### MEMORANDUM

TO: Steam Electric ELG Rulemaking Record

FROM: Lydia Lambert, ERG

DATE: April 19, 2013

SUBJECT: Pollutant Loadings Supporting Documentation (DCN SE03887)

1.0 S UMMARY OF SUPPORTING DOCUMENTATION

ERG is providing technical support to the U. S. Environmental Protection Agency (EPA) for development of revised effluent limitations guidelines and standards (ELGs) for the Steam Electric Power Generating Point Source Category. In support of the development of revised ELGs, ERG developed resources to calculate pollutant loadings generated from steam electric power plants to surface waters under th e current profile and future profile 1 for the baseline and eight regulatory options (Options 1, 2, 3a, 3b, 3, 4a, 4, and 5).

The methodology for calculating the pollutant loadings is presented in the following
documentation:

 Incremental Costs and Pollutant Remova ls for Proposed Effluent Limitation Guidelines and Standards for the Steam Electric Generating Point Source Category Report (DCN SE01957) – Section 10 (Pollutant Loadings and Reductions Methodology) of this report documents th e methodology for calculating the pollutant loadings by waste stream under the current profile.

 Flue Gas Desulfurization Future Pr ofile Sensitivity Analysis Memorandum (DCN SE01989) – This memorandum documents the methodology for calculating and evaluating the pollutant loadi ngs under the future profile.

 Memorandum to the Rulemaking Record: Methodologies for Estimating Costs and Pollutant Removals for Steam Electric ELG Regulatory Options 3a and 3b (DCN SE03881) – This memorandum documents the methodology for calculating and evaluating the pollutant loadi ngs for Options 3a and 3b.

1 Current profile includes waste streams generated by air pol lution controls that will likely be in operation at steam electric plants at the time EPA takes final action on this rulemaking. Future profile includes waste streams generated by future installations of air pollutio n controls at steam electric power plan ts that may result from some recently promulgated Clean Air Act requirements.Memorandum April 19, 2013 Page 2

 Memorandum to the Rulemaking Record: Methodologies for Estimating Costs and Pollutant Removals for Steam Electric ELG Regulatory Option 4a (DCN SE03834) –
This memorandum documents the methodol ogy for calculating a nd evaluating the pollutant loadings for Option 4a.

 Loadings Analysis for the Steam Elec tric ELGs Environmental Assessment (DCN SE01956) – This memorandum documents the methodology for calculating the pollutant loadings on a total plant-by -plant basis under the current profile.

 Water Quality Model Supporting Documentation Memorandum (DCN SE03888) – This memorandum identifies the supporting documentation that used the pollutant loadings to calculate total and dissolved po llutant concentrations in the water column and total pollutant concentration in the se diment, which are used as inputs in the
wildlife and human health models.

The results of the pollutant loadings calculations under the current profile are presented in the following sections of the Final Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for th e Steam Electric Power Generating Point Source Category (EA Report) (DCN SE01995):

 Section 3.2 (Loadings Associated with Combustion Wastewater);

 Section 4.2 (Leaching to Ground Water);

 Section 6.1 (Loading Reductions under th e Proposed Regulatory Options); and

 Section 6.4 (Improvements to Sensitiv e Environments and Watersheds).

A comprehensive listing of the pollutant loadings supporting documentation for the current profile is presented in Table 1-1 below. This table provi des the document control number (DCN), title, and abstract of each record item, and identifies wh ether the record item contains Confidential Business Information (CBI).

Table 1-1. Pollutant Loadings Record Items

DCN Title (Date) Abstract CBI a

SE02988 Loads Calculation Database for Options 1, 2, 3, 4, and 5 – Current Profile (082012) Database used to calculate the total load per plant-receiving water under the current profile for Options 1, 2, 3, 4, and 5. Input for Water Quality Model. Yes

SE03895 Loads Calculation Database for Options 3a, 3b, and 4a – Current Profile (041913) Database used to calculate the total load per plant-receiving water under the current profile for Options 3a, 3b, and 4a. YesMemorandum April 19, 2013 Page 3

Table 1-1. Pollutant Loadings Record Items

DCN Title (Date) Abstract CBI a

SE03507 Loads Calculation Database
– Future Profile – Questionnaire and IPM (091012) Database used to calculate the total load per plant-receiving water under the future profile. This scope includes plants with predicted future air pollution control installations identified in the Integrated Planning (IPM) projections for the final Mercury and Air Toxics Standards (MATS) rule and EPA’s Questionnaire for the Steam Electric Power Generating Effluent Guidelines. Input for Water Quality
Model. Yes

SE03508 Loads Calculation Database – Future Profile – IPM Only (091012) Database used to calculate the total load per plant-receiving water under the future profile. This scope includes plants with predicted future air pollution control installations identified in the Integrated Planning (IPM) projections for the final Mercury and Air Toxics Standards (MATS) rule. Input for Water Quality Model. Yes

SE03896 Loads Comparison Database for Option 3a - Current Profile (041913) Database used to calculate pollutant-specific adjustment factors to estimate potential water quality, wildlife, and human health impacts under Option 3a. Yes

SE03897 Loads Comparison Database for Option 3b - Current Profile (041913) Database used to calculate pollutant-specific adjustment factors to estimate potential water quality, wildlife, and human health impacts under Option 3b. Yes

SE03898 Loads Comparison Database for Option 4a - Current Profile (041913) Database used to calculate pollutant-specific adjustment factors to estimate potential water quality, wildlife, and human health impacts under Option 4a. Yes

SE02157 Metal Concentrations in Leachate Analysis Database (071712) Database contains leachate concentration data divided into three pH levels (i.e., acidic, neutral, and alkali), which is presented in the Final Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category Report. Yes

a – Record items containing CBI have been removed from the public record.