NC0003425_Fact Sheet_20170105

DEPARTEMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NC0003425
Summary
The Roxboro Steam Electric Plant is an electric generating facility that uses steam turbine generation (via
four coal-fired units with a total net capacity of 2558 MW). Units No. 1 and 2 (385 MWe and 670 MWe,
respectively) use condensers as cooling devices. Units No 3 and 4 (707MWe and 700 MWe, respectively)
use cooling towers as cooling devices.
The facility has three existing cooling water intake structures (CWISs) The source water for CWISs No.1
and 2 is the Hyco Reservoir The source water for CWIS no. 4 is the site's cooling canal. The facility total
intake is approximately 1,114 MGD. The facility discharges to subbasin 030205 in the Roanoke River
Basin. Discharges are mostly industrial, with a very small domestic flow (internal Outfall 008) piped to
the on-site ash pond. Discharges from the ash pond (internal Outfall 002), once -through cooling water
and FGD treatment system (internal outfall 010) are discharged to the Discharge Canal (outfall 003). The
Discharge Canal and Coal Pile Runoff (outfall 006) both discharge to Hyco Reservoir. The Hyco
Reservoir is a 17.6 km2 waterbody constructed in 1963 by CP&L to serve as a cooling water source. The
receiving waterbody is class WS-V,'B. The facility is located in the Lower Piedmont area of the state, the
applicable state water quality temperature standard is 32°C (89 6' F).
This facility is subject to EPA effluent guideline limits per 40 CFR 423 - Steam Electric Power Generating
Point Source Category which were amended November 3, 2015. The facility is also subject to the Cooling
Water Intake Structures Rules (40 CFR 125) effective October 14, 2014. The intake flow is > 125 MGD.
The facility operates five internal outfalls and two outfalls to Hyco Reservoir. Duke requested the
addition of three new outfalls on the permit; two to reflect the future treatment systems for the low
volume wastes as the ash basin will be closed and one for seeps and stormwater
Description of existing outfalls:
Outfall 003 - Heated Discharge Canal to Hyco Reservoir. The discharge canal combines all
internal outfalls (002, 005, 008, 009, 010) before discharging to Hyco Reservoir. In addition, once-
Facility Information
Applicant/ FaciliName-
Duke Energy Progress/ Roxboro Steam Electric Generating Plant
Applicant Address-
1700 Dunnaway Rd., Semora, NC 27343
Facility Address:
1700 Dunnaway Rd., Semora, NC 27343
Permitted Flow
Not limited
Type of Waste-
99 8 % Industrial, 0.2% - domestic
Facility/Permit Status.
Existing/ Renewal
County:
Person
Miscellaneous
Receiving Stream:
Hyco Reservoir Stream Classification:
WS -V, B
Subbasin:
03-02-05 303(d) Listed?:
No
Drainage Area mit :
Lake Primary SIC Code:
4911
Summer 7Q10 cfs
0 Regional Office:
RRO
30Q2 (cfs)
0 Quad
Olive Hill
Average Flow cfs :
0 Permit Writer:
Teresa Rodriguez
IWC (%)-
100% Date:
1/5/2017
Summary
The Roxboro Steam Electric Plant is an electric generating facility that uses steam turbine generation (via
four coal-fired units with a total net capacity of 2558 MW). Units No. 1 and 2 (385 MWe and 670 MWe,
respectively) use condensers as cooling devices. Units No 3 and 4 (707MWe and 700 MWe, respectively)
use cooling towers as cooling devices.
The facility has three existing cooling water intake structures (CWISs) The source water for CWISs No.1
and 2 is the Hyco Reservoir The source water for CWIS no. 4 is the site's cooling canal. The facility total
intake is approximately 1,114 MGD. The facility discharges to subbasin 030205 in the Roanoke River
Basin. Discharges are mostly industrial, with a very small domestic flow (internal Outfall 008) piped to
the on-site ash pond. Discharges from the ash pond (internal Outfall 002), once -through cooling water
and FGD treatment system (internal outfall 010) are discharged to the Discharge Canal (outfall 003). The
Discharge Canal and Coal Pile Runoff (outfall 006) both discharge to Hyco Reservoir. The Hyco
Reservoir is a 17.6 km2 waterbody constructed in 1963 by CP&L to serve as a cooling water source. The
receiving waterbody is class WS-V,'B. The facility is located in the Lower Piedmont area of the state, the
applicable state water quality temperature standard is 32°C (89 6' F).
This facility is subject to EPA effluent guideline limits per 40 CFR 423 - Steam Electric Power Generating
Point Source Category which were amended November 3, 2015. The facility is also subject to the Cooling
Water Intake Structures Rules (40 CFR 125) effective October 14, 2014. The intake flow is > 125 MGD.
The facility operates five internal outfalls and two outfalls to Hyco Reservoir. Duke requested the
addition of three new outfalls on the permit; two to reflect the future treatment systems for the low
volume wastes as the ash basin will be closed and one for seeps and stormwater
Description of existing outfalls:
Outfall 003 - Heated Discharge Canal to Hyco Reservoir. The discharge canal combines all
internal outfalls (002, 005, 008, 009, 010) before discharging to Hyco Reservoir. In addition, once-

NPDES PERMIT FACT SHEET Roxboro Steam Electric Plant
Page 2 NPDES No. NC00003425
through cooling water from condensers for units 1,2, and 3, once -through cooling water from
heat exchangers, seepage from ash pond, and stormwater runoff from plant drainage areas are
discharged to the discharge canal
• Outfall 006 - Coal Pile Runoff discharges directly to Hyco Reservoir. Coal pile runoff
wastewaters include runoff from the coal pile, limestone pile and gypsum pile, truck wheel wash
area and coal handling areas Treatment is accomplished by neutralization, sedimentation and
equalization.
Internal Outfall 002 - Ash Pond discharging to the discharge canal. The ash pond receives
wastewater from the following sources
• Bottom ash transport waters
• Silo wash water
• Ash landfill leachate and runoff (this landfill receives CCR from Mayo and Roxboro
plants)
• Dry -ash handling system wash water
• Blowdown from Unit 4 cooling tower
• Coal mill rejects and pyrites
• Sewage treatment plant effluent
• Low volume waste consisting of boiler blowdown, equipment maintenance cleaning
wastewaters, RO reject wastewater and floor drams Low volume wastes are treated by
neutralization
• Emergency overflow from FGD system blowdown.
• Internal Outfall 005 - Cooling tower blowdown from Unit 4
• Internal Outfall 008 - Treated dcmestic wastewater. The treatment system consists of a screen,
communitor, surge tank, aeration tank, clarifier, chlorine contact chamber and sludge holding
tank A new package plant will be installed to replace the existing plant
• Internal Outfall 009 - Chemical metal cleaning waste. Wastewaters from cleaning of the boilers is
generated every five to eight years. Every three to five years wastewaters are generated from
cleaning the heat exchangers. The wastewaters generated can be treated by evaporation or by
neutralization and precipitation.
• Internal Outfall 010 - Flue Gas Desulfurization (FGD) treatment system discharging to the
discharge canal The scrubber system removes SOx by mixing flue gas with a limestone slurry.
The blowdown from the scrubber is discharged to a gypsum settling pond system then to a
bioreactor which utilizes microorganisms to reduce soluble contammants to insoluble forms
(under anaerobic conditions) that then precipitate from solution. Wastewater is discharged to the
ash pond effluent channel. An emergency overflow from the FGD system blowdown discharges
to the ash pond
Proposed Outfalls:
Outfall 001 (Seeps) - Stormwater and four seeps from the ash landfill flow to the intake canal
through a common outfall This outfall was at one time permitted in a previous permit as outfall
001 and will be reinstated to monitor the seeps.
Internal Outfalls 012A and 012B - Low volume waste and other wastewaters. Duke will build two
basin treatment systems to treat wastewaters that now go to the ash basin.
2

NPDES PERMIT FACT SHEET Roxboro Steam Electric Plant
Page 3 NPDES No. NC00003425
CWA 316 (b)
The permittee shall comply with -the Coolmg 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
Temperature Mixing Zone - Outfall 003
The facility is located in the Lower Piedmont area of the state, the applicable state water quality
temperature standard is 32`C (89.6'F). The authorized temperature mixing zone for outfall 003 includes
the North Hyco Arm downstream of NC Hwy 57, the main body of Hyco Reservoir downstream of the
confluence of the Cobbs Creek Arm and the North Hyco Arm and the entire after bay lake. USGS data at
the after bay monitoring station (USGS Station 02077303) was reviewed for the period of January 2011 to
April 2016. Data shows that the temperature water quality standard was not exceeded for this period.
Maximum temperature recorded was 30 TC
Instream Monitoring
The permit requires monitoring of Hyco Reservoir in accordance to the Biological Monitoring Program as
approved by the Division Based on the Divisions review of the reports the fish community is
comparable to other piedmont reservoirs and no problems were noted
DATA REviEW/PERMIT REOUIREMENTS
Internal Outfall 002 - Ash Pond
This outfall is subject to the Effluent Limitations Guidelines (ELG) in Table 1.
Table 1 ELG Outfall 002 Prior to November 1, 2018
Pollutant Daily Maximum Monthly Average ELG
TSS 100 m / 1 30 m / 1 40 CFR 42312 b 4
Oil & Grease 20 mg/1 15 m /l 40 CFR 423.12 b 4
The current permit requires monitoring for flow and total selenium, limits for Oil & Grease and TSS A
summary of DMR data for the period of January 2011 to January 2016 is included in Table 2 There have
been no violations of permit limits or conditions
Table 2 DMR Summary Outfall 002
Parameter
Average
Maximum
Minimum
Flow
10 8 MGD
48.3 MGD
3.1 MGD
TSS
5m /1
21m /1
<25m /1
Total Selenium
14.6 µ /1
68 8 µ /1
< 10 µ /1
O&G
<5m /1
13.5m /1
<5m /1
Table 3 Monitoring Requirements/ Proposed Changes Outfall 002
Parameter
Monitonng requirements
Changes
Basis
Flow
Monitor
No changes
15A NCAC 2B 0505
TSS
30 mg/1 monthly aver
100 m /l daily max
No changes
40 CFR 423.12(b)(4)
Oil & Grease
15 mg/l monthly aver
20 mg/1 daily max
No Changes
40 CFR 42312(b)(4)
Total Selenium
Monthly monitoring
No changes
Pollutant of concern
Turbidity, pH
No requirement
Monitor
Pollutant of concern for
dewaterm / decantm
3

NPDES PERMIT FACT SHEET
Page 4
Roxboro Steam Electric Plant
NPDES No. NC00003425
Schedule of Compliance Fly Ash/Bottom Ash:
As per 40 CFR 42313 (k) (1) (i) bottom ash transport water shall not be discharged, compliance with this
section shall be as soon as possible beginning on November 1, 2018, but no later than December 31, 2023.
Duke utilizes wet bottom ash transport system. Duke is proposing to install a remote mechanical drag
chain system. Design of the system is expected to be completed in 8 months, followed by procurement in
12 months Construction is expected to be completed in 13 months Duke proposes a 16 month window
to optimize the system at full load and additional 6 months for potential permitting delays.
Consideration was given to the fact that Duke will be undertaking design, procurement and installation
activities in multiple facilities simultaneously. Duke will meet the no discharge of bottom ash
requirement by April 30, 2021.
Fly ash transport water is no longer discharged therefore Duke meets the compliance date of November
1, 2018
Internal Outfall 002 - Dewatering
To meet the requirements of the Coal Ash Management Act of 2014, the facility needs to dewater two ash
ponds by removing the interstitial water and excavate the ash to deposit it in landfills The facility's
highest discharge rate from the dewatering process will be 2 MGD The facility submitted data for the
standing surface water in the ash ponds, i iterstitial water in the ash, and interstitial ash water that was
treated by filters of various sizes The following pollutants were detected at concentrations higher than
the water quality standards- selenium, arsenic and molybdenum A new effluent and monitoring sheet is
included in the permit for the ash pond dewatering phase As this is an internal outfall the water quality
standards are not applied Monitoring will be required for selenium, arsenic, molybdenum, antimony
and copper
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.
Outfall 003 - Discharge Canal (Combined outfalls)
DMR/ Compliance Review
Data were reviewed for the period of January 2011 to March 2016 There have been no violations of
permit limits or conditions
Table 4 DMR Summary Outfall 003
Parameter
Average
Maximum
Minimum
Flow MGD
840
1130
69
TRC
Not discharged
TP (mg/1)
< 0.036
< 0 05
< 0 05
TN (mg/1)
0.68
108
0.44
Temperature (°C)
29
41
13°C
Total Arsenic (gg/1)
6.2
171
< 2.8
H SU
734
8
638
Toxicity Testing (003)
Current Requirement: Acute P/ F at 90%, February, May, August, November
Proposed Requirement. Acute P/ F at 90%, February, May, August, November
The facility passed 21 tests out of 21 tests performed for the period of January 2011 to January 2016.
11

NPDES PERMIT FACT SHEET Roxboro Steam Electric Plant
Page 5 NPDES No. NC00003425
Reasonable Potential Analysis Outfall 003•
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 from outfall 003
For the purposes of the RPA, the background concentrations for all parameters were assumed to be below
detection 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 " With the
approval of the Triennial Review (2007-2014) of the NC Water Quality Standards by the Environmental
Management Commission (EMC) in 2014 and US -EPA (with some exceptions) on April 6, 2016, the
NPDES Permitting Unit is required to implement the new dissolved metal standards in all permits public
noticed after April 6, 2016 The RPA included evaluation of dissolved metals' standards, utilizing
measured hardness value of 100 mg/L CaCO3 for hardness -dependent metals
A reasonable potential analysis was conducted for arsenic, copper, nickel, selenium, strontium, thallium,
chlorides and zinc Arsenic data used for the RPA was collected between 2011 and 2016. Data for the
remaining parameters was from a special study for the period of March 2010 to August 2011. Based on
this analysis, the following permitting actions are proposed for this permit:
• Monitoring_Only The following parameters will receive a monitor -only requirement since they
did not demonstrate reasonable potential to exceed applicable water quality standards/ criteria,
but the maximum predicted concentration was >50% of the allowable concentration Arsenic,
selenium, chloride.
• No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since
they did not demonstrate reasonable potential to exceed applicable water quality
standards/ criteria and the maximum predicted concentration was <50% of the allowable
concentration. copper, nickel, strontium, and zinc.
• Limit- The following parameter will receive a limit since it demonstrated reasonable potential to
exceed the applicable water quality standards/ criteria- thallium.
Mercury Evaluation Outfall 003:
A mercury evaluation was conducted in accordance with the permitting guidance developed for the
implementation of the statewide Mercury TMDL to determine the need for a limit and Mercury
Minimization Plan (MMP) Monitoring for mercury is not required for outfall 003 but mercury data was
collected during a special study during the period of March 2010 to August 2011 The water quality based
effluent limitation (WQBEL) for mercury is 12 ng/1 The technology based effluent limit (TBEL) is 47
ng/1 None of the annual averages exceeds the WQBEL or TBEL, no limit is required See the attached
mercury evaluation spreadsheet
Table 5 Mercury Evaluation
5
2010
2011
# of Samples
20
16
Annual Average, n /L
36
4.4
Maximum Value, n /L
763
692
TBEL, n /L
47
WQBEL, n /L
12.0
5

NPDES PERMIT FACT SHEET
Page 6
Table 6 Monitoring Requirements/ Proposed Changes Outfall 003
Roxboro Steam Electric Plant
NPDES No. NC00003425
Parameter
Monitoring
Changes
Basis
requirements/Limits
6 to 9 SU
40 CFR 42312
Flow
Monitor
No changes
15A NCAC 2B.0505
TRC
200 µg/l
Modified limit to 28 µg
State WQ standards, 15A NCAC
40 CFR 42313
instantaneous max
/1 daily max
2B .0200 The water quality
0.2 m /l 0 2 m /l
40 CFR 42313
d
standard is more stringent than
Total Zinc
1.0 m /l 10 m /l
40 CFR 42313
the effluent guidelines limit.
TP
Monitor
No changes
15A NCAC 2B 0500
TN
Monitor
No changes
15A NCAC 2B 0500
Temperature
Monitor
No changes
Approved Mixing zone
Total Arsenic
Monitor
No changes
Based on results from RPA,
Predicted concentration greater
than 50% of allowable
Total Selenium
No requirement
Quarterly monitoring
Based on results from RPA,
Predicted concentration greater
than 50% of allowable
Total Thallium
No requirement
0 24 µg/l Daily max
Based on results from RPA.
limit
0.24 µ /l Monthly Max
Chloride
No requirement
Quarterly monitoring
Based on results from RPA,
Predicted concentration greater
than 50% of allowable.
pH
6 to 9 SU
No changes
State WQ standards, 15A NCAC
2B 0200
Acute toxicity
P/F 90%
No changes
State WQ standards, 15A NCAC
2B.0200
Internal Outfall 005 - Cooling Tower Blowdown from Unit 4
This outfall is subject to the ELGs in Table 7
Table 7 ELG Outfall 005
Pollutant
Daily Maximum I Monthly Average
ELG
H
6 to 9 SU
40 CFR 42312
b
1
Free Available Chlorine
0 5 mg/1 —F-0.2
mg/l
40 CFR 42312 (d) (1)
126 Pollutants
No detectable amounts
40 CFR 42313
d
1
Total Chromium
0.2 m /l 0 2 m /l
40 CFR 42313
d
1
Total Zinc
1.0 m /l 10 m /l
40 CFR 42313
d
1
The permit includes monitoring for flow and Total Residual Chlorine (TRC), limits for Free Available
Chlorine, Total Chromium, Total Zinc and 126 priority pollutants
Special condition A (14) in the permit doesn't allow the discharge of the cooling tower blowdown to the
discharge canal, it has to be discharged tc the ash pond. With the modifications planned to the site and
the future closure of the existing ash pond Duke will like to have the option to discharge the blowdown
to the discharge canal This will continue to be an internal outfall subject to the same limits under 40 CFR
423. The limits apply before it comingles with any other waste stream so there is no change in limits or
other permit conditions by allowing the cooling tower blowdown to discharge into the discharge canal
2

NPDES PERMIT FACT SHEET
Page 7
Roxboro Steam Electric Plant
NPDES No. NC00003425
DMR/Compliance Review -
Data were reviewed for the period of January 2011 to January 2016. There have been no violations of
permit limits or conditions Flow was the only parameter monitored at this outfall since the facility did
not chlorinate or added chromium or zinc for maintenance activities Flow is reported as 7 2 MGD on a
daily basis
Table 8. Monitoring Requirements/ Proosed Chan es Outfall 005
Parameter
Monitoring
Requirements/Limits
Changes
Basis
Flow
Monitor
No changes
15A NCAC 2B 0505
Free available
500 µg/1 daily max
No changes
40 CFR 42313 (d)(1)
chlorine
200 g /1 monthly average
89
604
Total Residual
Monitoring
No changes
40 CFR 42313 (d)(2)
Chlorine
Total chromium
200 µg/1 daily max
No changes
40 CFR 42313 (d)(1)
200 g /1 monthly average
Total Zinc
1.0 mg/1 daily max
No changes
40 CFR 42313 (d)(1)
10 m/ 1 monthly average
The 126 priority
No detectable amount
No changes
40 CFR 42313 (d)(1)
pollutants
Outfall 006 - Coal Pile Runoff
This outfall is subject to the ELG in Table 9.
Table 9 ELG Outfall 006
Pollutant Daily Maximum
Monthly Average ELG
TSS 50 mg/1
40 CFR 42312 b 9
H — 6 to 9 SU - 40 CFR 42312 b 1
DMR/ Comphance Review:
Data were reviewed for the period of January 2008 to March 2013 There have been no violations of
permit limits or conditions
Table 10. DMR Summary Outfall 006
Parameter
Average
Maximum
Minimum
Flow MGD
023
005
0 002
TSS (mg/1)
2.6
76.6
< 2.5
H SU
739
89
604
Priority Pollutant Scan
The application included the results of one scan. Selenium was detected above the water quality
standard
7

NPDES PERMIT FACT SHEET
Page 8
Table 11 Monitoring Requirements/ Proposed Changes Outfall 006
Roxboro Steam Electric Plant
NPDES No. NC00003425
Parameter
Monitoring
Changes
Basis
Flow MGD
requirements/Limits
001
0.002
Flow
Monitor
No changes
15A NCAC 2B 05
TSS
50 mg/l instantaneous
Added Monthly average
40 CFR 423.12(b)(9),
BOD (mg/1)
max
limit of 30 mg/1
40 CFR 122.45
H
6 to 9 SU
No changes
40 CFR 42312 b 1
Total selenium
No requirement
5.0 µg/1 Monthly Average
RPA
pH
6 to 9 SU
56 g /1 Daily Max
State WQ standards, 15A 2B
Acute toxicity
P/F 90%No
changes
State WQ standards, 15A
BOD
30 mg/1 monthly
No changes
NCAC 2B 0200
Internal Outfall 008 - Domestic WWTP
Table 12 DMR Review Outfall 008
Parameter
Average
Maximum
Minimum
Flow MGD
0.007
001
0.002
TSS m /1
147
30
5
H SU
68
73
6.5
BOD (mg/1)
10.4
28
2.1
NH3N (mg/1)
08
1.6
<01
Table 13. Monitoring Requirements/ Proposed Changes Outfall 008
Parameter
Monitoring
Changes
Basis
Flow
requirements/Limits
No changes
15A NCAC 2B.0505
Flow
0.015 MGD
Add effluent page
WWTP will be upgraded during
10 m /l daily max
for 0.025 MGD
this permit cycle
TSS
30 mg/l monthly
No changes
NPDES rules for secondary
aver
treatment of domestic
TSS
45 m /l daily max
No changes
wastewater, 15A 2B .0400
pH
6 to 9 SU
No changes
State WQ standards, 15A 2B
Oil & Grease
15 mg/1 monthly aver
No changes
0200
BOD
30 mg/1 monthly
No changes
NPDES rules for secondary
aver
treatment of domestic
45 mg/1 daily max
wastewater, 15A 2B 0400
Total ammonia
Monitor
No changes
DWQ Policy
Internal Outfall 009 - Chemical cleaning
Table 14. Monitoring Requirements/Proposed Changes Outfall 009
Parameter
Monitoring
requirements/Limits
Changes
Basis
Flow
Monitor
No changes
15A NCAC 2B.0505
Total Copper
1.0 mg/l monthly aver
No changes
40 CFR 42313 (e)
10 m /l daily max
Total Iron
1.0 mg/1 monthly aver
No changes
40 CFR 42313 (e)
10 m /l daily max
TSS
30 mg/l monthly aver
No changes
40 CFR 423.13 (e)
100 m /l dailmax
Oil & Grease
15 mg/1 monthly aver
No changes
40 CFR 42313 (e)
20 m /l dail max
N.

NPDES PERMIT FACT SHEET Roxboro Steam Electric Plant
Page 9 NPDES No. NC00003425
Internal Outfall 010 - FGD
This outfall is subject to the Effluent Linutations Guidelines (ELG) in Table 15 These are new limitations
promulgated November 3, 2015
Table 15. ELG Outfall 010
Pollutant
Daily Maximum
I Monthly Average
ELG
Flow MGD
H
177
6 to 9 SU
40 CFR 42312 b
1
TSS
100 m / 1
30 m / 1
40 CFR 423.12 b
11
Oil and grease
20 mg/1
15 m /l
40 CFR 423.12
11
Total Arsenic
11 µ /l
8 µ /l
40 CFR 423.13
1 i
Total Mercury
788 ng/1
356 ng/1
40 CFR 423.13
1 i
Total Selenium
23 µ /l
12 µ /1
40 CFR 42313
1 i
Nitrate/nitrite
17 mg/1
4 4 mg/1
40 CFR 42313
1 i
The current permit includes monitoring for flow, total beryllium, total mercury, total antimony, total
selenium, total silver and total vanadium Table 16 includes a summary of DMR data for the period of
January 2011 to January 2016 There have been no violations of permit limits or conditions
Table 16 DMR Summary Outfall 010
Parameter
Average
Maximum
Minimum
Flow MGD
084
177
001
Total Beryllium (gg/1)
39
10
< 1
Total Mercury (gg/1)
108
96
< 1
Total Selenium (gg/1)
102
712
< 50
Total Silver (gg/1)
6
84
< 5
Total Antimony (µ /1)
31
70
< 25
Total Vanadium (µ /1)
< 25
< 25
< 5
Table 17 Monitor'g Requirements/ Proosed Changes Outfall 010
Parameter
Monitoring
requirements/Limits
Changes
Basis
Flow
Monitor
No changes
15A NCAC 2B 0505
Total Beryllium
Monitor
Remove monitoring
Internal outfall, not a
arameter of concern
Total Vanadium
Monitor
Remove monitoring
Internal outfall, not a
arameter of concern.
Total Antimony
Monitor
Remove monitoring
Internal outfall, not a
arameter of concern.
Total Silver
Monitor
Remove monitoring
Internal outfall, not a
parameter of concern
Total Arsenic
No monitoring
11 µg/1 daily max and
8 µg/l monthly average
40 CFR 42313 (g) (1) (i)
Total Selenium
Monitor
23 µg/l daily max and
12 µg/1 monthly
40 CFR 423.13 (g) (1) (i)
average
Nitrate/Nitrite
No monitoring
17 mg/1 daily max and
4 4 mg/1 monthly
40 CFR 42313 (g) (1) (1)
average
Total Mercury
Monitoring
788 ng/1 daily max and
356 ng/1 monthly
40 CFR 423.13 (g) (1) (1)
average
OJ

NPDES PERMIT FACT SHEET Roxboro Steam Electric Plant
Page 10 NPDES No. NC00003425
Schedule of Compliance FGD
40 CFR 423 establishes compliance dates for the new limitations. Permittee must meet limits as soon as
possible beginning on November 1, 2018 but no later than December 31, 2023
Duke utilizes a biological treatment system to treat FGD wastewaters. Duke anticipates that it will be
required to install physical/ chemical treatment followed by selenium reduction technology to meet the
FGD guidelines Evaluation of new technologies and design of the system is expected to take 30 months
The evaluation phase includes evaluation of existing treatment system, flow optimization, sitmg of the
new system within the plant, selection of technology and permitting. Procurement is expected to be
completed in 20 months, construction and tie -m expected to be completed in 16 months considering that
he -m has to be done during outages Startup and optimization under all expected operating conditions is
estimated for 15 months An additional 6 months is included in the schedule for potential permitting
delays. Duke will meet the FGD ELG by December 31, 2023 As the new treatment system will be placed
in operation and the old pond may still discharge until it is decommissioned. A new outfall is included in
the permit for the new system.
Provosed Outfalls:
Seeps -
The facility identified 16 unpermitted seeps The following seeps from the ash landfill discharge through
a common outfall to Hyco Reservoir at the intake canal- S-09, S-10, S-11, and S-12. The outfall used to be
the authorized outfall for the effluent from the old ash basin The seep flow into a concrete culvert and
channel that leads to the intake canal. An effluent channel determination was conducted by the Raleigh
Regional Office staff on December 15, 2016.
Seeps S-01, S-02, S-03, S-04, S-05, S-06, S-071 S-08, S-14, S-18, and S-19 are internal to outfall 003. Seeps 1
through 7 are chimney drains from the ash basin dam The flow from the combined seeps account for less
than 0 0005 % of the total discharge. These are considered de -minimum discharges and will be included
in the authorized wastewaters discharging through outfall 003.
Outfall 001
Four seeps discharge to the intake canal at Hyco Reservoir where former Outfall 001 used to discharged
The Division will reinstate outfall 001 to monitor the discharge from the seeps and stormwater The
following seeps discharge through outfall 001 S-09, S-10, S-11, and S-12
RPA
A RPA was conducted for proposed outfall 001 RPA was conducted for total arsenic, cadmium,
chlorides, total chromium, total copper, total lead, total mercury, total molybdenum, total nickel,
selenium, total zinc, antimony, sulfate and total thallium As a result of the RPA limits are required for
the following parameters fluoride, arsemr, sulfate and selenium.
Mercury
Mercury data was collected for the seeps during 2014 and 2015.2014 data was collected using method 245
which has a higher detection limit that 1631. Data for 2015 was used to evaluate a need for a limit The
annual average was 5 2 ng/1, no limit will be implemented
In addition to the limits described above all the seep outfalls will have monitoring requirements for
fluoride, total mercury, total barium, total iron, total manganese, total zinc, total arsenic, total cadmium,
total chromium, total copper, total lead, total nickel, and total selenium, and limits as described in Table
18.
10

NPDES PERMIT FACT SHEET
Page 11
Table 18 Outfall 001 Proposed Limits/ Monitoring -
Roxboro Steam Electric Plant
NPDES No. NC00003425
Parameter
Monitoring requirements/Limits
Basis
Flow
Monitor
15A NCAC 2B 0505
pH
6 to 9 SU
State WQ standards, 15A 2B .0200
Total copper, total antimony,
Monitor
Coal ash parameters of concern.
total lead, total zinc, total
100 mg/1 Daily Max
barium, total iron, total
15 mg/1 Monthly Average
40 CFR 423.12 (b)(3)
manganese, total mckel, total
20 mg/1 Daffy max
mercury, chlorides
Fluoride
Limit -18 mg/1
RPA
Total Arsenic
Limit -10 µ /1
RPA
Total Selenium
Limits 5 µg/1 Monthly Average
RPA
56 µg/1 Daily Max
Sulfates
Lm -tit - 250 mg/1 (Monthly average
RPA
& daily max)
TDS, Hardness, Conductivity
Monitor
Parameters of concern
Acute toxicity
Quarterly Limit
State WQ standards, 15A NCAC
213 0200
Low volume Waste Treatment Systems:
Two new treatment systems will be installed to treat wastewaters currently delivered to the ash basin
Low volume wastes, metal cleaning wastes, stormwater, and other miscellaneous wastes that are routed
to the ash basin will be rerouted to new treatment systems. Duke proposes two separate treatment
systems The new outfalls will be designated as outfall 012A and outfall 012B. The overflow from the
012B basin will be designated as outfall 012C. Duke estimated that design, construction and start up of
the new treatment system will be completed within 30 months of permit issuance.
Internal Outfall 012A - treatment system for the landfill leachate, silo wash water, contact and non -
contact storm water and discharging to the discharge canal
Table 19. Outfall 012A Proposed Limits/ Monitoring
Parameter
Monitoring
Basis
requirements/Limits
Flow
Monitor
15A NCAC 2B.0505
Total Suspended Solids
30 mg/1 Monthly Average
40 CFR 42312 (b)(3)
100 mg/1 Daily Max
Oil & Grease
15 mg/1 Monthly Average
40 CFR 423.12 (b)(3)
20 mg/1 Daffy max
Internal Outfall 012B - treatment system for plant low volume wastes, FGD treatment system effluent,
domestic waste treatment system, anhydrous ammonia emergency discharge, metal cleaning wastes,
stormwater runoff, and cooling tower blowdown The discharge from outfall 012B will go to the
discharge canal
11

NPDES PERMIT FACT SHEET
Page 12
Table 20. Outfall 012B Proposed Lunits/Momtormg:
Roxboro Steam Electric Plant
NPDES No. NC00003425
Parameter
Monitoring requirements/Limits
Basis
Flow
Monitor
15A NCAC 2B 0505
Total Suspended Solids
30 mg/1 Monthly Average
100 mg/1 Daffy Max
40 CFR 42312 (b)(3)
Oil & Grease
15 mg/1 Monthly Average
20 mg/1 Daily max
40 CFR 42312 (b)(3)
Ammonia
Monitor
Monitor during emergency discharge
of anh drous ammoma
Emergency Outfall 012C - The basm discharging through 012B will have an emergency overflow
Table 21. Outfall 012C Proposed Limits/ Monitoring*
Parameter
Monitoring
requirements/Limits
Basis
Flow
Monitor
15A NCAC 2B 0505
Total Suspended Solids
30 mg/1 Monthly Average
100 mg/1 Daily Max
40 CFR 42312 (b)(3)
Oil & Grease
15 mg/1 Monthly Average
20 mg/1 Daily max
40 CFR 423.12 (b)(3)
Ammonia
Monitor
Monitor during emergency
discharge of anhydrous ammonia
Arsenic
Monitor
Parameter of concern
Mercury
Monitor
Parameter of concern
Selenium
Monitor
Parameter of concern
Nitrate/ nitrite
Monitor
Parameter of concern
Copper
Monitor
Parameter of concern
Iron
Monitor
Parameter of concern
Public Notice/Public Hearing
The first draft of this permit was public noticed on August 30, 2016. A public hearing was held on
October 4, 2016 A second public notice is being published since the first notice went to a newspaper out
of the area
Summary of permit modifications:
• A separate effluent page for the dewatering of the ash ponds (Outfall 002) was added to the
permit
• Outfall 001 was reinstated to monitor discharge of seeps and stormwater
• A new internal outfall (Outfall 011) was added to the permit to monitor the discharge from the
proposed FGD treatment system
• Special Condition A (14) that prohibited the discharge of cooling tower blowdown from outfall
005 to the discharge canal was eliminated from the permit
• A special condition was added to describe Section 316(b) requirements for submittal of applicable
information
• A special condition was added to the permit to require an Ash Pond Closure Plan.
• A Special Condition was added to the permit to require compliance with Senate Bill 729 (Coal
Ash Management Act)
• Attachment 1 entitled "Groundwater Monitoring Plan' was added to the permit
12

NPDES PERMIT FACT SHEET
Page 13
Roxboro Steam Electric Plant
NPDES No. NC00003425
• Attachment 2 entitled "Plan for Identification of New Discharges' was added to the permit.
Summary of modifications to the first draft pernut-
• Condition A. (1) Effluent Limitations and Monitoring Requirements for seeps - monitoring
requirements were updated to include the same list of parameters monitored for seeps in other
Duke permits.
• Condition A (2) Effluent Limitations and Monitoring Requirements for the ash basin -
monitoring was added for arsenic, molybdenum, and chromium. In addition, a statement was
added with the requirement to use physical/ chemical treatment during dewatering
• Condition A (2) & A. (3) Effluent Limitations and Monitoring Requirements for the ash basin -
Statement regarding no discharge of fly ash was modified to read that no discharge of fly ash is
allowed. The statement pertaining to the schedule of compliance with the ELG for zero
discharge of bottom ash was corrected to read April 30, 2021 instead of November 1, 2018
• Condition A. (10) & A (11) Effluent Limitations and Monitoring Requirements for the FGD -
footnote 3 was corrected to read December 31, 2023
• Turbidity sampling was eliminated from internal outfall 002 Turbidity monitoring is included
at outfall 003
• Supplement to cover sheet was modified to include flows that were not listed and add
proposed outfalls and outfalls
• Condition A (6) Effluent Limitations and Monitoring Requirements outfall 006.
o Oil and Grease linuts were added since it receives truck wash waters
o The RPA was revised and limits for total selenium were added
• Condition A (4) Effluent Limitations and Monitoring Requirements for outfall 003-
• Footnote 4 was modified to include a statement regarding the addition of temperature
limits if the facility is not in compliance with the temperature water quality standard.
o Reporting of the temperature at the afterbay station was added to the monitoring
requirements for outfall 003, reporting of temperature at 4C, 4D was eliminated
o The RPA was revised and limits for thalhum were added.
• Condition A. (17)- temperature reporting requirements were modified
• A. (8) Effluent Limitations and Monitoring Requirements for outfall 008 - monitoring
requirements were modified to require quarterly monitoring for one year after the new plant
start operations, annual monitoring is required after one year of quarterly monitoring.
• Two new internal outfalls (Outfall 012A and 012B) were added to the permit for the two
proposed retention basins for the treatment of low volume wastes that are now sent to the ash
basin Duke will build two separate wastewater treatment systems to handle the wastes that go
to the ash pond These ponds will be in different locations in the site and will require each a
separate outfall into the effluent channel
• Outfall 012C was added to the permit for the emergency overflow of the proposed lined
retention basin discharging through outfall 012B.
• A table including a list of all the seeps locations was added to Condition A. (14)
Public Notice schedule
Draft permit to Public Notice January 22, 2017
Permit Scheduled to issue: March 10, 2017
STATE CONTACT
If you have any questions on any of the above information or on the attached permit, please contact
Teresa Rodriguez at [phone].
NAME
13
rll

Duke Energy
NC0003425
Freshwater RPA -
Qw (MGD) = 2.30
1Q10S (cfs) = 0.00
7Q10S (cfs) = 0.00
7Q10W (cfs) = 0.00
30Q2 (cis) = 0.00
Avg. Stream Flow, QA (cfs) = 0.00
Receiving Stream: NO HUC NUMBER
95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: Roxboro
IWC% @ 1Q10S = 100
IWC% @ 7Q10S = 100
IWC% @ 7Q10W = 100
IWC% @ 30Q2 = 100
IW -/.0 @ QA = 100
Stream Class: WS
Outfall Seeps 9 -13
Qw = 2.3 MGD
COMBINED HARDNESS (ma/L)
Acute = 99 mg/L
Chromic = 99 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard:3 val > 100 mg/L 1 val < 25 mg/L
default 99 mg/L (Effluent Hard Med = 100 mg/L)
PARAMETER
STANDARDS & CRITERIA (2)
U)
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
(1)
NC WQS / Applied '/2 FAV /
a
z
n ti Oet. Max Pred Cw Allowable Cw
Chronic Standard Acute
Acute (FW): 340.0
Arsenic
C
150 FW 340
ug, I
Limit
— — — — — — — — — — —
8 7 48.3
Chronic (FW): ---150.0
— —
Default C.V.
No value Allowable Cw
Arsenic
C
10 HH/WS
ug/L
Note: n!5 9
_>
Chronic (HH): 10.0
Limited data set
2 values > Allowable Ca
Acute: 65.00
Beryllium
NC
65 FW 65
ug'1
0 0
N/A
_ _ _
Chronic -----6.50—
—————————————
Acute: 6.690
Cadmium
NC
1.6678 1 R 6.6897
ug/L
8 0
NO DETECTS
Note: n < 9
Chronic: 1.668
Limited data set
Max MDL = 1
Acute: NO WQS
Chlorides
NC
250 WS
mel.
0 0
N/A
Chronic: 250.0 -
---------------------------
Acute: 2,793.8
Chromium III
NC
363.4201 FW 2793.8313
ug 1.
U 0
N/A
--Chronic-----36;.4 -
---------------------------
Acute: 16.0
Chromium VI
NC
I I P\V 16
ug'I.
0 0
N/A
_
--Chronic:-----11.0--
----------------------
Chromium, Total
NC
Irg'L
8 1 4.9
Note: n:5 9 Detaull C'.\
Monitor
Limited data set
Acute: 38.30
Monitor
Copper
NC
25.5442 FW 38.2981
ug/L
8 6 8.36
Note: n Default t
Chronic: 25.54
Limited
No value > Allowable Cw
Acute: 22.0
Cyanide
NC
5 FW 22
10
1 1,
0 0
NA
—
— — —
_ _ --- _ _-
Chronic: 5.0
— — --- — — — — — —
RPA seeps 09 13.xlsm, rpa
Page 1 of 3 1/17/2017

Duke Energy
NC0003425
Freshwater RPA - 95% Probabilitvl95% Confidence Using Metal Translators
Outfall Seeps 9 -13
Qw = 2.3 MGD
RPA seeps 09 13.xlsm, rpa
Page 2 of 3 1/17/2017
Acute: NO WQS
limit
Fluoride
NC
ItiOU I W
ug/L
6 4 2,140.0
1
__ _ _ _____ _ _
_____________________—_____
Note: n <_ 9 Default C.V.
Chronic: 1,800.0
Limited data set
No value > Allowable Cw
Acute: 347.352
Monitor
Lead
NC
13.5358 FW 347.3518
ug/L
8 1
3.971
Note: n!5 9
Default C.V.
Chronic: 13.536
Limited data set
No value > Allowable Cw
Acute: NO WQS
Mercury
NC
12 FW
0.5
ng(L
8 3 950.0
Note: n <_ 9 Default C.V.
Chronic: 12.0
Limited data set
5 values > Allowable Cw
Acute: NO WQS
Molybdenum
NC
2000 HH
u, -,I
8 7
209.0
)te: n!5 9
Default C.V.
_ —_— _
Chronic: 2,000.0
mited data set
No value > Allowable Cw
Acute (FW): 1,073.9
Nickel
NC
119.2776 FW 1073.9039
AWL
8 8
6.8
Chronic (FW): 119.3
Note: n!5 9
Default C.V.
No value > Allowable Cw
----------------
---------------------------
Nickel
NC
25,0000 \4'S
L
- imited-dataset
----
ChroniG�WS)— 75.0
No value > Allowable Cw
Acute: 56.0
Limit
Selenium
NC
5 VW 56
ug/L
8 3
119.5
Note: n!5 9
Default C.V
Chronic: 5.0
Limited data sei
values > Allowable Cw
Acute: 3.162
Silver
NC
0.06 1 W 3.1616
ug/L
0 0
N ;A—
Chronic: 0.060
Acute: 403.4
Monitor
Zinc
NC
406.7415 1 W 403.4414
ug/L
8 1 9.5
Note: n —< Default C.V.
----------------------------------------------
_—_—_____—_____—___________—_—_____Note:n<9
Chronic: 406.7
Limited dat:i
No value > Allowable Cw
Acute: NO WQS
Limit
Sulfates
NC
250 \\'S
mg/L
8 8 1,349.00000
—__ _ _
_—_—_—_____________—_—____
Note: n:5 9 Default C.V.
_
Chronic: 250.00000
Limited data set
values > Allowable Cw
Acute:
0 l
N/A
------—
Chronic:
--—--—------—
Acute:
U
N
---------------------------------------------
Chronic
Acute:
0 U
Nr1
----------------------------------------------
Chronic:
RPA seeps 09 13.xlsm, rpa
Page 2 of 3 1/17/2017

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Project Information
❑CHECK IF HQW OR ORW WQS
Facility Name Duke Energy
WWTP/WTP Class Roxboro
NPDES Permit NC0003425
Outfall Seeps 9 -13
Flow, Qw (MGD) 2.300 '
Receiving Stream Hyco Reservoir
HUC Number
Stream Class
[DApply WS Hardness WQC
7Q1 Os (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q1 Os (cfs)
Effluent Hardness (Median)
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
Data Source(s)
❑CHECK TO APPLY MODEL
WS
0.00
0.00
0.00
0.00
0.00 l
default 99 mg/L (Effluent Hard Med = 100 mg/L)
99 mg/L (Average)
99mg/L --rirr�il
99mg/L �—'_—
Par01
Par02
Par03
Par04
Par05
Par06E
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Trout
NC
1.6678
TR
6.6897
ug/L
Chlorides
Water Supply
NC
250
WS
mg/L.
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
363.4201
FW
2793.8313
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
25.5442
FW
38.2981
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10 ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
13.5358
FW
347.3518
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5 ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
119.2776
FW
1073.9039
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
3.1616
ug/L
Zinc
Aquatic Life
NC
406.7415
FW
403.4414
ug/L
Sulfates
Water Supply
NC
250
WS
mg/L
RPA seeps 09 13.xlsm, input
1/17/2017

REASONABLE POTENTIAL ANALYSIS
Use"PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
8.7912
7.4150
0.6000
8
1.90
25.4 ug/L
48.3 ug/L
RPA seeps 09 13.xlsm, data
1 - 1/17/2017
H2
Par01 & Par02
Use "PASTE SPECIAL
Use "PASTE SPECT
Effluent Hardness (monthly average
Values" then "COPY,
Upstream Hardness
.Values" then "COP
Arsenic
Maximum d
Maximum data
points =
points = 58 .
Date Data
BDL=1/2DL
Results
Date Data BDL=1/2DL Results
Date
Data
BDL=1/2DL
Results
100
100
Std Dev.
317.2953
1
100 100 Std Dev.
N/A
1
2.06
2.06
Std Dev.
8/26/2014 21
21
Mean
254.6000
2
Mean
100.0000
2
1.31
1.31
Mean
799
799
C.V. (default)
0.6000
3
C.V.
0.0000
3
< 1
0.5
C.V. (default)
265
265
n
5
4
n
1
4
25.4
25.4
n
88
88
10th Per value
47.80 mg/L
5
10th Per value
100.00 mg/L
5
1.7
1.7
Median Value:
99.00 mg/L
6
Average Value
99.00 mg/L
6
15.7
15.7
Mult Factor =
Max. Value
799.00 mg/L
7
Max. Value
100.00 mg/L
7
6.54
6.54
Max. Value
8
8
6.11
6.11
Max. Pred Cw
9
9
10
10
11
11
12
12
13
13
Use"PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
8.7912
7.4150
0.6000
8
1.90
25.4 ug/L
48.3 ug/L
RPA seeps 09 13.xlsm, data
1 - 1/17/2017

REASONABLE POTENTIAL ANALYSIS
9r04
Pall
Use "PASTE SF
Par10
Copper
then "COPY"
Values" than "i
imum data
Use"PASTE SPECIAL
Maxlints
Data
BDL=112DL
Results
Cadmium
values• "torr
Chromium, Total
1.44
Std Dev.
1.2379
0.7588
2
. Maximum data
1.69
Mean
1.5538
0.6000
3
< 1
0.5
C.V. (default)
0.6000
points 5ti
4
4.4
4.4
n
Date
Data
5
BDL=112DL
Results
Date
Data
BDL=1/2DL
Results
1
<
1
0.5
Std Dev.
0.0000
1
Max. Value
1
0.5
Std Dev.
2
<
1
0.5
Mean
0.5000
2
1
0.5
Mean
3
<
1
0.5
C.V.
0.0000
3
1
0.5
C.V. (default)
4
<
1
0.5
n
8
4
13
2.57
2.57
n
5
<
1
0.5
5
1
0.5
6
<
1
0.5
Mult Factor =
1.00
6
< 1
0.5
Mult Factor =
7
<
1
0.5
Max. Value
0.500 ug/L
7
< 1
0.5
Max. Value
8
<
1
0.5
Max. Pred Cw
O DETECTS ug/L
8
< 1
0.5
Max. Pred Cw
9
9
10
10
11
11
12
12
13
13
-2-
.
STE SPE
Pall
Use "PASTE SF
Copper
then "COPY"
Values" than "i
imum data
Maxlints
Data
BDL=112DL
Results
4Values"
= 58
7319
1.44
1.44
Std Dev.
1.2379
0.7588
2
1.69
1.69
Mean
1.5538
0.6000
3
< 1
0.5
C.V. (default)
0.6000
8
4
4.4
4.4
n
8
5
1.3
1.3
1.90
6
< 1
0.5
Mult Factor =
1.90
2.6 pg/L
7
1.6
1.6
Max. Value
4.40
4.9 pg/L
8
1
1
Max. Pred Cw
8.36
9
10
11
12
13
RPA seeps 09 13.xlsm, data
1/17/2017

REASONABLE POTENTIAL ANALYSIS
RPA seeps 09 13.xlsm, data
- 3 - 1/17/2017
Par15
Use"PASTE SPECIAL
Par14
Values" then "COPY"
Mercury
. Maximum data
E SPECIAL
points = 58
Fluoride
Date
en "COPY"
BDL=112DL
Results
0.5621
Lead
< 0.5
0.25
Std Dev.
0.6988
2
0.632
L,.Maximumdata
Mean
0.6000
3
< 1000
500
P703
8
4
< 1000
500
s = 58
5
< 1000
500
1.90
Date
Data
BDL=1/2DL
Results
2.090 ug/L
Date
Data
13.8
BDL=1/2DL
Results
8
1
230
230
Std Dev.
333.6265
1
<
1
0.5
Std Dev.
2
100
100
Mean
376.6667
2
<
1
0.5
Mean
3
13
C.V. (default)
0.6000
3
<
1
0.5
C.V. (default)
4
1000
1000
n
6
4
2.09
2.09
n
5
< 500
250
5
<
1
0.5
6
180
180
Mult Factor =
2.14
6
<
1
0.5
Mult Factor =
ug/L
7
< 1000
500
Max. Value
1000.0 ug/L
7
<
1
0.5
Max. Value
ug/L
8
Max. Pred Cw
2140.0 ug/L
8
<
1
0.5
Max. Pred Cw
9
9
10
10
11
11
12
12
13
13
RPA seeps 09 13.xlsm, data
- 3 - 1/17/2017
Par15
Use"PASTE SPECIAL
Values" then "COPY"
Mercury
. Maximum data
points = 58
Date
Data
BDL=112DL
Results
0.5621
1
< 0.5
0.25
Std Dev.
0.6988
2
0.632
0.632
Mean
0.6000
3
< 1000
500
C.V. (default)
8
4
< 1000
500
n
5
< 1000
500
1.90
6
< 1000
500
Mult Factor =
2.090 ug/L
7
13.8
13.8
Max. Value
3.971 ug/L
8
6.15
6.15
Max. Pred Cw
9
10
11
12
13
RPA seeps 09 13.xlsm, data
- 3 - 1/17/2017

REASONABLE POTENTIAL ANALYSIS
Par16
Use "PASTE SPECIA14
Use"PASTE SPECIAL
Selenium
Values" then "COPY"
Molybdenum
. Maximum data
poin .= 58
Nickel
. Maximum data
points = 58
Date
Data
iota = 58
Date
Data
BDL=112DL
Results
264.5099
1
54.6
54.6
Std Dev.
252.6040
2
35.6
35.6
Mean
0.6000
3
< 1
0.5
C.V.(default)
8
4
106
106
n
3
5
38
38
C.V. (default)
1.90
6
110
110
Mult Factor =
500.0 ng/L
7
14.3
14.3
Max. Value
950.0 ng/L
8
87
87
Max. Pred Cw
1
9
Mult Factor =
110.0 ug/L
7
10
1.1
Max. Value
209.0 ug/L
8
11
1
0.5
Max. Pred Cw
12
13
13
10
REASONABLE POTENTIAL ANALYSIS
-4-
Use "PASTE SPECIAL
Par17 & Par18
Values" then "COPY^
Use"PASTE SPECIAL
Selenium
Maximum d
Values" then "COPY"
poin .= 58
Nickel
. Maximum data
Date
Data
iota = 58
1.0862
1
2.18
2.18
0.9625
Date
Data
1
BDL=112DL
Results
41.2964
1
<
1.0
0.5
Std Dev.
55.7500
2
<
1.0
0.5
Mean
0.6000
3
<
1.0
0.5
C.V. (default)
8
4
7
3.6
3.6
n
6.8 pg/L
5
<
1.0
0.5
1.90
6
<
1
0.5
Mult Factor =
110.0 ug/L
7
1.1
1.1
Max. Value
209.0 ug/L
8
<
1
0.5
Max. Pred Cw
9
13
10
11
12
13
-4-
Use "PASTE SPECIAL
Values" then "COPY^
Selenium
Maximum d
poin .= 58
Date
Data
BDL=1/2DL
1.0862
1
2.18
2.18
0.9625
2
<
1
0.5
0.6000
3
<
1
0.5
8
4
62.9
62.9
5
<
1
0.5
1.90
6
1.86
1.86
3.6 pg/L
7
<
1
0.5
6.8 pg/L
8
<
1
0.5
9
10
11
12
13
RPA seeps 09 13.xism, data
1/17/2017

REASONABLE POTENTIAL ANALYSIS
RPA seeps 09 13.xlsm, data
- 5 - 1/17/2017
I
Par21
Par22
E SPEC
Use "PASTE SPECIAL
Use "PASTE SPECIAL
en "COF
Zinc
Values" then "COPY-
sulfates
Values" then "COPYum
data
L
.Maximum data
.Maximum datas
= 58
is = 58
Points = 58
Results
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=112DL
Results
Std Dev.
21.9191
1
<
5
2.5
Std Dev.
0.8839
1
210
210
Std Dev.
214.3301
Mean
8.6800
2
<
5
2.5
Mean
2.8125
2
150
150
Mean
229.7000
C.V. (default)
0.6000
3
<
5
2.5
C.V. (default)
0.6000
3
1.6
1.6
C.V. (default)
0.6000
n
8
4
<
5
2.5
n
8
4
710
710
n
8
5
<
5
2.5
5
190
190
Mull Factor =
1.90
6
<
5
2.5
Mult Factor =
1.90
6
66
66
Mult Factor =
1.90
Max. Value
62.9 ug/L
7
5
5
Max. Value
5.0 ug/L
7
290
290
Max. Value
710.000000 mg/L
Max. Pred Cw
119.5 ug/L
8
<
5
2.5
Max. Pred Cw
9.5 ug/L
8
220
220
Max. Pred Cw
mg/L
9
9
10
10
11
11
12
12
13
13
RPA seeps 09 13.xlsm, data
- 5 - 1/17/2017

Roxboro Steam Electric Plant
NC0003425 Freshwater RPA -
Qw (MGD) =
1109.00
IQIOS(cfs)=
0.00
7QIOS (cfs) =
0.00
7QIOW (cfs) =
0.00
30Q2 (cfs) =
0.00
Avg. Stream Flow, QA (cfs) =
0.00
Receiving Stream:
NO HUC NUMBER
95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
W WTP/W TP Class:
IWC% @ IQ10S = 100
IWC% @7QIOS= 100
IWC%@7Q10W= 100
IWC% @ 30Q2 = 100
I W%C @ QA = 100
Stream Class: WS
Outfall 003
Qw=1109 MGD
COMBINED HARDNESS (ma/L)
Acute = 25 mg/L
Chromic = 25 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard:O val > 100 mg/L 0 val < 25 mg/L
Effluent Hard Med = 25 mg/L
PARAMETER
STANDARDS 8 CRITERIA (2)
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
12
NC WQS / Applied /z FAV /
n # Det. Max Pred Cw Allowable Cw
(1)
d
z
Chronic Standard Acute
Acute (FW): 340.0
No RP, > 50% of allowable. Monitor Quarterly
Arsenic
C
150 FW 340
ug/L---------------------------------------_
58 6
5.0
Chronic (FW): 150.0
No value > Cw
Arsenic
C
10 HH/WS
ug/L
_Allowable_
Chronic (HH)_ ' 10.07
No value > Allowable Cw
Acute: 65.00
Beryllium
NC
6.5 FW 65
ug/L
0 0
N/A_
_ _ ____ _
__________________________
_
6.5_
Chronic 0
Acute: 3.240
Cadmium
NC
0.5899 FW 3.2396
ug/L
0 0
N/A
___ _ _ __
_________________________
_____
Chronic 0.590
Acute: NO WQS
No RP, > 50% of allowable. Monitor Quarterly
Chlorides
NC
250 WS
mgL
36 35
134.1
---------------------------------------------
Chronic 250.0
No value > Allowable Cw
Acute: NO WQS
Chlorinated Phenolic Compounds
NC
I A
ug/L
0 0
N/A
---------------------------------------------
Chronic 1.0
Acute: NO WQS
Total Phenolic Compounds
NC
300 A
ug/L
0 0
N/A
---------------------------------------------
Chronic 300.0
Acute: 905.1
Chromium III
NC
117.7325 FW 905.0818
pg/L
0 0
N/A_
N/A
— _ _ -------------------------------
_____
Ch ronic 117.7
Acute: 16.0
Chromium VI
NC
II FW 16
pg/L
0 0
N/A
_ ___
_________________________
_
nic 11.0
5;,T
Chromium, Total
i
NC
pg/L
0 0
N/A
Acute: 10.47
No RP
Copper
NC
7.8806 FW 10.4720
ug/L
36 0
NO DETECTS
_ _ _ _ _
—_Chronic- --7.88
________________________
RPA Outfall 003.xism, rpa
Page 1 of 2 1/6/2017

Roxboro Steam Electric Plant
Outfall 003
N(:00034L5
Freshwater
RPA - 95% Probability/95%
Confidence
Using Metal
Translators
QW = 1109 MGD
Max MDL = 5
Acute (FW): 3352
Nickel
NC
37.2313 FW 335.2087
jig/L
_ _ _ _ _ _ _
No RP
------------------------
36 36
1.5
Chronic (FVV): 37.2
N_ovalue>AllowableCw
Nickel
NC
25.0000 WS
µg/L
Chronic (WS): 25.0
------------------------
No value > Allowable Cw
Acute: 56.0
No RP, > 50% of allowable. Monitor Quarterly
Selenium
NC
5 FW 56
ug/L
36 36
4.1
--
--------------------------
No value > Allowable Cw
Acute: 125.7
Zinc
NC
126.7335 FW 125.7052
ug/L
36 7
113.4
No RP
-----------------Chronic126.7
-------------------------
No value > Allowable Cw
Acute: NO WQS
thallium
NC
0.24 WS
µg/L
37 1
0.28250
RP, limit
—Chronic: — 0.24000
-------------
I values > Allowable Cw
Acute: NO WQS
Strontium
NC
14000 WS
pg/L
36 36
271.36000
No RP
___ ___ _ _ _
Chronic 14000.00000
__________________________
No value > Allowable Cw
Acute:
0 0
N/A
— — — —
Chronic
.—.—_—.—.--- — ---.— — —
Acute:
0 0
N/A
_ _ - — — —
—Chronic----------
—'—'—'—'—'---'—'—'—'—'—'—
RPA Outfall 003.xism, rpa
Page 2 of 2 1/6/2017

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information
❑CHECK IF HQW OR ORW WQS
Facility Name Roxboro Steam Electric Plant
WWTP/WTP Class
NPDES Permit
NC0003425
003
Outfall
Flow, Qw (MGD)
1109.000
Hyco Reservoir
Receiving Stream
Human Health
Water Supply
HUC Number
WS
Stream Class
❑� Apply WS Hardness WQC
7010s (cfs)
0.00
7Q10w (cfs)
0.00
30Q2 (cfs)
0.00
QA (cfs)
0.00
1Q10s (cfs)
0:00
Effluent Hardness (Median)
25 mg/L
Upstream Hardness _ 99 mg/L (Average)
Combined Hardness Chronic ' ^ ^ ` 25 mg/L
Combined Hardness Acute r 25 mg/L
Data Source(s)
❑CHECK TO APPLY MODEL
Par01
Par02
Par03
Par04
Par05
Par06N
Par07
Paf08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L_
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L.
Cadmium
Aquatic Life
NC
0.5899
FW
3.2396
ug/L
Chlorides
Water Supply
NC
250
WS
nigiL
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
117.7325
FW
905.0818
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
7.8806
FW
10.4720
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10 ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
2.9416
FW
75.4871
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
Molybdenum
Water Supply
NC
160
WS
ug/L_
Nickel
Aquatic Life
NC
37.2313
FW
335.2087
Ng/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.2964
ug/L
Zinc
Aquatic Life
NC
126.7335
FW
125.7052
ug/L
thallium
Water Supply
NC
0.24
WS
Ng/L
Strontium
Water Supply
NC
14000
WS
pg/L.
RPA Outfall 003.x1sm, input
1/13/2017

H1
Effluent Hardness (monthly average
Date Data BDL=112DL Results
1 25 25 Std Dev.
2 Mean
3 C.V.
4 n
5 10th Per value
6 Median Value:
7 Max. Value
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
REASONABLE POTENTIAL ANALYSIS
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
-1-
Par01 & Par02
Arsenic
H2
Data
Use "PASTE SPECIAL
1
6/7/2011
Use "PASTE SPECT
Values" then "COPY"
0.9
Upstream Hardness
Values" then "COF
. Maximum data
1.4
1.4
. Maximum data
points = 58
1.7
points = 58
4
9/20/2011
Date Data BDL=112DL Results
5
N/A
5
1 100 100 Std Dev.
N/A
25.0000
2.5
2 Mean
100.0000
0.0000
5
3 C.V.
0.0000
1
<
4 n
1
25.00 mg/L
1/4/2012
5 10th Per value
100.00 1719
25.00 mg/L
9
6 Average Value
99.00 mg
25.00 mg/L
2.5
7 Max. Value
100.00 mg,
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
-1-
Par01 & Par02
Arsenic
Date
Data
BDL=112DL
1
6/7/2011
0.9
0.9
2
7/6/2011
1.4
1.4
3
8/2/2011
1.7
1.7
4
9/20/2011
<
5
2.5
5
10/4/2011
<
5
2.5
6
11/2/2011
<
5
2.5
7
12/6/2011
<
5
2.5
8
1/4/2012
<
5
2.5
9
2/7/2012
<
5
2.5
10
3/7/2012
<
5
2.5
11
4/3/2012
<
5
2.5
12
5/1/2012
<
5
2.5
13
6/5/2012
<
5
2.5
14
7/3/2012
<
5
2.5
15
8/1/2012
<
5
2.5
16
9/5/2012
<
5
2.5
17
10/3/2012
<
5
2.5
18
11/7/2012
<
5
2.5
19
12/5/2012
<
10
5
20
1/2/2013
<
10
5
21
2/12/2013
<
10
5
22
3/13/2013
<
10
5
23
4/3/2013
<
10
5
24
5/1/2013
<
10
5
25
6/6/2013
<
10
5
26
7/2/2013
<
10
5
27
8/7/2013
<
10
5
28
9/5/2013
<
10
5
29
10/3/2013
<
10
5
30
11/6/2013
<
10
5
31
12/4/2013
<
10
5
32
1/8/2014
<
10
5
33
2/5/2014
<
10
5
34
3/5/2014
<
10
5
35
3/14/2014
1.18
1.18
36
4/1/2014
<
10
5
37
5/7/2014
<
10
5
38
6/4/2014
<
10
5
39
7/2/2014
<
10
5
40
8/6/2014
<
10
5
41
9/3/2014
<
10
5
42
10/1/2014
<
10
5
43
11/5/2014
<
10
5
44
12/3/2014
<
10
5
45
1/7/2015
<
10
5
46
2/5/2015
<
10
5
47
3/4/2015
<
10
5
48
4/1/2015
<
10
5
RPA Outfall 003.xism, data
1/6/2017

REASONABLE POTENTIAL ANALYSIS
49
49
49
5/6/2015
<
10
5
50
50
50
6/3/2015
<
10
5
51
51
51
7/8/2015
<
10
5
52
52
52
8/5/2015
<
10
5
53
53
53
9/2/2015
<
10
5
54
54
54
10/7/2015
<
10
5
55
55
55
11/412015
<
10
5
56
56
56
12/2/2015
<
10
5
57
57
57
1/5/2016
1.16
1.16
58
58
58
2/2/2016
1.02
1.02
RPA Outfall 003.xlsm, data
- 2 - 1/6/2017

Mult Factor = 1.00
Max. Value 5.0 ug/L
Max. Pred Cw 5.0 ug/L
REASONABLE POTENTIAL ANALYSIS
3 -
RPA Outfall 003.xism, data
1/6/2017
Use "PASTE SPECI
Values" then -COF
. Maximum data
points = 58
Results
Std Dev.
1.4341
Mean
3.9631
C.V.
0.3619
n
58
Mult Factor = 1.00
Max. Value 5.0 ug/L
Max. Pred Cw 5.0 ug/L
REASONABLE POTENTIAL ANALYSIS
3 -
RPA Outfall 003.xism, data
1/6/2017

REASONABLE POTENTIAL ANALYSIS
RPA Outfall 003.xlsm, data
- 4 - 1/6/2017

REASONABLE POTENTIAL ANALYSIS
Par05 Use "PASTE SPECIAL. Pall Use -PASTE SPELL
Chlorides values" then "COPY" . Copper Values" then "COP
Maximum data points = . Maximum data
16 58 ,A points = 58
7 & Par18
Date Data
BDL=1/2DL
Results
1.1
1.1
Date Data
1.3
BDL=112DL
Results
0.86
0.86
1 3/2/2010 <
100
50
Std Dev.
22.8474
1
3/2/2010 <
5
2.5
Std Dev.
0.0000
1
2 3/16/2010
33
33
Mean
62.5
2
3/16/2010 <
5
2.5
Mean
2.5000
2
3 4/6/2010
31.1
31.1
C.V.
0.3658
3
4/6/2010 <
5
2.5
C.V.
0.0000
3
4 4/20/2010
3.03
3.03
n
36
4
4/20/2010 <
5
2.5
n
36
4
5 5/4/2010
38.5
38.5
1/4/2011
0.78
5
5/4/2010 <
5
2.5
2/2/2011
1
5
6 5/18/2010
31.6
31.6
Mult Factor =
1.1
6
5/18/2010 <
5
2.5
Mult Factor =
1.00
6
7 6/3/2010
32.5
32.5
Max. Value
123.0 mg/L
7
6/3/2010 <
5
2.5
Max. Value
2.50 ug/L
7
8 6/15/2010
38.2
38.2
Max. Pred Cw
134.1 mg/L
8
6/15/2010 <
5
2.5
Max. Pred Cw O
DETECTS ug/L
8
9 7/6/2010
42.8
42.8
9
7/6/2010 <
5
2.5
9
10 7/20/2010
41.4
41.4
10
7/20/2010 <
5
2.5
10
11 8/3/2010
44.8
44.8
11
8/3/2010 <
5
2.5
11
12 8/17/2010
56.7
56.7
12
8/17/2010 <
5
2.5
12
13 9/7/2010
57.7
57.7
13
9/7/2010 <
5
2.5
13
14 9/2112010
64.4
64.4
14
9121/2010 <
5
2.5
14
15 10/5/2010
66.6
66.6
15
10/5/2010 <
5
2.5
15
16 10/21/2010
69.4
69.4
16
10/21/2010 <
5
2.5
16
17 111/2/2010
70.6
70.6
17
11/2/2010 <
5
2.5
17
18 11/16/2010
59.6
59.6
18
11/16/2010 <
5
2.5
18
19 12/7/2010
67.7
67.7
19
12/7/2010 <
5
2.5
19
20 12/21/2010
77.2
77.2
20
12/21/2010 <
5
2.5
20
21 1/4/2011
83.6
83.6
21
1/4/2011 <
5
2.5
21
22 1/18/2011
82.7
82.7
22
1/18/2011 <
5
2.5
22
23 2/2/2011
84.7
84.7
23
2/2/2011 <
5
2.5
23
24 2/15/2011
90.3
90.3
24
2/15/2011 <
5
2.5
24
25 3/1/2011
91.9
91.9
25
3/1/2011 <
5
2.5
25
26 3/14/2011
90
90
26
3/14/2011 <
5
2.5
26
27 4/5/2011
78.8
78.8
27
4/5/2011 <
5
2.5
27
28 4/19/2011
73.2
73.2
28
4/19/2011 <
5
2.5
28
29 5/3/2011
66
66
29
5/3/2011 <
5
2.5
29
30 5/17/2011
71
71
30
5/17/2011 <
5
2.5
30
31 6/7/2011
58.4
58.4
31
6/7/2011 <
5
2.5
31
32 6/21/2011
67.4
67.4
32
6/21/2011 <
5
2.5
32
33 7/6/2011
69.4
69.4
33
7/6/2011 <
5
2.5
33
34 7/19/2011
74.4
74.4
34
7/19/2011 <
5
2.5
34
35 8/2/2011
66.6
66.6
35
8/2/2011 <
5
2.5
35
36 8/16/2011
123
123
36
8/16/2011 <
5
2.5
36
37
37
37
38
38
38
39
39
39
40
40
40
41
41
41
42
42
42
43
43
43
44
44
44
45
45
45
46
46
46
47
47
47
48
48
48
-5-
Nickel
Date Data
BDL=112DL
3/2/2010
1.1
1.1
3/16/2010
1.3
1.3
4/6/2010
0.86
0.86
4/20/2010 <
0.5
0.25
5/4/2010
0.78
0.78
5/18/2010 <
0.5
0.25
6/3/2010 <
0.5
0.25
6/15/2010 <
0.5
0.25
7/6/2010
0.84
0.84
7/20/2010
0.66
0.66
8/3/2010 <
0.5
0.25
8/17/2010 <
0.5
0.25
9/7/2010
0.56
0.56
9/21/2010 <
0.5
0.25
10/5/2010 <
0.5
0.25
10/21/2010
1.1
1.1
11/2/2010
0.5
0.5
11/16/2010
0.54
0.54
12/7/2010
0.69
0.69
12/21/2010
0.71
0.71
1/4/2011
0.78
0.78
1/18/2011
0.76
0.76
2/2/2011
1
1
2/15/2011
0.89
0.89
3/1/2011
1
1
3/14/2011
0.8
0.8
4/5/2011
0.7
0.7
4/19/2011
0.65
0.65
5/3/2011
0.59
0.59
5/17/2011
0.69
0.69
6/7/2011 <
0.5
0.25
6/21/2011
0.54
0.54
7/6/2011
0.69
0.69
7/19/2011 <
2.5
1.25
8/2/2011 <
1
0.5
8/16/2011 <
0.5
0.25
RPA Outfall 003.xism, data
1/6/2017

REASONABLE POTENTIAL ANALYSIS
49
49
49
50
50
50
51
51
51
52
52
52
53
53
53
54
54
54
55
55
55
56
56
56
57
57
57
58
58
58
RPA Outfall 003.xlsm, data
- 6 - 1/6/2017

REASONABLE POTENTIAL ANALYSIS
Par19
Use"PASTE SPECIAL
Values" then "COPY'
. Maximum data
Par21
points = 58
Results
Zinc
Std Dev.
0.3083
Mean
0.6383
C.V.
0.4829
n
36
Mult Factor =
1.12
Max. Value
1.3 Ng/L
Max. Pred Cw
1.5 yg/L
REASONABLE POTENTIAL ANALYSIS
Par19
Selenium
STE SPE
then "CO
Par21
Zinc
Use "PASTE SPECIAL
Values" then "COPY"
Par22
imum daW ^
. Maximum data
ints = 58
il.
points = 58
Date Data
BDL=112DL
Results
Date Data
BDL=112DL
Results
1
3/1/2010
1.5
1.5
Std Dev.
.4927
1
3/2/2010 <
5
2.5
Std Dev.
13.5841
1
2
3/16/2010
1.4
1.4
Mean
9806
2
3/16/2010 <
5
2.5
Mean
6.3361
2
3
4/6/2010
1.5
1.5
C.V.
0.2488
3
4/6/2010 <
5
2.5
C.V.
2.1439
3
4
4/20/2010
1.5
1.5
n
36
4
4/20/2010 <
5
2.5
n
36
4
5
5/4/2010
1.8
1.8
5
5/4/2010
7.9
7.9
5
6
5/18/2010
1.5
1.5
Mult Factor =
1.06
6
5/18/2010 <
5
2.5
Mult Factor =
1.37
6
7
6/3/2010
1.5
1.5
Max. Value
3.9 ug/L
7
6/3/2010 <
5
2.5
Max. Value
82.8 ug/L
7
8
6/15/2010
1.6
1.6
Max. Pred Cw
4.1 ug/L
8
6/15/2010
82.8
82.8
Max. Pred Cw
113.4 ug/L
8
9
7/6/2010
1.6
1.6
9
7/6/2010 <
5
2.5
9
10
7/20/2010
1.5
1.5
10
7/20/2010 <
5
2.5
10
11
8/3/2010
1.8
1.8
11
8/3/2010 <
5
2.5
11
12
8/17/2010
1.8
1.8
12
8/17/2010 <
5
2.5
12
13
9/7/2010
1.8
1.8
13
9/7/2010 <
5
2.5
13
14
9/21/2010
1.7
1.7
14
9/21/2010 <
5
2.5
14
15
10/5/2010
2
2
15
10/5/2010 <
5
2.5
15
16
10/21/2010
2.1
2.1
16
10/21/2010
10.1
10.1
16
17
11/2/2010
2.5
2.5
17
1112/2010 <
5
2.5
17
18
11/16/2010
1.9
1.9
18
11/16/2010 <
5
2.5
18
19
12/7/2010
1.8
1.8
19
12/7/2010 <
5
2.5
19
20
12/21/2010
1.7
1.7
20
12/21/2010 <
5
2.5
20
21
1/4/2011
1.7
1.7
21
1/4/2011 <
5
2.5
21
22
1/18/2011
2.2
2.2
22
1/18/2011 <
5
2.5
22
23
2/2/2011
2.3
2.3
23
2/2/2011
5.6
5.6
23
24
2/15/2011
2.7
2.7
24
2/15/2011 <
5
2.5
24
25
3/1/2011
2.6
2.6
25
3/1/2011 <
5
2.5
25
26
3/1412011
2.7
2.7
26
3/14/2011 <
5
2.5
26
27
4/5/2011
2.4
2.4
27
4/5/2011 <
5
2.5
27
28
4119/2011
2.1
2.1
28
4/19/2011 <
5
2.5
28
29
5/3/2011
2.2
2.2
29
5/3/2011 <
5
2.5
29
30
5/17/2011
1.9
1.9
30
5/17/2011 <
5
2.5
30
31
6/7/2011
1.9
1.9
31
6/7/2011
7.2
7.2
31
32
6/21/2011
3.9
3.9
32
6/21/2011
17.5
17.5
32
33
7/6/2011
1.9
1.9
33
7/6/2011
12
12
33
34
7/19/2011
2.5
2.5
34
7/19/2011 <
25
12.5
34
35
8/2/2011
1.9
1.9
35
8/2/2011 <
10
5
35
36
8/16/2011
1.9
1.9
36
8/16/2011 <
5
2.5
36
37
37
37
38
38
38
39
39
39
40
40
40
41
41
41
42
42
42
43
43
43
44
44
44
45
45
45
46
46
46
47
47
47
48
48
48
-7-
_pte
/2010
3/16/2010
4/6/2010
4/20/2010
5/4/2010
5/18/2010
6/3/2010
6/15/2010
7/6/2010
7/20/2010
8/3/2010
8/17/2010
9/7/2010
9/21/2010
10/5/2010
10/21/2010
11/2/2010
11/16/2010
1217/2010
12/21/2010
1/4/2011
1/18/2011
2/2/2011
2/15/2011
311/2011
3/14/2011
4/5/2011
4/19/2011
5/3/2011
5/17/2011
6/7/2011
6/21/2011
7/6/2011
7/19/2011
8/2/2011
8/16/2011
RPA Outfall 003.xlsm, data
1/6/2017

REASONABLE POTENTIAL ANALYSIS
49
49
49
50
50
50
51
51
51
52
52
52
53
53
53
54
54
54
55
55
55
56
56
56
57
57
57
58
58
58
RPA Outfall 003.xism, data
- 8 - 1/6/2017

REASONABLE POTENTIAL ANALYSIS
Use "PASTE SPE
Values" then "CO,
. Maximum data
points = 58
_
Par23
1
thallium
103
Data
Results
Std Dev.
BDL=1/2DL
Results
<
0.1
0.05
Std Dev.
<
0.1
0.05
Mean
<
0.1
0.05
C.V.
<
0.1
0.05
n
<
0.1
0.05
n
<
0.1
0.05
Mult Factor =
<
0.1
0.05
Max. Value
<
0.1
0.05
Max. Pred Cw
<
0.1
0.05
0.250000 Ng/L
<
0.1
0.05
116
Max. Value
0.11
0.11
8
<
0.1
0.05
Max. Pred Cw
<
0.1
0.05
7/6/2010
<
0.1
0.05
<
0.1
0.05
153
<
0.1
0.05
<
0.1
0.05
154
<
0.1
0.05
12
<
0.1
0.05
<
0.1
0.05
9/7/2010
<
0.1
0.05
<
0.1
0.05
206
<
0.1
0.05
<
0.1
0.05
196
<
0.1
0.05
16
<
0.1
0.05
<
0.1
0.05
111/2/2010
<
0.1
0.05
<
0.1
0.05
225
<
0.1
0.05
<
0.1
0.05
227
<
0.1
0.05
20
<
0.1
0.05
<
0.5
0.25
1/4/2011
<
0.2
0.1
<
0.1
0.05
245
<
0.2
0.1
REASONABLE POTENTIAL ANALYSIS
Use "PASTE SPE
Values" then "CO,
. Maximum data
points = 58
_
Par23
1
Date Data
3/2/2010
103
Strontium
BDL=1/2DL
103
Results
Std Dev.
a "PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
47.6474
0.0354
0.0597
2
3/16/2010
110
110
Mean
188.8056
0.5926
3
4/6/2010
109
109
C.V.
0.2524
37
4
4/20/2010
115
115
n
36
5
5/4/2010
129
129
1.13
6
5/18/2010
118
118
Mult Factor =
1.06
0.250000 Ng/L
7
6/3/2010
116
116
Max. Value
256.000000 Ng/L
0.282500 Ng/L
8
6/15/2010
127
127
Max. Pred Cw
271.360000 Ng/L
9
7/6/2010
137
137
10
7/20/2010
153
153
11
8/3/2010
154
154
12
8/17/2010
168
168
13
9/7/2010
191
191
14
9/21/2010
206
206
15
10/5/2010
196
196
16
10/21/2010
195
195
17
111/2/2010
218
218
18
11/16/2010
225
225
19
12/7/2010
227
227
20
12/21/2010
220
220
21
1/4/2011
215
215
22
1/18/2011
245
245
23
2/2/2011
256
256
24
2/15/2011
252
252
25
3/1/2011
256
256
26
3/14/2011
244
244
27
4/5/2011
226
226
28
4/19/2011
219
219
29
5/3/2011
210
210
30
5/17/2011
211
211
31
6/7/2011
195
195
32
6/21/2011
218
218
33
7/6/2011
211
211
34
7/19/2011
197
197
35
8/2/2011
217
217
36
8/16/2011
208
208
37
38
39
40
41
42
43
44
45
46
47
48
-9-
RPA Outfall 003.xlsm, data
1/6/2017

49
50
52
53
54
55
56
57
58
REASONABLE POTENTIAL ANALYSIS
10 -
RPA Outfall 003.xlsm, data
1/6/2017

Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Project Information
❑CHECK IF HQW OR ORW WQS
Roxboro
[2]Apply WS Hardness WQC
NC0003425
006
1.810
Hyco Lake
rW
7Q10s (cfs)
Aquactic Life
0.00
7Q10w (cfs)
FW
0.00
30Q2 (cfs)
Arsenic
0.00
QA (cfs)
0.00
1Q10s (cfs)
0.00
Effluent Hardness (Median)
M
_
25 mg/L
Upstream Hardness
_:.
v -----`--
99 mg/L (Average) --------I
Combined Hardness Chronic
_
_ _ _ 25 mg/L
Combined Hardness Acute
NC
25 mg/L
Data Source(s)
❑CHECK TO APPLY MODEL
Par01
Par02
Par03
Par04
Par05
Par06N
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQs Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L_
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Trout
NC
0.5899
TR
2.0145
ug/L
Chlorides
Water Supply
NC
250
WS
mg/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
117.7325
FW
905.0818
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
Ng/L
Copper
Aquatic Life
NC
7.8806
FW
10.4720
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10 ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
2.9416
FW
75.4871
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5 ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
37.2313
FW
335.2087
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.2964
ug/L
Zinc
Aquatic Life
NC
126.7335
FW
125.7052
ug/L
RPA 006.x1sm, input
1/18/2017

Roxboro
NC0003425
Freshwater RPA -
Qw (MGD) = 1.81
1Q10S (cfs) = 0.00
7Q10S (cfs) = 0.00
7Q10W (cfs) = 0.00
30Q2 (cfs) = 0.00
Avg. Stream Flow, QA (cfs) = 0.00
Receiving Stream: NO HUC NUMBER
95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
W WTP/WTP Class:
IWC% @ 1Q10S = 100
IWC% @ 7Q10S = 100
IWC%@7Q10W= 100
IWC% @ 30Q2 = 100
IW%C @ QA = 100
Stream Class: WS
Outfall 006
Qw = 1.81 MGD
COMBINED HARDNESS (mg/L)
Acute = 25 mg/L
Chromic = 25 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard:O val > 100 mg/L 0 val < 25 mg/L
Effluent Hard Med = 25 mg/L
PARAMETER
TYPE
(1)
STANDARDS 8 CRITERIA (2)
�
N
F
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NC WQS / Applied '/z FAV
Chronic Standard Acute
n # Det. Max Pred Cw Allowable Cw
Acute: 56.0
1 1 5.4
Selenium
NC
5 FW 56
ug/L
Add limit
_ _ _ _______ _
Note: n < 9 Default C.V. Chronic 5.0
__________________________
Limited data se l values > Allowable Cw
Zinc
NC
126.7335 FW 125.7052
ug/L
1 1 12.6
Acute: 125.7
No RP
Note: n < 9 Default C.V.
---------------------------------------------
Chronic: 126.7
Limited data set
No value > Allowable Cw
Acute:
0 0
N/A
Chronic ----------
-------------------------
RPA 006.xlsm, rpa
Page 1 of 1 1/18/2017

Par19
1
2
3
4
5
6
7
8
9
10
11
12
REASONABLE POTENTIAL ANALYSIS
Selenium
Use "PASTE SPECIAL
Values" then "COPY"
Par21
. Maximum data
points = 58
Date Data BDL=1/2DL Results
5.4 5.4 Std Dev.
N/A
1
Mean
5.4000
2
C.V.
0.0000
3
n
1
4
5
Mult Factor =
1.00
6
Max. Value
5.4 ug/L
7
Max. Pred Cw
5.4 ug/L
8
9
10
11
12
Zinc
Date Data BDL=112DL Results
12.6 12.6 Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
I�
Use"PASTE SPECI
Values" then "COF
. Maximum data
points = 58
12.6000
0.0000
1
1.00
12.6 ug/L
12.6 ug/L
RPA 006.xlsm, data
1/18/2017

1/17/17 WQS =
12
ng/L
MERCURY WQBEL/TBEL EVALUATION
V:2013-5
Annual Limit 12 ng/L with
Facility Name: Roxboro Outfall 001
Quarterly Monitoring
MMP Required
Total Mercury 1631E PQL = 0.5
ng/L
7Q10s =
0.000 cfs WQBEL = 12.00
ng/L
Date Modifier
Data Entry
Value
Permitted Flow =
2.300 47
ng/L
8/23/2014 <
1000
500
> TBEL
8/24/2014 <
1000
500
> TBEL
8/25/2014 <
1000
500
> TBEL
8/26/2014 <
1000
500
> TBEL
5/14/2015
13.8
13.8
11/17/2015
6.15
6.15
ai vaL
LV.¢1as — 6- r>d(L,
5/14/2015 <
0.5
0.5
11/16/2015
0.632
0.632

1/18/17 WQS = 12
Facility Name: Roxboro 003
Total Mercury 1631E PQL = 0.5 ng/L
Date Modifier Data
3/2/2010
3/16/2010
4/6/2010
4/20/2010
5/4/2010
5/18/2010
6/3/2010
6/15/2010
7/6/2010
7/20/2010
8/3/2010
8/17/2010
9/7/2010
9/21/2010
10/5/2010
10/21/2010
11/2/2010
11/16/2010
12/7/2010
12/21/2010
1/4/2011
1/18/2011
2/2/2011
2/15/2011
3/1/2011
3/14/2011
4/5/2011
4/19/2011
5/3/2011
5/17/2011
6/7/2011
6/21/2011
7/6/2011
7/19/2011
8/2/2011
8/16/2011
5.96
4.97
4.19
3.61
3.8
3.36
7.63
3.67
2.75
1.7
1.32
2.33
1.52
1.99
2.28
6.42
5.14
3.51
2.05
3.18
4.25
4.85
6.11
6.92
6.71
6.33
4.24
2.91
3.35
5.69
4.7
4.71
2.32
1.44
2.88
2.71
ng/L
Value
5.96
4.97
4.19
3.61
3.8
3.36
7.63
3.67
2.75
1.7
1.32
2.33
1.52
1.99
2.28
6.42
5.14
3.51
2.05
3.18
4.25
4.85
6.11
6.92
6.71
6.33
4.24
2.91
3.35
5.69
4.7
4.71
2.32
1.44
2.88
2.71
MERCURY WQBEL/TBEL EVALUATION
No Limit Required
MMP Required
7Q10s = 0.000 cfs WQBEL =
Permitted Flow = 1109.000
V:2013-5
12.00 ng/L
47 ne/L
3.6 ng/L - Annual Average for 2010
4.4 ng/L - Annual Average for 2011