MEMORANDUM

TO: Steam Electric Rulemaking Record

FROM: Elizabeth Gentile, ERG

DATE: September 30, 2015

SUBJECT: Steam Electric Effluent Guidelines Non-Water Quality Environmental 

Impacts for NSPS/PSNS

1. INTRODUCTION/BACKGROUND

The elimination or reduction of one form of pollution has the potential to aggravate other 

environmental problems, an effect frequently referred to as cross-media impacts. Under sections 

304(b) and 306 of the Clean Water Act, EPA is required to consider non-water quality 

environmental impacts (NWQIs) in developing effluent limitations guidelines and standards

(ELGs). Accordingly, ERG evaluated the effect of these regulations on energy usage, air 

emissions, solid waste generation and management, and water usage. For more information on 

the methodology and results for the NWQIs estimated for the industry, see ERG’s memorandum 

“Steam Electric Effluent Guidelines Non-Water Quality Impacts” (NWQI memorandum) [ERG, 

2015a]. 

2. NEW SOURCE NWQI ESTIMATES

ERG also evaluated the increases of energy and fuel usage, sludge generation, and air emissions

for new sources (i.e., new generating units that will be subject to the New Source Performance 

Standards (NSPS)). ERG estimated compliance costs associated with nine different NSPS 

scenarios. ERG calculated the NWQI associated with NSPS scenarios 4 and 9, for three model 

size plants: 350 MW, 600 MW, and 1,300 MW. ERG only calculated NWQIs associated with 

NSPS Scenarios 4 and 9 because they capture all of the NWQI elements associated with FGD 

and leachate. ERG expects the NWQIs associated with the other seven scenarios would be 

similar, if not the same. A description of the scenarios is provided below:

• Scenario 4: Existing plant with and existing surface impoundment (determined to 

have no capacity for additional combustion residuals), an onsite landfill, wet FGD 

scrubber, and dry bottom ash handling system. 

• Scenario 9: New, Greenfield plant with no surface impoundments, an onsite 

landfill, wet FGD scrubber, dry bottom ash handling system, and combustion 

residual leachate that is treated separately from the FGD wastewater.

For more information on the NSPS scenarios and methodology for estimating costs, see ERG’s 

memorandum “Steam Electric NSPS Cost Methodology” [ERG, 2015b].
Memorandum

September 30, 2015

Page 2

ERG used the same methodology as described in Sections 1 through 5 of ERG’s NWQI 

memorandum to estimate NWQI for the NSPS scenarios [ERG, 2015a]. However, for auxiliary 

energy requirements, EPA used national air emission factors (US) for IPM model run year 2025

(see Table 3-1 in ERG’s NWQI memorandum). ERG used the Regulatory Option B national air 

emission factors (US) for IPM model run year 2025 to calculate air emissions associated with 

increased auxiliary electricity for Regulatory Options A and B. ERG used the Regulatory Option 

D national air emission factors (US) for model run year 2025 to calculate air emissions 

associated with increased auxiliary electricity for Regulatory Options C, D, E, and F. The new 

source NWQI results for the three model plant sizes are presented in Table 2-1, Table 2-2, and 

Table 2-3. The specific calculations used to estimate the new source NWQI can be found in 

Attachment 1 to this memorandum (DCN SE05905A1).

As shown in Table 2-1 through Table 2-3, the NWQIs for Regulatory Option F, the selected 

regulatory option for PSNS/PSES, are higher than compared to Regulatory Option D, the 

selected regulatory option for BAT/PSES. However, simply because the NWQI values are higher 

does not mean Regulatory Option F NWQIs are not acceptable. Since there is nothing inherently 

different between an existing and new source, EPA’s NWQI analysis with respect to existing 

sources is instructive and provides additional perspective [ERG, 2015a]. As explained in ERG’s

“Steam Electric Effluent Guidelines Non-Water Quality Environmental Impacts for BAT/PSES” 

memorandum, EPA found that even if all of the existing plants and generating units incurred

costs to comply with Regulatory Option F, the increased NWQI are acceptable. The same 

rationale applies to NSPS/PSNS, particularly in light of the few, if any, new coal-fired plants or 

generating units predicted by the Integrated Planning Model [U.S. EPA, 2015].
Memorandum

September 30, 2015

Page 3

Table 2-1. Calculated Sum of NWQI for New Sources Evaluated for the Steam Electric Rulemaking for 350 MW Model Plant

NSPS 

Scenario

Regulatory 

Option

Electrical 

Energy Usage

(MWh/year)

Fuel

(GPY)

Sludge 

(tons/year)

NOx Emissions 

(tons/year)

SOx Emissions 

(tons/year)

CO2 Emissions 

(tons/year)

CH4 Emissions 

(tons/year)

4

A 216 165 4,060 0.0652 0.0648 101 0.00298

B 1,370 168 4,140 0.411 0.411 634 0.0187

C 1,370 168 4,140 0.411 0.411 633 0.0187

D 1,370 168 4,140 0.411 0.411 633 0.0187

E 1,370 168 4,140 0.411 0.411 633 0.0187

F 5,540 1,290 31,900 1.67 1.66 2,570 0.0757

9

A 216 165 4,060 0.0652 0.0648 101 0.00298

B 1,370 168 4,140 0.411 0.411 634 0.0187

C 1,370 168 4,140 0.411 0.411 633 0.0187

D 1,370 168 4,140 0.411 0.411 633 0.0187

E 1,630 190 4,670 0.49 0.489 754 0.0222

F 5,810 1,310 32,400 1.75 1.74 2,690 0.0793
Memorandum

September 30, 2015

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Table 2-2. Calculated Sum of NWQI for New Sources Evaluated for the Steam Electric Rulemaking for 600 MW Model Plant

NSPS Scenario

Regulatory 

Option

Electrical 

Energy Usage

(MWh/year)

Fuel

(GPY)

Sludge 

(tons/year)

NOX Emissions 

(tons/year)

SOX Emissions 

(tons/year)

CO2 Emissions 

(tons/year)

CH4 Emissions 

(tons/year)

4

A 412 269 6,630 0.124 0.124 192 0.00568

B 1,900 275 6,770 0.57 0.569 878 0.0259

C 1,900 275 6,770 0.57 0.569 878 0.0259

D 1,900 275 6,770 0.57 0.569 878 0.0259

E 1,900 275 6,770 0.57 0.569 878 0.0259

F 9,120 2,110 52,100 2.74 2.74 4,220 0.125

9

A 412 269 6,630 0.124 0.124 192 0.00568

B 1,900 275 6,770 0.57 0.569 878 0.0259

C 1,900 275 6,770 0.57 0.569 878 0.0259

D 1,900 275 6,770 0.57 0.569 878 0.0259

E 2,180 311 7,670 0.654 0.653 1,010 0.0297

F 9,400 2,150 53,000 2.82 2.82 4,350 0.128
Memorandum

September 30, 2015

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Table 2-3. Calculated Sum of NWQI for New Sources Evaluated for the Steam Electric Rulemaking for 1,300 MW Model 

Plant

NSPS 

Scenario

Regulatory 

Option

Electrical 

Energy Usage

(MWh/year)

Fuel

(GPY)

Sludge 

(tons/year)

NOX Emissions 

(tons/year)

SOX Emissions 

(tons/year)

CO2 Emissions 

(tons/year)

CH4 Emissions 

(tons/year)

4

A 1,070 582 14,300 0.322 0.32 497 0.0147

B 3,550 594 14,700 1.07 1.06 1,640 0.0484

C 3,550 594 14,700 1.07 1.06 1,640 0.0484

D 3,550 594 14,700 1.07 1.06 1,640 0.0484

E 3,550 594 14,700 1.07 1.06 1,640 0.0484

F 19,900 4,570 113,000 5.98 5.97 9,220 0.272

9

A 1,070 582 14,300 0.322 0.32 497 0.0147

B 3,550 594 14,700 1.07 1.06 1,640 0.0484

C 3,550 594 14,700 1.07 1.06 1,640 0.0484

D 3,550 594 14,700 1.07 1.06 1,640 0.0484

E 3,910 673 16,600 1.17 1.17 1,810 0.0534

F 20,300 4,650 115,000 6.09 6.08 9,390 0.277
Memorandum

September 30, 2015

Page 6

REFERENCES

1. ERG. 2015a. Eastern Research Group, Inc. Memorandum to the Steam Electric Rulemaking 

Record. “Steam Electric Effluent Guidelines Non-Water Quality Impacts.” (September 30).

DCN SE05574.

2. ERG. 2015b. Eastern Research Group, Inc. Memorandum to the Steam Electric Rulemaking 

Record. “Steam Electric NSPS Cost Methodology.” (September 30). DCN SE05844.

3. U.S. EPA. 2015. Regulatory Impact Analysis for the Effluent Limitations Guidelines and 

Standards for the Steam Electric Power Generating Point Source Category. (September 30).

EPA-821-R-15-004.