NC0024392_Draft Permit Comments_20150706

eo(•) DUKE Duke Energy
ENERGY. McGuire Nuclear Station
12700 Halters Ferry Road
Huntersville,NC 28078
June 29, 2015
Ms. Teresa Rodriguez, Environmental Engineer
NPDES Complex Permitting Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617 RECEIVED/DENR/DWR
Subject: McGuire Nuclear Station JUL 0 6 2015
NPDES Permit No. NC0024392
Mecklenburg County Perm fling ual ter tion
ty
Certified Mail: 7010 2780 0000 7412 4267
Dear Ms. Rodriguez:
In accordance with your letter dated June 3, 2015, Duke Energy staff have reviewed the
proposed draft permit and the accompanying Fact Sheet and offer the following comments in
response to your bulleted changes:
• Federal effluent guidelines in 40 CFR 423.12 specify free available chlorine limits for once
through cooling waters. To conform to these guidelines total residual chlorine was modified to
free available chlorine for outfall 001.
Comment:
Duke Energy agrees with this approach.
• The emergency discharge of turbine building sumps was added to the wastewaters authorized
for discharge at outfall 005.
Comment:
Duke Energy agrees with this approach.
• A monthly average limit of 0.24 ug/L for Total Thallium was added to outfall 001. Thallium
was detected in the priority pollutant scan at a concentration greater than the concentration
specified in the steam electric effluent guidelines.
Comment:
Duke Energy does not agree with this approach and believes both monitoring and the limit for
Total Thallium should be removed for several reasons:
1. Duke Energy does not believe that one sample or single data point from the priority
pollutant analysis is sufficient information to justify imposition of either monitoring or an
effluent limit.

2. Depending on methodology, there are known interference issues that could cause false
elevated concentrations for Thallium. A thorough and complete outfall 001 Thallium
analytical study should be completed prior to the issuance of an effluent limit.
3. The values reported on Form 2C for Outfall 001 are below the PQL (practical quantitation
limits)for method 200.8 for Thallium, therefore should not be used as the basis for
instituting an effluent limit.
4. Establishing a discharge limit below the PQL does not seem appropriate due to the
inherent difficulty in obtaining accurate results.
5. Based upon our review of the NC Water Quality Standards, there is no established
numerical standard for Thallium.
• As a result of a Reasonable Potential Analysis monitoring for sulfide(should be sulfate)was
eliminated from the effluent monitoring requirements for outfall 002. DMR data shows that
this parameter does not have reasonable potential to exceed the action level standards.
Comment:
Duke Energy appreciates your consideration and agrees with this approach. It should be
noted and corrected in the Permit Cover Letter, Fact Sheet and Reasonable Potential Analysis
that the parameter being evaluated for removal is sulfate and not sulfide.
• Total residual chlorine monitoring frequency for outfall 002 shall be monthly. Chlorine is used
in the water treatment plant process which produces a backwash wastestream routinely
discharged to outfall 002. As there is no monitoring data for chlorine for outfall 002 the
Division is implementing monthly monitoring to evaluate the need for a TRC limit.
Comment:
Duke Energy appreciates your consideration and agrees with this approach.
• The Division approved Duke Energy's request for an alternative schedule to submit 316(b)
application requirements. See special condition A. (22).
Comment:
Duke Energy appreciates your consideration and agrees with this approach.
• A special condition was added to the draft permit to address the Environmental Protection
Agency's (EPA's) pending requirement for permittees to provide electronically submitted
Discharge Monitoring Reports (eDMRs). The Division intends to fully implement the eDMR
program as soon as practical. See Condition A. (23).
Comment:
Duke Energy is agrees with this approach.
• Our review also identified several other items for which we would like to offer the following
comments:
1. On item 3 of the"Supplement to Permit Cover Sheet", the current reference to the two 2.5
MG settling ponds should be corrected to reflect"(both with HDPE liners)"as opposed to"(1
with HDPE line, 1 clay-lined)".

2. For outfall 001, should references to "total residual chlorine" in Note 5 be eliminated since
the parameter is being converted to"free available chlorine"?
3. For outfall 004, pH monitoring and a limit of 6.0—9.0 was added. Duke Energy would like to
request that the pH monitoring and limit be applied to outfall 001 and remove pH monitoring
and limits from outfall 004 since outfall 004 is an internal outfall to outfall 001.
4. For outfall 005, a limit of 6.0—9.0 was added where the parameter was previously only
monitored. Outfall 005 includes several inputs but is dominated by site stormwater flows.
This outfall is a designated outfall for the McGuire individual stormwater permit
(NCS000020)as outfall 001. Due to the variability of inputs, and challenges for any
necessary pH controls at this outfall, Duke Energy requests that only monthly pH monitoring
be required for an initial two year period. This two year period would enable us to conduct a
treatment evaluation, and if appropriate, determine appropriate pH controls for this outfall.
If the Division believes that monitoring and/or an effluent limit for Thallium is necessary, or pH
limits for Outfalls 004 and 005 are required, Duke Energy would appreciate the opportunity to
meet with you and other appropriate staff to discuss this matter.
If you have any questions or wish to discuss this matter further, please do not hesitate to
contact Mr. John Williamson, McGuire Nuclear Station Environmental Coordinator at(980) 875-
5894.
I certify, under penalty of law, that this document and all attachments were prepared under my
direct supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based upon my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate,
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations.
Sincerel4O7w
Steven D. Capps
Duke Energy, McGuire Nuclear Station
Site Vice President
cc: Mr. John Williamson, Environmental Coordinator, McGuire Nuclear Station
Mr. Don Safrit, Senior Environmental Specialist, Permitting and Compliance, Carolinas