## MEMORANDUM

TO: Bill Swietlik, EPA

FROM: Jill Lucy, ERG

DATE: April 19, 2013

SUBJECT: Loadings Analysis for the Steam Electric ELGs Environmental Assessment (SE01956)

The U.S. Environmental Protection Agency (EPA) is proposing revised effluent limitations guidelines and standards (ELGs) for the Steam Electric Power Generating Point Source Category (40 CFR 423). In support of the development of the revised ELGs, ERG supported EPA in conducting an environmental assessment (EA) to evaluate the environmental impact of pollutant loadings released under current (i.e., baseline) discharge practices and assess the potential environmental improvement from pollutant loading reductions under varying regulatory options.

Pollutants commonly found in combustion wastewater, such as metals, nutrients, and total dissolved solids (TDS) (including bromides and chlorides), can cause considerable harm to surface waters, aquatic life, wildlife, and human health. This memorandum provides a summary of the data and calculations performed to estimate pollutant loadings from steam electric power plants for the waste streams evaluated as part of the proposed ELGs and presented in EPA’s Environmental Assessment for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (EA Report) (DCN SE01995) . The evaluated waste streams include flue gas desulfurization (FGD) wastewater, fly ash transport water, bottom ash transport water, and landfill and surface impoundment leachate wastewater.

1.0 B ACKGROUND ON 

### P OLLUTANT 

### L OADINGS 

### M ETHODOLOGY



### ERG calculated pollutant loadings on a plant-by-plant basis for all steam electric power plants that fell within the scope of the proposed ELGs. The loadings methodology and

calculations are documented in Section 10 of EPA’s Technical Development Document for the Proposed Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (TDD) (DCN SE01964), and Incremental Costs and Pollutant Removals for Proposed Effluent Limitation Guidelines and Standards for the Steam Electric Generating Point Source Category (Costs and Loads Report) (DCN SE01957). 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 (lbequivalent/yr). EPA developed TWPE to account for differences in toxicity across pollutants and provide the means to compare mass loadings of different pollutants on the basis of their toxic potential. EPA multiplies a mass loading of a pollutant in pounds per year by a pollutant-specific weighting factor, called the toxic weighting factor (TWF), to derive a "toxic-equivalent" loading,

### Memorandum April 19, 2013 Page 2

or TWPE. EPA has developed TWFs for more than 1,900 pollutants based on aquatic life and human health toxicity data, as well as physical/chemical property data [U.S. EPA, 2006].

Table 1-1 presents the pollutants included in the loadings methodology. For the EA, ERG considered a subset of these pollutants. Specifically, ERG considered the following when determining which pollutants to include in the EA loadings analyses:

 Is the pollutant present in waste streams evaluated in the EA (i.e., fly ash transport water, bottom ash transport water, FGD wastewater, and/or landfill and surface impoundment leachate)?

 Have elevated levels of the pollutant been observed in surface waters or wildlife from exposure to combustion wastewater?

### Memorandum April 19, 2013 Page 3

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

Pollutant Associated Waste Streams Evaluated in EAFly AshTransportWaterBottom AshTransportWaterFGDWastewaterLeachate

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 X Copper X X X X

Iron X X X X

Lead X 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 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

Sulfate

Tin

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

### Memorandum April 19, 2013 Page 4

2.0 L OADINGS 

### F ROM 

### E VALUATED 

### W ASTE 

### S TREAMS 

### A T 

### S TEAM 

### E LECTRIC 

### P OWER 

### P LANTS



### ERG used the following four methods to evaluate the pollutant loadings from evaluated waste streams discharging from steam electric power plants:

1. Total pounds and TWPE of pollutant loadings discharged to receiving waters.

2. Comparison of steam electric evaluated waste stream loadings to those from other point source categories.

3. Comparison of steam electric evaluated waste stream loadings to those from publicly owned treatment works (POTWs).

4. Comparison of average pollutant loadings by waste stream from a steam electric plant to pollutant loadings discharged by a “typical” POTW.

These four methods of evaluation are described in the following sections.

2.1 Pollutant Loadings to Receiving Waters

As discussed in Section 1.0 of this memorandum, the EA loadings analyses included only a subset of the pollutants included in the pollutant loadings calculations completed for the proposed ELGs. Table 2-1 presents the baseline annual pollutant loadings discharged in the evaluated waste streams for select pollutants considered for analysis in the EA.

Table 2-1. Annual Baseline Discharges of EA-Evaluated Pollutants from the Evaluated

Waste Streams

Pollutant a TWF b Annual Discharge, pounds (lbs) Annual TWPE, poundequivalents (lb-eq)

Metals Manganese 0.07043 14,500,000 1,020,000
Cadmium 23.1168 31,900 738,000
Boron 0.00834 54,300,000 453,000 Mercury 117.118 2,820 330,000
Arsenic 4.0413 79,200 320,000
Selenium 1.1213 225,000 252,000
Thallium 1.0271 164,000 168,000
Lead 2.24 64,400 144,000
Aluminum 0.0647 1,970,000 128,000 Copper 0.6348 69,900 44,400
Nickel 0.1089 287,000 31,200
Iron 0.0056 4,990,000 27,900
Zinc 0.0469 393,000 18,400
Chromium VI 0.5166 11,800 6,090
Vanadium 0.035 158,000 5,530

Total Metals c 1,790,000,000 4,800,000

### Memorandum April 19, 2013 Page 5

Table 2-1. Annual Baseline Discharges of EA-Evaluated Pollutants from the Evaluated

Waste Streams

Pollutant a TWF b Annual Discharge, pounds (lbs) Annual TWPE, poundequivalents (lb-eq)

Nutrients Total Nitrogen Not applicable 30,400,000 Not applicable Total Phosphorus Not applicable 682,000 Not applicable

Other

Chlorides 2.435 X 10

- 05 1,640,000,000 39,800

Total Pollutants c ,d 5,500,000,000 8,320,000

Source: U.S. EPA, 2013a; U.S. EPA, 2006.
a – The list of pollutants included in this table is only a subset of pollutants included in the loadings analysis (see Section 10 of the TDD).
b – TWFs for the following metals apply to all metal compounds: arsenic, chromium, copper, lead, manganese, mercury, nickel, selenium, thallium, vanadium, and zinc. EPA updated TWFs for boron, chlorides, chromium compounds, and iron for the Steam Electric ELGs pollutant loadings analysis.
c – To avoid double-counting of dissolved metals, the totals include all pollutants from the loadings analysis with the excepti on of TDS. Annual baseline discharges of TDS from the evaluated waste streams total approximately 7,120,000,000 pounds.
d – The totals represent the pollutant loadings in discharges of the evaluated waste streams – specifically, FGD wastewater, fl y ash transport wastewater, bottom ash transport wastewater, and leachate (see Section 10 of the TDD).



### 2.2 Comparison of Evaluated Waste Stream Loadings from Steam Electric Power Plants to Those from Other Point Source Categories

ERG completed two evaluations as part of the pollutant loadings comparison to other point source categories. The first included comparing TWPE loadings from the evaluated waste streams at steam electric power plants (regulated under 40 CFR 423) to TWPE loadings from all other point source categories. The second analysis compared the TWPE loadings from the evaluated waste streams at steam electric power plants to the other top point source category dischargers.

To determine pollutant loadings from other point source categories, ERG used the loadings calculated by EPA as part of its 2012 Effluent Guidelines Program Plan and 2010 Effluent 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 Effluent Guidelines Program Plan is 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 source of the data for the 2010 Effluent Guidelines Program Plan is the Technical Support Document for the 2010 Effluent Guidelines Program Plan (EPA 821-R-09-006) [U.S. EPA, 2011].

The calculation and results of the first total pollutant loadings comparison analysis are documented in the ERG memorandum, Comparison of Steam Electric Industry Toxic Loadings to Other Industrial Dischargers (DCN SE02155). ERG calculated that the total TWPE loadings from the evaluated waste streams at steam electric power plants account for at least 50 to 60 percent of the toxic pollutants reported to be discharged in industrial National Pollutant Discharge Elimination System (NPDES) permits.

### Memorandum April 19, 2013 Page 6

Table 5-3 of the Technical Support Document for the 2010 Effluent Guidelines Program

Plan [EPA 821-R-09-006] presents the TWPE discharges for point source categories evaluated by EPA. 1 

### Table 2-2 presents the total loadings from the top ten discharging categories, along with the estimated TWPE for the evaluated waste streams at steam electric power plants.

Table 2-2. Pollutant Loadings for the Final 2010 Effluent Guidelines Planning Process: Top 10 Point Source Categories

40 CFR Part Point Source Category Total TWPE (lb-eq/yr) 423 Steam Electric Industry – Evaluated Waste Streams 8,320,000 a 430 Pulp, Paper And Paperboard 1,030,000 419 Petroleum Refining 1,030,000 421 Nonferrous Metals Manufacturing 994,000 418 Fertilizer Manufacturing 826,000 414 Organic Chemicals, Plastics And Synthetic Fibers 649,000 440 Ore Mining And Dressing 448,000 415 Inorganic Chemicals Manufacturing 299,000
444 Waste Combustors 254,000
410 Textile Mills 250,000

Source: U.S. EPA, 2011.
a – As presented in Section 10 of the TDD, EPA estimates that 8,320,000 TWPE are discharged annually from steam electric power plants associated with the waste streams evaluated as part of the proposed rule.



### 2.3 Comparison of Evaluated Waste Stream Loadings from Steam Electric Power

Plants to Those from POTWs

To provide additional perspective on the magnitude of the pollutant loadings included in the loadings analysis, ERG calculated pollutant loadings discharged from an average POTW. EPA selected POTWs for comparison because, for point sources, POTWs and steam electric plants dwarf all other point source discharges in terms of total TWPE of metals discharged to waters in the United States [U.S. EPA, 2010]. 2 

### In addition, the approximately 16,000 POTWs are

1 EPA did not calculate steam electric point source categories as part of the annual review because EPA had already begun revising Part 423. “Because the Steam Electric rulemaking is underway, EPA excluded discharges from these facilities from further consideration under the current planning cycle.” See Section 5.2.1 of the Technical Support Document for the 2010 Effluent Guidelines Program Plan [EPA 821-R-09-006].

2 Based on metal loadings (total TWPE) calculated by EPA’s DMR Pollutant Loading Tool, 2010 data, by Standard Industrial Classification (SIC) code. The top two industries are SIC 4952 – sewerage systems (i.e., POTWs) and SIC 4911 – electrical

services.

EPA’s DMR Pollutant Loading Tool is an online tool ( http://cfpub.epa.gov/dmr/ ) that calculates pollutant loadings from permit and DMR data from EPA‘s Permit Compliance System (PCS) and Integrated Compliance Information System for the National Pollutant Discharge Elimination System (ICIS-NPDES). The tool also ranks dischargers, industries, and watersheds based on pollutant mass and toxicity, and presents “top 10” lists to help users determine which facilities and industries are producing these discharges and which watersheds are impacted. Facilities report pollutant discharge monitoring data in their DMR as mass-based quantities (e.g., pounds per day) and/or concentrations (e.g., mg/L). The DMR Pollutant Loading Tool allows users to gather annual loadings data. For this EA, EPA reviewed the 2010 loadings reported in DMRs.

The use of the DMR data has its limitations. Only pollutants included in the facility’s NPDES permit are included in the PCS an d ICIS-NPDES databases; therefore, if a facility does not have mercury limitations, mercury discharges from that facility will no t be included in the total for industrial discharges. States (or other permitting authorities) have some discretion as to which d ata

### Memorandum April 19, 2013 Page 7

located across the United States, are known to have consistent wastewater influent characteristics, and are a common metric used for point source evaluations.

2.3.1 Calculation of Average Discharge Flow Rate from a Typical POTW

ERG defined an average (or typical) POTW discharge as equaling an effluent flow rate between 3 and 5 million gallons per day (MGD). 3 

### This was based on the number of POTWs in various flow rate categories as reported in Metcalf and Eddy, 2003. ERG used the Metcalf and Eddy data and performed the following calculations:

 Step 1. Use midpoint of flow ranges as the average flow for the number of facilities represented in that flow rate group. For example, the average flow rate for the group:

1.001 – 10.0 MGD is calculated as:

[1.001 + 10.0] = 5.5005 MGD

2 For the group >100 MGD , ERG assumed an average flow rate of 100 MGD.

 Step 2. Multiply the average flow rate by the number of facilities in each group.

 Step 3. Sum the results of Step 2 and divide by the total number of facilities in all groups (15,986 POTWs). The result is an average discharge rate weighted by number of facilities in each flow rate group.

Σ (Scaled flow rate by number of facilities) group 

### Total Number of Facilities in All Groups

The data and calculations performed are included in Table 2-3. The calculated average flow rate from a typical POTW is 3.0 MGD. To expand the number of facilities that would be included as typical or average when selecting monitoring data, ERG chose to use the average flow rate range

of 3 to 5 MGD.

For comparison purposes, ERG also calculated the average flow rate reported for POTWs in the 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). ERG used the POTW2009 database table and calculated the average flow rate across all database entries (see Queries POTW flow1 and POTW flow 2 in the database). The calculated average flow rate is 3.6

MGD.

they make available (or enter) in PCS and ICIS-NPDES. For example, permitting authorities enter DMR and permit information for facilities that are considered major dischargers. However, they do not necessarily enter DMR or permit information into PCS for minor dischargers or facilities covered by a general permit.

3 For comparison, the average discharge flow rate for the steam electric waste streams of concern are 0.5 MGD for FGD wastewater; 2.4 MGD for fly ash sluice water; 1.8 MGD for bo ttom ash sluice water; and 0.06 MGD for leachate (U.S. EPA, 2012b).

### Memorandum April 19, 2013 Page 8

Table 2-3. Number of POTWs by Flow Range

Flow Ranges (MGD) a Number of POTWs a Average Flow Calculation to Scale Flow Rate by Number of POTWs

0 - 0.100 6,444 0.05 [6,444 × 0.05] = 322

0.101 - 1.0 6,476 0.5505 [6,476 × 0.5505] = 3,565

1.001 - 10.0 2,573 5.5005 [2,573 × 5.5005] = 14,153

10.001 - 100.0 446 55.0005 [446 × 55.00005] = 24,530

>100.0 47 100 [47 × 100] = 4,700

Total Number of

POTWs:

15, 986 Average Flow scaled by

Number of POTWs:

3.0 MGD
a – Based on 1996 data from Metcalf and Eddy, 2003 (page 14).
MGD – Million gallons per day.



### 2.3.2 Calculation of Pollutant Loadings from a Typical POTW

EPA calculated the average pollutant loadings discharged from a typical POTW using EPA’s 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). ERG developed queries in the database, as follows:

 Query POTW query selects the POTWs that discharge between 3 and 5 MGD included in the database table, DMR2009_download . The query links DMR2009_Download and DMRFAC2009 and PRAM Codes (provides description of the monitoring parameter) and uses two criteria for data selection:

1. DMR2009_Download : AVG_Flow = “Between 3 and 5” (MGD)

2. DMRFAC2009 : Facility Type = “POTW”

 Query POTW query2 calculates the average DMR loadings (in pounds and TWPE per year) for each pollutant. Table 2-4 presents the results of the database queries.

Table 2-4. Average Pollutant Loadings for POTWs Discharging Between 3 and 5 MGD

Parameter

Code Pollutant (Parameter Description) Pollutant Loading (lb/yr) Pollutant TWPE (lb-eq/yr) Average Flow Rate (MGD) b

01105 Aluminum, total (as Al) 3,587.99 215.28 4.07

01002 Arsenic, total (as As) 45.95 185.63 3.83

01022 Boron, total (as B) 1,536.20 12.81 3.85

01027 Cadmium, total (as Cd) 3.54 81.91140558 3.884276824

01032 Chromium, hexavalent (as Cr) 17.69 9.022483591 3.942416667

01042 Copper, total (as Cu) 153.99 97.01 3.836265231

01045 Iron, total (as Fe) 2,533.32 14.19 3.922394928

01051 Lead, total (as Pb) 48.53 108.70 3.906622537

01055 Manganese, total (as Mn) 353.96 24.78 3.828868421

### Memorandum April 19, 2013 Page 9

Table 2-4. Average Pollutant Loadings for POTWs Discharging Between 3 and 5 MGD

Parameter

Code Pollutant (Parameter Description) Pollutant Loading (lb/yr) Pollutant TWPE (lb-eq/yr) Average Flow Rate (MGD) b

71900 Mercury, total (as Hg) 3,178.97 372,289.13 3.964028137

01067 Nickel, total (as Ni) 30.61 3.06 3.861026891

01147 Selenium, total (as Se) 18.45 20.67 3.898502866

01059 Thallium, total (as Tl) 9.94 10.14 3.744368

Vanadium, total No data No data No data

01092 Zinc, total (as Zn) 453.30 18.13 3.937479809

00600 Nitrogen, total (as N) 123,059.42 Not applicable 3.898905349

00665 a Phosphorus, total (as P) 17,778.60 Not applicable 3.86

00940 Chloride (as Cl) 1,614,511.49 39.31 3.89

Total dissolved solids (TDS) No data No data No data

Source: U.S. EPA, 2013b.
a – Phosphorous loadings are also reported under parameter code 51426; however, ERG did not include these loadings due to their low value (251.32 lbs/yr) when compared to parameter code 00665.
b – Flow rate included for informational purposes; ERG did not use the flow data for any further analysis.



### 2.3.3 Results of Comparison

To compare the total annual loadings from the evaluated waste streams at the 290 steam electric plants included in the loadings analysis (see Table 2-1) to total annual loadings from POTWs, ERG determined the number of typical POTWs that would discharge the equivalent of the evaluated waste streams for the 290 steam electric plants. To calculate this, ERG divided the annual loadings value for a pollutant, listed in Table 2-1, by the annual loadings of a typical POTW, listed in Table 2-4. For example, the steam electric plants in this analysis discharge 225,000 pounds of selenium per year. A typical POTW discharges 18.45 pounds of selenium per year (rounded to 18 pounds per year). The number of typical POTWs whose discharge of selenium is equivalent to the steam electric plant discharges is:

225,000 lb/yr = 12,500 POTWs (compared to 290 steam electric power plants) 18 lb/yr

Because TWPEs are calculated using the same TWF regardless of industry, the number of typical POTWs discharging the same TWPE as the steam electric power plants is also 12,500 POTWs. Table 2-5 presents the number of typical POTWs that would discharge an equivalent amount of pollutant loadings to surface water compared to the 290 steam electric power plants in this analysis.

### Memorandum April 19, 2013 Page 10

Table 2-5. Estimated Number of POTW Equivalents for Total Pollutant Loadings from the

Evaluated Waste Streams

Pollutant Annual Discharge by Steam Electric Power Plants, lbs a Annual Discharge by Typical POTW, lbs b Equivalent Number of Typical POTWs
Aluminum 1,970,000 3,590 550
Arsenic 79,200 46 1,720
Boron 54,300,000 1,540 35,300
Cadmium 31,900 4 7,980
Chromium VI 11,800 18 655 Copper 69,900 154 454
Iron 4,990,000 2,530 1,970
Lead 64,400 49 1,320 Manganese 14,500,000 354 41,000 Mercury 2,820 3,180 <1
Nickel 287,000 31 9,250
Selenium 225,000 18 12,500
Thallium 164,000 10 16,400
Vanadium 158,000 No data No data
Zinc 393,000 453 868 Total Nitrogen 30,400,000 123,000 247 Total Phosphorus 682,000 17,800 38
Chlorides 1,640,000,000 1,610,000 1,020
TDS 7,120,000,000 No data No data

a – U.S. EPA, 2013a.

b – U.S. EPA, 2013b.



### 2.4 Comparison of Average Steam Electric Waste Stream Loadings to Typical POTW Loadings

To provide additional perspective on the magnitude of the pollutant loadings from steam electric power plants, ERG compared loadings for the evaluated waste streams to those of a typical POTW. The evaluated waste streams include FGD wastewater, fly ash wastewater, bottom ash wastewater, and leachate. Table 2-6 presents total pollutant loadings for the evaluated waste streams (for the 290 plants) and the annual loadings from a typical POTW.

Example calculation: The average FGD wastewater discharge of selenium equals 1,490 pounds per year from a single steam electric power plant. A typical POTW discharges 18 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:

1,490 lb/yr = 83 POTWs (compared to 1 steam electric power plant) 18 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 power plant (of selenium) is also 83 POTWs. Table 2-7 presents the number of POTWs that would discharge an equivalent amount of pollutant loadings to surface water compared to the average waste stream discharge from a steam electric power plant.MemorandumApril 19, 2013Page 11Table 2-6. Comparison of Average Pollutant Loadings in the Evaluated Waste Streams to a Typical POTWPollutantAverage Plant FGDDischargea,bAverage Plant Fly AshDischargea,cAverage Plant BottomAsh Dischargea,dAverage PlantLeachate Dischargea,eTypical POTWDischargea,fLoadings(lbs/yr)TWPE(lb-eq/yr)Loadings(lbs/yr)TWPE (lbeq/yr)Loadings(lbs/yr)TWPE(lb-eq/yr)Loadings(lbs/yr)TWPE(lb-eq/yr)Loadings(lbs/yr)TWPE(lb-eq/yr)Aluminum2,500 162 7,660 495 2,220 144 1,110 71.9 3,590 215Arsenic10.1 40.9 479 1,940 69 279 11.1 44.7 46 186Boron410,000 3,420 18,900 158 8,330 69.5 4,780 39.8 1,540 13Cadmium133 3,070 58.6 1,350 30.5 705 0.594 13.7 4 82Chromium VI6.7 3.46 77.6 40.1 7.95 4.11 (g) (g) 18 9Copper26.1 16.6 280 178 113 72 2.11 1.34 154 97Iron1,850 10.4 5,850 32.7 8,610 48.2 15,100 84.4 2,530 14Lead5.93 13.3 206 461 134 299 0.335 0.751 49 109Manganese115,000 8,090 3,680 259 680 47.9 1,050 74.2 354 25Mercury6.58 771 8.65 1,010 3.33 390 0.26 30.4 3,180 372,000Nickel1,030 112 239 26.1 451 49.1 16.6 1.81 31 3Selenium1,490 1,670 257 289 44.7 50.2 20.5 23 18 21Thallium19.3 19.8 300 308 427 439 0.359 0.369 10 10Vanadium25.9 0.908 428 15 50.7 1.77 876 30.7 no data no dataZinc1,630 76.7 790 37 338 15.9 40.1 1.88 453 18Total Nitrogenh109,000 - 39,000 - 39,400 - (g) - 123,000 -Total Phosphorush651 - 1,810 - 1,320 - (g) - 17,800 -Chlorides12,800,000 311 265,000 6.46 187,000 4.55 155,000 3.78 1,610,000 -TDS44,100,000 - 3,690,000 - 4,350,000 - 993,000 - no data no dataa – All values are rounded to three significant figures.b – Average FGD loadings are based on 117 plants assumed to discharge FGD wastewater under baseline conditions [U.S. EPA, 2013a].c – Average fly ash loadings are based on 93 plants assumed to discharge fly ash sluice under baseline conditions [U.S. EPA, 2013a].d – Average bottom ash loadings are based on 244 plants assumed to discharge bottom ash sluice under baseline conditions [U.S.EPA, 2013a].e – Average leachate loadings are based on 102 plants assumed to discharge leachate under baseline conditions [U.S. EPA, 2013a].f – Typical POTW loadings are based on average loadings calculated by DMRLoadsAnalysis2009_v02.mdb for POTWs discharging 3 to 5MGD of wastewater.g – EPA did not calculate loadings for this pollutant and waste stream. See Section 10 of the TDD.h – EPA has not developed a TWF for this pollutant; therefore ERG did not calculate a TWPE value.MemorandumApril 19, 2013Page 12Table 2-7. Results of Comparison of Average Pollutant Loadings in the Evaluated Waste Streams to a Typical POTWPollutantNumber of POTWs Equivalent to:Average Plant FGDDischargeAverage Plant Fly AshDischargeAverage Plant Bottom AshDischargeAverage Plant LeachateDischargeAluminum2,500 /3,590 = <1 7,660 /3,590 =2 2,220/3,590 =<1 1,110 /3,590 =<1Arsenic10.1 /46 = <1 479 /46 =10 69/46 =2 11.1 /46 =<1Boron410,000 /1,540 = 266 18,900 /1,540 =12 8,330/1,540 =5 4,780 /1,540 =3Cadmium133 /4 = 33 58.6 /4 =15 30.5/4 =8 0.594 /4 =<1Chromium VI6.7 /18 = <1 77.6 /18 =4 7.95/18 =<1 Not calculatedCopper26.1 /154 = <1 280 /154 =2 113/154 =<1 2.11 /154 =<1Iron1,850 /2,530 = <1 5,850 /2,530 =2 8,610/2,530 =3 15,100 /2,530 =6Lead5.93 /49 = <1 206 /49 =4 134/49 =3 0.335 /49 =<1Manganese115,000 /354 = 325 3,680 /354 =10 680/354 =2 1,050 /354 =3Mercury6.58 /3,180 = <1 8.65 /3,180 =<1 3.33/3,180 =<1 0.26 /3,180 =<1Nickel1,030 /31 = 33 239 /31 =8 451/31 =15 16.6 /31 =<1Selenium1,490 /18 = 83 257 /18 =14 44.7/18 =2 20.5 /18 =1Thallium19.3 /10 = 2 300 /10 =30 427/10 =43 0.359 /10 =<1Vanadium Not calculated Not calculated Not calculated Not calculatedZinc 1,630 /453 = 4 790 /453 =2 338 /453 =<1 40.1 /453 =<1Total Nitrogen 109,000 /123,000=<1 39,000 /123,000 =<139,400/123,000 =<1 Not calculatedTotal Phosphorus651 /17,800=<1 1,810 /17,800 =<11,320/17,800 =<1 Not calculatedChlorides 12,800,000 /1,610,000=8 265,000 /1,610,000=<1187,000 /1,610,000 =<1 155,000 /1,610,000 =<1TDS Not calculated Not calculated Not calculated Not calculated

### Memorandum April 19, 2013 Page 13

3.0 L OADINGS TO THE 

### C HESAPEAKE 

### B AY AND THE 

### G REAT 

### L AKES



### 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, ERG performed the following steps:

1. Identified steam electric power plants discharging the evaluated waste streams to the watershed and their pollutant loadings at baseline.

2. Performed a literature search to identify studies or data collected on the total industrial or point source discharges of pollutants included in the EA analysis.

3. Compared the steam electric evaluated waste stream discharges to literature data.

4. Compared the steam electric evaluated waste stream discharges to a typical POTW (see Section 2.3 for methodology).

3.1 Evaluation of Steam Electric Power Plant Discharges to the Chesapeake Bay

Based on survey data and further review of discharge locations, ERG identified 20 steam electric power plants discharging to the Chesapeake Bay watershed. Based on the loadings analysis completed for the steam electric proposed ELGs, these plants discharge 2.2 million pounds of nitrogen and 60,000 pounds of phosphorus to the Bay annually from the evaluated waste streams [U.S. EPA, 2012a; U.S. EPA, 2012b] . See Table 3-1 for a list of pollutant loadings used for this analysis. Attachment 1 of this me morandum lists the 20 steam electric power plants discharging to the Chesapeake Bay watershed.

During the literature search, ERG found two references with pollutant loadings data for industrial or point source discharges to the Chesapeake Bay: 1) the December 2010 EPA report, Chesapeake Bay Total Maximum Daily Load for Nitrogen, Phosphorus and Sediment (DCN SE01910), which included loadings data on total nitrogen and total phosphorus and 2) the Chesapeake Bay Program’s 1999 Chesapeake Bay Basin Toxics Loading and Release Inventory (DCN SE01903), which included loadings data for metals included in the EA. ERG also contacted other EPA programs, including the Chesapeake Bay Program Office, to obtain additional or more recent data, but did not find additional data sources.

From the December 2010 EPA report, EPA identified 1,679 NPDES-permitted facilities discharging industrial wastewaters in the Chesapeake Bay watershed. In 2009, these facilities contributed an estimated 7.3 million pounds of total nitrogen and 1.27 million pounds of total phosphorus to the Bay, an estimated 3 percent and 8 percent, respectively, of all nitrogen and phosphorus loadings delivered to Chesapeake Bay watershed [U.S. EPA, 2010b]

.

The 1999 Chesapeake Bay Basin Toxics Loading and Release Inventory from the Chesapeake Bay Program included charts showing range and midpoint of loadings estimated by discharge source type for multiple pollutants (see pages i-10 through i-12). ERG used best engineering judgment to estimate the midpoint of the chart for point source discharges of the

### Memorandum April 19, 2013 Page 14

following pollutants included in the report: arsenic, cadmium, copper, lead, mercury, and zinc. Table 3-1 in the following section presents the estimates.

3.1.1 Comparison of Pollutant Loadings: Steam Electric Power Plants and Other Point Source Discharges to the Chesapeake Bay Watershed

To calculate the percentage of point source loadings entering the Chesapeake Bay

watershed from the steam electric power evaluated waste streams, ERG completed the following

calculations:

X lbs/yr from evaluated waste streams = Percentage of Loadings from Evaluated Waste Streams Y lbs/yr from all point source dischargers

For nitrogen: 2.2 million lbs/yr = 30% 7.3 million lbs/yr

For phosphorus: 0.060 million lbs/yr = 5% 1.27 million lbs/yr

Calculations for the metal loadings comparison were completed using the same approach as

described above.

Table 3-1 presents the baseline pollutant loadings for the evaluated waste streams and the estimated loadings from all point sources to the Chesapeake Bay watershed. The results indicate that pollutant loadings from the evaluated waste streams represent a large portion of the point source metal loadings to the Chesapeake Bay watershed for arsenic, cadmium, lead, and zinc.

The estimated total point source loadings of arsenic from the 1999 Chesapeake Bay Basin Toxics Loading and Release Inventory [Chesapeake Bay Program, 1999] was less than the estimated amount of arsenic discharged in eval uated waste streams from the 20 steam electric power plants. This inconsistency may be due to incomplete data sets. In the report, the Program noted that point source loadings are based on best available data and estimated only for major facilities (facilities with a flow of 0.5 MGD or greater) included in EPA’s Permit Compliance System (PCS). As part of their NPDES permits, many point sources are not required to monitor for arsenic and other pollutants associated with the evaluated waste streams; therefore, the report might not fully account for these pollutant loadings. In addition, the data are over 10 years old and metal pollutant loadings to the Bay may have changed during that time.

### Memorandum April 19, 2013 Page 15

Table 3-1. Comparison of Steam Electric Evaluated Waste Stream Pollutant Loadings to Other Point Source Discharges to the Chesapeake Bay Watershed

Pollutant Steam Electric Baseline Loadings to the Chesapeake Bay Watershed, lbs/year a Total Point Source Loadings to the Chesapeake Bay Watershed, lbs/year b,c Percentage of Point Source Loadings from

Steam Electric Plants Arsenic 5,180 3,500 (c) 100% Cadmium 1,820 3,000 (c) 61% Copper 5,150 78,100 (c) 7% Lead 5,630 15,000 (c) 38% Mercury 168 2,660 (c) 6% Zinc 21,500 125,000 (c) 17% Total Nitrogen 2,200,000 7,340,000 (b) 30% Total Phosphorus 60,000 1,270,000 (b) 5%

Sources: a – U.S. EPA, 2012a; U.S. EPA, 2012b. b – U.S. EPA, 2010b. c – Chesapeake Bay Program, 1999.



### 3.1.2 Calculation of Equivalent Number of Typical POTWs that Discharge the Same Pollutant Loadings as Steam Electric Power Plants to the Chesapeake Bay

Watershed

To provide additional perspective on the magnitude of the loadings, EPA calculated the equivalent number of typical POTWs that would discharge loadings equal to the 20 steam electric power plants that discharge the evaluated waste streams to the Chesapeake Bay watershed. Table 3-2 presents total pollutant loadings for the evaluated waste streams discharging to the Chesapeake Bay and the number of typical POTWs that would discharge equivalent loadings.

### Memorandum April 19, 2013 Page 16

Table 3-2. Estimated Number of POTW Equivalents for Pollutant Loadings to the Chesapeake Bay Watershed from the Evaluated Waste Streams

Pollutant Steam Electric Discharge to the Chesapeake Bay Watershed (20 Plants), lbs/yr a Typical POTW Discharge (see Section 2.3), lbs/yr Number of Typical POTWs Equivalent to 20 Steam Electric Plants Discharging to the Chesapeake Bay b

Arsenic 5,180 46 5,180 / 46 = 113
Cadmium 1,820 4 1,820 / 4 = 455

Chromium VI 681 18 681 / 18 = 38 Copper 5,150 154 5,150 / 154 = 33
Lead 5,630 49 5,630 / 49 = 115 Mercury 168 3,180 168 / 3,180 = <1
Nickel 20,700 31 20,700 / 31 = 668
Selenium 10,100 18 10,100 / 18 = 561
Thallium 16,700 10 16,700 / 10 = 1,670
Zinc 21,500 453 21,500 / 453 = 48 Total Nitrogen 2,200,000 123,000 2,200,000 / 123,000 = 18 Total Phosphorus 60,000 17,800 60,000 / 17,800 = 3

a – U.S. EPA, 2012a; U.S. EPA, 2012b.
b – Equivalent number of POTWs is estimated by dividing the total annual pollutant loadings to the Chesapeake Bay by the average POTW loadings presented in Table 2-5 for POTWs with an effluent flow rate of 3 to 5 MGD.



### 3.2 Evaluation of Steam Electric Power Plant Discharges to the Great Lakes

Based on survey data and further review of discharge locations, ERG identified 26 steam electric power plants discharging to the Great Lakes watershed . ERG estimated the total loadings associated with the evaluated waste streams from the 26 steam electric power plants using data from the loadings analysis (U.S. EPA, 2012a; U.S. EPA, 2012b). Table 3-3 lists the steam electric power plant loadings used for this analysis. Attachment 1 of this memorandum lists the 26 steam electric power plants discharging to the Great Lakes watershed.

Table 3-3. Steam Electric Pollutant Loadings to the Great Lakes Watershed

Pollutant Steam Electric Baseline Loadings to the

Great Lakes Watershed (lbs/year)
Arsenic 4,170
Cadmium 1,410

Chromium VI 380 Copper 5,180
Lead 5,840 Mercury 117
Nickel 18,300
Selenium 6,240
Thallium 15,900
Zinc 19,800 Total Nitrogen 1,990,000 Total Phosphorus 53,200

Source: U.S. EPA, 2012a; U.S. EPA, 2012b.

### Memorandum April 19, 2013 Page 17

During the literature search, ERG found one reference with nutrient loadings data for industrial or point source discharges to the Great Lakes. ERG contacted other EPA programs, including EPA Region 5 Water Division, but did not identify loadings data for metals. D.M. Robertson and D. A. Saad’s October 2011 article, “Nutrient Inputs to the Laurentian Great Lakes by Source and Watershed Estimated Using SPARROW Watershed Models” in the Journal of the

American Water Resources presents estimated annual loadings of total phosphorus and total nitrogen into each Great Lake, normalized to 2002. Table 3-4 presents the relevant data included

in Table 4 of the article.

Table 3-4. Estimated U.S. Annual Loadings of Total Phosphorus and Total Nitrogen to

the Great Lakes

Great Lake Total Phosphorus Total Nitrogen

2002 Total U.S. Load (tonnes) a 2002 Total U.S. Load from

Direct Point Sources (tonnes) 2002 Total U.S. Load (tonnes) a

Erie 4,610 1,150 136,000

Huron 927 126 25,900

Michigan 3,430 374 70,000

Ontario 1,800 464 32,800

Superior 782 75 10,900

Source: Robertson, 2011.
a – Loadings from the U.S. part of each lake’s watershed, and do not include direct atmospheric deposition.



### The article provides data for total phosphorus in both the total U.S. loadings and U.S. loadings from point sources. ERG used the loadings from point sources for the comparison analysis. The only calculation steps were the summation of the loadings from all five Great Lakes and converting the metric tonnes to pounds using the following conversion factor:

1 metric tonne = 1000 kilogram (kg)/tonne × 2.2046 lbs/kg = 2,204.6 lbs

The annual total phosphorus loadings from point sources to the Great Lakes are 2,189 tonnes, or 4.8 million pounds.

To estimate the annual total nitrogen loadings from point sources, ERG used information provided in the literature article that states the percentage of loadings to the Great Lakes attributed from point sources. In the Abstract section, the authors write “Point sources were also significant, contributing [approximately] 14 – 44% of the (phosphorus) and 13 – 34% of the (nitrogen).” Using the range of numbers provided, ERG determined the range of total nitrogen loadings from point sources. The total loadings to the Great Lakes from the U.S. are 275,600 tonnes, or 608 million pounds. Between 13 and 34% of these total nitrogen loadings is from point sources, or between 79 and 207 million pounds.

### Memorandum April 19, 2013 Page 18

3.2.1 Comparison of Pollutant Loadings: Steam Electric Power Plants and Other Point Source Discharges to the Great Lakes Watershed

To calculate the percentage of point source loadings entering the Great Lakes watershed

from the steam electric power evaluated waste streams, ERG completed the following

calculations:

X lbs/yr from evaluated waste streams = Percentage of Loadings from Evaluated Waste Streams Y lbs/yr from all point source dischargers

For nitrogen: 1.99 million lbs/yr = Between 1% and 2.5% 79 to 207 million lbs/yr

For phosphorus: 0.0532 million lbs/yr = 1% 4.8 million lbs/yr

3.2.2 Calculation of Equivalent Number of Typical POTWs that Discharge the Same Pollutant Loadings as Steam Electric Power Plants to the Great Lakes

Watershed

To provide additional perspective on the magnitude of the loadings, EPA calculated the equivalent number of typical POTWs that would discharge loadings equal to the 26 steam electric power plants that discharge the evaluated waste streams to the Great Lakes watershed. Table 3-5 presents total pollutant loadings for the evaluated waste streams discharging to the Great Lakes and the number of typical POTWs that would discharge equivalent loadings.

### Memorandum April 19, 2013 Page 19

Table 3-5. Estimated Number of POTW Equivalents for Pollutant Loadings to the Great

Lakes Watershed from the Evaluated Waste Streams

Pollutant Steam Electric Discharge

to the Great Lakes Watershed (26 Plants), lbs/yr a Typical POTW Discharge (see Section 2.3), lbs/yr Number of Average POTWs Equivalent to 26 Steam Electric Plants Discharging

to the Great Lakes b

Arsenic 4,170 46 4,170 / 46 = 91
Cadmium 1,410 4 1,410 / 4 = 353

Chromium VI 380 18 380 / 18 = 21 Copper 5,180 154 5,180 / 154 = 34
Lead 5,840 49 5,840 / 49 = 119 Mercury 117 3,180 117 / 3,180 = <1
Nickel 18,300 31 18,300 / 31 = 590
Selenium 6,240 18 6,240 / 18 = 347
Thallium 15,900 10 15,900 / 10 = 1,590
Zinc 19,800 453 19,800 / 453 = 44 Total Nitrogen 1,990,000 123,000 1,990,000 / 123,000 = 16 Total Phosphorus 53,200 17,800 53,200 / 17,800 = 3

a – U.S. EPA, 2012a; U.S. EPA, 2012b.
b – Equivalent number of POTWs is estimated by dividing the total annual pollutant loadings to the Great Lakes by the average POTW loadings presented in Table for POTWs with an effluent flow rate of 3 to 5 MGD. Numbers may vary due to rounding.



### 4.0 R EFERENCES



### Chesapeake Bay Program. 1999. Chesapeake Bay Basin Toxics Loading and Release Inventory. Annapolis, MD (May). DCN SE01903.

Metcalf and Eddy, Inc. 2003. Wastewater Engineering: Treatment and Reuse . McGraw-Hill, Inc.

4th edition. DCN SE01967.

Robertson. 2011. D.M. Robertson and D. A. Saad. Nutrient Inputs to the Laurentian Great Lakes by Source and Watershed Estimated Using SPARROW Watershed Models. Journal of the American Water Resources Association, Vol 47, No. 5. October.

U.S. EPA. 2006. Toxic Weighting Factor Development in Support of CWA 304(m) Planning Process. Washington, DC. (June). EPA-HQ-OW-2004-0032-1634. DCN SE01952.

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

Available online at: http://cfpub.epa.gov/dmr/ . DCN SE01959.

U.S. EPA. 2010b. Chesapeake Bay Total Maximum Daily Load for Nitrogen, Phosphorus and Sediment. Washington, DC. (December). DCN SE01910.

U.S. EPA. 2011. Technical Support Document for the 2010 Effluent Guidelines Program Plan. EPA 821-R-09-006. Washington, DC. (October). DCN SE07320.

### Memorandum April 19, 2013 Page 20

U.S. EPA. 2012a. Chesapeake Bay and Great Lakes Proximity Database. Washington, DC. DCN

SE03571.

U.S. EPA. 2012b. Loads Preparation Database for Chesapeake Bay and Great Lakes Analysis. Washington, DC. DCN SE02990.

U.S. EPA, 2013a. Technical Development Document for the Proposed Effluent LimitationsGuidelines and Standards for the Steam Electric Power Generating Point Source Category (EPA821-R-13-002)

. Washington, DC. DCN SE01964.

U.S. EPA. 2013b. DMRLoadsAnalysis2009_v02.mdb: Tables and Queries Used for the Steam Electric Industry ELGs. DCN SE01961.Attachment 1April 19, 2013Page A-1Attachment 1: Steam Electric Power Plants Discharging to the Chesapeake Bay and Great Lakes WatershedsTable A-1 Steam Electric Power Plants Directly Discharging to the Chesapeake Bay WatershedCOMIDPlant NameReceiving Water Name8151995 PPL Montour Chillisquaque Creek14640413 Clinch River Plant Clinch River8677721 Dan River Steam Station Dan River8679473 Belews Creek Steam Station Dan River10054602 Chesapeake Energy Center Deep Creek14638941 Clinch River Plant Dumps Creek14365710 Mount Storm Power Station Four Mile Run8696233 Roxboro Steam Plant Hyco Lake8548185 Bremo Power Station James River10067405 Dominion - Chesterfield Power Station James River8099955 AES Westover, LLC Little Choconut Creek8693517 Mayo Electric Generating Plant Mayo Reservoir14365968 Mount Storm Power Station Mount Storm Lake6908685 Glen Lyn Plant New River11690558 Brandon Shores Patapsco River11908816 Chalk Point Generating Station Patuxent River4507392 Dickerson Generating Station Potomac River4532873 Mirant Mid-Atlantic, LLC Potomac River8653054 Clover Power Station Roanoke River14365968 Mount Storm Power Station Stony River4518760 Sunbury Generation LP Susquehanna River4722211 PPL Brunner Island Susquehanna River8152547 PPL Montour Susquehanna River11690522 Brandon Shores Wagner Plant Discharge Canal4672489 Shawville West Branch Susquehanna RiverSource: U.S. EPA, 2012a; U.S. EPA, 2012b.Attachment 1April 19, 2013Page A-2Table A-2 Steam Electric Power Plants Directly Discharging to the Great Lakes WatershedsCOMIDPlant NameReceiving Water NameLake Basin28125104 Avon Lake Power Plant Lake Erie Erie25769231 JR Whiting Power Plant Lake Erie Erie9840314 Dunkirk Generating Plant Lake Erie Erie30726982 Monroe Power Plant Lake Erie Erie9840092 Dunkirk Generating Plant Van Buren Bay Creek Erie12919103 Harbor Beach Power Plant Lake Huron Huron12927619 JC Weadock Power Plant Saginaw Bay Huron12927619 DE Karn Power Plant Saginaw Bay Huron12005077 Pulliam Fox River Michigan9005799 J. B. Sims Generating Station Grand River Michigan12245290 Eckert Station Grand River Michigan9017879 James De Young Generating Station Lake Macatawa Michigan12169377 Pleasant Prairie Power Plant Lake Michigan Michigan3397270 NIPSCO Michigan City Generating Station Lake Michigan Michigan3398586 NIPSCO Bailly Generating Station Lake Michigan Michigan9017399 JH Campbell Power Plant Lake Michigan Michigan12169333 Oak Creek Power Plant Lake Michigan Michigan12170709 Waukegan Station Lake Michigan Michigan12176006 Edgewater Generating Station Lake Michigan Michigan12162650 Valley Power Plant Menomonee River Michigan12135490 B C Cobb Power Plant Muskegon Lake Michigan9017837 JH Campbell Power Plant Pigeon Lake Michigan12254504 Michigan South Central Power Agency Saint Joseph River Michigan21979641 AES Cayuga LLCaCayuga Lake Ontario21978203 AES Greenidge LLC Keuka Outlet Ontario15561361 AES – Somerset Lake Ontario Ontario21979923 AES Greenidge LLC Seneca Lake Ontario12026640 Presque Isle Power Plant Lake Superior Superior1767108 Laskin Energy Center Partridge River SuperiorSource: U.S. EPA, 2012a; U.S. EPA, 2012b.a – The outfall coordinates and the receiving water name were claimed CBI in the Steam Electric Survey. However, EPA waived theclaim because the plant’s outfall coordinatesand receiving water were identified in a publically available source [AES Eastern Energy LP, 2010].