### MEMORANDUM

TO: Bill Swietlik, EPA

FROM: Deb Bartram, T.J. Finseth, Jill Lucy, Patrick Goodwin, ERG

DATE: April 19, 2013

SUBJECT: Comparison of Steam Electric Industry Toxic Loadings to Other Industrial Dischargers (SE02155)

The U.S. Environmental Protection Agency (EPA) is proposing revised effluent limitations guidelines and standards (ELGs) for the Steam Electric Power Generating Point Source Category (40 CFR 423). In support of th e development of the revised ELGs, ERG supported EPA in calculating pollutant loadings from steam electric power plants, as total pounds and as toxic-weighted pound equivale nts (TWPEs). This memorandum provides a summary of the data and calculati ons performed to estimate the tota l loadings of toxic pollutants reported to be discharged to United States wa ters in industrial Nati onal Pollutant Discharge Elimination System (NPDES) permits, and the percen tage of those toxic loadings that result from discharges by the steam electric industry. ERG cal culated that the total pollutant loadings from steam electric power plants account for at least 50 to 60 percent of the toxic pollutants reported in industrial NPDES permits. This result is documented in EPA’s Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (EA Report) (DCN SE01995).

As part of the engineering support to EPA, ERG calculated pollutant loadings on a plantby-plant basis for all steam electric power plants that fell into scope of the proposed ELGs. The loadings methodology and calculations ar e documented in Section 10 of EPA’s Technical Development Document for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (TDD) (DCN SE01964). The total TWPE discharges from steam electric power plants are 5.2 million pounds per year excluding sulfides and 8.3 million pounds per year including sulfides.

To estimate the total TWPE from other industr ial dischargers, ERG used data reported to EPA’s Discharge Monitoring Report (DMR) syst em for 2009. In support of its 304m annual review under Work Assignment 9-05, EPA compiled the DMR data into the DMRLoads2009_v02.mdb database (see DCN 07709, EPA-HQ-OW-2010-0824). ERG used the
data tables in the DMR database and devel oped queries for the Steam Electric ELGs (see DCN SE01961), as follows:

1. Use database table PSC/SIC Crosswalk to identify standard industrial category (SIC) codes that fall under point source category 40 CFR 423. The resulting SIC codes are 4911 (electric services), 4931 (e lectric and other services combined), 4939 (combinationMemorandum April 19, 2013 Page 2

utilities), and 4961 (steam and air conditioni ng supply). For purposes of this analysis, these four SIC codes represen t the steam electric industry.

2. In a query ( TWPE_minus_steam electric ), select all TWPE results (lb-eq/yr) in database
table DMR2009 for all parameters (i.e., pollutants) and all facilities that fall under any SIC code except those for the steam electric industry. See the databa se for the results.

3. Building on the first query, sum the total TWPE (lb-eq/yr) for all parameters and facilities, except those identif ied as steam electric (query TWPE_minus_steam electric
total ). The total TWPE is 5.3 million pounds.

Calculations

Total TWPE from industrial sources re porting discharges under NPDES permits:

Excluding Sulfides

5.2 million lb-eq/yr (steam electric) + 5.3 million lb -eq/yr (non-steam electric) = 10.5 million lb-eq/yr

Including Sulfides

8.3 million lb-eq/yr (steam electric) + 5.3 million lb -eq/yr (non-steam electric) = 13.6 million lb-eq/yr

Percentage of TWPE (i.e., toxic discharg es) accounted for by steam electric plants:

Excluding Sulfides

5.2 million lb-eq/yr = 50 percent 10.5 million lb-eq/yr

Including Sulfides

8.3 million lb-eq/yr = 61 percent 13.6 million lb-eq/yr