MEMORANDUM 

TO: Steam Electric Rulemaking Record 

FROM: Danielle Lewis, ERG 

DATE: September 30, 2015 

SUBJECT: Plant-Specific Compliance Cost Estimates for the Treatment of FGD 

Wastewater with Chemical Precipitation Followed by Evaporation 

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

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

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

As part of the analyses for the ELGs, EPA, with support from ERG, estimated incremental 

compliance costs associated with installing and operating the various technologies and practices 

that make up the regulatory options considered by EPA. As described in the Technical 

Development Document for the Effluent Limitations Guidelines and Standards for the Steam 

Electric Power Generating Point Source Category (DCN SE05904) and Incremental Costs and 

Pollutant Removals for the Final Effluent Limitations Guidelines and Standards for the Steam 

Electric Power Generating Point Source Category (DCN SE05831) (Costs and Loads Report) 

EPA analyzed six regulatory options for the final rule. These six regulatory options include new 

or revised effluent limitations and standards on specific wastestreams generated by steam electric 

power plants. These wastestreams include flue gas desulfurization (FGD) wastewater, fly ash 

transport water, bottom ash transport water, combustion residual leachate, flue gas mercury 

control (FGMC) wastewater, and gasification wastewater. Table 1 summarizes the technology 

basis for each wastestream under each regulatory option, Options A, B, C, D, E, and F. As one 

moves from Option A to Option F, there is a greater estimated reduction in pollutant discharges 

from steam electric power plants. 

Table 1. Steam Electric Power Generating Point Source Category Regulatory Options 

Wastestreams

Technology Basis for Regulatory Options 

A B C D E F 

FGD 

Wastewater 

Chemical 

Precipitation 

Chemical 

Precipitation + 

Biological 

Treatment 

Chemical 

Precipitation + 

Biological 

Treatment 

Chemical 

Precipitation + 

Biological 

Treatment 

Chemical 

Precipitation + 

Biological 

Treatment 

Evaporation 

Fly Ash 

Transport 

Water 

Dry Handling Dry Handling Dry handling Dry handling Dry handling Dry handling 

Bottom Ash 

Transport 

Water 

Impoundment 

(Equal to BPT) 

Impoundment 

(Equal to BPT) 

Dry 

handling/Closed 

loop (for units 

>400 MW); 

Impoundment 

Dry handling/ 

Closed loop 

Dry handling/ 

Closed loop 

Dry handling/ 

Closed loop 
Memorandum 

September 30, 2015 

Page 2 

Table 1. Steam Electric Power Generating Point Source Category Regulatory Options 

Wastestreams

Technology Basis for Regulatory Options 

A B C D E F 

(Equal to 

BPT)(for units 

≤400 MW) 

FGMC 

Wastewater 

Dry handling Dry handling Dry handling Dry handling Dry handling Dry handling 

Gasification 

Wastewater 

Evaporation Evaporation Evaporation Evaporation Evaporation Evaporation 

Combustion 

Residual 

Leachate 

Impoundment 

(Equal to BPT) 

Impoundment 

(Equal to BPT) 

Impoundment 

(Equal to BPT) 

Impoundment 

(Equal to BPT) 

Chemical 

Precipitation 

Chemical 

Precipitation 

Nonchemical 

Metal 

Cleaning 

Wastes 

[Reserved] [Reserved] [Reserved] [Reserved] [Reserved] [Reserved] 

 For each of the regulatory options, EPA estimated plant-specific compliance costs for the 

individual treatment technologies using the methodologies described in the Costs and Loads 

Report. These plant-specific costs for individual treatment technologies were then combined to 

calculate total industry costs associated with each regulatory option. 

 Under Regulatory Option F, EPA would establish ELGs for FGD wastewater based on 

treatment using an evaporation system. EPA developed a methodology to estimate compliance 

costs for each plant discharging FGD wastewater to install or upgrade an existing FGD 

wastewater treatment system to an evaporation treatment system. EPA’s methodology for 

estimating compliance costs associated with evaporation treatment of FGD wastewater is 

described in Section 6.3 of the Cost and Loads Report. 

 EPA revised the methodology for estimating evaporation treatment system costs based on 

comments received on the proposed Steam Electric ELG. Revisions to the cost methodology 

include the following: 

 Revised estimate of indirect capital costs – EPA estimated indirect capital costs (i.e., 

engineering and supervision, construction expenses, contractor’s fees, and contingency 

fees) as a combined cost based on a percentage of total equipment costs. 

 Increased equipment costs to account for added redundancy – EPA added an escalation 

factor to the purchased equipment costs to account for the purchase of redundant 

equipment for the evaporation treatment system. 

 Increased capital and operating and maintenance (O&M) costs to account for chemical 

treatment – EPA added capital costs associated with chemical addition systems to add 

polymer, sulfuric acid, sodium hydroxide (caustic), anti-foam, and anti-scalant to the 

treatment system. EPA also included the O&M cost associated with purchasing these 

chemicals. 

 Revised operating labor costs – EPA increased the plant staff requirement to operate the 

evaporation system from one operator to three operators. 
Memorandum 

September 30, 2015 

Page 3 

 Revised maintenance labor and maintenance materials cost – EPA increased the costs 

associated with maintenance labor and maintenance materials to account for more 

frequent maintenance activities to clean and replace parts within the evaporation system. 

The Cost and Loads Report includes specific details on the development of these revised cost 

elements. 

 EPA determined there was no need to revise the electricity costs associated with the 

evaporation treatment system. The plant-specific costs for the electricity required by the 

evaporation treatment system remain unchanged from costs for electricity estimated at proposal. 

Due to changes in the equipment cost methodology for evaporation and other plant-specific 

changes to the FGD wastewater treatment flow rates, EPA estimates that on an industry level 

these electricity costs will remain relatively unchanged. EPA determined there was no need to 

include additional electricity costs for any of the new equipment added to the evaporation 

treatment system since proposal (i.e., new chemical addition systems) because these systems use 

such a small amount of electricity, 9 kWh per day per system, it is insignificant when compared 

to the energy consumption of the treatment system. Additionally, EPA did not include additional 

electricity costs for redundant equipment because the purpose for the additional equipment is to 

add redundancy to the system and therefore the amount of equipment operating at any one time 

would be unchanged. For example, adding an additional pump for redundancy would not 

increase the electricity demand for the system because it would act as backup for an operating 

pump, and would only operate whenever the other pump is shutdown or otherwise out of service. 

EPA also determined that it was not necessary to revise electricity costs because any changes 

related to revisions to FGD wastewater flow rates would not significantly change the capital or 

O&M costs for the evaporation system. As described in the Cost and Loads Report, electricity 

usage is directly related to the FGD wastewater flow rate; thus, any change to flow rate would 

result in a proportional change to electricity costs. 

EPA estimated compliance costs several different ways to evaluate the effect of the final 

ELG on the steam electric industry. In these different cost approaches EPA considered other 

rulemakings affecting the steam electric industry, to include the coal combustion residuals 

(CCR) rule and Clean Power Plan (CPP). In the cost estimates that account for CCR and CPP, 

EPA identified 3 plants with an increase in FGD wastewater flow from proposal and 13 plants 

with a decrease in FGD wastewater flow from proposal. 

 Attachment 1 includes plant-specific compliance cost estimates for all plants discharging 

FGD wastewater for the cost approach accounting for both the CCR rule and CPP, and for the 

cost approach accounting for only the CCR rule. Table 2 summarizes the total industry capital 

and O&M costs estimate for each cost approach. 

Table 2. Industry-Level Estimated Compliance Cost for FGD Wastewater Treatment 

using Evaporation 

Cost Approach Total Capital Cost Total O&M Cost 

With CCR and CPP $6,190,000,000 $661,000,000

With CCR $7,690,000,000 $821,000,000

Note: Compliance costs assume that oil-fired generating units and generating units with a capacity of 50 MW or less 

do not install the technology basis for FGD wastewater treatment. 

Note: Compliance costs rounded to three significant figures.