Main Intake Canal. Duke Energy requests that this section be updated to reflect a similar
site conditions. See corrected language below:
Stormwater outfalls SW005, SWO07 and Drainage Area 10 discharge to the Emergency Service
Water Intake Canal, which goes back into the plant. Stormwater outfall SW-A does not contain
Industrial Activity. Any modifications to these outfalls that result in a potential stormwater
discharge associated with past or present industrial activities will require a modification of this
permit.
SWO05 should also be removed from Part D Table 1 since it discharges to the Emergency
Service Water Intake Canal as explained above. The bulleted item in Part D Table 1 for the
SWO05 description should also be removed from this section.
This was not clear during the permit review and public notice processes. The permit will be updated
to reflect this change.
H. Duke Energy understands that fecal coliform is included in the monitoring parameters for
SW-001 and SW-005 due to the presence of lift stations in those drainage areas. However,
there is also an abundance of wildlife at the plant that is likely to contribute fecal coliform to
stormwater. Duke Energy requests that language be added to the Tier 1 response
requirements stating that if the exceedance is for fecal coliform, then Duke Energy will
provide and document additional oversight of the lift station(s). If, after this effort by Duke
Energy to provide additional management of the lift station(s), the fecal coliform benchmark
is exceeded, then Duke Energy will be granted Tier relief rather than progressing to Tiers 2
and 3.
The process of requesting Tier Response Relief is already set in the permit,therefore additional
language is not needed. Please work with the Raleigh Regional Office if there are exceedances of
Fecal Coliform to determine what, if any, Tier Response actions are needed.

Permit NCS000606
Table 1. Summary of Quarterly Baseline Sampling Requirements for Stormwater Discharges for
Outfall SWO01
Parameter Code for Parameter Frequency' Benchmark
Reporting
C0530 Total Suspended Solids(TSS) Quarterly 100 mg/L
00400 pH 2 Quarterly 6 s.u.—9 s.u.
46529 Total Rainfall of Sampled Event - -
(inches)3
Non-Polar Oil&Grease for drainage
00552 areas that use>55 gallons/month of Quarterly 15 mg/L
oil on average per EPA Method 1664
(SGT-HEM)
NCOIL Estimated Average Monthly Oil - -
Usage at the Facility(gallons)
C0310 Biochemical Oxygen Demand Quarterly 30 mg/L
(BOD5)
00340 Chemical Oxygen Demand(COD) Quarterly 120 mg/L
C0610 Ammonia Nitrogen(Summer)*° Quarterly 5.6 mg/L
C0610 Ammonia Nitrogen(Winter)*4 Quarterly 15 mg/L
C0600 Total Nitrogen Quarterly 30 mg/L
31616 Fecal Coliform Quarterly 1,000 col/100 mL
01042 Total Copper Quarterly 10 µg/L
01051 Total Lead Quarterly 75 µg/L
01092 Total Zinc Quarterly 126 µg/L
00900 Hardness—Total as[CaCO3 or(Ca+ Quarterly -
*Summer:April 1 —October 31
*Winter:November 1 —March 31
Footnotes:
1. Measurement frequency: Quarterly during a measurable storm event. If the facility is monitoring monthly
due to Tier Two or Tier Three response actions,the facility shall continue a monthly monitoring and
reporting schedule in Tier Two or Tier Three status until relief is granted.
2. If pH values outside this range are recorded in sampled stormwater discharges, but ambient precipitation
pH levels are lower,then the lower threshold of this benchmark range is the pH of the precipitation
(within instrument accuracy) instead of 6 s.u.. Readings from an on-site or local rain gauge(or local
precipitation data)must be documented to demonstrate background concentrations were below the
benchmark pH range.
Page 13 of 40

Permit NCS000606
3. For each sampled measurable storm event,the total precipitation must be recorded.An on-site rain gauge
is required. Where isolated sites are unmanned for extended periods of time, a local rain gauge reading
may be substitute for an on-site reading.
4. Monitoring may cease after four(4)consecutive samples show results below detection.
5. Hardness sampling should be performed in conjunction with testing for hardness dependent metals
(copper, lead, and zinc).
• Outfall SW001: Drainage area includes warehouse numbers 6 and 9,paved and gravel-surfaced
parking areas, gravel-surfaced storage yards, rail lines, service transformers, scrap metal and
solid waste dumpsters, four(4) sewage lift stations, and grassed yard areas.
Page 14 of 40

Permit NCS000606
Table 2. Summary of Quarterly Baseline Sampling Requirements for Stormwater Discharges for
Outfalls SWO02 and SWO06
Parameter Code for Parameter Frequency 1 Benchmark
Reporting
C0530 Total Suspended Solids(TSS) Quarterly 100 mg/L
00400 pH z Quarterly 6 s.u.—9 s.u.
46529 Total Rainfall of Sampled Event - -
(inches)3
Non-Polar Oil&Grease for drainage
00552 areas that use>55 gallons/month of Quarterly 15 mg/L
oil on average per EPA Method 1664
(SGT-HEM)
NCOIL Estimated Average Monthly Oil - -
Usage at the Facility(gallons)
C0310 Biochemical Oxygen Demand Quarterly 30 mg/L
(BOD5)
00340 Chemical Oxygen Demand(COD) Quarterly 120 mg/L
31616 Fecal Coliform Quarterly 1,000 col/100 mL
Footnotes:
1. Measurement frequency: Quarterly during a measurable storm event. If the facility is monitoring monthly
due to Tier Two or Tier Three response actions,the facility shall continue a monthly monitoring and
reporting schedule in Tier Two or Tier Three status until relief is granted.
2. If pH values outside this range are recorded in sampled stormwater discharges, but ambient precipitation
pH levels are lower,then the lower threshold of this benchmark range is the pH of the precipitation
(within instrument accuracy)instead of 6 s.u. Readings from an on-site or local rain gauge(or local
precipitation data)must be documented to demonstrate background concentrations were below the
benchmark pH range.
3. For each sampled measurable storm event,the total precipitation must be recorded.An on-site rain gauge
is required.Where isolated sites are unmanned for extended periods of time,a local rain gauge reading
may be substitute for an on-site reading.
• Outfall SWO02: Drainage area includes Diesel Generator Building, northern portion of the cooling
tower, Major Projects Building, one (1) 6,500 gallon phosphoric acid tank,three (3) 4,500 gallon
water treatment chemical tanks, service transformers, sewage lift station, gravel-surfaced parking
areas, rail lines, and grassed yard areas.
• Outfall SWO06: Drainage area includes one (1) Water Treatment Building, Paint Shop, Chemical
Warehouse, Mobile Equipment Area,a portion of the Service Building, a portion of the Bulk
Warehouse, a portion of the Waste Processing Building,the Neutralization Basin,the Settling Basin,
gasoline storage tanks, diesel fuel storage tanks, used oil storage tanks, oil/water separator and
adjacent 1,000 gallon used oil collection tank, service transformers,three(3) sewage lift stations, one
(1) 8,315 gallon sulfuric acid storage tank,a fueling area, a water treatment facility, solid waste
compactor,paved roads, gravel-surfaced areas, external storage areas,parking areas, and grassed
areas. Intermittently,the auxiliary boiler heat exchanger and draining of filtered water and
decriminalized water storage tanks will be routed to the outfall.
Page 15 of 40

Permit NCS000606
Table 3. Summary of Quarterly Baseline Sampling Requirements for Stormwater Discharges for
Outfall SWO03
Parameter Code for Parameter Frequency i Benchmark
Reporting
C0530 Total Suspended Solids(TSS) Quarterly 100 mg/L
00400 pH z Quarterly 6 s.u.—9 s.u.
46529 Total Rainfall of Sampled Event - -
(inches)3
Non-Polar Oil&Grease for drainage
00552 areas that use>55 gallons/month of Quarterly 15 mg/L
oil on average per EPA Method 1664
(SGT-HEM)
NCOIL Estimated Average Monthly Oil - -
Usage at the Facility(gallons)
00340 Chemical Oxygen Demand(COD) Quarterly 120 mg/L
50060 Total Residual Chlorine Quarterly 28 µg/L
Footnotes:
1. Measurement frequency: Quarterly during a measurable storm event. If the facility is monitoring monthly
due to Tier Two or Tier Three response actions,the facility shall continue a monthly monitoring and
reporting schedule in Tier Two or Tier Three status until relief is granted.
2. If pH values outside this range are recorded in sampled stormwater discharges, but ambient precipitation
pH levels are lower,then the lower threshold of this benchmark range is the pH of the precipitation
(within instrument accuracy) instead of 6 s.u.. Readings from an on-site or local rain gauge(or local
precipitation data) must be documented to demonstrate background concentrations were below the
benchmark pH range.
3. For each sampled measurable storm event,the total precipitation must be recorded.An on-site rain gauge
is required. Where isolated sites are unmanned for extended periods of time, a local rain gauge reading
may be substitute for an on-site reading.
• Outfall SWO03: Drainage area includes the southern portion of the Cooling Tower, one (1) 5,600
gallon sodium hypochlorite tank, other small water treatment chemical storage tanks, chemical
storage building, Cooling Tower circulating water pumps, transformer yard, paved parking areas,
and grassed yard areas.
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Permit NCS000606
Table 4. Summary of Quarterly Baseline Sampling Requirements for Stormwater Discharges for
Outfalls SWO04 and SWO12 SW-B
Parameter Code for Parameter Frequency' Benchmark
Reporting
C0530 Total Suspended Solids(TSS) Quarterly 100 mg/L
00400 pH 2 Quarterly 6 s.u.—9 s.u.
46529 Total Rainfall of Sampled Event - -
(inches)3
Non-Polar Oil&Grease for drainage
00552 areas that use>55 gallons/month of Quarterly 15 mg/L
oil on average per EPA Method 1664
(SGT-HEM)
NCOIL Estimated Average Monthly Oil - -
Usage at the Facility(gallons)
00340 Chemical Oxygen Demand(COD) Quarterly 120 mg/L
Footnotes:
l. Measurement frequency: Quarterly during a measurable storm event. If the facility is monitoring monthly
due to Tier Two or Tier Three response actions,the facility shall continue a monthly monitoring and
reporting schedule in Tier Two or Tier Three status until relief is granted.
2. If pH values outside this range are recorded in sampled stormwater discharges, but ambient precipitation
pH levels are lower,then the lower threshold of this benchmark range is the pH of the precipitation
(within instrument accuracy) instead of 6 s.u.. Readings from an on-site or local rain gauge(or local
precipitation data)must be documented to demonstrate background concentrations were below the
benchmark pH range.
3. For each sampled measurable storm event,the total precipitation must be recorded.An on-site rain gauge
is required. Where isolated sites are unmanned for extended periods of time,a local rain gauge reading
may be substitute for an on-site reading.
• Outfall SWO04: Drainage area includes gravel-surfaced switchyard,paved roads and parking
areas, and grassed yard areas.
• Outfall SW012 (SW-B): Drainage area includes two facility maintenance storage buildings,
gravel-surface roads, paved and gravel-surfaced external storage areas, and grassed and wooded
areas.
Page 17 of 40

Permit NCS000606
Table 5. Summary of Quarterly Baseline Sampling Requirements for Stormwater Discharges for
Outfalls SWO08 and SWO09
Parameter Code for Parameter Frequency' Benchmark
Reporting
C0530 Total Suspended Solids(TSS) Quarterly 100 mg/L
00400 pH z Quarterly 6 s.u.—9 s.u.
46529 Total Rainfall of Sampled Event - -
(inches)3
Non-Polar Oil&Grease for drainage
00552 areas that use>55 gallons/month of Quarterly 15 mg/L
oil on average per EPA Method 1664
(SGT-HEM)
NCOIL Estimated Average Monthly Oil - -
Usage at the Facility(gallons)
C0310 Biochemical Oxygen Demand Quarterly 30 mg/L
(BODO
00340 Chemical Oxygen Demand(COD) Quarterly 120 mg/L
01042 Total Copper Quarterly 10 µg/L
01051 Total Lead Quarterly 75 µg/L
01092 Total Zinc Quarterly 126 µg/L
00900 Hardness—Total as[CaCO3 or(Ca+ Quarterly -
Mg)
Footnotes:
l. Measurement frequency: Quarterly during a measurable storm event. If the facility is monitoring monthly
due to Tier Two or Tier Three response actions,the facility shall continue a monthly monitoring and
reporting schedule in Tier Two or Tier Three status until relief is granted.
2. If pH values outside this range are recorded in sampled stormwater discharges,but ambient precipitation
pH levels are lower, then the lower threshold of this benchmark range is the pH of the precipitation
(within instrument accuracy) instead of 6 s.u.. Readings from an on-site or local rain gauge(or local
precipitation data)must be documented to demonstrate background concentrations were below the
benchmark pH range.
3. For each sampled'measurable storm event,the total precipitation must be recorded.An on-site rain gauge
is required. Where isolated sites are unmanned for extended periods of time, a local rain gauge reading
may be substitute for an on-site reading.
4. Hardness sampling should be performed in conjunction with testing for hardness dependent metals
(copper, lead, and zinc).
• Outfall SWO08: Drainage area includes Generator Rewind Building, a legacy stormwater
detention pond, paved roads, gravel-surfaced areas, external storage areas,parking areas, and
grassed areas.
Page 18 of 40

Permit NCS000606
• Outfall SW009: Drainage area includes tanker unloading station and fuel forwarding pumps for
the two (2) Emergency Diesel Generator underground fuel oil storage tanks, service transformer,
paved roads, gravel-surfaced areas, external storage areas, and grassed areas
Additional GutfaIls
Stormwater outfall SW005 discharges to the Primary Intake Canal, which goes back into the plant.
Stormwater outfalls SW007 and Drainage Area 10 discharge to the Emergency Service Water Intake
Canal, which goes back into the plant. Stormwater outfall SW-A does not contain Industrial Activity.
Any modifications to these outfalls that result in a potential stormwater discharge associated with
past or present industrial activities will require a modification of this permit.
Should the permittee identify or create any new stormwater outfalls, remove any stormwater outfalls
identified in this permit, or alter any drainage areas that change the potential pollutants in runoff
discharged through corresponding outfalls, the permittee will submit a request to NC DEMLR to modify
this permit. For any newly discovered pipes or outfalls,the permittee must evaluate the structure and
provide a report of the status and planned actions to NC DEQ within 14 days. The permittee must either
(1) request modification of this permit and modify the SWPPP accordingly, or(2) eliminate potential
discharges by removal, plugging, or combination of both.
D-3. Methodology for Collecting Samples
(a) Outfall monitoring efforts shall begin with the first measurable storm event that occurs during the
facility's normal operating hours and begins at least 72 hours after the previous measurable storm
event.
(b) Grab samples shall be collected within the first 30 minutes of discharge. If physical separation
between outfalls prevents collecting samples from all outfalls within the first 30 minutes of
discharge, then the permittee may continue collecting samples until all outfalls that are
discharging have been sampled.
(c) Outfalls that are not discharging during or after the first measurable storm event shall be sampled
during the next measurable storm event, until a sample has been collected from every outfall.
(d) If, during an entire monitoring period, there is no discharge from an outfall during any measurable
storm event that occurs during the facility's normal operating hours and begins at least 72 hours
after the previous measurable storm event,then the permittee shall report "No Discharge" in the
DMR and shall record "No Discharge" in the SWPPP. In this case, the DMR shall be submitted
within 30 days after the end of the monitoring period. Lack of a discharge from an outfall for the
monitoring period shall not constitute failure to monitor as long as this condition is met.
(e) Sampling is not required to be performed outside of the facility's normal operating hours or
during adverse weather conditions.
(f) Samples collected shall be characteristic of the volume and nature of the permitted discharge.
(g) If the sampled storm event coincides with a known non-stormwater discharge that is deemed
permitted under 15A NCAC 02H .0106, then this shall be noted on the stormwater discharge
monitoring report.
Page 19 of 40