NCS000554_Buck CTCC Staff Report_20120130

North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H Sullins Dee Freeman
Governor Director Secretary
STAFF REVIEW AND EVALUATION
NPDES Stormwater Permit
Facility Name.
NPDES Permit Number
Facility Location.
Type of Activity:
SIC Code (if applicable).
Receiving Streams.
River Basin-
Stream Classification
Proposed Permit Requirements
Monitoring Data.
Response Requested by (Date).
Central Office Staff Contact:
Duke Energy Carolinas, LLC - Buck Combustion Turbine Combined
Cycle Station (CTCC)
NCS000554
1385 Dukeville Road, Salisbury, NC (Rowan County)
Combustion Turbine Combined Cycle (CTCC) Electric Generation
(Natural Gas Fired)
4911
See Figure 1- Yadkin River (High Rock Lake)
Yadkin River Basin, Sub -basin 03 -07 -04
WS -V t` 1 . = h; ' ,'Y
See attached draft permit
See Table 1
January 30, 2012
Return to: Bethany Georgoulias, (919) 807 -6372
Description of Onsite Activities:
Buck Combustion Turbine Combined Cycle (CTCC) Station will be a new 620 MW natural gas -fired
CTCC electric generation station This site is being constructed at the same property as the
currently operating Buck Steam Station (coal -fired power plant) but will be an independent operation
The Buck CTCC Station is scheduled to begin operating in December 2011
Water treatment and maintenance chemicals will be stored on site The Buck CTCC will have one
stormwater outfall (SW001) from a detention pond that drains approximately 14 acres (12 acres
impervious).
Documents Reviewed:
• NPDES Stormwater Permit Application Materials (EPA Forms 1 & 2F)
• National Heritage Program (NHP) Threatened and Endangered Species Database
• 303(d) List (2010 Assessment)
• 2008 Yadkin Basinwide Plan
Pagel of S

NCS000554
Figure 1: Map of Facility
Page 2 of 5
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Page 2 of 5

NC§000554
Central Office Review Summary:
Owner's Other Permits.
•
NP ES Wastewater Permit NCO04774 (discharge to Buck Steam Station ash settling basin)
• Air Permit TV037886T27
• RCRA Hazardous Waste Permit NCD043678929
2 Industrial Materials and Potential Stormwater Contaminants on Site,
• Most chemical storage, if exposed, will be located within concrete containments
• All transformer containments discharge to the oil /water separator (wastewater discharge)
• All open containments (including tanker unloading stations) discharge directly to consolidated
wastewater sump Most covered containments will be non - discharge containments
• Lube oils, diesel fuel, and mineral oil will be present at the site.
• Ammonia will be stored at the site (20,000 gal tank on western side of facility, inside
containment draining to sump; 300 gal tank inside Steam Turbine Building).
• Raw Water Treatment facility chemicals stored under common shed inside containment.
Chemicals include sodium hypochlorite, ferric sulfate, and caustic.
• Cooling Tower has adjacent chemical feed skid with chemical storage under shed, unloading pad
is sloped and curbed, and drains to sump. Chemicals include sodium hypochlorite, dispersant,
micro biocide, and general water treatment (not specified)
3 Impairments and Basinwide Plan (2008) Recommendations This segment of the Yadkin River (Upper
portion of High Rock Lake) is impaired for copper, turbidity, chorophyll a and low pH (excessive -
nutrients driven). Just downstream of the proposed discharge, the Yadkin River /High Rock Lake is
impaired for turbidity and chlor a The Division has initiated TMDL development for High Rock Lake.
The current Basinwide Plan recommends continued support for Best Management Practices (BMPs)
implementation, sediment and erosion control local programs, and local stormwater control ordinances
This draft permit does not propose nutrient monitoring because this project's built -upon area was subject
to post - construction BMP requirements and because potential industrial sources are minimal
4 Threatened and Endangered Species- No aquatic species identified in the vicinity of this site (NHP Virtual
Workroom, accessed December 21, 2011)
5 Location. This facility is located on the same property as the Buck Steam Station coal -fired power plant
that will be shutting down. The stormwater drainage area is confined to the industrial operations at the
CTCC plant The Buck CTCC is approximately 2,000 feet south and upland of the older Buck Steam Station,
the plant is also situated northwest of the ash settling basin See site plan and maps for more details
Page 3 of 5

Permit Recommendations:
Analytical Monitoring:
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1. The draft permit proposes total suspended solids (TSS) monitoring because (1) this conventional
pollutant indicates changes in the effectiveness of the detention pond BMP, (2) TSS is a standard potential
pollutant from industrial activities; and (3) turbidity is a parameter of concern for this part of the Yadkin
River /High Rock Lake (see impairment information).
2 The draft permit proposes pH monitoring because of the nature of several chemicals stored on -site
(caustic, acids, etc.) pH is a standard parameter in industrial stormwater permits with analytical
monitoring because it is a rapid indicator of acidic or alkaline contaminants and because pH is important
to interpreting the toxicity of other data
3 The draft permit proposes "Non -polar Oil and Grease" /Total Petroleum Hydrocarbons (TPH) [EPA
Method 1664 (SGT -HEM)] monitoring because of the Tube oil, mineral oil, and diesel fuel stored on site
This method is not the same as the more expensive GC analyses commonly used to measure "TPH," and
isolates petroleum -based oils, rather than also capturing vegetable -based oils or animal fats, which would
not be expected here Even though some diesel fuel may be lost in the solvent extraction step of Method
1664 (SGT -HEM), the quantity of diesel in the emergency generator is smaller than the other oils and
confined to the doubled - walled container inside it.
4. There is a significant storage of ammonia at this facility; however, this draft permit does not propose
ammonia or nitrite /nitrate monitoring (potential indicators for ammonia contamination) because of the
protections in place to prevent stormwater exposure. Any spills from the 20,000 gallon tank outside or
smaller tank inside the Steam Turbine Building would route to the wastewater sump or oil /water
separator, respectively, and then go to the ash settling basin (discharge permitted under a separate
NPDES wastewater permit) A Stormwater Management Plan and proper BMPs should provide adequate
measures at this brand new facility to readily identify any problems and prevent ammonia from being
discharged in the stormwater
Permittee contact: Mark McGary with Duke Energy, (704) 634 -7098
Page 4 of 5

•NCS000554
Recommendations: Based on the documents reviewed, the application information submitted on September 22,
2011 is sufficient to issue an Individual Stormwater Permit
Prepared by (Signature) Date 12- 3 O 20
Stormwater Permitting Unit Supervis , Date Z 3a 2p �/
for Bradley
it -n
Concurrence by Regional
RO Water Quality Supervisor Date
Regional Office Staff Comments (attach additional pages as necessary)
Page 5 of 5

To: Bethany Georgoulias
From: Rob Krebs W�t 1716
Prepared By. Michael Parke d))o
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January 30, 2012
NCS000554 Duke Energy Carolinas, LLC - Buck Steam Station
Rowan County
Site inspection conducted on April 15, 2011, by Michael Parker. Facility contact: Mr. Mark McGary
(704) 634 -7098 (cell) and Mr. Steve Jones, Plant Manager. This request is for a new SW permit. This
facility is in the business of producing electricity via Combustion Turbine Combined Cycle (CTCC)
generation. The SW outfall for this facility eventually drains to the Yadkin River, which is currently
classified as WS -V and is listed as impaired for copper, turbidity, chlorophyll a, and low pH. A
TMDL is being developed for High Rock Lake, which begins dust below the proposed point of
discharge.
Duke Energy intentionally designed the new Buck CTCC to have minimal SW outfalls and minimize
the amount of exposure to areas that are associated with the industrial processes. The Buck CTCC
plant shares the site with the Buck Steam Station (NC0004774), but the Buck Steam Station is slated to
be closed in 2015. The area surrounding the new Buck CTCC plant is primarily wash stone with
paved access roads transecting the site The entire Buck CTCC site encompasses approximately 14
acres SW and wastewater flows not sent to the site's ash basin (see list below) will be routed to an
existing SW detention pond where settling will occur prior to being released to the Yadkin River. All
chemical and oil handling areas are provided with some means of secondary containment At this
time, the only SW that will be directed to the detention pond will be roof drains and external paved
parking areas.
The construction of the Buck CTCC units will introduce several new waste streams to the facilities
NPDES wastewater permit (NC0004774). The new waste streams that will be directed to the facilities
ash basin (outfall 002) for final treatment include:
• Service water - Make -up water from the Yadkin that is treated by on -site water treatment
facilities.
• Boiler Make -up water /Condensate - Chemical additions are added such as de- scalers and pH
control
• Condenser Cooling Water - Water used to supply the cooling towers.
• Chiller Cooling Towers
• HRSG and Auxiliary Boiler Blow Down
• Closed Loop Cooling System
• Sanitary Waste Treatment System - Sanitary wastewater from the employees will be pumped
to a package type WWTP with disinfection. Effluent from this facility will be routed to the ash
basins.
• Plant Drainage System - Yard and floor drains are routed through an oil /water separator and
eventually into the plant's ash basins.

Page Two
In summary, Duke Energy has gone to great measures to minimize the potential for SW to come into
contact with the chemicals and storage facilities found in the industrial process areas at the new Buck
CTCC facility The site's SW detention pond will further assist in pollutant removal and compliance
with the proposed benchmark values. Such being the case, this Office recommends issuance of the
subject permit.
/mlp