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 contai ns some general information for the three generating units.

Unit Installation

Date Gross

Capacity (MW) Particulate

Control NOx Control SO 2 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 gene rating units.

• Coleman currently has 107 employees, of which nine are as sociated with the operation of the FGD system.

• Coleman burns approximately 1.4 million tons of coal per y ear. The plant was originally constrained to burn low sulfur coal; however, with the installation of the FGD system, the plant also installed a blending sys tem 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 re ceive coal via truck.

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

• The sulfur content of the coal used at Coleman is typi cally 5.2 lbs SO 2 /MBTU.

• The coal pile runoff is collected in a runoff pond desig ned to hold up to a 10-year, 24-hour storm event (4.64”). From the coal pile runoff po nd, the wastewater is pumped to the ash pond system.Page 2

• 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 sa mples from the coal pile runoff pond and measured the pH. The table below presents t he 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 sho wn 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 movi ng ash out of the ponds during this time period.

• Coleman stated that the plant does not have the capabilit y 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 c reate a marketable product and with low NOx burners in place, Coleman does n ot believe that is achievable without the use of expensive carbon remova l methods;

 Coleman estimates it would cost approximately $50 million and additional land to install a dry ash handling and storage system ser vicing 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 f ollowing ash ponds, shown

in Attachment 2:

 Ash Pond A (“current pond”) – Ash Pond A was built around 1980 a nd has a discharge point (Outfall 002) if needed; Coleman only monitors this outfall if there is a discharge. The pond is approximate ly 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 diverte d to Ash Pond A.Page 3

During the site visit, the pond was observed to have standi ng water which Coleman noted was being pumped to Ash Pond A

 “Old Parking Lot Pond” – This pond was the original ash pon d and has since been converted into a parking lot, located near th e 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 han dle water and have a discharge (Outfall 007). The pond site covers 97 acr es and is located about 1 mile from the plant. The current pond de pth is 32 feet and the pond design allows for the berm to be raised an additi onal 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 rec irculation, meaning the plant does not typically discharge from the ash ponds. Plant staff closely monitors the water levels in the ponds to ensure that th ey do not overflow or need to discharge.

• Coleman stated that the only reason they would need to di scharge 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 th at they maintain the ponds at a lower level during the rainy season because they kn ow they will be getting

rainfall.

• Coleman stated that water is removed from the ash syst em through evaporation from the ponds, evaporation of bottom ash quench water i n the boiler, and some water that goes out the bottom of the ponds (e.g., thr ough the clay liner). The ash pond is the source for ash sluice water. Whenever addi tional 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 tha t the need to do so is rare in the winter, but may be necessary weekly during the summ er.

• 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 g ypsum 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 have n’t discharged from it yet. Coleman stated that they haul the gypsum and dre dged ash to Ash Pond D using trucks (instead of sluicing the wastes) because Weste rn Kentucky Energy does not own the property between the plant and the ash pond. Ash Pond D was

built with excavated dirt.Page 4

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 syste m removes 96-97 percent of the sulfur dioxide from the flue gas.

• The scrubber blowdown is fed continuously to the filter f eed (“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 sy stem is designed to handle a maximum chlorides level of 10,000 ppm.

• The blowdown from the scrubber is transferred to the prima ry hydroclones to separate the gypsum solids. The underflow from the prima ry hydroclones is sent to a vacuum belt filter to dry the gypsum. The gypsum i s washed as it is applied

to the vacuum belt filter.

• The dry gypsum is transferred to the new ash pond for s tockpiling/storage. Coleman does not currently have a market for their gyps um.

• The overflow from the primary hydroclones is transferre d to the secondary hydroclones or to the reclaim water tank. The underflow from the secondary hydroclones is transferred to the reclaim water tank and t hen 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, filt rate from the gypsum vacuum filter press, and the sump located in the gypsum de watering 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 r emove 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 s ettling 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 polym er within the clarifier, including Buchman Labs, Betz, and Nalco. Polymer dosage is determined by visual observation of the clarity of clarifier overf low.Page 5

• The underflow solids from the clarifier are transferr ed 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 s urge tank. From the surge tank the wastewater is sent through a multimedia sand filte r. Coleman does not monitor the effluent from the sand filter; however, th e 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 delet erious effects of the

chlorides.

• The wastewater leaving the sand filters is transferred t o 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. T he plant is waiting for a new permit to be issued. Coleman stated that they e xpect 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 disch arging to the river.

• Coleman stated that they have submitted their permit re newal application and that they expect to have the permit in the near future.Page 6Table 1. Site Visit AttendeesNameOrganization (Representing)TelephoneE-mailTom Shaw E.ON U.S./Western Kentucky EnergyTom.shaw@eon-us.comDuane BrauneckerWestern Kentucky EnergyDaryl ChinnWestern Kentucky EnergyPatrick GrimesWestern Kentucky EnergyMike JonesWestern Kentucky EnergyWayne O’BryanWestern Kentucky EnergyKen RiegerWestern Kentucky EnergyPat WaldeckWestern Kentucky EnergyMark BertramBig Rivers Electric CooperativeDonna HillUWAG(205) 257-5234 dbhill@southernco.comSara BeardState of Kentucky/Department ofWater(502) 564-8158 x4925sara.beard@ky.govRon Jordan EPA/Office of Water (202) 566-1003 jordan.ronald@epa.govDeb Bartram ERG (Contractor to EPA) (703) 633-1669 deborah.bartram@erg.com