MEMORANDUM 

TO: Steam Electric Rulemaking Record

FROM: Anna Dimling, ERG 

Dan-Tam Nguyen, ERG 

DATE: September 30, 2015

SUBJECT: Development Memorandum for the Flue Gas Desulfurization (FGD) 

Wastewater Data in the Steam Electric Analytical Database for the Final 

Rule 

1.0 INTRODUCTION

 ERG is providing technical support to the U.S. Environmental Protection Agency’s 

Office of Water, Engineering and Analysis Division (EPA) for development of the effluent 

limitations guidelines and standards (ELGs) for the Steam Electric Power Generating Industry. 

As part of this technical support, ERG performed a detailed review of flue gas desulfurization 

(FGD) wastewater analytical data to identify acceptable data for use in identifying FGD 

wastewater pollutants of concern (POC), calculating pollutant loadings for FGD wastewater 

discharges, and performing the treatment effectiveness analysis. This memorandum describes the 

data sources evaluated for FGD wastewater and the methodology ERG used to review each of 

the identified data sources. 

 This memorandum supplements the Development Memorandum for the Steam Electric 

Analytical Database for the Final Rule (DCN SE05876) (hereafter, “analytical database memo”). 

Using the results of this data review, ERG developed the FGD analytical data set which includes 

all data EPA used as a part of the ELGs. ERG provides documentation of revised or edited FGD 

wastewater data and rationale for FGD wastewater data excluded from use in engineering 

analyses. 

2.0 ANALYTICAL DATA SOURCES

 ERG performed a detailed review of the following sources of data containing information 

related to FGD wastewater data: 

 Responses to the Questionnaire for the Steam Electric Power Generating Effluent 

Guidelines (“Steam Electric Survey”; DCN SE05903). 

 EPA sampling episodes at steam electric power plants (e.g., EPA Field Sampling, EPA 

Detailed Study Program). 

 Plant self-monitoring data requested and received from operating companies (e.g., EPA 

CWA 308 Monitoring Program, Industry-Submitted Plant Data). 
Memorandum 

September 30, 2015 

Page 2 

 Analytical data obtained from technical or industry sources (e.g., Public Comments, 

Electric Power Research Institute (EPRI) Reports, Wastewater Studies). 

Section 2.1 discusses EPA’s data acceptance criteria, Section 2.2 summarizes all the data sources 

that were accepted and compiled into the analytical database, and Section 2.3 describes data 

sources that were not accepted for use for subsequent analyses associated with the final rule (e.g., 

POC analysis, pollutant loadings analyses, and treatment effectiveness analysis). 

2.1 Data Acceptance Criteria 

ERG evaluated the data sources and applied general data acceptance criteria for primary 

and existing data sources, as described in the Quality Assurance Project Plan for the Steam 

Electric Effluent Guidelines Rulemaking (“QAPP”) [ERG, 2013a]. In addition, Table 2-1 lists the 

specific data acceptance criteria ERG used to identify FGD wastewater concentration data for 

inclusion in analyses for identifying POCs, effectively treating pollutants, and for characterizing 

discharges of FGD wastewater. 

Table 2-1. FGD Wastewater Data Acceptance Criteria 

Acceptance Criteria POC 

Analysis

Treatment 

Effectiveness 

Analysis

Loadings 

Analysis 

Sample locations must be unambiguous and clearly described such that it 

can be categorized by type of wastewater and level of treatment (e.g., 

untreated, partially treated). 

  

Sample must be representative of a BAT treatment system.  

For biphasic samples (i.e., those with solids content >1%), sample analysis 

must provide results for both phases. 

  

Data are provided as sample-specific results. EPA did not consider results 

that were presented as industry averages or plant-specific long-term 

averages

  

Analytical data must contain all information needed for EPA’s analyses 

(e.g., concentration of total suspended solids and total/dissolved metals on 

same collection date for FGD surface impoundment determination) 

  

Data are representative of typical full-scale (e.g., not results from a pilotor bench-scale study) and typical plant operations. 

  

Sample analysis must be completed using EPA accepted analytical 

methods.

  

Data must not be duplicative of other accepted data.   

Sample data must provide sufficient information to identify units.   

Non-detect results were not accepted if no limit (e.g., reporting limit (RL)) 

was provided. 

  

Data are verified as FGD wastewater, and have been received directly 

from the operating company of the plant or from a reputable source. 

  

2.2 Data Sources Accepted for Use 

 ERG reviewed all data sources and determined which to include in the analytical 

database. Table 2-2 presents a summary of the FGD wastewater data that met EPA’s data 

acceptance criteria and were compiled in the analytical database. The following sections further 

describe each data source in more detail.
Memorandum 

September 30, 2015 Page 3 

Table 2-2. FGD Wastewater Data Sources Accepted for Use and Included in the Analytical Da

Plant Name Data Set Document Control Number(s) Wastestream Classification Date Range 

Allen 

EPA Field Sampling Program SE01307 FGD Purge, CP Effluent, Bio Effluent 8/2/2010 - 8/6/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A04 FGD Purge, CP Effluent, Bio Effluent 10/5/2010 - 1/13/2011 Classica

Mercury

EPA Data Requesta SE01809, SE04360A001 FGD Purge, CP Effluent, Bio Effluent 9/9/2009-5/23/2011; 5/10/2010-10/22/2013 Classica

Mercury

Belews Creek 

EPA Field Sampling Program SE01305 FGD Purge, CP Effluent, Bio Effluent 6/7/2010-6/10/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A01 FGD Purge, CP Effluent, Bio Effluent 10/6/2010-1/17/2011 Classica

Mercury

EPA Data Requesta SE01808, SE04360A003 FGD Purge, CP Effluent, Bio Effluent 8/4/2008-5/25/2011; 6/9/2010-11/28/2013 Classica

Mercury

Brindisi EPA Field Sampling Program SE02013 FGD Purge, FGD Evaporator Distillate, FGD Crystallizer Condensate 4/6/2011 - 4/7/2011 Classica

Mercury

Dickerson 

EPA Field Sampling Program SE01308 FGD Purge, CP Effluent, SBR Effluent 8/23/2011 - 8/27/2011 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A05 FGD Purge, CP Effluent, SBR Effluent 9/29/2010-1/12/2011 Classica

Mercury

Hatfield's Ferry 

EPA Field Sampling Program SE01310 FGD Purge, CP Effluent 12/6/2010-12/9/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A07 FGD Purge, CP Effluent 10/15/2010-2/9/2011 Classica

Mercury

EPA Data Request 

SE04679A1, SE04316A7, SE04316A8, SE04316A11 

CP Effluent 6/30/2009 - 12/10/2013 Classica

Mercury

Iatan EPA CWA 308 Monitoring Program SE01326A08 FGD Purge, FGD Evaporator Distillate 1/24/2011 - 1/28/2011 Classica

Mercury

Keystone 

EPA Field Sampling Program SE01309 FGD Purge, CP Effluent 9/13/2010-9/16/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A06 FGD Purge, CP Effluent 10/7/2010-1/13/2011 Classica

Mercury
Memorandum 

September 30, 2015 Page 4 

Plant Name Data Set Document Control Number(s) Wastestream Classification Date Range 

EPA Data Request SE04678A1 FGD Purge, CP Effluent 1/3/2012-12/30/2013 Chloride

Miami Fort 

EPA Field Sampling Program SE01304, SE01311b FGD Purge, CP Effluent 7/12/2010-7/15/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A03 FGD Purge, CP Effluent 9/28/2010-1/14/2011 Classica

Mercury

EPA Data Request SE04360A123, SE04331A6 FGD Purge, CP Effluent 7/1/2009-12/3/2013 Arsenic, Duke Energy Comment on the Proposed Rule 

4305, Appendix A (Table A-6 and A-7) CP Effluent 7/1/2009-5/8/2013 Arsenic, 

Monfalcone EPA Field Sampling Program SE03795, SE03796 FGD Purge, FGD Evaporator Distillate, FGD Crystallizer Condensate 4/1/2011 Metals (i

Selenium

Mountaineer EPA Data Request SE04375 FGD Purge 2/13/2013 - 11/14/2013 Arsenic, Pleasant Prairie 

EPA Field Sampling Program SE01306 FGD Purge, CP Effluent 6/21/2010-6/24/2010 Classica

Mercury

EPA CWA 308 Monitoring Program SE01326A02 FGD Purge, CP Effluent 9/30/2010-1/26/2011 Classica

Mercury

We Energies Comment on the Proposed Rule 4475A02 

FGD Purge, CP Primary 

Clarifier Effluent, CP 

Effluent 

10/4/2007-7/24/2013 Arsenic, 

EPA Data Request SE04666A1 CP Effluent 11/7/2012-12/18/2013 Arsenic, 

Roxboro Long-Term Characterization Data SE01812 FGD Purge, Bio Effluent, FGD Pond Effluent, Comingled Wastewater 6/3/2008 - 6/2/2009 Classica

Selenium

a-EPA received plant self-monitoring date sets from Duke Energy’s Allen and Belews Creek Stations for the proposed rule and final ELG

b-Provided the CBI and sanitized version of the Final Sampling Episode Report for Duke Energy’s Miami Fort Station. 
Memorandum 

September 30, 2015 

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2.2.1 EPA Field Sampling Program 

 Between July 2007 and April 2011, EPA conducted a sampling program at different 

steam electric power plants in the United States and Italy to collect wastewater characterization 

data and treatment performance data associated with FGD wastewater. 

EPA conducted sampling episodes at the following plants: 

 Duke Energy’s Miami Fort Station, Ohio [ERG, 2012a]. 

 Duke Energy Carolina’s Belews Creek Steam Station, North Carolina [ERG, 2012b]. 

 We Energies’ Pleasant Prairie Power Plant, Wisconsin [ERG, 2012c]. 

 Duke Energy Carolina’s Allen Steam Station, North Carolina [ERG, 2012d]. 

 Mirant Mid-Atlantic, LLC’s Dickerson Generating Station, Maryland [ERG, 2012e]. 

 NRG Energy’s Keystone Generating Station, Pennsylvania [ERG, 2012f]. 

 FirstEnergy’s Hatfield’s Ferry Power Station, Pennsylvania [ERG, 2012g]. 

 Enel’s Federico II Power Plant (Brindisi), Italy [ERG, 2012h] 

 Each sampling episode report describes the sampling activities and presents the analytical 

results from the sampling episode. For more information about the EPA field sampling program, 

see Section 3.4.1 of the Technical Development Document for the Effluent Limitations 

Guidelines and Standards for the Steam Electric Power Generating Point Source Category 

(“TDD”; EPA-821-R15-007). 

 EPA determined that the plants listed above represent the steam electric power industry 

in terms of FGD wastewater characteristics and FGD wastewater treatment. EPA conducted 

sampling episodes at plants containing each of the three technologies the best available 

technology economically achievable (BAT) regulatory options are based on: 

 Chemical precipitation (including hydroxide and sulfide precipitation and iron 

coprecipitation) (e.g., Pleasant Prairie, Miami Fort, Keystone, Hatfield’s Ferry, 

Dickerson). 

 Chemical precipitation (including hydroxide and sulfide precipitation and iron 

coprecipitation) followed by anoxic/anaerobic biological treatment (e.g., Belews 

Creek, Allen). 

 Chemical precipitation/iron coprecipitation (including hydroxide and sulfide 

precipitation and iron coprecipitation) followed by vapor-compression evaporation 

(evaporation) (e.g., Brindisi). 

ERG included these data in the analytical database because they are EPA-collected data 

in support of the rulemaking. Therefore, the data collection activities followed EPA’s quality 

assurance (QA) procedures detailed in the QAPP. 
Memorandum 

September 30, 2015 

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2.2.2 EPA CWA 308 Monitoring Program 

EPA required steam electric power plants to collect samples that were used to supplement 

the EPA on-site sampling program. Each of the seven plants selected for the EPA field sampling 

program was required to participate in the CWA 308 monitoring program so EPA could evaluate 

the variability associated with the performance of the FGD wastewater treatment system. EPA 

also required additional plants (not sampled by EPA) to participate in its CWA 308 monitoring 

program to characterize other wastestreams or treatment technologies, including Kansas City 

Power & Light’s Iatan Station, which was the only plant in the United States operating an 

evaporation system to treat FGD wastewater at the time of EPA’s sampling program. 

EPA directed the following plants to collect FGD wastewater samples under the CWA 

308 monitoring program: 

 Duke Energy Carolina’s Belews Creek Steam Station, North Carolina [ERG, 2012i]. 

 We Energies’ Pleasant Prairie Power Plant, Wisconsin [ERG, 2012j]. 

 Duke Energy’s Miami Fort Station, Ohio [ERG, 2012k]. 

 Duke Energy Carolina’s Allen Steam Station, North Carolina [ERG, 2012l]. 

 Mirant Mid-Atlantic, LLC’s Dickerson Generating Station, Maryland [ERG, 2012m]. 

 NRG Energy’s Keystone Generating Station, Pennsylvania [ERG, 2012n]. 

 FirstEnergy’s Hatfield’s Ferry Power Station, Pennsylvania [ERG, 2012o]. 

 Kansas City Power and Light’s Iatan Generating Station, Missouri [ERG, 2012p]. 

For more information about the EPA CWA 308 Monitoring Program, see Section 3.4.2 of 

the TDD or “Power Plant Monitoring Data Collected under Clean Water Act Section 308 

Authority ("CWA 308 Monitoring Data")” [ERG, 2012q]. ERG included these data in the 

analytical database because the data collection program followed EPA’s QA procedures detailed 

in the QAPP. 

2.2.3 Industry-Submitted Plant Data 

 ERG compiled industry-submitted plant data provided during the proposed rule public 

comment period and EPA data requests into the analytical database. Upon reviewing the 

comments received, EPA determined additional information was needed or would be useful in 

evaluating FGD wastewater characterization and treatment performance. Therefore, in response 

to the comments on the proposed rule and to evaluate issues raised in the comments, EPA 

requested additional long-term plant self-monitoring FGD wastewater data from operating 

companies to augment the data collected in the EPA field sampling and EPA CWA 308 sampling 

programs. EPA provided operating companies with plant-specific direction for the type of FGD 

wastewater data EPA was requesting, as well as table shells with the desired format for reporting 

the sample results. EPA also requested operating companies provide FGD operational data, such 

as coal information, FGD system information (e.g., daily chloride, pH, ORP), and unit electricity 

generation. 
Memorandum 

September 30, 2015 

Page 7 

ERG compiled industry-submitted data in response to the EPA data requests from the 

following plants: 

 Duke Energy Carolina’s Belews Creek Steam Station, North Carolina [Duke Energy 

2011a; Duke Energy 2014]. 

 We Energies’ Pleasant Prairie Power Plant, Wisconsin [We Energies, 2014]. 

 Duke Energy’s Miami Fort Station, Ohio [Duke Energy, 2014]. 

 Duke Energy Carolina’s Allen Steam Station, North Carolina [Duke Energy 2011b; 

Duke Energy 2014]. 

 FirstEnergy’s Hatfield’s Ferry Power Station, Pennsylvania [FirstEnergy, 2014a; 

FirstEnergy, 2014b]. 

 NRG Energy’s Keystone Generating Station, Pennsylvania [NRG Energy, 2014]. 

 American Electric Power’s Mountaineer Plant, West Virginia [AEP, 2014]. 

In addition, ERG evaluated all comments for possible sources of FGD analytical data. 

ERG identified two data sets obtained through public comments on the proposed rule that 

followed EPA’s criteria and QA procedures. ERG compiled FGD wastewater data submitted as 

part of public comments on the proposed rule for: 

 Duke Energy’s Miami Fort Station, Ohio [Duke Energy, 2013]. 

 We Energies’ Pleasant Prairie Power Plant, Wisconsin [We Energies, 2013]. 

 ERG compared the FGD wastewater analytical data provided in public comments to data 

EPA already compiled to ensure it was not duplicative. ERG determined that the We Energies 

comment data did not overlap with previously compiled data; however, a portion of the Duke 

Energy Comment Data overlapped with the Miami Fort EPA request data and only the additional 

unique data was compiled into the analytical database. 

 ERG requested FGD wastewater analytical data from plants to supplement the EPA field 

sampling and EPA CWA 308 Monitoring data. ERG requested FGD wastewater data from Duke 

Energy’s Allen and Belews Creek Station for the proposed rule. In addition, ERG requested 

additional FGD plant self-monitoring data from Allen, Belews Creek, Miami Fort, Pleasant 

Prairie, Hatfield’s Ferry, and Mountaineer plants. All of these data were included in the 

analytical database. EPA and ERG corresponded with the operating companies to clarify 

questions about the analytical data and certify that the data was reputable. Table 2-3 presents the 

name and source (by DCN) of the industry correspondence. 

Table 2-3. Correspondence Summaries for Industry-Submitted Plant Data 

Operating Company Plant Name DCN 

Duke Energy 

Allen Steam Station 

Belews Creek Steam Station SE04331 

Miami Fort Station 

FirstEnergy Hatfield’s Ferry Power Station SE04316 

NRG Energy Keystone Generating Station SE04318 
Memorandum 

September 30, 2015 

Page 8 

We Energies Pleasant Prairie Power Plant SE04328 

2.2.4 State-Provided Data 

 EPA interacted with states and EPA regional permitting authorities throughout the 

development of this rule. Through these interactions, EPA obtained Progress Energy's Roxboro 

Plant monitoring data from The North Carolina Department of Environment and Natural 

Resources (NCDENR). The FGD analytical data contained several types of wastewater, 

including FGD purge, FGD settled pond effluent, anaerobic bioreactor effluent with and without 

ash pond effluent, and NPDES discharge data [NCDENR, 2011]. All of these data were included 

in the analytical database. 

2.3 Additional Data Sources Considered but Not Accepted for Use 

This section summarizes data sources that ERG reviewed and did not meet EPA’s data 

acceptance criteria for use. 

2.3.1 EPA Field Sampling Program 

EPA requested the collection of 1-day grab samples from a second plant in Italy, A2A’s 

Centrale di Monfalcone (Monfalcone). This plant treats FGD wastewater using a system 

comprising chemical precipitation followed by evaporation. Monfalcone personnel collected 

samples of the FGD influent to wastewater treatment, the distillate from the brine concentrator, 

and the condensate from the crystallizer. Site visit notes and the corresponding analytical results 

are included in the rulemaking record. These data were not compiled into the analytical database 

because EPA collected only one day of data for this treatment system [ERG, 2013b]. 

2.3.2 Industry-Submitted Plant Data 

 ERG obtained industry-submitted plant data provided during the proposed rule public 

comment period and EPA data requests that were not compiled into the analytical database. EPA 

received FGD wastewater data from the Utility Water Action Group (UWAG) as a part of public 

comment; however, all of this data were duplicative of more detailed FGD wastewater data 

provided in EPA’s data request [UWAG, 2013]. In addition, EPA acquired FGD wastewater data 

from EPA’s data request for pilot-scale studies performed at Cliffside Steam Station and Wateree 

Station; but these data were not representative of full-scale operations [Duke Energy, 2014; 

SCANA; 2014]. 

2.3.3 Steam Electric Survey Data 

 The Steam Electric Survey (Question B6-1) asked plants whether monitoring data was 

collected for untreated FGD scrubber purge or slurry discharge in the 12 months prior to 

receiving the survey for any of the following analytes: 

 Metals (including monitoring data for total recoverable or dissolved metals analyses, 

or trace metals analyses). 

 Ammonia. 
Memorandum 

September 30, 2015 

Page 9 

 Nitrate/Nitrite. 

 Total Kjeldahl nitrogen (TKN). 

 Total cyanide. 

 If the plant indicated that FGD purge monitoring data were collected, the Steam Electric 

Survey (Question B6-2, Table B-9) requested submittal of the data. EPA received plant selfmonitoring data from 36 steam electric power plants for untreated FGD scrubber purge [ERG, 

2015a]. EPA determined that that data set would not be included in the analytical database 

because analytical data was duplicative, sample location not able to be verified, sample location 

not appropriate for purge/treatment data, data provided did not contain all information needed for 

EPA’s analyses, and/or analytical methods were not acceptable for EPA’s analyses. 

 Steam electric power plants also provided FGD wastewater data in Part D of the Steam 

Electric Survey (Question D2-1 through D2-4). The responses identified potential FGD 

wastewater treatment studies. ERG documented the review of the Part D wastewater studies in 

FGD Analytical Data Review Matrix (“FGD Review Matrix”; DCN SE05877), including ERG’s 

rationale for whether the data were accepted for use. 

2.3.4 EPRI Reports 

Electric Power Research Institute (EPRI) is a research-oriented trade association for the 

steam electric industry. EPRI conducts research funded by the steam electric industry and has 

extensively studied wastewater discharges from FGD systems. EPA received technical reports 

from the trade association and as part of plant responses to the Steam Electric Survey. 

 ERG reviewed EPRI reports that were provided by industry, in the supplemental files of 

the Steam Electric Survey responses, in public comments on the proposed ELGs, by EPRI, or 

publically available online. For more information, see the FGD Review Matrix (DCN SE05877). 

In addition, EPA received EPRI reports from EPA that were reviewed and determined to not 

follow EPA’s criteria for compilation into the analytical database. Table 2-4 presents the EPRI 

reports containing FGD wastewater data that EPA reviewed. 

Table 2-4. Reports and Studies Containing FGD Wastewater Data Submitted to EPA 

from EPRI 

Title of Report/Study DCN 

PISCES Wastewater Characterization Field Study, Sites D and F SE01820; 

SE01822 

The Fate of Mercury Absorbed in Flue Gas Desulfurization (FGD) Systems SE01814 

Flue Gas Desulfurization (FGD) Wastewater Characterization: Screening Study SE01816 

EPRI Technical Manual: Guidance for Assessing Wastewater Impacts of FGD Scrubbers SE01817 

Update on Enhanced Mercury Capture by Wet FGD: Technical Update SE01815 

Selenium Removal by Iron Cementation from a Coal-Fired Power Plant Flue Gas Desulfurization 

Wastewater in Continuous Flow System – A Pilot Study 

SE0409A2 
Memorandum 

September 30, 2015 

Page 10 

Table 2-4. Reports and Studies Containing FGD Wastewater Data Submitted to EPA 

from EPRI 

Title of Report/Study DCN 

Laboratory and Pilot Evaluation of Iron and Sulfide Additives with Microfiltration for Mercury 

Water Treatment 

SE0409A3 

Impact of Wet Flue Gas Desulfurization (FGD) Design and Operating Conditions on Selenium 

Speciation: 2009 Update 

SE04369 

Current Practices for Flue Gas Desulfurization (FGD) Water Management and Treatment in Ponds SE04367 

Pilot-Scale and Full-Scale Evaluation of Treatment Technologies for the Removal of Mercury and 

Selenium in Flue Gas Desulphurization Water 

SE04362 

Impact of Wet Flue Gas Desulfurization (FGD) Design and Operating Conditions on Selenium 

Speciation: 2010 Update 

SE04370 

Review of Water Treatment Technologies for Selenium Removal Implemented at Power Plants SE04363 

Evaluation of Mercury Speciation and Its Treatment Implication in Flue Gas Desulfurization Waters SE04368 

Thermal Flue Gas Desulfurization Wastewater Treatment Processes for Zero Liquid Discharge 

Operations 

SE04365 

Selenium Speciation and Management in Wet FGD Systems SE04364 

Corrosion in Wet Flue Gas Desulfurization (FGD) Systems: Technical Root Cause Analysis of 

Internal Corrosion on Wet FGD Alloy Absorbers 

SE04366 

Pilot Evaluation of the Anaerobic Membrane Bioreactor Technology for Flue Gas Desulfurization 

Wastewater Treatment 

SE05615 

Pilot Evaluation of the PironoxTM System for Flue Gas Desulphurization Wastewater Treatment SE05616 

Pilot Evaluation of a Fluidized Bed Reactor/Membrane Bioreactor Technology for Flue Gas 

Desulfurization Wastewater Treatment 

SE05617 

Pilot Evaluation of the ABMet Technology for Flue Gas Desulphurization Wastewater Treatment SE05618 

Pilot Evaluation of the ZVI BlueTM Technology for Flue Gas Desulphurization Wastewater 

Treatment 

SE05619 

2.3.5 Detailed Study Sampling Data 

As part of the detailed study performed prior to beginning the rulemaking process, EPA 

conducted a sampling program to characterize FGD wastewaters generated by coal-fired power 

plants. Between July 2007 and October 2008, EPA collected one-day grab samples of FGD 

untreated and treated wastewater at Big Bend, Homer City, Widows Creek, Mitchell, and Belews 

Creek. EPA used these data to evaluate treatment technologies, analyze best management 

practices for reducing pollutant discharges, and develop questions for the Steam Electric Survey. 

EPA analyzed the samples for total metals (including 25 specific metals), hexavalent chromium, 

nitrogen compounds, and other classical analytes. These data were not compiled because ERG 

determined that the FGD samples from the detailed study were not collected and sampled with 

similar quality assurance stringency as EPA’s field sampling program. For more information 

about data collected during the EPA’s detailed study, see Steam Electric Power Generating Point 

Source Category: Detailed Study Report [U.S. EPA, 2009]. 
Memorandum 

September 30, 2015 

Page 11 

3.0 ANALYTICAL DATA CORRECTIONS AND EXCLUSIONS

After compiling accepted data into the analytical database, ERG further evaluated the 

FGD wastewater data to ensure it was representative of typical FGD purge and treatment 

operations. In this review, ERG determined which data compiled in the database were acceptable 

for use in subsequent analyses (see Error! Reference source not found.Table 2-1). ERG 

corrected data based on review of analytical laboratory reports and discussions with the specific 

plant or company representatives. ERG identified inconsistencies in the data and confirmed 

corrected values with the plants prior to making corrections to the analytical database. 

ERG, with EPA, also corresponded with the plants to discuss the variability of the data 

and relevant operating information during those time periods (see Table 2-3). Based on these 

discussions, EPA identified data points within a given data set that do not meet EPA’s data 

acceptance criteria (see Table 2-1). 

3.1 FGD Analytical Data Changes/Additions 

In order to represent the most accurate data, ERG made corrections and/or additions to 

the analytical data spreadsheets provided by industry. These changes or additions were 

confirmed with the operating company or another more reputable source (e.g., analytical 

laboratory report). For more information about ERG’s correspondence with the operating 

companies, see Table 2-3. ERG documented all the changes to the FGD analytical data compiled 

in the analytical database by a unique record identification number. This documentation contains 

the identifying fields (e.g., date collected, analyte, amount, reporting limit (RL), wastewater 

classification) along with a summary of the change (e.g., changed dilution factor, added RL, 

changed amount) and source (e.g., lab report comparison (DCN), follow up correspondence 

(DCN)). ERG provides this documentation as an attachment to this memorandum (see 

SE05880A1). 

3.2 Unacceptable Analytical Methods 

 ERG reviewed FGD wastewater analytical data to evaluate whether the analytical 

methods used were accepted for use in calculating pollutant loadings and effluent limitations. For 

more information about EPA’s evaluation of the analytical methods, see the Review of Analytical 

Methods Used for Industry Self-Monitoring Data Considered for FGD Wastewater Effluent 

Limits (“Analytical Methods Memo”; DCN SE06278). 

3.3 Uncharacteristic and Atypical Operations 

 ERG excluded samples collected during atypical or uncharacteristic operations (e.g., pipe 

leak, commissioning period, atypical chemical addition). ERG analyzed the FGD wastewater 

data for outliers (i.e., very low/high pollutant concentrations) and followed up with the plant to 

determine whether the FGD scrubber or FGD wastewater treatment system was operating under 

normal conditions during the time of sample collection. For more details about this analysis, see 

the “Effluent Limitations for FGD Wastewater, Gasification Wastewater, and Combustion 

Residual Leachate for the Final Effluent Limitations Guidelines and Standards for the Steam 
Memorandum 

September 30, 2015 

Page 12 

Electric Rulemaking” [Westat, 2015]. For more information about the correspondence with 

operating companies, see Table 2-3. 

4.0 USES OF SAMPLING DATA

 ERG applied the acceptance criteria, described in Section 2.0, to all of the data compiled 

into the FGD analytical data set. Table 4-1 presents which data sources were accepted and used 

in the POC analysis, the treatment effectiveness analysis, and the pollutant loadings analysis as a 

result of ERG’s review. 

EPA discusses the subsequent analyses for the FGD analytical data set further in the 

“Pollutants of Concern (POC) Analysis Methodology for FGD Wastewater, Combustion 

Residual Leachate, and Gasification Wastewater”(“POC Memo”; DCN SE05342) and Section 

11 of the Influent Costs and Pollutant Removals for the Final Effluent Limitations Guidelines 

and Standards for the Steam Electric Power Generating Point Source Category (“Cost & Loads 

Report”; DCN SE05831). 
Memorandum 

September 30, 2015 Page 13 

Table 4-1. Summary of Sources and Uses of FGD Analytical Data 

Data Source Data Set 

Plant 

Identification 

POC 

Analysis 

Treatment 

Effectiveness 

Analysis 

EPRI, 1997-2001 Appendix A PISCES Site D EPRI, 1997-2001 Appendix A PISCES Site F Duke Energy, 2013 

Duke Energy Comment on the Proposed Rule Miami Fort  

ERG, 2012l EPA CWA 308 Monitoring Program Allen   ERG, 2012i EPA CWA 308 Monitoring Program Belews Creek   ERG, 2012m EPA CWA 308 Monitoring Program Dickerson ERG, 2012o EPA CWA 308 Monitoring Program Hatfield's Ferry   ERG, 2012p EPA CWA 308 Monitoring Program Iatan ERG, 2012n EPA CWA 308 Monitoring Program Keystone   ERG, 2012k EPA CWA 308 Monitoring Program Miami Fort   ERG, 2012j EPA CWA 308 Monitoring Program Pleasant Prairie   Duke Energy, 2014; Duke Energy 2011b EPA Data Request Allen   Duke Energy, 2014; Duke Energy 2011a EPA Data Request Belews Creek   Duke Energy, 2014 EPA Data Request Cliffside FirstEnergy, 2014a; FirstEnergy, 2014b EPA Data Request Hatfield's Ferry  NRG Energy, 2014 EPA Data Request Keystone   Duke Energy, 2014 EPA Data Request Miami Fort   AEP, 2014 EPA Data Request Mountaineer We Energies, 2014 EPA Data Request Pleasant Prairie  U.S. EPA, 2009 EPA Detailed Study Analytical Data Unidentified ERG, 2012d EPA Field Sampling Program Allen   ERG, 2012b EPA Field Sampling Program Belews Creek   ERG, 2012h EPA Field Sampling Program Brindisi ERG, 2012e EPA Field Sampling Program Dickerson  
Memorandum 

September 30, 2015 Page 14 

ERG, 2012g EPA Field Sampling Program Hatfield's Ferry   ERG, 2012f EPA Field Sampling Program Keystone   ERG, 2012a EPA Field Sampling Program Miami Fort   ERG, 2013b EPA Field Sampling Program Monfalcone ERG, 2012c EPA Field Sampling Program Pleasant Prairie   NCDENR, 2011 Long-Term Characterization Data Roxboro SCANA, 2015 SCANA Data Request Wateree ERG, 2015a 

Steam Electric Survey Part B FGD Purge Data 36 Plants 

ERG, 2015b Steam Electric Survey Part D Studies 5 Plants UWAG, 2013 UWAG Comment on the Proposed Rule Allen UWAG, 2013 UWAG Comment on the Proposed Rule Belews Creek UWAG, 2013 UWAG Comment on the Proposed Rule Hatfield's Ferry UWAG, 2013 UWAG Comment on the Proposed Rule Miami Fort UWAG, 2013 UWAG Comment on the Proposed Rule Pleasant Prairie We Energies, 2013 

We Energies Comment on the Proposed Rule Pleasant Prairie   
Memorandum 

September 30, 2015 

Page 15 

5.0 REFERENCES

1. AEP. 2014. Response to EPA Data Request: Mountaineer. (7 March). DCN SE04375. 

2. Duke Energy. 2011a. Response to EPA Data Request: Belews Creek. (17 August). DCN 

SE01808. 

3. Duke Energy. 2011b. Response to EPA Data Request: Allen. (17 August). DCN 

SE01809. 

4. Duke Energy. 2013. Comments of Duke Energy on Effluent Limitations Guidelines and 

Standards for the Steam Electric Power Generating Point Source Category. (7 June) EPAHQ-OW-2009-0819-4305. 

5. Duke Energy. 2014. Response to EPA Data Request. (28 March). DCN SE04360. 

6. EPRI. 1997 - 2001. Electric Power Research Institute. PISCES Water Characterization 

Field Study, Sites A-G. Palo Alto, CA. DCNs SE01818-01823. 

7. ERG. 2012a. Eastern Research Group, Inc. Final Sampling Episode Report, Duke 

Energy’s Miami Fort Station. (13 April). DCN SE01304 and SE01311. 

8. ERG. 2012b. Eastern Research Group, Inc. Sampling Episode Report, Duke Energy 

Caronlinas’ Belews Creek Steam Station. (13 April). DCN SE01305. 

9. ERG. 2012c. Eastern Research Group, Inc. Sampling Episode Report, We Energies’ 

Pleasant Prairie Power Plant. (13 April). DCN SE01306. 

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Carolinas’ Allen Steam Station. (13 April). DCN SE01307. 

11. ERG. 2012e. Eastern Research Group, Inc. Sampling Episode Report, Mirant MidAtlantic, LLC’s Dickerson Generating Station. (13 April). DCN SE01308. 

12. ERG. 2012f. Eastern Research Group, Inc. Sampling Episode Report, RRI Energy’s 

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Memorandum 

September 30, 2015 

Page 16 

16. ERG. 2012j. Eastern Research Group, Inc. CWA 308 Monitoring Report, Appendix B 

Pleasant Prairie. (21 March). DCN SE01326A02. 

17. ERG. 2012k. Eastern Research Group, Inc. CWA 308 Monitoring Report, Appendix C 

Miami Fort. (21 March). DCN SE01326A03. 

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Iatan. (21 March). DCN SE01326A08. 

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Under Clean Water Act Section 308 Authority ("CWA 308 Monitoring Data").” (27 

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Rulemaking. (5 April). DCN SE02951. 

25. ERG. 2013b. Eastern Research Group, Inc. Final Monfalcone Site Visit Notes. (11 

March). DCN SE03795 and SE03796. 

26. ERG. 2015a. Steam Electric Technical Questionnaire Database (“Steam Electric 

Survey”). (September 30). DCN SE05903. 

27. ERG. 2015b. FGD Analytical Data Review Matrix (“FGD Review Matrix”). (30 

September). DCN SE05877. 

28. ERG. 2015c. Eastern Research Group, Inc. “Development Memorandum for the Steam 

Electric Analytical Database for the Final Rule.” (30 September). DCN SE05876. 

29. ERG. 2015d. “Pollutants of Concern (POC) Analysis Methodology for FGD Wastewater, 

Combustion Residual Leachate, and Gasification Wastewater” (“POC Memo”). (30 

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30. FirstEnergy. 2014a. Response to EPA Data Request: Hatfield’s Ferry (21 February). 

DCN SE04679. 
Memorandum 

September 30, 2015 

Page 17 

31. FirstEnergy. 2014b. Follow Up Correspondence with FirstEnergy about Hatfield’s Ferry 

Station. DCN SE04316. 

32. NCDENR. 2011. North Carolina Department of Environment and Natural Resources. 

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SE01812. 

33. NRG Energy. 2014. Response to EPA Data Request: Keystone. (21 February). DCN 

SE04678. 

34. SCANA. 2014. Response to Wateree Pilot Test Data Request. (24 December). 

DCNSE05872. 

35. U.S. EPA. 2009. Steam Electric Power Generating Point Source Category: Final Detailed 

Study. EPA 821-R-09-008. Washington, DC (October). Available online 

at: http://water.epa.gov/lawsregs/guidance/cwa/304m/archive/upload/2009_10_26_guide

_steam_finalreport.pdf. DCN SE00003. 

36. UWAG. 2013. Comments of UWAG on Effluent Limitations Guidelines and Standards 

for the Steam Electric Power Generating Point Source Category. (26 September). EPAHQ-OW-2009-0819-4655-A19. 

37. We Energies. 2013. Comments of We Energies on Effluent Limitations Guidelines and 

Standards for the Steam Electric Power Generating Point Source Category. (20 

September). EPA-HW-OW-0819-4475. 

38. We Energies. 2014. Response to EPA Data Request: Pleasant Prairie. (10 February). 

DCN SE04666. 

39. Westat. 2015. Memorandum to Ronald Jordan: “Effluent Limitations for FGD 

Wastewater, Gasification Wastewater, and Combustion Residual Leachate for the Final 

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SE05733.