NC0005088_Hearing Officer's Report & Recommendations_20170131

January 31, 2017
MEMORANDUM
To: Jay Zimmerman
From: George Smith, Assistant Regional Supervisor 0
Water Quality Regional Operations Section
Winston-Salem Regional Office
RI COED/DSR
r_LB 0 8 2011
Water Quality
Permitting section
Subject: Hearing Officer's Report and Recommendations
Duke Energy Carolinas, LLC - Draft NPDES Wastewater Permit No. NC0005088
Rogers Energy Complex, Rutherford County
I served as the Hearing Officer for a public hearing held on November 10, 2016, at 6:00
pm at the Boiling Springs Town Hall, Boiling springs, NC. The purpose of the public
hearings was to allow the public to comment on the draft NPDES wastewater permit for
Duke Energy Carolinas, LLC's Rogers Energy Complex.
In addition to listening to oral comments at the public hearings, I have reviewed all
written comments received during the public comment period which ended on
November 10, 2016. In preparation of this report I have considered all of the public
comments, the public record, and the site visits for the three facilities.
The report has been prepared using the following outline:
I. Site History / Background
II. Public Hearing and Comments Summary
III. Recommendations
IV. Attachments

Hearing Officer Report
PUBLIC HEARING - DRAFT NPDES PERMIT No. NC0005088 FOR DUKE ENERGY
CAROLINAS, LLC TO DISCHARGE WASTEWATER
FROM THE ROGERS ENERGY COMPLEX, 573 DUKE POWER RD,
MOORESBORO, NC., RUTHERFORD COUNTY
I. History/ Background
Duke Energy's Rogers Energy Complex (REC) is a steam electric generating facility
currently operating two coal fired units, Units 5 and 6. Unit 5 started operation in 1972
and Unit 6 in 2012. Generating capacity for the two units totals 1500 megawatts. Each unit
has a Flue Gas Desulfurization (FGD) system. The site has an industrial landfill for
combustion byproducts where fly ash, bottom ash, gypsum and WWTP sludge is
deposited. The REC is permitted to discharge to the Broad River under permit
NC0005088.
The ash basin receives wastewaters collected in the Yard Drainage Basin (effluent from
the domestic WWTP, cooling tower blowdown from Unit 5, landfill leachate, floor drains,
treated FGD wet scrubber water, limestone unloading and storage area, and stormwater),
sluiced ash, cooling tower blowdown from Unit 6, equipment backwashes, boiler
blowdown, drainage from recirculating cooling systems, demineralizing resin, cooling
water from heat exchangers, rinse water from limestone unloading and storage area,
stormwater, and miscellaneous waste streams. The ash basin effluent is discharged to
the Broad River at outfall 002.
The permit includes a new outfall for a proposed low volume waste treatment system
(outfall 005) and two overflow outfalls from collection basins (outfalls 002B and 002C).
Duke identified 21 unpermitted seeps, 11 seeps discharge to the Broad River and 10 to
Suck Creek. The permit includes 18 outfalls to monitor seeps. § 130A-309.210 of the Coal
Ash Management Act (CAMA) of 2014 requires owners of coal combustion residuals
surface impoundments to identify and assess all discharges from the impoundments and
to implement corrective action to prevent unpermitted discharges from the
impoundments to the surface waters of the State. Identification of discharges includes
engineered channels designed or improved for the purpose of collecting water from the
toe of the impoundment (toe drains), as well as non -engineered seeps and weeps. One
method of proposed corrective action allowed under the Act is to make application for a
National Pollutant Discharge Elimination System (NPDES) permit amendment to bring
the unpermitted discharge under permit regulations. A Discharge Assessment Plan for
the unpermitted discharges at the Rogers Energy Complex was submitted by Duke
Energy to the department on September 30, 2014.
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A summary of the proposed changes to the NPDES permit can be found on the Fact
Sheet for NPDES Permit Development in Attachment B.
II. Public Hearing and Comments Summary
A public hearing was held on November 10, 2016 at the Boiling Springs Town Hall, 114
East College Ave., Boiling Springs, NC. The purpose of the public hearing was to allow
the public to comment on the draft NPDES wastewater permit.
Notice of the hearing (Attachment E.) was published in the Asheville Citizen -Times on
September 22, 2016 and posted on the DEQ, DWR website. The public comment period
closed on November 10, 2016.
Approximately 58 people attended the public hearing including 10 staff members of the
Division of Water Resources and the hearing officer. A total of 48 individuals signed
the attendance sign in sheets at the hearing (Attachment F. and G.). The hearing officer
provided opening comments and Teresa Rodriguez with the Division of Water
Resources gave a brief overview of the draft NPDES wastewater permits. Eleven
individuals registered in advance of the hearing to provide oral comments. Speakers
were allowed three minutes to comment. The list of speakers is included as Attachment
F. The written comments provided at the public hearing are included with other
written comments in Attachment C.
One speaker was a representative from Duke Energy and supported the issuance of the
permit. The remaining speakers were generally opposed to the NPDES draft permit.
A. Comments Presented at the Public Heating
The following is a summary of oral comments received at the public hearing:
•
Don't issue the permit until the water lines for the neighboring properties are
installed and the site is cleaned up.
Response: The NPDES permit regulates the discharge of wastewater to waters of
the state. The NPDES program does not implement the requirement to install
water supply lines to the neighboring properties.
• Objection to the temperature mixing zone.
Response: The footnote addressing the thermal mixing zone will be removed
from condition A.(1) as it's no longer applicable since units 1-4 have been
decommissioned.
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• Acute toxicity testing should be required for each event that requires the use of
the emergency overflow.
Response: The permit requires the permittee to conduct toxicity test every time
the emergency overflow would discharge to the Broad River.
• Discharges from seeps are illegal, should not be allowed.
Response: § 130A-309.210 of CAMA requires owners of coal combustion
residuals surface impoundments to identify and assess all discharges from the
impoundments and to implement corrective action to prevent unpermitted
discharges from the impoundments to the surface waters of the state.
Identification of discharges includes engineered channels designed or improved
for the purpose of collecting water from the toe of the impoundment (toe drains),
as well as non -engineered seeps and weeps. One method of proposed corrective
action allowed under the Act is to make application for an NPDES permit
amendment to bring the unpermitted discharge under permit regulations. A
Discharge Assessment Plan for the unpermitted discharges at the Rogers Energy
Complex was submitted by Duke Energy to the Department on September 30,
2014. The facility identified 35 unpermitted seeps from the ash settling basin and
the ash landfill. Under the draft NPDES Permit, 18 seeps are considered to be
discharging through delineated effluent channels. The effluent channels were
delineated by DWR staff on August 23, 2016, in accordance with 15A NCAC 02B
.0228. The draft permit requires the permittee to demonstrate that water quality
standards in the receiving stream are not contravened. This demonstration must
be submitted to the Division no later than 180 days from the effective date of the
permit.
Permit should include deadline for construction of a wastewater treatment to
treat the dewatering and decanting water capable of removing pollutants to safe
levels.
Response: Duke is working on several comprehensive projects at multiple
facilities. The schedules for construction will be planned with the scope of the
projects. Schedule of compliance for the construction of new treatment units are
not included in permits. The permit includes requirements for utilizing a
physical/ chemical treatment to treat the water removed from the ash basin.
Treatment must address all the known pollutants present in the wastewater.
Even though limits were implemented based on a reasonable potential analysis,
the facility must comply with all water quality standards.
• It is illegal to convert waters of the state to effluent channels.
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Response: The Effluent Channels at the Rogers Energy Complex have been
delineated in accordance with the requirements of 15A NCAC 02B .0228
The Reasonable Potential Analysis (RPA) doesn't account for groundwater
entering the river and creek.
Response: The RPA analysis is designed to evaluate the contribution of a point
source discharge to surface water, is not a tool for evaluating groundwater. Once
groundwater enters an effluent channel it becomes a regulated wastestream per
40 CFR 122.2. Groundwater not discharged through the effluent channels is
regulated under a separate program.
• Illegal to issue a permit for facility that is violating the water quality standards.
Response: The permit was based on existing federal and state rules and
regulations and will provide compliance with the water quality standards in the
receiving water bodies. The permit has requirements for sampling surface waters
and water quality standards violations will be addressed.
• Duke Energy should clean up the ash basin and move the ash to lined landfills
away from the water.
Response: §130A-309.213 of CAMA required the department to develop a
proposed classification system for all coal combustion residuals surface
impoundments, including active and retired sites. §130A-309.214 requires
owners of coal combustion residual surface impoundments to submit a proposed
closure plan for the Departments approval. High-risk impoundments shall be
closed no later than December 31, 2019, intermediate -risk impoundments shall be
closed no later than December 31, 2024, and low-risk impoundments shall be
closed no later than December 31, 2029. The decision regarding the ultimate
closure of the ash ponds will be made outside of the NPDES permitting process.
• Not enough limits for decanting/ dewatering and seeps. Permit should include
limits for toxic metals. No limits on flow.
Response: The limits and monitoring requirements in the draft NPDES permit
are based on state and federal rules, regulations, and policies. The state conducts
a RPA to determine the need for monitoring or limit for a particular
constituent. The EPA approved procedure is approved by the EPA and its used
to establish permit limits. The analysis considers the 126 parameters in the
renewal application and additional data collected by the permittee. The RPA is
conducted on the parameters that are above detection level and have appropriate
state water quality standard/EPA criteria. The analysis included arsenic,
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cadmium, chloride, chromium, fluoride, lead, mercury, molybdenum, nickel,
selenium, zinc, antimony, sulfates, and thallium. Limits were implemented for
parameters that showed reasonable potential to exceed the water quality
standard or federal water quality criteria. Monitoring is included for metals and
coal ash constituents that dont have limits. Flow limits are implemented in
NPDES permits for treatment systems with a defined treatment capacity. Ponds
with long retention times are not limited for flow. The limits are determined
using the highest reported effluent flow in conjunction with the river low flow
conditions which is a conservative approach.
• Have independent party do the sampling with the Divisions overseeing.
Response: The NPDES program is a self-monitoring program as established in
Section 309 of the CWA and 40 CFR 122.41 The state conducts inspections and
compliance checks. The regulation contains provisions for penalties and criminal
charges for violators.
The public hearing recording as an mp3 file is included as Attachment D.
B. Comments received by e-mail
DWR received 60 email comments using the following form letter:
"Duke Energy's coal ash dumps at the Rogers Energy Complex/Cliffside power plant have
been polluting our waters and threatening our communities for decades. Duke Energy's own
studies show that the dumps are causing violations of surface water standards in Suck Creek
and will continue contaminating the groundwater for a century or more unless the site is
sufficiently remediated. Papering over these problems is not the solution we need. DEQ
should not allow these coal ash dumps to pour unchecked and unsafe levels of heavy metals
and toxics like arsenic, selenium, mercury and others into groundwater and through
unpermitted seeps and leaks into creeks and the Broad River. This pollution contaminates the
waters we rely on for drinking, fishing, and recreation and spoils important wildlife habitat.
The new draft wastewater discharge permit for Cliffside does not alleviate these problems,
and instead gives Duke a free pass to pollute our waters and communities in perpetuity.
DEQ should withdraw the permit as written and amend it to protect environmental quality
and public health by:
-Refusing to allow Duke Energy to use natural streams and wetlands as its personal effluent
waste channels. DEQ should protect these streams and wetlands, not abandon them.
-Refusing to permit most of the more than 30 illegal seeps at the site. DEQ should require
Duke Energy to clean up its coal ash pollution, not allow it to continue polluting in
perpetuity.
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-Including safe limits for toxic heavy metals and constituents like arsenic, cadmium, and
selenium for every permitted outfall. The current permit does not include numeric limits,
allowing Duke to dump untold amounts of contamination into our waters.
-Prohibiting the compliance boundary from crossing the Broad River. It's unacceptable to co-
opt our River into Duke's dumping zone."
Response:
- Effluent channels have been designated in accordance with the requirements of
15A NCAC 02B.0228.
- § 130A-309.210 of CAMA requires owners of coal combustion residuals surface
impoundments to identify and assess all discharges from the impoundments and
to implement corrective action to prevent unpermitted discharges from the
impoundments to the surface waters of the state. Identification of discharges
includes engineered channels designed or improved for the purpose of collecting
water from the toe of the impoundment (toe drains), as well as non -engineered
seeps and weeps. One method of proposed corrective action allowed under the
Act is to make application for a National Pollutant Discharge Elimination System
(NPDES) permit amendment to bring the unpermitted discharge under permit
regulations. This approach was approved by the EPA.
- The limits and monitoring requirements in the draft NPDES permit are based on
the state and federal rules, regulations, and policies. The state conducts a RPA to
determine the need for a monitoring or limit for a particular constituent. The EPA
approved procedure is approved by the EPA and its used to establish permit limits. The
analysis considers the 126 parameters in the renewal application and additional
data collected by the permittee. The RPA is conducted on the parameters that are
above detection level and have appropriate state water quality standard/EPA
criteria. The analysis included arsenic, cadmium, chloride, chromium, fluoride,
lead, mercury, molybdenum, nickel, selenium, zinc, antimony, sulfates, and
thallium. Limits were implemented for parameters that showed reasonable
potential to exceed the water quality standard or federal water quality criteria.
Monitoring is included for metals and coal ash constituents that don't have
limits.
- According to 15A NCAC 02L.0107, individually permitted sites have a
compliance boundary established at a set horizontal distance from the waste
boundary (or the property boundary, whichever is closest to the source), the
distance depending whether the permit was permitted prior to December 30,
1983 or after December 30, 1983. Thus the Compliance Boundary is established
by rule.
Email comments are included as Attachment C.
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C. Comment Letters
Written comments on the draft permit were received from Duke Energy, Southern
Environmental Law Center, and Clean Water for North Carolina.
The following is a summary of comments received from Duke Energy:
• Limits on chromium and zinc- remove these parameters from pages 3 and 6 and
replace with the option to calculate the priority pollutants from maintenance
chemicals.
Response: Limits for chromium and zinc still apply to the discharge of cooling
tower blowdown.
• Pages 3, 8, 9 and 11, limitations on copper andiron -the permit proposes limits
for chemical metal cleaning for copper more restrictive than the ELG limit of 1
mg/l. Duke requests the limit be changed to 1 mg/1.
Response: The Division does not agree to change the copper limit. The Division
evaluates limits considering both technology based effluent limits (TBEL) and
water quality based effluent limits (WQBEL) and implements the most stringent
limit. The copper WQBEL is more stringent than the TBEL and it protects for the
water quality standard.
Limitation on Thallium - remove thallium limits in pages 3,11, 20, 21, 22,24 and
25. North Carolina hash t adopted thallium standards, information in IRIS to
determine criteria contains poor quality studies, no determination that the limit
is necessary to protect narrative standard.
Response: Both Federal (40 CFR 122.44) and State regulations (15A NCAC 02B.
0208) support the implementation of limits for pollutants that have not been
adopted as state water quality standards. The Division follows recommendations
for human health criteria developed by the EPA.
• Limitations on turbidity - remove turbidity limits in pages 3, 4, 6, and 7. These
outfalls have TSS limits.
Response: Turbidity is listed as a state water quality standard and is
independent of compliance with the total suspended solids limits which is a
technology based limit. The Division has agreed with the EPA to include
turbidity limits for the discharge from ash ponds.

Monitoring limitations on seeps - eliminate all monitoring requirements for
seeps 128, 129, 130, 131 and 132. These seeps are located in rough terrain that
represent safety concerns. Eliminate monitoring for all parameters except low
volume waste parameters and allow for instream monitoring to identify the
parameters of concern.
Response: The Division does not agree to eliminate the requirements in the
permit.
• Chronic toxicity - on page 3 of 6 change monthly frequency to quarterly.
Response: The Division does not agree to change the frequency to quarterly.
Monitoring frequencies were established for dewatering and decanting after
discussions with the EPA and are consistent with other permits.
• Continuous pH and TSS monitoring - request to do in -process monitoring and
allow to be limited by routine monitoring.
Response: These requirements will remain in the permit as they were agreed to
with the EPA for dewatering and decanting of the ash basins.
Change to flow diagram- Flue Gas Desulfurization system (FGD) will not
discharge in to the proposed Wastewater Treatment System, discharge of the
FGD will combine with the effluent from the proposed treatment system before
discharging to the Broad River.
Response: The permit will be clarified to reflect this modification.
• RPA demonstrations - the long term average flow should be used in the RPA
instead of the maximum flow. Request to verify the summation of the seeps and
objects to the methodology of multiplying the flow by 10.
Response: The procedure used by the Division to determine reasonable potential
when the outfall does not have a flow limit is to use the maximum monthly flow
for the period in review. This flow represents the critical condition which is used
to derive limits protective of water quality. The Division follows the same
procedure for all permittees and there is no basis for changing the flow to the
monthly average.
The RPA for the seeps were revised by grouping the seeps based in origin and
location. Seeps outfalls were modified to implement the limits based on the
results of the revised RPA. The methodology to multiply the flow by 10 was
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agreed upon with the EPA and executed in the same manner for all the Duke
permits to provide a safety factor since the seeps are not constant in nature.
• No discharge of bottom ash transport water - on page 3 of fact sheet add
statement about the proposed system to be installed.
Response: The fact sheet will be revised to add information regarding the
schedule of compliance for bottom ash and description of the proposed system.
The following is a summary of comments received from the Southern Environmental
Law Center on behalf of Mountain True:
• Approach for permitting seeps violates the CWA. Discharge of seeps should not
be permitted. Seeps cant be permitted as effluent channels. 14 seeps that were
not covered are point source discharges through groundwater. Inadequate
monitoring for seeps. Procedure for permit modifications are not clear.
Response: § 130A-309.210 of CAMA requires owners of coal combustion
residuals surface impoundments to identify and assess all discharges from the
impoundments and to implement corrective action to prevent unpermitted
discharges from the impoundments to the surface waters of the state.
Identification of discharges includes engineered channels designed or improved
for the purpose of collecting water from the toe of the impoundment (toe drains),
as well as non -engineered seeps and weeps. One method of proposed corrective
action allowed under the Act is to make application for a NPDES permit
amendment to bring the unpermitted discharge under permit regulations. This
approach was approved by the EPA. A Discharge Assessment Plan for the
unpermitted discharges at the Rogers Energy Complex was submitted by Duke
Energy to the Department on September 30, 2014. The facility identified 35
unpermitted seeps from the ash settling basin and the ash landfill. Under the
draft NPDES Permit, 18 seeps are considered to be discharging through
delineated effluent channels. The effluent channels were delineated by DWR
staff on August 23, 2016, in accordance with 15A NCAC 02B .0228. The draft
permit requires the permittee to demonstrate that water quality standards in the
receiving stream are not contravened. This demonstration must be submitted to
the Division no later than 180 days from the effective date of the permit.
The 14 seeps that were not covered in the permit are either not directly
discharging to surface waters or the collected data didn t indicate the presence of
coal ash pollutants.
10

The monitoring requirements in the permit are based on state and federal rules,
regulations, and policies. The established frequency is sufficient to conduct a
valid statistical analysis of the effluent data.
The permit does not authorize unidentified seeps in advance, if new seeps are
found, Duke Energy shall apply for a permit modification and the permit will be
re -opened, the modified permit will be publically noticed and open for
comments from all interested parties.
• Permit fails to account for discharge of wastewater through hydrologically
connected groundwater.
Response: The NPDES program regulates point source discharges to the Waters
of the US. The infiltration of the wastewater to the groundwater does not fit the
definition of the point source discharge. The groundwater contamination is being
regulated under a separate program within DWR. The comprehensive impact of
the facility is being assessed by instream monitoring of the receiving water.
Groundwater monitoring is performed independently from point source
monitoring.
• Can't issue a permit for a facility that is violating the state water quality
standards. Require limits for thallium and aluminum, instream monitoring is
inadequate.
Response: The proposed permit was based on the existing federal and state
rules and regulations and will provide compliance with the water quality
standards in the receiving water bodies. The permit has requirements for
sampling surface waters and water quality standards violations will be
addressed. Limits were based on a reasonable potential analysis. Thallium limits
were implemented were applicable. Aluminum did not show reasonable
potential. Instream monitoring is required for arsenic, selenium, mercury
(method 1631E), chromium, lead, cadmium, copper, zinc, bromide, hardness,
and total dissolved solids (TDS). The Division considers these requirements
sufficient to evaluate the impact of the discharge.
• Draft permit violates requirements applicable to waters classified as critical
areas.
Response: The segment of the Broad River where the discharges occurs does not
have critical area designation. The classification for the segment is WS -IV.
• RPA is inadequate because it doesri t address hydrologically connected
groundwater or other streams and wetlands, is not performed for all
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jurisdictional waters. Limit for thallium should be applied for dewatering.
Turbidity footnote for dewatering outfall 002 should be changed to match the
Sutton permit.
Response: The Division conducted EPA -recommended analyses to determine the
reasonable potential for toxicants to be discharged at levels exceeding water
quality standards or EPA criteria by this facility from all permitted outfalls
discharging to the Broad River and Suck Creek. The reasonable potential
procedure is not a tool for evaluating groundwater or wetlands. The NPDES
program regulates point source discharges to the Waters of the US, the
infiltration of the wastewater to the groundwater does not fit the definition of the
point source discharge. The groundwater contamination is being regulated
under a separate program within DWR. The comprehensive impact of the facility
is being assessed by groundwater and instream monitoring.
Limits for thallium were established based on the results of the RPA. Data for the
water in the ash basin show reasonable potential for thallium. Data for the
interstitial water does not show reasonable potential.
The turbidity footnote will be updated to be consistent with other Duke permits.
• Permit doesn't impose sufficiently stringent Technology Based Effluent
Limitations. The ash pond discharge should have limits for cadmium, selenium,
mercury, silver and nickel. No justification for extended deadlines for meeting
Effluent Limitation Guidelines (ELG) compliance should be sooner.
Response: The EPA has recently conducted a comprehensive study of all waste
streams generated by the power plants and considered all potential pollutants of
concern. Based on the results of this study the EPA used all applicable rules and
regulations and produced an update to 40 CFR 423 in 2015. The EPA decided
that TBELs for all parameters of concern are not necessary because "Effluent
limits and monitoring for all pollutants of concern is not necessary to ensure that
the pollutants are adequately controlled because many of the pollutants originate
from similar sources, have similar treatability, and are removed by similar
mechanisms. Because of this, it may be sufficient to establish effluent limits for
one pollutant as a surrogate or indicator pollutant that ensures the removal of
other pollutants of concern." Therefore, the effluent guidelines have been
recently promulgated in there is no need for BPJ decisions.
Following RPA procedures limits were implemented for parameters that
demonstrated reasonable potential to exceed the water quality standards. RPA
included data for cadmium, selenium, mercury, silver, and nickel. Results show
no reasonable potential to exceed the standards for these parameters.
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The fact sheet was modified to include the justifications for the compliance dates
for ELGs.
• Permit violates groundwater rules. Standards violations at the compliance
boundary. Compliance boundary cant extend to the other side of the river.
Groundwater monitoring should comply with groundwater rules.
Response: According to 15A NCAC 02L .0106 (e), Any person conducting or
controlling an activity that is conducted under the authority of a permit initially issued
by the Department prior to December 30, 1983 pursuant to G.S. 143-215.1 or G.S.
130A-294, and that results in an increase in concentration of a substance in excess of the
standards at or beyond the compliance boundary specified in the permit, shall.... (4)
implement an approved corrective action plan for restoration of groundwater quality at
or beyond the compliance boundary, in accordance with a schedule established by the
Secretary.
This rule indicates current permits that exceed 02L standards have actions they
must take while still being permitted. This rule does not indicate these facilities
cannot continue to be permitted or must have additional conditions that address
violations; however, it does require for the facility to take corrective action. The
Coal Ash facility at the Rogers Energy Complex is in this process. In addition,
the CAMA directs each Coal Ash facility under 130A-309.211 to (a) provide a
groundwater assessment for any groundwater exceedances, and (b) provide a
corrective plan to address restoration of groundwater quality. Closure plans
must be submitted no later than December 31, 2019, which must include
...provisions for completion of activities to restore groundwater... according to 02L
requirements. Once classifications are finalized, each impoundment, depending
on their classification, will be closed under options provided by 130A-309.214.
According to 15A NCAC 02L.0107, individually permitted sites have a
compliance boundary established at a set horizontal distance from the waste
boundary (or the property boundary, whichever is closest to the source), the
distance depending whether the permit was permitted prior to December 30,
1983 or after December 30,1983. Thus the Compliance Boundary is established
by rule.
As for groundwater monitoring, Duke Energy continues to do extensive
groundwater monitoring, which DEQ approved under their Interim Monitoring
Plan.
• The permit is in violation of the removed substances provision.
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Response: The disposal of the coal ash in wet lagoons has been authorized by the
EPA in accordance with the CWA. New -federal regulations will gradually phase
out the use of coal ash lagoons. The permit does not allow the discharge of coal
ash from any of the outfalls.
• Thermal mixing zone requires thermal variance.
Response: The footnote addressing the thermal mixing zone was removed from
the permit as it's no longer applicable.
The following is a summary of comments received from Clean Water for North
Carolina:
• New seeps - don't permit seeps, use enforcement action. If seeps are permitted
monitor twice monthly. Permit must be reopened if permitting more discharges
are discovered (seeps).
Response: § 130A-309.210 of CAMA requires owners of coal combustion
residuals surface impoundments to identify and assess all discharges from the
impoundments and to implement corrective action to prevent unpermitted
discharges from the impoundments to the surface waters of the state.
Identification of discharges includes engineered channels designed or improved
for the purpose of collecting water from the toe of the impoundment (toe drains),
as well as non -engineered seeps and weeps. One method of proposed corrective
action allowed under the Act is to make application for a NPDES permit
amendment to bring the unpermitted discharge under permit regulations. A
Discharge Assessment Plan for the unpermitted discharges at the Rogers Energy
Complex was submitted by Duke Energy to the Department on September 30,
2014. Under the permit, the seeps would be monitored and subject to applicable
effluent limits which would ensure that seep discharges would not result in
unacceptable impacts to surface waters. Incorporation of the seeps in to the
NPDES permit is considered an interim measure until the coal ash
impoundments are closed. The draft permit requires that the facility continue to
implement a plan for the identification of new seeps. A seep identification
survey shall be conducted semi-annually and new seeps are to be reported to the
Division within five days of detection.
The monitoring requirements in the permit are based on state and federal rules,
regulations, and poficies. The established frequency is sufficient to conduct a
valid statistical analysis of the effluent data.
The permit does not authorize unidentified seeps in advance, if the new seeps
are found, Duke Energy shall apply for a permit modification and the permit will
14

be re -opened, the modified permit will be publically noticed and open for
comments from all interested parties. The permit language will be modified to
make this DEQ position more clear.
Thermal discharges - thermal mixing zone fails to protect downstream aquatic
life.
Response: The footnote addressing the thermal mixing zone was removed from
the permit as it's no longer applicable.
Decanting/ dewatering and effluent monitoring/ limits - keep the limit for
thallium during decanting. Conduct, monitoring weekly for both dewatering and
decanting. There must be clear provisions and independent oversight to
determine impacts of drawdown rates of the ash pond.
Response: Limits for thallium were established based on the results of the RPA.
Data for the water in the ash basin show reasonable potential for thallium. Data
for the interstitial water does not show reasonable potential.
Include deadline for construction of emergency basins, require toxicity testing at
each event that requires the use of the emergency overflow.
Response: Duke is working on several comprehensive projects at multiple
facilities. The schedules for construction will be planned with the scope of the
projects. Schedule of compliance are not included in permits for the construction
of new treatment units. Toxicity testing is required for every discharge event.
Define the locations for turbidity upstream background samples with a
respectable range of the discharge outfalls.
Response: The upstream sampling locations as implemented in the permit are
above the influence of the discharge.
Copies of the comment letters are attached to this report.
III. Recommendations
Based on the review of the public record, written and oral public comments, the
North Carolina General Statutes and Administrative Code, the Coal Ash
Management Act of 2014, the site visit and discussions with other DWR staff, I
recommend to the Division Director that the draft NPDES permit for the Rogers
Energy Complex be modified and issued with the following minor changes:
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1. Remove temperature mixing zone footnote in Condition A. (1)
2. Revise fact sheet to include the justification for the schedule of compliance with
the new ELGs.
3. Clarify permit,to indicate that the FGD treatment system will not discharge into
the new wastewater treatment system but will be combined with the treatment
system effluent before discharging to the Broad River.
4. Update turbidity footnote to be consistent with other Duke permits.
IV. Attachments
A. NPDES Application
B. Draft Permit and Fact Sheet
C. Comments Received During Public Comment Period
D. Public Hearing Transcript, Including Oral Comments
E. Notice of Public Hearing
F. Speaker Sign -in Sheets
G. Non -speaker Sign -in Sheets
IR