NC0004979_Major Modification_20191113

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
NORTH CAROLINA
Environmental Quality
November 13, 2019
Mr. Paul Draovitch, Senior Vice President
Environmental, Health and Safety
Duke Energy Progress, LLC
Mail Code EC 13K
P.O. Box 1006
Charlotte, North Carolina 28201-1006
Subject: Draft NPDES Major Modification
Permit NC0004979
Allen Steam Station
Gaston County
Facility Class I
Dear Mr. Draovitch:
The Division has received your request to extend the compliance schedule
for FGD wastewater from 02 / 28/ 2020 to 11 / 01 / 2020 due to the latest EPA
changes to 40 CFR 423. The request has been granted. Enclosed with this letter is
1 page that includes necessary modification. Please review this page to ensure
thorough understanding of the conditions and requirements it contains.
The draft permit modification contains the following significant changes
from your current permit:
• The FGD compliance date has been extended until 11 / 01 / 2020.
Please provide any comments you have regarding the draft permit to this
office by December 13, 2019. At this time, the Division is also publishing a notice
in the newspapers of general circulation in Gaston County, inviting public comment
on the Draft Modification. Following the 30-day comment period, we will review all
pertinent comments received and take appropriate action on the permit
modification.
�D_EQ,
1%.r
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11617Mail Service Center I Raleigh, North Carolina 27699-1617
919.70T 3601

If you have any questions about the NPDES permit process, please contact
me at the following e-mail address: sergei.chernikovnncdenr.gov, or telephone
number: 919-707-3606.
Sincerely,
4rgeiChernikov, Ph.D.
Environmental Engineer III
Complex NPDES Permitting Unit
cc: Central Files
NPDES Files
EPA Region IV (e-copy)
Mooresville Regional Office/Water Quality (e-copy)
Mooresville Regional Office/PWS (e-copy)
WSS/Aquatic Toxicology Unit (e-copy)
Page 2 of 2

Permit NC0004979
A. (8.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Internal Outfall 005)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until permit expiration, the Permittee is
authorized to discharge from internal outfall 005- treated FGD wet scrubber wastewater to ash settling basin.
Such discharges shall be limited and monitored2 by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Fre uenc
Sample
Type
Sample
Location'
Flow, MGD
Monitor & Report
Monthly
Pump logs or
similar
readings
Effluent
Total Arsenic
8.0 µg/L4
11.0 µg/1_4
Quarterly
Grab
Effluent
Total Mercury3, ng/L
356.0 ng/L4
788.0 ng/L4
Quarterly
Grab
Effluent
Total Selenium
12.0 µg/1,4
23.0 µg/1,4
Quarterly
Grab
Effluent
Nitrate/nitrite as N
4.4 mg/L4
17.0 mg/L4
Quarterly
Grab
Effluent
pH
Monthly
Grab
Effluent
Footnotes:
1. "Effluent" shall be defined as the discharge from the FGD wastewater treatment system prior to commingling
with other waste streams.
2. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR
application system. Please See Special Condition A. (26.).
3. The facility shall use method 1631E.
4. In accord with the Steam Electric Effluent Limitations Guidelines for FGD wastewater (40 C.F.R.
423), these limits shall become effective on November 1, 2020. This permit may be reopened and
modified if changes are made to 40 C.F.R. 423.
This permit shall be reopened and modified to reflect any changes in the 40 CFR 423.
All flows shall be reported on monthly DMRs. If no flow occurs during a given month, the words "no
flow" shall be clearly written on the front of the DMR. All samples shall be of a representative discharge.
The facility shall operate the FGD treatment system until all coal-fired units are retired.
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