MEMORANDUM 

TO: Steam Electric Point Source Category ELG Rulemaking Record 

FROM: Patrick Goodwin, ERG 

 

DATE: September 30, 2015 

SUBJECT: Review of Confidential Business Information for the Environmental 

Assessment (DCN SE04514) 

ERG supported the U.S. Environmental Protection Agency (EPA) in the development of 

final effluent limitations guidelines and standards (ELGs) for the Steam Electric Power 

Generating Point Source Category (40 CFR Part 423). ERG completed environmental 

assessment (EA) analyses to evaluate environmental and human health impacts under current 

(i.e., baseline) discharge practices and potential improvements associated with the regulatory 

options (Options A, B, C, D, and E).1

 The results of these analyses are presented in the 

Environmental Assessment for the Effluent Limitations Guidelines and Standards for the Steam 

Electric Power Generating Point Source Category (EA Report), Document No. EPA-821-R-15-

006 (DCN SE04527). The EA included the following analyses: 

 Literature review, including documentation of environmental impacts from steam 

electric power plant wastewater discharges and summary of damage cases; 

 Quantitative assessment of water quality impacts and potential impacts to wildlife and 

human receptors; and 

 Qualitative assessment of water quality impacts and potential impacts to wildlife and 

human receptors, including comparison of baseline pollutant loadings to other point 

source discharges) and discharges to sensitive environments (impaired waters, waters 

under a fish consumption advisory, drinking water sources, Chesapeake Bay 

watershed, and Great Lakes watershed). 

As part of the public docket, EPA includes references and documentation to explain the 

ELG review process and results of the analyses presented in public documents and the preamble. 

This memorandum describes how ERG identified confidential business information (CBI) in the 

EA analyses and how ERG redacted CBI data from the EA documentation for inclusion in the 

public docket. 

 

1

 During development of the final rule, EPA decided not to base the final rule on Option F for existing sources due primarily to

the high cost of that Option, particularly in light of the costs associated with other rulemakings expected to impact the steam

electric power generating industry (see Section VIII.C.1 of the preamble). As a result, EPA chose not to conduct particular 

analyses for Option F to the same extent that it did for some of the other options considered. 
Memorandum 

September 30, 2015 

Page 2 

For the literature review, all information is from non-confidential sources (i.e., no survey 

response data). Therefore, none of the literature review sources presented in the record needed to 

be redacted due to CBI concerns. This included the Literature Search Database (DCN SE01962), 

the Database of Damage Cases and Other Documented Site Impacts from Pollutants in 

Combustion Residuals and Steam Electric Power Plant Wastewater (DCN SE04518), and cited 

literature references in the EA Report. Some of the literature sources, however, are protected by 

copyright and have therefore been excluded from the electronic docket system 

(http://www.regulations.gov/). Copyrighted materials are available for review at the EPA Docket 

Center. See the User Guide to the Docket for the Rulemaking for the Steam Electric Power 

Generating Effluent Limitations Guidelines (DCN SE03974) for further details. 

For the quantitative and qualitative assessments, the only sources of CBI data collected 

by EPA are as follows: 

 Drinking Water NHD Indexed Dataset (DCN SE03569) – The national dataset 

contains the location of public wells and drinking water intakes (as identified by 

EPA’s Office of Ground Water and Drinking Water). The dataset is considered EPA 

sensitive information and is excluded from the public record. 

 Questionnaire for the Steam Electric Power Generating Effluent Guidelines (Steam 

Electric Survey) – The survey results that ERG used as inputs to the EA analyses 

(e.g., the national-scale immediate receiving water (IRW) model, loadings analyses, 

and case study models) that may have been marked as CBI include the location of 

plant outfalls, receiving water names, and cooling water flow rates. 

 Pollutant Loadings – Plant-specific, wastestream-specific, and receiving waterspecific pollutant loadings used as inputs to the IRW model and case study models 

were calculated using data from the questionnaire, specifically pollutant 

concentrations and wastewater flow rates. A portion of the steam electric power 

plants claimed these data as CBI. For a complete listing of the supporting 

documentation used to calculate the pollutant loadings, see the memorandum 

“Pollutant Loadings Supporting Documentation” (DCN SE04515). 

ERG used plant-specific data as inputs to the IRW model. ERG determined that two of 

the plants evaluated under the EA claimed their outfall locations as CBI and one plant claimed 

the receiving water name as CBI. However, ERG was able to identify publicly available sources 

that provided the outfall locations and receiving water names. ERG cites the publicly available 

sources where the outfall and receiving water information for these plants is presented in the 

public record (ERG, 2015a). For the IRW model, ERG used cooling water flow rates for a subset 

of steam electric power plants. To protect CBI, ERG excluded the cooling water flow rates from 

the public record (ERG, 2015a; ERG, 2015b). 

The IRW model used site-specific pollutant loadings. The pollutant loadings are excluded 

from the public record and remain confidential. To protect CBI, output data calculated in the 

IRW model using the pollutant loadings (e.g., pollutant concentrations in the water column and 

fish) are also excluded from the public record. 
Memorandum 

September 30, 2015 

Page 3 

For the case study models, ERG selected steam electric power plants that did not make 

CBI claims on their pollutant loadings. See the ERG memorandum, “Technical Approach for 

Case Study Water Quality Modeling of Aquatic Systems in Support of the Final Steam Electric 

Power Generating Industry Environmental Assessment” (DCN SE05570) for further discussion. 

The qualitative loadings analyses included only aggregate pollutant loadings. Because no 

plant-level loadings data will be provided in the public record, the aggregate results presented in 

the EA Report are not CBI-deducible data. 

1.0 REFERENCES

ERG. 2015a. Water Quality Model: Plant and Receiving Water Characteristics. Chantilly, VA. 

DCN SE04513. 

ERG. 2015b. Supporting Documentation for Summarization of Environmental Assessment 

Analyses. Chantilly, VA. DCN SE04449. 

U.S. EPA. 2010. U.S. Environmental Protection Agency. Questionnaire for the Steam Electric 

Power Generating Effluent Guidelines. OMB Approval Number: 2040-0281. Washington, DC. 

(2 June). DCN SE00402-SE00402A09.