### MEMORANDUM

TO: Bill Swietlik , EPA

FROM: Jill Lucy , ERG

DATE: September 30 , 2015

SUBJECT: Loadings Analysis for the Steam Electric ELGs Environmental Assessment

(DCN SE0 44 46 )

ERG supported t he 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). As part of the environmental assessment (EA)

, ERG evaluated the environmental impact of pollutant loadings released under current ( i.e.

, baseline) discharge practices and assess ed the potential environmental improvement from pollutant loading removals associated with the r egulatory op tions (Options A, B, C, D, and E)

. 1
The results of this analysis 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)

. ERG calculated pollutant loadings and removals under two separate industry baseline scopes:

1. The “ With CCR” scope accounts for the Coal Combustion Residuals (CCR) rulemaking

. See the EA Report for the results of the analyses under this scope.

a. 222 immediate receiving waters included in the environmental assessment (195 steam electric power plants)

. 2

b. 209 immediate receiving waters included in the IRW model used for the EA ( 188 steam electric power plants).

2. The “With CCR and CPP” scope accounts for both the CCR rulemaking and the Clean Power Plan [Clean Air Act Section 111(d)]. See Appendix I of the EA Report for the results of the analyses under this scope.

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.

2 EPA also calculated loadings for in direct discharges to publicly owned treatment works. Four of the 195 steam electric power plants discharge both directly and indirectly. There are also seven additional steam electric power plants that discharge indirectly only.Memorandum

September 30 , 2015 Page 2

a. 172 immediate receiving waters included in the environmental assessment ( 148

steam electric power plants)

.
b. 163 immediate receiving waters included in the IRW model used for the EA (143 steam electric power plants)

.

This memorandum provides a summary of the data and calculations performed as part of the EA loadings analysis an d includes the following sections:

 Section 1: Background on Pollutant Loadings Methodology.

 Section 2: Industry Pollutant Loadings.

 Section 3: Comparison of Steam Electric Power Plant Pollutant Loadings to Publicly Owned Treatment Works Loadings.

 Section 4: Pollutant Loadings to Sensitive Environments.

 Section 5: Pollutant Removals Associated with the Regulatory Options.

 Section 6: References.

ERG developed the MS ExcelTM spreadsheet, EA Loadings Analyses (With CCR) (DCN SE04464) and the MS ExcelTM spreadsh eet, EA Loadings Analyses (With CPP) (DCN SE04473), to support this analysis and perform the calculations. Re sults of the EA loadings analysi s are presented i n the EA Report.

1.0 B ACKGROUND ON P OLLUTANT L OADINGS M ETHODOLOGY

ERG calculated pollutant loadings on a plant

- by

- plan t basis for all steam electric power plants that discharge one of the evaluated wastestreams and would achieve pollutant removals

under the final ELGs

. The evaluated wastestreams include flue gas desulfurization (FGD) wastewater, fly ash transport water, bottom ash transport water, and combustion residual

leachate. The loadings methodology and calculations are document ed in Section 10 of the EPA

report, Technical Development Document for Effluent Limitations Guidelines and Standards for

th e Steam Electric Power Generating Point Source Category (TDD) ( EPA

- 821

- R

- 15

- 007 ) and the EPA report

, Incremental Costs and Pollutant Removals for the Final Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source C ategory (Costs and Loads Report) (DCN SE05831 ). The ERG memorandum, “Pollutant Loadings Supporting Documentation” (DCN SE04515), lists the resources developed to complete the EA loadings analysis.

Pollutant loadings are presented in the TDD, Costs and Loads Report, and the EA Report

in two ways: pounds per year (lbs/yr) and toxic

- weighted pound equivalents ( TWPE ) per year (lb

- equivalent/yr) . EPA developed TWPE to account for differences in toxicity across pollutants and provide the means to compare mas s loadings of different pollutants on the basis of their toxic potential

. To calculate TWPE, ERG multiplie d the mass loading of each pollutant in pounds per year b y its pollutant

- specific toxic weighting factor (TWF)

. See the ERG memorandum “ Review

of Toxi c Weighting Factors in Support of the Final Steam Electric Effluent LimitationsMemorandum

September 30 , 2015 Page 3

Guidelines and Standards ” (DCN SE04479) for further details on TWFs and the use of TWPE in ELG development.

Table 1

- 1 presents the pollutants included in the loadings methodology. For the EA, ERG considered a subset of these pollutants. Specifically , ERG considered presence of the pollutant in the evaluated wastestreams; documented elevated levels of the pollutant in surface waters or wildlife from exposure to steam ele ctric power plant wastewater; and magnitude of the pollutant loadings to receiving waters.Memorandum

September 30 , 2015 Page 4

Table 1

- 1. Pollutants Included in the Steam Electric ELG Pollutant Loadings Analysis and EA Loadings Analyses

Pollutant Associated Waste Streams Evaluated in EA

FGD

Wastewater Bottom Ash

Transport

Water Fly Ash

Transport

Water Combustion

Residual

Leachate
Included in EA Loadings Analyses

Aluminum X X X X

Arsenic X X X X

Boron X X X X

Cadmium X X X X Chromium (VI) X X Copper X X X X

Iron X X X X

Lead X X X Manganese X X X X Mercury X X X X

Nickel X X X X

Selenium X X X X

Thallium X X X X

Vanadium X X X X

Zinc X X X X

Chloride X X X X Total dissolved solids (TDS) X X X X Phosphorus, total X X X

Nitrate / Nitrite as N a X X X Nitrogen, Total Kjeldahl a X X Not Included in EA Loadings Analyses

Ammonia

See Section 10 of the TDD Antimony

Barium Beryllium Biochemical oxygen demand

Calcium Chemical oxygen demand

Chromium

Cobalt Cyanide, total Magnesium Molybdenum

Silver

Sodium

Tin

Titanium Total suspended solids

a

– Included in analysis as total nitrogen. Total nitrogen is equal to nitrate/nitrite + Total Kjeldahl Nitrogen (TKN).Memorandum

September 30 , 2015 Page 5

2.0 P OLLUTANT L OADINGS TO I MMEDIATE R ECEIVING W ATERS

As discussed in Section 1.0 of this memorandum, the EA loadings analysis included only a subset of the pollutants included in the pollutant loadings calculations completed for the steam electric power generating point source category ELG s

. To calculate the annual pollutant loadings (lbs/yr), ERG performed the following steps for the “With CCR” scope:

1. Calculated total loadings by pollutant and evaluated wastestream ( in grams per day (g/day) ) as presented in Final Steam EA Loads Mo del (CCR) (DCN SE0562 0 ). 3

2. Converted the loadings from g/ day to lbs/yr using the following conversion factor:
[ (lb/453.59 g) x (365 d ay /yr) ].

3. Calculated total nitrogen loadings by adding nitrate/nitrite as N loadings and TKN loadings together.

4. Summed the evaluated wastestream loadings by pollutant to determine total steam electric power plant loadings for each pollutant.

Following calculation of the pollutant loadings for steam electric power plants (industry total), ERG multiplied each pollutant loading by the pollutant

- spec ific TWF. This resulted in the annual TWPE (lb

- eq/yr).

Section 3 (Table 3

- 2) of the EA Report presents the baseline annual pollutant loadings discharge d in the evaluated waste streams for select pollutants considered for analysis in the EA (with CCR scope ). The total industry loadings included in the table is based on pollutant loadings presented in Section 10 of the TDD.

To calculate the annual pollutant loadings (lbs/yr), ERG performed the following steps for the “With CCR and CPP” scope:

1. Calculated tot al loadings by pollutant and evaluated wastestream ( g/day ) as presented

in Final Steam EA Loads Model (CPP) (DCN SE05622 )

. 4

2. Converted the loadings from g/day to lbs/yr using the following conversion factor:
[ (lb/453.59 g ram ) x (365 d ay /yr) ].

3. Calculated total nitrogen loadings by adding nitrate/nitrite as N loadings and TKN loadings together.

4. Summed the evaluated wastestream loadings by pollutant to determine total steam electric power plant loadings for each pollutant.

3 For the pollutant loadin gs and removals presented in this memorandum, ERG included indirect dischargers to protect confidential business information.

4 For the pollutant loadings and removals presented in this memorandum, ERG included indirect dischargers to protect confidential business information.Memorandum

September 30 , 2015 Page 6

Following calculation of the pollu tant loadings for steam electric power plants (industry total), ERG multiplied each pollutant loading by the pollutant

- specific TWF. This resulted in the annual TWPE (lb

- eq/yr).

Appendix I (Table I

- 3) of the EA Report presents the baseline annual polluta nt loadings discharge d in the evaluated wastestreams for select pollutants considered for analysis in the EA (with CCR and CPP scope). The total industry loadings presented in the table are based on pollutant loadings presented in Section 10 of the TDD.

Co mparison of Pollutant Loadings from Steam Electric Power Plants to Other Direct Dischargers

To provide perspective on the environmental impacts, ERG compared the TWPE loadings from the evaluated waste streams at steam electric power plants to the other to p point source category dischargers

. Section 3 (Table 3

- 3 ) and Appendix I (Table I

- 4) of the EA Report present the calculated TWPE loadings from the steam electric power industry under the baseline

scopes
, “ with CCR” and “with CCR and CPP, ” respectively.

ERG also compared the TWPE loadings from the evaluated wastestreams at steam electric power plants to other industrial discharges reported under NPDES permits. The TWPE discharges from the evaluated wastestreams from steam electric power plants totaled 2 .6 8

million lb

- eq/yr (“w ith CCR” scope) and 2 .14 million lb

- eq/yr (“ w ith CCR and CPP” scope). To

determin e pollutant loadings from non

- steam electric industrial dischargers operating under NPDES permits , ERG used the loadings calculated by EPA as part of its 2012 E ffluent Guidelines Program Plan and 2010 E ffluent Guidelines Program Plan (see http://water.epa.gov/lawsregs/lawsguidance/cwa/304m/ for more details on this program). The

source of the data for the 2012 E ff luent Guidelines Program Plan was the discharge monitoring report (DMR) database, DMRLoadsAnalysis2009_v02.mdb (the database with tables and queries

used for the steam electric ELGs is included in the record as DCN SE01961)

. The E RG memorandum, “ Comparison of Steam Electric Industry Toxic Loadings to Other Industrial Dischargers ” ( DCN SE02155) presents t he calculation of total TWPE from non

- steam electric industrial sources reporting discharges under NPDES permits , which totals 5.3 million lb

- eq/yr [ERG, 2013a]

.

To calculate the contribution of steam electric power plants to toxic discharges from industrial point sources reporting under NPDES permits, ERG completed the following

calculations:

1. Calculate t otal TWPE from all indus trial sources reporting discharges under NPDES permits:

“With CCR” Scope

2.68 million lb

- eq/yr (steam electric) + 5.3 million lb

- eq/yr (non

- steam electric) = 7.98 million lb

- eq/yrMemorandum

September 30 , 2015 Page 7

“With CCR and CPP” Scope

2.14 million lb

- eq /yr (steam electric) + 5.3 million lb

- eq/yr (non

- steam electric) = 7.44 million lb

- eq/yr

2. Calculate p ercentage of TWPE (i.e., toxic discharges) accounted for by steam electric

power plants:

“With CCR” Scope

2. 68 million lb

- eq/yr = 3 4 percent

7.98 million lb

- eq/yr

“With CCR and CPP” Scope

2.14 million lb

- eq/yr = 29 percent

7.44 million lb

- eq/yr

3.0 C OMPARISON OF E VALUATED W ASTE S TREAM L OADINGS FROM S TEAM

E LECTRIC P OWER P LANTS TO T HOSE FROM POTW S

ERG completed the following analyses to evaluate the pollutant loadings from evaluated wastestreams discharging from steam electric power plants:

1. Compare d pollutant loadings to those from publicly owned treatment works (POTWs).

2. Compare d average pollutant loadings by wastestream from a steam electric power plant to pollutant loadings discharged by a “typical” POTW.

The ERG memorandum, “ Loadings Analysis for the Steam Electric ELGs Environmental

Assessment ” ( DCN SE0 1956), presents the calculation of average dis charge flow rate from a typical POTW (3 to 5 million gallons per day) and calculation of pollutant loadings from POTWs that discharge between 3 and 5 million gallons per day. ERG used the same POTW pollutant loadings but adjusted the TWPE for seven pollutants with whose TWFs had been revised since the memorandum was developed . Table 3

- 1 presents the POTW pollutant loadings

from DCN SE01956 and the adjustment made to incorporate the revised TWFs.Memorandum

September 30 , 2015 Page 8

a

– See the ERG memorandum, “Loadings Analysis for the Steam Electric ELGs Environmental Assessment” ( DCN

SE01956 )

. b

– See the ERG memorandum, “Review of Toxic Weighting Factors in support of the Final Steam Electric Effluent Limitations Guidelines and Standards” (DCN SE04479). Table 3

- 1. Revised Average POTW TWPE

Pollutant TWF (2013) Average POTW Discharge (lb

- eq/yr) a Updated TWF

(Sept. 2015) b Revised Average

POTW Discharge (lb

- eq/yr)

Aluminum 0.0647 215

Arsenic 4.04 186 3.47 159

Boron 0.00834 12.8

Cadmium 23.1 81.9 22.8 80.6

Chromium VI 0.517 9.02

Copper 0.635 97.0 0.623 95.3

Iron 0.0056 0 14.2

Lead 2.24 109

Manganese 0.070 24.8 0.103 36.1

Mercury 117 372,000 110 350,000

Nickel 0.109 3.06

Selenium 1.12 20.7

Thallium 1.03 10.1 2.85 28.2

Vanadium 0.035 0 No data 0.280 No data

Zinc 0.0469 18.1

Nitrogen, total No value Not applicable

Phosphorus, total No value Not applicable

Chloride 2 .435E

- 05 39.3

Total dissolved solids (TDS) No value No dataMemorandum

September 30 , 2015 Page 9

3.1 Results of Comparison

To compare the total annual loadings from the evaluated waste streams at the 195 steam
electric power plants included in the EA loadings analysis to total annual loadings from POTWs, ERG determined the number of typical POTWs that wou ld discharge the equivalent of the

evaluated waste streams for the 195 steam electric power plants. To calculate this , ERG divided

the annual pollutant

- specific loadings from the steam electric power plants by the annual pollutant

- specific loadings of a t ypical POTW. 5

For example, steam electric power plants (with CCR) discharge 140 ,000 pounds of selenium per year [see Section 3.2 (Table 3

- 2) of the EA Report] . A typical POTW discharge s 18. 5 pounds of selenium per year. The number of typical POTWs whose discharge of selenium is equivalent to the steam electric plant discharges is:

140 ,000 lb/yr = 7,57 0 POTWs (compared to 195 steam electric power plants)

18 .5 lb/yr

Because TWPEs are calculated using the same TWF regardless of industry, the number

of typical POTWs discharging the same TWPE as the 195 stea m electric power plants is also 7,57 0 POTWs.

ERG completed the comparison using t he MS ExcelTM spreadsheets, EA Loadings Analyses (With CCR) (DCN SE04464) and EA Loadings Analyses (With CPP) (DCN SE04473). Results of the POTW comparison are included in Section 3.2 (Table 3

- 5) and Appendix I (Table I

- 6) of the EA Report for the “with CC R” and “with CCR and CPP” scopes, respectively.

3.2 Comparison of Average Steam Electric Waste Stream Loadings to Typical POTW

Loadings

ERG compared l oadings for the evaluated waste streams to those of a typical POTW. The

evaluated waste streams include FGD was tewater, fly ash transport water, bottom ash transport

wate r , and combustion residual leachate

. Error! Reference source not found. The EA Report

presents average pollutant loadings for the evaluated wastestreams from a steam electric power plant and the annual pollutant loadings from a typical POTW

.

5 Pollutant loadings for the EA analysis are included in the databases, Final Steam EA Loads Mo del (CCR) (DCN SE05620) and Final Steam EA Loads Model (CPP) (DCN SE05622).Memorandum

September 30 , 2015 Page 10

Example calculation: The average FGD wastewater d ischarge of selenium equals 1,41 0 pounds per year from a single steam electric power plant . A typical POTW discharge s 18 .5 pounds of selenium per year. The number of POTWs whose discharge is equivalent to the

average FGD wastewater discharge from a steam electric power plant (of selenium) is:

1,41 0 lb/yr = 76 POTWs (compared to 1 steam electric power plant)

18 .5 lb/yr

Because TWPEs are calculated using the same TWF regardless of industry, the number

of typical POTWs discharging the same TWPE as the average FGD wastewater discharge from a

steam electric power plant (of selenium) is also 76 POTWs.

ERG completed the comparison using t he MS ExcelTM spreadsheets DCN SE04464 and

DCN SE04473. See Section 3.2 (Table 3

- 4) of the EA Report for the “with CCR” results and Appendix I (Table I

- 5) of the EA Report for the “with CCR and CPP” results.

4.0 L OADINGS TO S ENSITIVE E NVIRONMENTS

ERG evaluated pollutant loadings from evaluated waste streams that discharge to two sensitive watersheds, the Chesapeake Bay (an estuary) and the Great Lakes. For both watersheds,

ER G i dentif

ied steam electric power plants discharging the evaluated waste streams to the watershed and their pollutant loadings at baseline. The ERG memorandum, “Proximity Analysis Methodology” (DCN SE04448) identifies the steam electric power plants and immediate receiving waters dis charging to the watershed s. Pollutant loadings for the two watersheds are

included in the following database s:

 Final Steam EA Proxi mity Analysis

- Great Lakes and Chesapeake Bay Loads (CCR) (DCN SE04551) for the “with CCR” scope

.

 Final Steam EA Proximity Analysis

- Great Lakes and Chesapeake Bay Loads (CPP) (DCN SE05622) for the “with CCR and CPP” scope.

The MS Excel TM spreadsheets, DCN SE04464 and DCN SE04473, calculate the

summation of the pollutant loadings presented in the EA Report. The baseline pollutant loadings for the two watersheds are included in the EA Report:

 Section 3.4.1 (Table 3

- 10) presents the baseline pollutant load ings to the Great Lakes

watershed (with CCR).

 Section 3.4.2 (Table 3

- 11) presents the baseline pollutant loadings to the Chesapeake Bay watershed (with CCR).

 Appendix I (Table I

- 8) presents the baseline pollutant loadings to the Great Lakes watershed (with CCR and CPP).

 Appendix I (Table I

- 9) presents the baseline pollutant loadings to the Chesapeake Bay watershed (with CCR and CPP).Memorandum

September 30 , 2015 Page 11

Pollu tant removals for the Great Lake s watershed under the regulatory options and pollutant removals for the Chesapeake Bay watershed under the final rule are presented in

Section 7. 4.4 of the EA Report.

ERG also calculated pollutant removals from impaired waters

. The ERG memorandum,

“Pr oximity Analysis Methodology” (DCN SE04448) documents how ERG identified impaired
waters. ERG used the databases, Final Steam EA IRW Model

- Miscellaneous Calculatio ns for EA Report (CCR) (DCN SE 0 4604) and Final Steam EA IRW Model

- Miscellaneous

Calculati ons for Preamble and EA Report (CPP) (DCN SE04608 ) , to identify the pollutant loadings to impaired waters under baseline and under the regulatory options . The MS ExcelTM spreadsheet, Pollutant Loadings to Impaired Waters (DCN SE06518) documents the analysis and calculations performed. Results are presented in Section 7.4.1 (Table 7

- 12) of the EA Report for “with CCR” scope and Appendix I (Table I

- 31) for the “with CCR and CPP” scope.

5.0 P OLLUTANT R EMOVALS A SSOCIA TED WITH THE R EGULATORY O PTIONS

To calculate the pollutant removals associated with the regulatory options, ERG performed the following steps

1. Calculated total loadings by pollutant and evaluated wastestream ( g/day ) as presented

in Final Steam EA Loads Mo del (CCR) (DCN SE05620) and Final Steam EA Loads Model (CPP) (DCN SE05622) for the treatment technologies

.
2. Converted the loadings from g/day to lbs/yr using the following conversion factor:
[ (lb/453.59 g ) x (365 d ay /yr) ].

3. Summed the evaluated wastestream loadings by pollutant to determine total steam

ele ctric power plant loadings for each pollutant. The pollutant loadings used varied by option:

a. Option A: FGD wastewater ( pollutant loadings based on chemical precipitation);

f ly a sh transport water ( d ry o ption); b ottom a sh transport water ( pollutant loadings equal to b aseline); c ombustion residual l eachate ( pollutant loadings equal to b aseline)

.
b. Option B: FGD wastewater ( pollutant loadings based on biological treatment ); f ly

a sh transport water ( d ry o ption); b ottom a sh transport water ( pollutant loadings

equa l to b aseline); c ombustion residual l eachate ( pollutant loadings equal to

b aseline)

.

c. Option C: FGD wastewater ( pollutant loadings based on biological treatment ); f ly

a sh transport water ( dry o ption); b ottom a sh transport water (Option C treatment technolog y 6 ); c ombustion residual l eachate ( pollutant loadings equal to b aseline)

.

6 Dry handling/closed loop (for units >400 MW); impoundment (equal to BPT) for units ≤400 MW

.Memorandum

September 30 , 2015 Page 12

d. Option D: FGD wastewater ( pollutant loadings based on biological treatment ); f ly

a sh transport water ( dry o ption); b ottom a sh transport water (dry option/closed loop ); c ombustion residual l eachate ( pollutant loadings equal to b aseline)

.

e. Option E: FGD wastewater ( pollutant loadings based on biological treatment ); f ly

a sh transport water ( dry o ption); b ottom a sh transport water (dry option/closed loop ); c ombustion residual leachate ( pollutant loadings based on chemical precipitation )

.

4. Calculated total nitrogen loadings by adding nitrate/nitrite as N loadings and TKN loadings together.

5. Multiplied by the TWFs to calculation TWPE per year for each option.

6. Calculated the pollutant remova ls for each option (baseline pollutant loadings minus Option pollutant loadings.

7. Calculated the percent reduction in pollutant loadings for each option compared to

baseline.

ERG completed these calculations in the MS ExcelTM spreadsheets, DCN SE04464 and

D CN SE04473 . The results are presented in the EA Report :

 Section 7.1 (Table 7

- 3 and Table 7

- 4 ) presents the pollutant removals and percent reduction based on the regulatory options (with CCR).

 Appendix I (Table I

- 22 and Table I

- 23 ) presents the pollutant removals and percent reduction based on the regulatory options (with CCR and CPP).

6.0 R EFERENCES

ERG. 2013 a . “ Comparison of Steam Electric Industry Toxic Loadings to Other Industrial Dischargers .” DCN SE02155

.

ERG. 2013b. “ Loadings Analysis for the St eam Electric ELGs Environmental Assessment .”

DCN SE01956

.

ERG. 2015 a . EA Loadings Analyses (with CCR). MS ExcelTM spreadsheet. (July 24). DCN

SE04464.

ERG. 2015b. EA Loadings Analyses (with CPP). MS ExcelTM spreadsheet. (August 13).

DCN SE04473.

ERG

. 2015 c . “ Review of Toxic Weighting Factors in support of the Final Steam Electric

Effluent Limitations Guidelines and Standards .” DCN SE04479.

U.S. EPA. 2010. Discharge Monitoring Report (DMR) Pollutant Loading Tool: 2010 Data.

Available online at: http://cfpub.epa.gov/dmr/ . DCN SE 01959.Memorandum

September 30 , 2015 Page 13

U.S. EPA. 2011. Technical Support Document for the 2010 Effluent Guidelines Program Plan

. EPA 821

- R

- 09

- 006

. Washington, DC

. (October). DCN SE07320.

U. S. EPA. 201 3

. DMRLoadsAnalysis2009_v02.mdb : Tables and Queries Used for the Steam Electric Industry ELGs. DCN SE 01961

.