Need to return call by / at/between and . Signature: ___________________________ 

 Project No.: 0172.07.029.041 DISTRIBUTION 

Page _1_ of _2_

Project Name: Steam Electric Rulemaking 

TELEPHONE CALL RECORD 

 Outgoing Call 

Date: 04/13/2010 Time: 2:15 pm EST 

Company Name: Ameren Energy 

 Coffeen Power Station 

 Duck Creek 

 

Contact Name: Mike Smallwood 

Phone No.: Office: (314) 554-4581 

 Cell: (314) 435-3211 

Name: Elizabeth Sabol Eastern Research Group

GENERAL SUBJECT : Plant FGD and Ash Handling Operations 

 

TOPICS DISCUSSED AND ACTION TAKEN 

On Wednesday, April 7, at 1:00 pm, I called Ameren Energy to speak with Jennifer Spalding regarding the 

Coffeen and Duck Creek Power Stations in Illinois. I left a message for Ms. Spalding asking her to return my 

call, or forward my information on to the correct facility contact. Ms. Spalding directed me to Mike Smallwood. 

I left a message with Mr. Smallwood asking him to return my call to discuss the FGD and ash handling 

operations at the facilities. I also explained that EPA was looking to conduct a site visit at one or both of the 

facilities, the last week in April. 

On Tuesday, April 8, at 2:00 pm, Mr. Smallwood returned my call to discuss the potential date(s) of the EPA 

site visit(s) and the FGD and ash handling operations at the facilities. The following is a summary of our 

discussion for each plant. 

Coffeen Power Station: 

Mr. Smallwood stated that Coffeen operates two generating units and each has a coal-fired cyclone boiler. He 

stated that Unit 1 has a gross capacity of 360 MW, and a net capacity of 340 MW. He also stated that Unit 2 has 

a gross capacity of 590 MW, and a net capacity of 560 MW. During our conversation, Mr. Smallwood stated 

that Unit 1 is currently in an outage, but is projected to be operating by the end of April. 

Mr. Smallwood stated that both units are equipped with an FGD scrubber system, each unit having its own 

separate absorber. He stated that the FGD scrubber systems on each unit are identical, Hitachi spray tower 

designs, with forced air oxidation. 

I asked Mr. Smallwood the frequency at which the plant blows down from the absorbers. Mr. Smallwood 

explained that both units at the Coffeen plant were designed to burn a high sulfur coal (6-6.5 pounds of sulfur 

per million BTU), but now burn a low sulfur coal blend (consisting of Power River Basin (PRB) coal) which 

requires less frequent blowdown. He stated that the facility mainly blows down to prevent lines from plugging 

and that it is hard to “guess” the frequency of blowdown, but that he would follow-up with that information. 

However, Mr. Smallwood stated that they usually blowdown when the solids concentration exceeds 20 percent. 

He also stated that the design chlorides concentration for the absorber is 55,000 ppm; however, the current 

chlorides concentration is only 2,100 ppm. 
Need to return call by / at/between and . Signature: ___________________________ 

Mr. Smallwood explained that Coffeen operates the FGD scrubber systems as a closed loop system, meaning 

there is no discharge from the system. He stated that the scrubber blowdown is transferred to a gypsum stack 

that collects the FGD wastewater and recycles it back to the FGD scrubber. The gypsum stack is a double-lined 

pond, where the gypsum is dewatered. Currently, Coffeen bypasses the initial double-lined gypsum stack 

because it has not been completed. Coffeen expects to complete the double-lined gypsum stack by the end of 

summer 2010. The scrubber wastewater is currently being transferred directly to the double-lined reclaim basin 

until it is sent back to the FGD scrubber. Any stormwater or leachate collected from the gypsum stack is also 

sent to the reclaim basin, and ultimately sent back to the FGD scrubber. 

I asked Mr. Smallwood about the flowrate from the absorber to the gypsum stack. He stated that Unit 2, the 

only unit currently in operation, recently reported a flowrate of 1,600 gpm from the absorber to the reclaim 

basin, and 1,800 gpm recycled back into the absorber. 

The Coffeen plant has one inactive, capped pond. There is also a landfill located at the plant for the disposal of 

fly and bottom ash. Stormwater collected from the landfill is transferred to the reclaim basin and recycled back 

to the FGD scrubber. Coffeen is working to update their NDPES permit to allow stormwater discharge from the 

landfill. 

Duck Creek: 

Mr. Smallwood stated that Duck Creek operates one generating unit with a coal-fired cyclone boiler. He stated 

that the unit has a gross capacity of 400 MW and a net capacity of 372 MW. During our conversation, Mr. 

Smallwood stated that the unit is currently in an outage, but is projected to be operating by the end of April. 

Mr. Smallwood stated that the generating unit is equipped with an FGD scrubber system. He stated that the 

FGD scrubber system is a Hitachi spray tower design, with forced air oxidation. 

I asked Mr. Smallwood the frequency at which the plant blows down from the absorber. Mr. Smallwood 

explained that the same situation described for the Coffeen plant, is also occurring at the Duck Creek plant. He 

again stated that the plant mainly blows down to prevent lines from plugging and that it is hard to “guess” the 

frequency of blowdown, but that he would follow-up with that information. However, Mr. Smallwood stated 

that they usually blowdown when the solids concentration exceeds 20 percent. He also stated that the design 

chlorides concentration for the absorber is 55,000 ppm; however, the current chlorides concentration is only 

1,500 ppm. 

Mr. Smallwood explained that Duck Creek operates the FGD scrubber system as a closed loop system, meaning 

there is no discharge from the system. He stated that the scrubber blowdown is transferred to a gypsum stack 

that collects the FGD wastewater and recycles it back to the FGD scrubber. The gypsum stack is a double–lined 

pond, where the gypsum is dewatered. The excess water collected in the gypsum stack, is sent to a double-lined 

reclaim basin until it is sent back to the FGD scrubber. Any stormwater or leachate collected from the gypsum 

stack is also sent to the reclaim basin, and ultimately sent back to the FGD scrubber. 

The Duck Creek plant has a series of inactive ponds, which the plant is currently in the process of closing. 

There is also a landfill located at the plant for the disposal of fly and bottom ash. Stormwater collected from the 

landfill is sent to the reclaim basin and recycled back to the FGD scrubber.