Final Notes from Site Visit at 

Western Kentucky Energy’s Kenneth C. Coleman Station 

on February 23, 2009 

EPA conducted a site visit at Western Kentucky Energy’s Kenneth C. Coleman Station 

(Coleman) located in Hawesville, Kentucky on February 23, 2009 to learn about the operations 

at the plant, specifically the FGD wastewater handling system. Table 1, located at the end of 

these notes, identifies the site visit participants. 

These notes describe the information collected during the site visit and the pre-site visit phone 

call, which was held on February 11, 2009. 

Plant Overview 

• Coleman operates three coal-fired generating units at the power plant, with a 

gross generating capacity of 485 MW. The table below contains some general 

information for the three generating units. 

Unit 

Installation 

Date 

Gross 

Capacity 

(MW) 

Particulate 

Control NOx Control SO2 Control 

1 1969 160 ESP (cold-side) Low NOx burner 

2 1970 160 ESP (cold-side) Low NOx burner 

3 1972 165 ESP (cold-side) Low NOx burner 

Single wet FGD 

system services all 

three units 

• Coleman was originally sited for the operation of four generating units; however, 

only three units were built. An aluminum smelting plant located nearby uses 

approximately 75% of Coleman’s generating output. 

• Coleman does not operate SCRs or SNCRs on any of the generating units. 

• Coleman currently has 107 employees, of which nine are associated with the 

operation of the FGD system. 

• Coleman burns approximately 1.4 million tons of coal per year. The plant was 

originally constrained to burn low sulfur coal; however, with the installation of 

the FGD system, the plant also installed a blending system to allow use of high 

sulfur coal as well. 

• Coleman currently uses three suppliers of Illinois basin bituminous coal. Coal is 

received by barge, although the plant is also equipped to receive coal via truck. 

• Coleman currently stores approximately 25 days of coal on site. 

• The sulfur content of the coal used at Coleman is typically 5.2 lbs SO2/MBTU. 

• The coal pile runoff is collected in a runoff pond designed to hold up to a 10-year, 

24-hour storm event (4.64”). From the coal pile runoff pond, the wastewater is 

pumped to the ash pond system. 
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• Coleman recently cleaned out the coal pile runoff pond and installed limestone 

gravel to control the pH in the pond. 

• Prior to the site visit, Coleman personnel collected samples from the coal pile 

runoff pond and measured the pH. The table below presents the results of the 

measurements. 

Date pH (S.U.) 

2/12/2009 7.63 

2/18/2009 7.77 

• Coleman is located on approximately 270 acres. 

• Coleman has a pond that was originally used to store metal cleaning wastewater; 

however, this pond has been out of service since the mid 1980s. 

Ash Handling and Wastewater Treatment 

• Coleman stated that each unit has a wet fly ash and a wet bottom ash sluice 

system. The ash handling system for the plant is shown in Attachment 1. 

• According to EIA data, the ash sluice system costs $1.8 million to operate in 2005 

($300K for collection and $1.5 million for disposal/landfill). Coleman stated the 

values are inflated because the plant was actively moving ash out of the ponds 

during this time period. 

• Coleman stated that the plant does not have the capability to handle the ash with a 

dry system. The reasons cited for not using a dry system include: 

 Coleman is located in a very rural location and it is a challenge to find 

markets for the dry ash; 

 Carbon levels would need to be less than 3 percent to create a marketable 

product and with low NOx burners in place, Coleman does not believe that 

is achievable without the use of expensive carbon removal methods; 

 Coleman estimates it would cost approximately $50 million and additional 

land to install a dry ash handling and storage system servicing fly and 

bottom ash on all three generating units; and 

 Coleman does not currently have a landfill. 

• Coleman has in the past or is currently operating the following ash ponds, shown 

in Attachment 2: 

 Ash Pond A (“current pond”) – Ash Pond A was built around 1980 and 

has a discharge point (Outfall 002) if needed; Coleman only monitors this 

outfall if there is a discharge. The pond is approximately 24 feet deep, 

with banks up to 35 feet high, and covers an area of 60 acres. It is 

designed to last 15 years. 

 Ash Pond C (“old pond”) – Ash Pond C was built in 1976 and is now 

closed. Storm water from the pond is currently diverted to Ash Pond A. 
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During the site visit, the pond was observed to have standing water which 

Coleman noted was being pumped to Ash Pond A 

 “Old Parking Lot Pond” – This pond was the original ash pond and has 

since been converted into a parking lot, located near the guard shack. It 

covers approximately 15 acres. 

 Ash Pond D (“new pond”) – This pond was completed in August 2008 at a 

cost of approximately $3.2 million, and is currently used by the plant to 

store ash and gypsum, which are trucked from the plant to the pond site. 

Coleman intends for the pond to eventually be used to handle water and 

have a discharge (Outfall 007). The pond site covers 97 acres and is 

located about 1 mile from the plant. The current pond depth is 32 feet and 

the pond design allows for the berm to be raised an additional 12 feet. 

• Coleman stated that the ash ponds are clay-lined. 

• Pyrites are sluiced along with ash to the ash pond. 

• Coleman operates the ash pond system with complete recirculation, meaning the 

plant does not typically discharge from the ash ponds. Plant staff closely 

monitors the water levels in the ponds to ensure that they do not overflow or need 

to discharge. 

• Coleman stated that the only reason they would need to discharge would be due to 

a large rainfall. However, Coleman stated that they use Ash Pond A to control the 

rainfall they receive. Additionally, Coleman stated that they maintain the ponds 

at a lower level during the rainy season because they know they will be getting 

rainfall. 

• Coleman stated that water is removed from the ash system through evaporation 

from the ponds, evaporation of bottom ash quench water in the boiler, and some 

water that goes out the bottom of the ponds (e.g., through the clay liner). The ash 

pond is the source for ash sluice water. Whenever additional water is needed to 

makeup for evaporative and other losses, the ash sluice pumps pull suction from 

the cold side of the condenser. Plant staff stated that the need to do so is rare in 

the winter, but may be necessary weekly during the summer. 

• Coleman stated that they dredge the ash out of Ash Pond A year round and 

transfer it to Ash Pond D. Coleman stated that the gypsum and ash that are put in 

Ash Pond D are segregated. Coleman stated that Ash Pond D has a NPDES 

permitted outfall and a discharge structure, but they haven’t discharged from it 

yet. Coleman stated that they haul the gypsum and dredged ash to Ash Pond D 

using trucks (instead of sluicing the wastes) because Western Kentucky Energy 

does not own the property between the plant and the ash pond. Ash Pond D was 

built with excavated dirt. 
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FGD System and Wastewater Handling 

• Coleman operates a limestone, forced oxidation wet FGD scrubber system 

servicing all three generating units. A process flow diagram for the FGD system 

is included as Attachment 3. 

• The FGD scrubber system has five recirculation spray headers and one limestone 

slurry feed spray header. 

• No additives are used in the scrubber system. The FGD system removes 96-97 

percent of the sulfur dioxide from the flue gas. 

• The scrubber blowdown is fed continuously to the filter feed (“hold”) tanks. The 

solids in the reaction tank are controlled at about 20-22 percent solids. 

• Coleman stated that the chlorides level in the scrubber is typically 6,000 to 7,000 

ppm, but they have operated near 9,000 ppm at times. The system is designed to 

handle a maximum chlorides level of 10,000 ppm. 

• The blowdown from the scrubber is transferred to the primary hydroclones to 

separate the gypsum solids. The underflow from the primary hydroclones is sent 

to a vacuum belt filter to dry the gypsum. The gypsum is washed as it is applied 

to the vacuum belt filter. 

• The dry gypsum is transferred to the new ash pond for stockpiling/storage. 

Coleman does not currently have a market for their gypsum. 

• The overflow from the primary hydroclones is transferred to the secondary 

hydroclones or to the reclaim water tank. The underflow from the secondary 

hydroclones is transferred to the reclaim water tank and then recycled back to the 

reaction tank of the FGD scrubber. The overflow from the secondary hydroclones 

is transferred to the FGD wastewater treatment system. A diagram of the 

treatment system is included as Attachment 4. 

• Sources of water to the reclaim water tank include the primary hydroclone 

overflow, underflow from the secondary hydroclone, filtrate from the gypsum 

vacuum filter press, and the sump located in the gypsum dewatering area. Water 

collected in the reclaim water tank is sent back to the reaction tank of the FGD 

scrubber. 

• The FGD wastewater treatment system is designed to remove suspended solids 

and consists of a clarifier and multimedia sand filter. The FGD wastewater first 

enters the clarifier, where a polymer is added to aid in settling the solids. The 

clarifier is designed for a 160 gpm flow rate. The current purge flow rate is 

approximately 120 gpm when all three generating units are running. Coleman 

stated that they have used three different suppliers of polymer within the clarifier, 

including Buchman Labs, Betz, and Nalco. Polymer dosage is determined by 

visual observation of the clarity of clarifier overflow. 
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• The underflow solids from the clarifier are transferred to the current ash pond 

(Ash Pond A), which has a discharge point through Outfall 002. 

• The overflow from the clarifier is transferred to a surge tank. From the surge tank 

the wastewater is sent through a multimedia sand filter. Coleman does not 

monitor the effluent from the sand filter; however, the chlorides are typically 

about 6,000 ppm. Coleman would be concerned with reusing the effluent as 

sluice water or elsewhere in the system due to the deleterious effects of the 

chlorides. 

• The wastewater leaving the sand filters is transferred to an in-line mixer, where it 

is mixed with fresh river water and then transferred to the plant seal well. From 

the seal well, the wastewater is commingled with the discharge side of the oncethrough cooling water and discharged. 

• Coleman stated that the FGD wastewater is commingled with the cooling water to 

ensure the chlorides level is below 400 ppm. 

• Coleman stated that they do not currently have any limits on the FGD wastewater 

discharge; however, they do conduct routine monitoring. The plant is waiting for 

a new permit to be issued. Coleman stated that they expect there will be 

additional monitoring requirements and some permit limits when the permit is 

issued. Although Coleman does not have a limit for TSS, the plant is trying to 

remove the solids from the wastewater prior to discharging to the river. 

• Coleman stated that they have submitted their permit renewal application and that 

they expect to have the permit in the near future. 
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 Table 1. Site Visit Attendees 

Name Organization (Representing) Telephone E-mail Tom Shaw E.ON U.S./Western Kentucky Energy Tom.shaw@eon-us.comDuane Braunecker Western Kentucky Energy Daryl Chinn Western Kentucky Energy Patrick Grimes Western Kentucky Energy Mike Jones Western Kentucky Energy Wayne O’Bryan Western Kentucky Energy Ken Rieger Western Kentucky Energy Pat Waldeck Western Kentucky Energy Mark Bertram Big Rivers Electric Cooperative Donna Hill UWAG (205) 257-5234 dbhill@southernco.com Sara Beard State of Kentucky/Department of Water (502) 564-8158 x 4925 sara.beard@ky.gov Ron Jordan EPA/Office of Water (202) 566-1003 jordan.ronald@epa.gov Deb Bartram ERG (Contractor to EPA) (703) 633-1669 deborah.bartram@erg.c