### 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 I NTRODUCTION

ERG is providing technical support to the U.S. Environmental Protection Agency’s Office of Water, Engineering and Analysis Di vision (EPA) for development of the effluent limitations guidelines and standards (ELGs) fo r the Steam Electric Power Generating Industry. As part of this techni cal support, ERG performed a detailed review of fl ue gas desulfurization (FGD) wastewater analytical data to identi fy acceptable data for use in identifying FGD wastewater pollutants of concern (POC), calcu lating pollutant loadings for FGD wastewater discharges, and performing the tr eatment effectiveness analysis. This memorandum describes the

data sources evaluated for FGD wastewater a nd 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 anal ytical data set which includes all data EPA used as a part of the ELGs. ER G provides documentation of revised or edited FGD

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

2.0 A NALYTICAL D ATA S OURCES

ERG performed a detailed review of the follo wing 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 re quested 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 (E PRI) Reports, Wastewater Studies).

Section 2.1 discusses EPA’s data acceptance criteria, Section 2.2 su mmarizes all the data sources that were accepted and compiled into the analyt ical database, and Sec tion 2.3 describes data

sources that were not acce pted 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 ac ceptance 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 id entify FGD wastewater concentration data for inclusion in analyses for identi fying POCs, effectively treating po llutants, 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 wastew ater 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 av erages or plant-specific long-term

averages   

Analytical data must contain all in formation 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 comple ted 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., re porting 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 determ ined which to include in the analytical database. Table 2-2 presents a summary of th e FGD wastewater data that met EPA’s data acceptance criteria and were compiled in the anal ytical database. The following sections further

describe each data source in more detail.MemorandumSeptember 30, 2015Page 3Table 2-2. FGD Wastewater Data Sources Accepted for Use and Included in the Analytical DatabasePlant NameData SetDocument ControlNumber(s)WastestreamClassificationDate RangeAnalytesAllenEPA Field SamplingProgramSE01307FGD Purge, CP Effluent,Bio Effluent8/2/2010 - 8/6/2010Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA CWA 308Monitoring ProgramSE01326A04FGD Purge, CP Effluent,Bio Effluent10/5/2010 - 1/13/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA Data RequestaSE01809,SE04360A001FGD Purge, CP Effluent,Bio Effluent9/9/2009-5/23/2011;5/10/2010-10/22/2013Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)Belews CreekEPA Field SamplingProgramSE01305FGD Purge, CP Effluent,Bio Effluent6/7/2010-6/10/2010Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA CWA 308Monitoring ProgramSE01326A01FGD Purge, CP Effluent,Bio Effluent10/6/2010-1/17/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA Data RequestaSE01808,SE04360A003FGD Purge, CP Effluent,Bio Effluent8/4/2008-5/25/2011;6/9/2010-11/28/2013Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)BrindisiEPA Field SamplingProgramSE02013FGD Purge, FGDEvaporator Distillate, FGDCrystallizer Condensate4/6/2011 - 4/7/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)DickersonEPA Field SamplingProgramSE01308FGD Purge, CP Effluent,SBR Effluent8/23/2011 - 8/27/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA CWA 308Monitoring ProgramSE01326A05FGD Purge, CP Effluent,SBR Effluent9/29/2010-1/12/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)Hatfield'sFerryEPA Field SamplingProgramSE01310 FGD Purge, CP Effluent 12/6/2010-12/9/2010Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA CWA 308Monitoring ProgramSE01326A07 FGD Purge, CP Effluent 10/15/2010-2/9/2011Classicals, Metals (including Arsenic,Mercury, Selenium, Nitrate/Nitrate as N)EPA Data RequestSE04679A1,SE04316A7,SE04316A8,SE04316A11CP Effluent6/30/2009 -12/10/2013Classicals, Metals (including Arsenic,Mercury, Selenium)IatanEPA CWA 308Monitoring ProgramSE01326A08FGD Purge, FGDEvaporator Distillate1/24/2011 - 1/28/2011Classicals, Metals (including Arsenic,Mercury, Selenium)KeystoneEPA Field SamplingProgramSE01309 FGD Purge, CP Effluent 9/13/2010-9/16/2010Classicals, Metals (including Arsenic,Mercury, Selenium)EPA CWA 308Monitoring ProgramSE01326A06 FGD Purge, CP Effluent 10/7/2010-1/13/2011Classicals, Metals (including Arsenic,Mercury, Selenium)MemorandumSeptember 30, 2015Page 4Plant NameData SetDocument ControlNumber(s)WastestreamClassificationDate RangeAnalytesEPA Data Request SE04678A1 FGD Purge, CP Effluent 1/3/2012-12/30/2013 Chloride, Arsenic, MercuryMiami FortEPA Field SamplingProgramSE01304, SE01311bFGD Purge, CP Effluent 7/12/2010-7/15/2010Classicals, Metals (including Arsenic,Mercury, Selenium)EPA CWA 308Monitoring ProgramSE01326A03 FGD Purge, CP Effluent 9/28/2010-1/14/2011Classicals, Metals (including Arsenic,Mercury, Selenium)EPA Data RequestSE04360A123,SE04331A6FGD Purge, CP Effluent 7/1/2009-12/3/2013 Arsenic, MercuryDuke Energy Commenton the Proposed Rule4305, Appendix A(Table A-6 and A-7)CP Effluent 7/1/2009-5/8/2013 Arsenic, MercuryMonfalconeEPA Field SamplingProgramSE03795, SE03796FGD Purge, FGDEvaporator Distillate, FGDCrystallizer Condensate4/1/2011Metals (including Arsenic, Mercury,Selenium)Mountaineer EPA Data Request SE04375 FGD Purge2/13/2013 -11/14/2013Arsenic, Mercury, Selenium, AmmoniaPleasantPrairieEPA Field SamplingProgramSE01306 FGD Purge, CP Effluent 6/21/2010-6/24/2010Classicals, Metals (including Arsenic,Mercury, Selenium)EPA CWA 308Monitoring ProgramSE01326A02 FGD Purge, CP Effluent 9/30/2010-1/26/2011Classicals, Metals (including Arsenic,Mercury, Selenium)We Energies Comment onthe Proposed Rule4475A02FGD Purge, CP PrimaryClarifier Effluent, CPEffluent10/4/2007-7/24/2013 Arsenic, Mercury, SeleniumEPA Data Request SE04666A1 CP Effluent 11/7/2012-12/18/2013 Arsenic, MercuryRoxboroLong-TermCharacterization DataSE01812FGD Purge, Bio Effluent,FGD Pond Effluent,Comingled Wastewater6/3/2008 - 6/2/2009Classicals, Metals (including Mercury,Selenium)a-EPA received plant self-monitoring date setsfrom Duke Energy’s Allen and Belews CreekStations for the proposed rule and finalELGs.b-Provided the CBI and sanitized version of the Final Sampling Episode Report for Duke Energy’s Miami Fort Station.Memorandum September 30, 2015 Page 5

2.2.1 EPA Field Sampling Program

Between July 2007 and April 2011, EPA conduc ted a sampling program at different steam electric power plants in the United States and Italy to collect wast ewater 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 sa mpling activities and presents the analytical results from the sampling episode. For more in formation 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 El ectric 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 wastew ater 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 hydroxi de and sulfide precipitation and iron coprecipitation) (e.g., Pleasan t Prairie, Miami Fort, Ke ystone, Hatfield’s Ferry, Dickerson).

 Chemical precipitation (including hydroxi de and sulfide precipitation and iron coprecipitation) followed by anoxic/anaer obic biological treatment (e.g., Belews Creek, Allen).

 Chemical precipitation/iron coprecipit ation (including hydr oxide and sulfide precipitation and iron coprecipitation) fo llowed by vapor-compression evaporation (evaporation) (e.g., Brindisi).

ERG included these data in the analytical da tabase 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 Page 6

2.2.2 EPA CWA 308 Monitoring Program

EPA required steam electric power plants to co llect samples that were used to supplement the EPA on-site sampling program. Each of the se ven plants selected for the EPA field sampling program was required to participate in the CW A 308 monitoring program so EPA could evaluate the variability associated with the performan ce of the FGD wastewater treatment system. EPA also required additional plants (not sampled by EPA) to par ticipate in its CWA 308 monitoring program to characterize other wastestreams or treatment technologies, including Kansas City Power & Light’s Iatan Station, which was the on ly 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 colle ct 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 collecti on 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 th e analytical database . Upon reviewing the comments received, EPA determined additional info rmation was needed or would be useful in evaluating FGD wastewater charac terization and treatmen t performance. Therefore, in response to the comments on the proposed rule and to ev aluate issues raised in the comments, EPA requested additional long-term plant self-mon itoring 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 pl ant-specific direction for the type of FGD wastewater data EPA was requestin g, as well as table shells with the desired format for reporting the sample results. EPA also requested operatin g 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 res ponse 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 F GD analytical data. ERG identified two data sets obtained through public comments on the proposed rule that followed EPA’s criteria and QA procedures. ER G 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 duplic ative. 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 da ta from plants to supplement the EPA field sampling and EPA CWA 308 Monitoring data. ERG re quested FGD wastewater data from Duke Energy’s Allen and Belews Creek Station for th e proposed rule. In addition, ERG requested additional FGD plant self-monitoring data fr om Allen, Belews Creek, Miami Fort, Pleasant Prairie, Hatfield’s Ferry, and Mountaineer plan ts. 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

SE04331 Belews Creek Steam Station

Miami Fort Station FirstEnergy Hatfield’s Ferry Power Station SE04316 NRG Energy Keystone Generating Station SE04318Memorandum September 30, 2015 Page 8

We Energies Pleasant Prairie Power Plant SE04328

2.2.4 State-Provided Data

EPA interacted with states and EPA re gional permitting authorities throughout the development of this rule. Through these intera ctions, EPA obtained Progress Energy's Roxboro Plant monitoring data from The North Carolina Department of Environment and Natural Resources (NCDENR). The FGD an alytical data contained se veral types of wastewater, including FGD purge, FGD settled pond effluent, anaer obic bioreactor efflue nt with and without ash pond effluent, and NPDES discharge data [NCD ENR, 2011]. All of these data were included in the analytical database.

2.3 Additional Data Sources Consid ered 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 (Monf alcone). This plant treats FGD wastewater using a system comprising chemical precipitation followed by ev aporation. Monfalcone personnel collected samples of the FGD influent to wastewater treatm ent, the distillate from the brine concentrator, and the condensate from the crys tallizer. 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 duplic ative 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 pilo t-scale studies performed at Cli ffside Steam Station and Wateree Station; but these data were not representativ e of full-scale operati ons [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 a ny 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 su bmittal 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 woul d 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 prov ided 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 F GD 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”; DC N 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 recei ved technical reports from the trade association and as part of plant responses to the Steam Electric Survey.

ERG reviewed EPRI reports that were provi ded 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 informa tion, see the FGD Review Matrix (DCN SE05877). In addition, EPA received EPRI re ports 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 wastewat er 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 SE0409A2Memorandum 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 Treatmen t 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 Tr eatment Processes for Ze ro 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 prio r to beginning the rulemaking process, EPA conducted a sampling program to characterize F GD wastewaters generated by coal-fired power plants. Between July 2007 and October 2008, EP A collected one-day grab samples of FGD

untreated and treated wastewater at Big Bend, Homer C ity, Widows Creek, Mi tchell, and Belews

Creek. EPA used these data to evaluate treat ment technologies, anal yze best management practices for reducing pollutant discharges, and develop questions for the Steam Electric Survey. EPA analyzed the samples for total metals (incl uding 25 specific metals), hexavalent chromium, nitrogen compounds, and other cl assical analytes. These data were not compiled because ERG determined that the FGD samples from the deta iled 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 A NALYTICAL D ATA C ORRECTIONS AND E XCLUSIONS

After compiling accepted data into the anal ytical database, ERG further evaluated the

FGD wastewater data to ensure it was representative of ty pical 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 a nd discussions with the specific plant or company representatives. ERG identifie d inconsistencies in th e data and confirmed corrected values with the plants prior to ma king corrections to the analytical database.

ERG, with EPA, also corresponded with the plan ts 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 se t 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 anot her more reputable source (e.g., analytical laboratory report). For more information about ERG’s corre spondence 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 id entification number. This documentation contains the identifying fields (e.g., da te collected, analyte, amount, reporting limit (RL), wastewater classification) along with a summary of the ch ange (e.g., changed dilu tion factor, added RL, changed amount) and source (e.g., lab report co mparison (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 evaluati on 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 atypica l 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 wa stewater treatment system was operating under normal conditions during the time of sample collection. For more de tails about this analysis, see

the “Effluent Limitations for FGD Wastewat er, Gasification Wastew ater, and Combustion

Residual Leachate for the Final Effluent Limita tions Guidelines and Standards for the SteamMemorandum September 30, 2015 Page 12

Electric Rulemaking” [Westat, 2015]. For more information about the correspondence with operating companies, see Table 2-3.

4.0 U SES OF S AMPLING D ATA

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 an alysis, and the pollutant loadings analysis as a

result of ERG’s review.

EPA discusses the subsequent analyses for th e FGD analytical data set further in the “Pollutants of Concern (POC) Analysis Methodology for FGD Wastewater, Combustion Residual Leachate, and Gasification Wastewat er”(“POC Memo”; DCN SE05342) and Section

11 of the Influent Costs and Pollutant Removals for th e Final Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (“Cost & Loads Report”; DCN SE05831).MemorandumSeptember 30, 2015Page 13Table 4-1. Summary of Sources andUses of FGD Analytical DataData SourceData SetPlantIdentificationPOCAnalysisTreatmentEffectivenessAnalysisLoadingsAnalysisNo DataAcceptedfor UseEPRI, 1997-2001 Appendix A PISCES Site DEPRI, 1997-2001 Appendix A PISCES Site FDuke Energy, 2013Duke Energy Comment on the ProposedRule 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 Energy2011b EPA Data Request Allen  Duke Energy, 2014; Duke Energy2011a 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 DataUnidentified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 MemorandumSeptember 30, 2015Page 14ERG, 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, 2015aSteam Electric Survey Part B FGDPurge Data36 PlantsERG, 2015b Steam Electric Survey Part D Studies5 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, 2013We Energies Comment on the ProposedRule Pleasant Prairie  Memorandum September 30, 2015 Page 15

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