AMERICAN

" 111CJRIC POWIR

American Electric Power 1 Riverside Plaza Columbus, OH 43215

- 2373 AEP.com March
7, 2014 Ron Jordan Engineering and Analysis Division (4303T) Office of Water U.S. Environmental Protection Agency 1200 Pennsylvania

A venue

, NW Washington

, DC 20460 Re: Follow up to Comments
on Proposed Steam Electric Effluent Guidelines AEP Mountaineer Plant (EPA Plant Survey ID- 04543; FGD-1) Contains "Confidential Business Information" Dear Mr. Jordan: In response
to the EPA data request of February

6, 2014

, American Electric Power (AEP)
is providing flue gas desulfurization (FGD) waste water characterization
and treatment performance data for the AEP Mountaineer Plant. This includes the following information: 1. Metal and inorganic concentration data for the FGD and leachate treatment system during the period January 2012 through December 2013 from the following sample points (attachment: AEP- Mountaineer Analytical Data Table): o FGD wastewater influent
to the chemical precipitation treatment system; o FGD wastewater effluent from the chemical precipitation treatment system (prior to commingling with leachate); o Leachate waste stream prior to commingling with FGD wastewater and upstream of the biological treatment system; o Combined FGD and leachate wastewater upstream of the biological treatment system; and o Combined FGD and leachate wastewater effluent from the biological treatment system. 2 . AEP began operating the biological treatment system on November

I 0 , 2011. 3. The organosulfide additive, Metclear MR2405 from GE Betz

, was primarily used in the FGD chemical precipitation wastewater treatment system for the specified time period(MSDS attached). However, due to supply problems,

a different organosulfide product, Metclear MR2416, was used during January and February of2012 (MSDS attached). 4. Specifications used to determine appropriate coals for use at the plant have been provided (see attached specifications and related explanation). 5. The type and source of coal used at the plant. Sulfur and chlorine content of the coal used at the plant as available,

as well as coal blend information (attachment:AEPSE04298A 1_Data Request Spreadsheet_ Mountaineer). 6. Available information
on the chloride concentration, pH, and average daily ORP values for the following sampling locations, are provided: o Within the FGD scrubber system; o For the influent
to the FGD chemical precipitation wastewater treatment system; and o For the influent
to the FGD/leachate biological wastewater treatment system. 7. Electric generation output (MW-hr) for the generating unit is also provided (attachment: AEP-SE04298A

1_ Data Request Spreadsheet_ Mountaineer)

. Please note that it was not possible
to provide selected information
for the following categories: 1. Daily coal source information

- This information

is not collected on a daily basis. Coal

is moved from rail cars or barges to the coal pile or directly into the boiler, subsequently, specific information
on exactly when and what coal went to the boiler
is not available. Coal chlorine content information

is only available on a contract basis or by request. Coal sulfur content information that is available for the requested time period has been provided (attachment: AEP-SE04298Al_Data Request Spreadsheet_Mountaineer). 2. FGD scrubber system CFGD -1)

- There are gaps in the average daily chloride concentration record due to weekends, holidays and outages, when the requested information was not collected. Average daily ORP information was not recorded until monitoring instruments were installed during October 2012. 3. FGD wastewater treatment system- The average daily influent chloride concentration and ORP data were not recorded. Average daily pH information has been provided. 4. FGD biological wastewater treatment system- Gaps in the daily chloride concentration record are due to weekends, holidays and outages, when the requested information

is not collected. AEP is also providing the requested supplemental information, including: • A list of the chemicals and dosages added to the treatment system, including the location of injection points (see attached flow diagram); • A process flow diagram of the sampled system (attached); and • Laboratory reports associated with the sampling data (will be delivered on a CD).Please note that in accordance with the requirements

of 40 CFR §2.203

, AEP is asserting

a claim of business confidentiality with respect
to certain of the requested information. AEP has indicated on the face of individual documents, through the use of a legend or stamp including the word "Confidential" that the document contains confidential business information entitled
to protection under 40 CFR Part 2. The information generally contains operational detail, vendor information

or other information that, if disclosed publicly, would harm the competitive position of the AEP companies

in the electricity markets. We ask that EPA treat the marked information in accordance with the requirements

of 40 CFR Part 2. AEP considers the coal specification and sulfur data, all organosulfide and treatment chemical vendors, and the flow diagram, with all chemical injection locations and treatment dosages
to be confidential business information (CBI). If you have any questions regarding the data submittal

, please contact me at 614-716-1255

or at twlohn

e r @ a ep. c o m
. Sincerely

, Timothy W. Lohner

, Ph.D. Environmental Services Enclosure: Laboratory Reports on CD Attachments: Completed AEP Mountaineer Analytical Data Table (w / e-version only) AEP Mountaineer Coal Specifications Completed AEP-SE04298Al

_ Data Request Spreadsheet

_ Mountaineer

(w /eversion only) MSDS

- Metclear MR2405 MSDS

- Metclear MR2416 Mountaineer FGD wastewater treatment flow diagrams