Questions for Homer City Regarding FGD System and FGD Wastewater Treatment System

NOTE: For questions that are asking you to confirm information, please correct any information that is 

incorrect (e.g., if the FGD wastewater treatment system operation has changed from the description listed 

in the questions, please provide a description of how it now operates). Additionally, please identify 

which information, if any, is considered confidential business information.

1. Please confirm the following information:

• Generating Unit 1 exhausts to a wet FGD system;

No – Generating Unit 3 exhausts to a wet FGD system;

• Generating Units 2 and 3 do not exhaust to a wet FGD system;

No – Generating Units 1 and 2 do not exhaust to a wet FGD system

• A limestone forced oxidation FGD system is operated on Unit 1;

No - A limestone forced oxidation FGD system is operated on Unit 3

• Formic acid additive is added to the FGD system. No other additives are added; 

True formic acid is added to the FGD system.

• A SCR is operated on Unit 1; and

True SCR is operated on Unit 1. SCR is operated on Units 2 and 3 also.

• The Unit 1 SCR is operated on a year-round basis.

SCR is operated on Units 1, 2, and 3 throughout the year. 

2. Are any new units and/or new FGD systems planned to begin operation in 2010?

No new FGD units planned to begin operation in 2010.

• If so when would they become operational and when would they start sending wastewater to 

a treatment system?

Not applicable

3. Please confirm the wastewater treatment system has the following steps:

• Feed tank; Yes

• 1st stage neutralization tank (lime, ferric chloride, air, and polymer addition) Yes

• 1st stage clarification (polymer addition); Yes

• 2nd stage neutralization tank (lime, ferric chloride, air, and polymer addition) Yes

• 2nd stage clarification (polymer addition); Yes

pH adjustment tank (nutrients, phosphoric acid, and corn syrup addition) Yes

• Heat exchanger; Yes

• Biological reactor; and Yes

• Sand filters. Yes

4. Please confirm that the system only treats FGD scrubber purge wastewater. 

Yes, only treating FGD wastewater

5. Who designed the FGD wastewater treatment system?

ALSTOM
6. For which pollutants is the plant trying to optimize removals?

• What pollutant concentration levels need to be achieved by the system?

The following are final effluent limitations for the FGD wastewater treatment system. 

Parameter Daily Maximum Monthly Average

TSS 100 mg/l daily max, 30 mg/l monthly avg

cBOD5 50 mg/l daily max, 25 mg/l monthly avg

Oil & Grease 20 mg/l daily max, 15 mg/l monthly avg

Beryllium 1.6 mg/l daily max, 0.8 mg/l monthly avg

Lead 0.2 mg/l daily max, 0.1 mg/l monthly avg

Selenium 1.6 mg/l daily max, 0.8 mg/l monthly avg

• What pollutant concentration levels is the system achieving?

For 2008-CY to 2009-CY– The discharge from FGD wastewater treatment system outfall:

TSS 7 mg/l avg

cBOD5 4 mg/l avg

Selenium 0.76 mg/l avg

Oil & Grease 5 mg/l avg

Beryllium 0.05 mg/l avg

Lead 0.05 mg/l avg

• Has the state set limits for any pollutants from this waste stream and where are those limits 

effective? Please refer to the NPDES permit limits listed above. There are no other 

NPDES- required monitoring points. 

• Is this an internal point or after commingling with other wastewater? 

Not applicable

• If it is commingled with other waste streams, which waste streams is it commingled with?

Not applicable

7. Is the plant planning to make any changes to the operation of the FGD wastewater treatment 

system? No planned changes. 

• If so, what changes are planned? Not applicable

• When are the changes planned? Not applicable

8. Please confirm that the FGD wastewater treatment system operates and discharge continuously. 

FGD operates when Unit 3 is in operation. 

9. Does the plant have any planned outages scheduled between April and November 2010?

• When are the planned outages expected to occur?

Unit outages information is confidential.