### MEMORANDUM

TO: Steam Electric Rulemaking Record

FROM: Elizabeth Sabol, ERG TJ Finseth, ERG

DATE: April 19, 2013

SUBJECT: Surface Impoundment Listings Supportin g the Steam Electric Rulemaking

ERG is providing technical support to the U.S. Environmental Protection Agency’s Office of Water, Engineering and Analysis Division (E AD) for development of effluent limitations guidelines and standards (ELGs) for the Steam Electric Power Generati ng Industry. EPA, with the support of ERG, distributed the Questionnaire for the Steam Electric Power Generating Effluent Guidelines (Steam Electric Survey) to 733 power plants in the summer of 2010 to gather plant-specific data on the steam electric industr y. The Steam Electric Survey requested data on plant operations in 2009. The St eam Electric Survey comprised the following nine parts:

Part A: Steam Electric Power Plant Operations Part B: FGD Systems Part C: Ash Handling Part D: Pond/Impoundment Systems and Ot her Wastewater Treatment Operations Part E: Wastes from Cleaning Metal Process Equipment Part F: Management Practices for Ponds/Impoundments and Landfills Part G: Leachate Sampling Data for Ponds/Impoundments and Landfills

Part H: Nuclear Power Generation

Part I: Economic and Financial Data

EPA used the collected data to inform various analyses including, but not limited to, estimating the compliance costs and pollutant removals asso ciated with the proposed ELGs, developing the profile of the industry, and obtai ning characterization data for the wastestreams generated by the industry. EPA analyzed the Steam Electric Surv ey responses, stored in the Steam Electric Technical Questionnaire Database (technical database) [DCN SE 01958], to determine the listing of impoundments reported in the Steam Electric Survey and the types of materials stored in each impoundment (e.g., fly ash, bottom ash, FGD solids). This memorandum describes the impoundment information in the Steam Electric Su rvey and the two impoundment listings used to support the Steam Electric ELGs.

1.0 S UMMARY OF P OND /I MPOUNDMENT I NFORMATION IN THE S TEAM E LECTRIC S URVEY

Part A, Section 3 of the Steam Electric Surv ey (Pond/Impoundments) requ ests a listing of all onsite surface impoundments at the plant. For e ach impoundment reported, plants provided the following information: plant designation, location, liner (yes/no), leachate collection (yes/no),Memorandum April 19, 2013 Page 2

closest distance to nearest surface water, year in itially brought online, inactive status (yes/no), and solid waste/process wastewater stored in the surface impoundment.

Part D, Section 4.1 (Active/Inactive/Open a nd Planned Pond/Impoundment Unit Information) requests more specific information (e.g., type of liner, dimensions of the pond, pond expansions) for those impoundments that contain combustion residuals. In addition, Part D, Section 2 (Pond/Impoundment System and Wast ewater Treatment System Identif ication) requests the plant to identify all the impoundment systems at the pl ant containing combustion residuals. For each impoundment system, the plant provided a system di agram and the influents and effluents to the impoundment system (including flow rates).

Additional information for surface impoundments can be found in certain plant-submitted supplemental survey files including the wa ter balance diagrams, pond/impoundment system diagrams, and questions requesting the destinatio n of certain process wa stewaters (e.g., Question C2-9, Table C-4 (Storage Destina tions that Receive Fly Ash)).

2.0 EPA I MPOUNDMENT L ISTING FROM P ART A OF THE S TEAM E LECTRIC S URVEY

EPA analyzed the survey responses from Part A, Section 3 (Tables A-4 and A-5), using a Statistical Analysis System (SAS) program, to create a complete listing of all impoundments (active/retired/planned) reported in the survey and the type of combus tion residuals (if any) disposed of or stored in the impoundment. Th e responses of Table A-5 (Wastes Stored or Disposed of in Plant Pond/Impoundment Units) were examined and EPA noted which impoundments contained fly ash, bottom ash, FGD, or no combustion residuals. EPA identified 2,608 impoundments (active, inactive, open, retired or planned) repor ted in Part A, Section 3 of the Steam Electric Survey. EPA flagged 1,169 activ e, inactive, open or retired impoundments containing ash and/or FGD solids. See DCN SE 00986 for the complete listing of impoundments reported in response to Part A of the Steam Electri c Survey, the types of materials stored in each impoundment, and a summary of the search criteria used to iden tify impoundments containing or storing ash and/or FGD materials.

This impoundment listing was generated using only the Part A, Section 3 data. EPA used this impoundment listing in industry profile analyses supporting the Steam El ectric ELGs, including the numbers presented in the Technical Development Document for the Proposed Effluent Limitations Guidelines and Standards for th e Steam Electric Power Generating Point Source Category (Steam Electric TDD) [DCN SE01964].

3.0 EPA I MPOUNDMENT L ISTING FROM A LL D ATA IN THE S TEAM E LECTRIC S URVEY

EPA has coordinated the data and analyses fo r the EPA Office of Water (OW) Steam Electric ELG rulemaking and the EPA Office of Resour ce Conservation and Recovery (ORCR) Coal Combustion Residuals (CCR) rule making. In doing so, EPA determined that the Part A data

alone were not sufficient for the coordination effort and therefore, ERG re-evaluated the listing of surface impoundments reported in response to the Steam Electric Survey and the types of materials disposed of or stored in the impoundment s, using Part A, Section 3 data in combination with water balance diagrams, fly ash transport water/bottom ash transport water/ FGD scrubber blowdown and purge destination information in Parts B and C, and impoundment system

information in Part D of the Steam Electric Survey. ERG identified 1,305 impoundments (active,Memorandum April 19, 2013 Page 3

inactive, open, or retired) using data from Parts A, B, C, and D of the Steam Electric Survey containing fly ash, bottom as h, FGD, and/or leachate. 1 Based on those impoundments identified, ERG flagged 1,187 active, inactive, open or re tired impoundments containing ash and/or FGD materials (i.e., impoundment flagged as leac hate only were not included in the 1,187). Additionally, there are 1, 097 impoundments included in the listing if retired impoundments were excluded. See DCN 01327 for the complete listing of impoundments identified from this analysis and the types of material s stored in each pond.

EPA used this impoundment listing for analyses associated with coordinating with ORCR, analyses identifying impoundments as potential closures and partia l closures as a result of the Steam Electric ELGs [DCN SE02125], and the id entification of impoundments requiring best management practice (BMP) costs for the estim ated compliance costs for the Steam Electric ELGs [DCN SE01957].

1 EPA flagged impoundments including leachate for this analysis. However, because EPA cannot confirm whether the leachate is from landfills containing combustion residuals or landfills contai ning other plant wastes based on the information provided in response to the Steam Electric Survey, EPA did not include leachate only impoundments in many of the analyses conducted with the impoundment listing.