NC0000396_Permit Modification 2004_20040510

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Progress Energy
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CERTIFIED MAIL 7003 1680 0002 1069 8380
File No.: 12520A Date: May 10, 2004
Ms. Susan Wilson O V
North Carolina Department of Environment and Natural Resources
Division of Water Quality
1617 Mail Service Center 3
Raleigh, NC 27699-1617 �`( ,
vN`-`c�
Subject: Progress Energy Carolinas, Inc. (PEC) var"
Asheville Steam Electric Plant ,0041: 00'
NPDES Permit No. NC0000396
NPDES Permit Modification - Flue Gas Desulfurization A : ewater
Dear Ms. Wilson:
As was discussed and emailed to you on March 17, 2004, by Louise England of Progress
Energy Carolinas, Inc., enclosed is an amendment to the NPDES permit application for
Asheville Steam Electric Plant. Previously water from the ash pond was to be used as chloride
dilution water. Because the additional metals loading from the ash pond water would have
required a much larger constructed wetland, the decision has been made to use water from
Lake Julian as chloride dilution water. Water from Lake Julian will be combined with the
clarified FGD water prior to entering an equalization basin. The discharge of the equalization
basin is routed through the wetland and is then combined with ash pond effluent and discharged
to the French Broad River via Outfall 001. Enclosed is a table with expected concentrations of
parameters in the scrubber wastewater and revised Attachments 2 and 3 of the NPDES permit
application.
If you have any questions regarding any information in this submittal please call Louise England
at [phone].
1 certify, under penalty of law, that this document and all attachments were prepared under my direction
or supervision in accordance with a system designed to assure that qualified personnel properly gather
and evaluate the information submitted. Based on 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. l am aware that there are
significant penalties for submitting false information, including the possibility of fines and imprisonment for
knowing violations.
Sincerely,
William A. Phipps
Plant Manager—Asheville Plant
Progress Energy Carolinas,Inc.
Asheville Steam Plant
200 CP&L Drive
Arden,NC 28704

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Progress Energy Carolinas, Inc
Asheville Steam Electric Plant
FGD Blowdown Estimated Concentrations
The flowrate of the FGD blowdown will be approximately 0.108 MGD. The flowrate of
the dilution water will be approximately 0.432 MGD
Parameter Estimated FGD Blowdown
Concentration (ppm)
Antimony 0.080
Arsenic 0.058
Barium 2.185
Beryllium 0.002
Boron 0.283
Cadmium 0.007
Chloride 20,000
Chromium 0.073
Cobalt 0.075
Copper 0.059
Fluoride 12.0
Lead __ 0.092
Manganese 11.654
Mercury 0.027
Molybdenum 0.015
Nickel 0.433
Selenium 3.654
Silver 0.007
Sulfate 7,098
Thallium 0.055
Vanadium 0.052
Zinc 3.149

French Broad > Make-Up
River Water Intake Stormwater Old Ash Pond
VFlue
D Settling X ) Desulfurization V > Clarifier . > n
Eq ualiaA
Zone
B Y
—
IUnits 1 &2 S Lake Julian
Condensers A Outfall 002
Lake
NIntake
Julian Structure _� Circulating Water F—)11' Ash Sump
_ to Heat Exchanger
A I Y
l___U Diesel T
Fire > Fire Preheater Ash Evaporation
Pump Protection Cleaning Sluice in Boilers
System Water Water TL
Chemical Metal
Service Water Vendor supplied Q R Cleaning Waste V
A — water treatment G Constructed
Wetland
I
r y
Combustion M > E I Z
Turbine Site
New
> Low Volume E > Ash Pond Secondary French Broad
Waste Sources > Settling River
A A Basin A Outfall 001
Storm Water J H
K
1 Dam Seepage
Coal Pile
Public Potable and C Public Runoff Attachment 2-form 2C-Item IIA Flows,Sources of
Water ) Sanitary > Sewage Pollution.and Treatment Technolooies
Supply System System Progress Energy Carolinas,Inc.
Asheville Steam Electric Plant
Buncombe County Page 1 of 2

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Progress Energy Carolinas, Inc.
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NCOO00396
Attachment 2
Form 2C - Item Il-A Flow, Sources of Pollution, and Treatment Technologies
Stream Name Average Flow Comments
A Ash Pond Discharge 3.10 MGD Outfall 001
B Intake to Once-through Cooling&Circulating 250.1 MGD
Water to Heat Exchangers
C Plant Potable and Sanitary Uses 0.002 MGD To POTW
D Makeup to Lake from River 7500 gpm Maximum Flow
E Low Volume Wastes
• Ash Hopper Seals 0.05 MGD
• Sandbed Filter Backwash 2600 Gal/event Rare Usage
• Water Softener Regeneration and Washing 3100 Gal/event Rare Usage
• Boiler Blowdown 0.006 MGD Startup-Estimated
F Circulating Water from Heat Exchangers 19.3 MGD Estimated
G Ash Sluice Water 2.0 MGD Estimated
H Dam Seepage 0.09 MGD Calculated
I City Water Supply to Boiler Makeup 0 MGD Rare Usage
J Coal Pile Runoff 0.01 MGD Based on Average Annual
Rainfall of 47"and 50%Runoff
K Storm Water 0.052 MGD Estimated
L Chemical Metal Cleaning Wastes 0-90,000 Gallons Normal Practice is Evaporation
(0 gallons anticipated)
M Water From Combustion Turbine Facility 0-0.02 MGD Intermittent
Operation
N From Lake to Intake 250.15 MGD Estimated
O Intake to Service Water 0.05 MGD Estimated
Q Fire Protection Water 0.010 MGD Estimated
R Air Preheater Cleaning 10,000 gallons/event Estimated
S Discharge to Lake Julian 248.4 MGD Outfall 002-Estimated
T Emergency Fire Protection Water 0 Used for fire fighting
U Diesel Fire Pump to Lake Julian 0.128 MG/week Estimate-pump testing
✓ Flue Gas Desulfurization Blowdown 0.108 MGD Estimated
X Intake to FGD system 0.864 MGD Estimated
Y Chloride Dilution Water 0.432 MGD Estimated
Z Constructed Wetland Discharge 0.54 MGD Estimated
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Carolina Power & Light Company
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NC0000396
Attachment 3
Form 2C - Item Il-B Flow, Sources of Pollution, and Treatment Technologies
The Asheville Steam Electric Plant is located in Arden, North Carolina south of Asheville, North
Carolina. The Asheville Steam Electric Plant is a coal-fired, steam cycle electric generating
plant with two generating units. Two Internal Combustion (IC) Turbines are also located on the
plant site. The plant has a 320-acre cooling lake (Lake Julian) on the east side of the French
Broad River in Buncombe County, North Carolina.
Chemical constituents contained in the discharges from this plant will, in part be representative
of the naturally occurring chemical quality of the intake water and will also have chemical
constituents of such quality and quantity associated with similar discharges for fossil generating
facilities of this size, type and in this geographical location. Either all or part of the elements
listed on the Periodic Table, either singularly or in any combination, may from time to time be
contained in the discharge.
Outfall 001 - Discharge from Ash Pond to French Broad River
The Plant's ash pond, which is located east of the French Broad River and south of the plant,
discharges into the French Broad River. The ash pond receives ash sluice water, low volume
wastes, coal pile runoff, air preheater cleaning water, fire protection system drainage, chemical
metal cleaning wastes (potentially), storm water and other waters from the Combustion Turbine
Facility constructed on the Plant's site. The proposed wheel wash and weigh stations will also
discharge to the Ash Pond. The Pond provides treatment by sedimentation and neutralization
to the above-referenced individual waste streams. Water leaves the ash pond via a standpipe
with skimmer and flows by pipe and lined ditch to a secondary basin, where it is discharged by
overflow to a ditch that coveys it to the French Broad River. Detailed descriptions of the
individual waste streams are below.
Ash Sluice Water
Fly ash and bottom ash from both units are hydraulically conveyed by an ash sluice pipeline to
the ash pond. An Amine Enhanced Fuel Lean Gas Reburn (AEFLGR) process will be installed
on Unit 1 in the spring of 2000. This process utilizes urea to reduce NOx emissions and will be
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Carolina Power& Light Company
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NC0000396
used in high ozone months (approximately May through September). A byproduct of this
process is ammonia which will be carried to the ash pond via ash sluice water.
Coal Pile Runoff
Storm water runoff from the coal pile is collected in drainage ditches that surround the coal pile.
The drainage ditches are routed to the ash pond for treatment. During maintenance activities,
sludges removed from catch basins, sumps, etc. may be transported to the old and/or the new
ash pond for disposal.
Storm Water
Storm water runoff from the plant area, parking lots, combustion turbine area, oil storage and
handling facility and the plant's 115 KV substation is routed to the ash pond for treatment.
During maintenance activities, sludges removed from catch basins, sumps, etc. may be
transported to the old and/or the new ash pond for disposal.
Low Volume Wastes
Boiler water make up is withdrawn from Lake Julian and purified utilizing vendor supplied
equipment. A second option is to perform these activities using plant equipment to filter, soften,
and evaporate make up water with the filter backwash, softener regeneration, and softener
rinses discharged to the ash pond. The water softeners are regenerated using salt. Boiler
water is treated with ammonia, hydrazine, and sodium hydroxide. Boiler and evaporator
blowdown and drainage is sent to the ash pond and may contain small quantities of the
chemicals. Some molybdate waste from the closed cooling water system is created through
valve leakage and maintenance activities and is discharged to the ash pond. A furnace ash
hopper seal is maintained by using plant service water. A standard operation water level is
maintained in a seal trough for the ash hopper seal. Overflow from this trough is discharged to
the ash pond. A sodium hydroxide solution is fed into this flow stream as necessary for ash
pond pH adjustment. Coal dust suppression is achieved by spraying a proprietary chemical on
coal at different stages of coal use. Small amounts of excess dust suppression chemical have
the potential to be discharged to the ash pond via plant drains or coal pile runoff. Small
amounts of urea waste from bulk urea unloading operations are discharged to the ash pond.
All plant area floor drains are routed to the ash pond and include equipment drainage and wash
down along with rainfall runoff. During maintenance activities, sludges removed from catch
basins, sumps, etc. may be transported to the old and/or the new ash pond for disposal.
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Carolina Power & Light Company
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NC0000396
In many cases, added chemicals are consumed or chemically altered during the plant
processes. Only trace amounts might be recoverable in water entering the ash pond.
Detectable levels of these chemicals would not be expected to occur in ash pond discharges.
Flue Gas Desulfurization Blowdown (Low Volume Waste)
The Flue Gas Desulfurization (FGD) system directs flue gas into an absorber where a limestone
(calcium carbonate) slurry is sprayed. Sulfur dioxide in the flue gas reacts with the limestone to
produce calcium sulfate (gypsum). This system reclaims any unreacted limestone slurry to be
reused in the absorber. A small blowdown stream is used to maintain the chloride
concentration in the reaction tank. The blowdown stream is passed through a clarifier to
remove solids and the chloride concentration in the waste stream is diluted using water from
Lake Julian. A constructed wetland is used to remove metals, mercury and selenium
specifically, and the treated wastewater is discharged into the secondary settling pond.
Air Preheater Cleaning (Low Volume Waste)
After the Amine Enhanced Fuel Lean Gas Reburn (AEFLGR) system is operational, the air
preheater will be water washed on a more frequent basis. It is expected to require cleaning
once per year or more frequently as needed. The wastewater from this activity will be
discharged to the ash pond.
Chemical Metal Cleaning Wastes
The boilers are chemically cleaned every five-to-eight years using a weak citric acid solution.
This cleaning solution and its rinses are stored on site for disposal by evaporation in an
operating unit's furnace. Typical cleanings would result in a waste of approximately 80,000
gallons. Should evaporation not be used, the waste can be routed to a treatment basin for
neutralization and precipitation prior to being conveyed to the old ash pond with permission of
the DWQ, to the newer ash pond, or other means of disposal. Cleaning of other heat
exchanger surfaces may produce 5,000-10,000 gallons every three-to-five years.
Other Wastes
Operation of the combustion turbine (CT) generation facility may produce turbine blade wash
water, inlet filter cooling water, various condensate waters, and water from equipment and tank
drains. These wastewaters will be collected in the storm water collection system of the CT site
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Carolina Power& Light Company
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NC0000396
and routed to the ash pond. During maintenance activities, sludges removed from catch
basins, sumps, etc. may be transported to the old and/or the new ash pond for disposal.
- Plant Potable and Sanitary System -
The supply of water for plant potable and sanitary use is obtained from the Asheville/Buncombe
Water Authority system and waste from this system is discharged to the Metropolitan Sewage
District System.
- 230 KV Substation Storm Water-
Storm water runoff from the substation located adjacent to the plant is conveyed to the old ash
pond.
Outfall 002 - Discharge to Lake Julian
Once-Through Cooling Water
This flow provides condenser cooling water for the generating units 1 and 2. Maximum
condenser flows for units 1 and 2 are 124 MGD and 162 MGD, respectively.
Once-through cooling water is used to supply non-contact cooling water for the component
closed cooling water system. The component closed cooling water system flows combine with
unit 1 and 2 condenser flows prior to discharge to Lake Julian. Maximum component closed
cooling water system flows for unit 1 and 2 are 9.1 MGD and 10.2 MGD, respectively.
Discharge flow to Lake Julian is calculated at the intake to units1 and 2 condensers and to the
circulating water to the heat exchanger. The discharge of water from the heat exchangers is
routed to an ash sump. The majority of this water is further routed to the discharge of units 1
and 2 condensers. Less than one per cent of the flow to the ash sump is used to supply ash
sluice water, preheater cleaning water, and fire protection water.
Control of biological fouling on heat-exchanger surfaces is accomplished by addition of sodium
hypochlorite as required, which is usually less that 2 hours per day per unit, with a net total
residual chlorine of less than 0.2 ppm discharged during that period. Cooling is accomplished
by evaporation from the surface of Lake Julian and mixing and convection with lake waters.
Make up for Lake Julian is from the French Broad River, natural runoff and creek flows. Water
is pumped from the French Broad River during dry periods to supplement the flow. Although
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Carolina Power& Light Company
Asheville Steam Electric Plant
National Pollutant Discharge Elimination System Permit Number NC0000396
discharge from Lake Julian to the river is extremely rare, any occurrence would be during
periods of heavy rainfall.
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