MEMORANDUM

Date: December 16, 2011

Subject: Emission Reduction Costs for Beyond-the-floor Mercury Rate for Existing Units 

Designed to Burn Low Rank Virgin Coal

From: Kevin Culligan, SPPD/OAQPS

To: EPA-HQ-OAR-2009-0234

For the final rule, EPA has recalculated the beyond the floor control costs for existing 

units designed to burn low rank virgin coal using a methodology similar to that used in the IPM 

analysis done for the MATS proposal. In the final rule, we have not recalculated control costs 

based on the other methodology used in the proposal which used ACI capital and operating costs 

provided in the ICR. We have not used that approach because it was based upon an assumption 

that all units would need to have a baghouse (also known as a fabric filter – FF – either existing 

or newly installed) in order to meet the MACT PM standard and that the ACI would be used with 

the baghouse. EPA has considered and used additional information demonstrating that high 

levels of mercury removal can be achieved with injection of brominated activated carbon and the 

addition of a FF is not necessary. Furthermore, based on additional analysis related to the PM 

standard, EPA believes that most lignite units will not need to install new FF, therefore, EPA 

believes a costing methodology based on this assumption would be inappropriate.

For this analysis, EPA calculated beyond-the-floor costs for mercury controls by

assuming injection of brominated activated carbon at a rate of 3.0 lb/MACF for units with ESPs 

and injection rates of 2.0 lb/MACF for units with baghouses (also known as fabric filters). The 

rate of 2.0 lb/MACF for fabric filters is consistent with the rate assumed in all other IPM 

analyses for this rule. The rate of 3.0 lb/MACF for units with ESPs is lower than the rate of 5.0 

lb/MACF assumed in the IPM analysis. EPA believes that this rate is appropriate, because a 

higher rate would likely result in reductions beyond those needed to meet the BTF standard of 

4.0 lb/TBtu. Figure 1 in "Activated Carbon Injection for Mercury: Overview"

1

suggests that > 

90% control can be achieved at lignite-fired units at a < 2.0 lb/MACF injection rate for units with 

installed FF and using treated (i.e., brominated) AC. The figure also suggests that > 90% Hg 

control can be achieved at lignite-fired units at < 3.0 lb/MACF injection rate for units with 

installed ESPs and using treated AC. As Table 1 below shows, based on the IPM analysis, all 

units would need to achieve reductions of less than 90%, therefore lower assumed injection rates 

are appropriate.

 

1 Fuel Processing Technology 89 (2010) 1310
Table 1 – Emission Reduction Rates Required to Meet Standard of 4 lb/TBtu.

EPA also assumed a disposal cost of $25/ton for ash comingled with activated carbon. 

This cost is consistent with a range of studies. DOE/NETL, in a recent study examining the 

costs of ACI, assumed total disposal costs of $17/ton for non-hazardous fly ash. They assumed 

$35/ton for fly ash that would have otherwise been sold for beneficial reuse (lost revenue of 

$18/ton plus disposal costs of $17/ton for non-hazardous fly ash). 2In an EPA study, $25 - $30 

per ton were assumed as total disposal costs.3

EPA recently modeled site-specific disposal costs for the RIA4for the proposed rule 

regulating coal combustion residuals (CCRs), including fly ash. Those costs were examined for 

units burning low rank virgin coal. The disposal costs varied by state/region. For Texas the 

incremental costs attributable to Hg control were $18.13/ton, while for North Dakota and 

Montana, the incremental costs attributable to Hg control were $32.31/ton.

 

2 Environmental Sci. Technol. 2007, 41, 1365]. 

3 Environmental Sci. Technol. 2006, 1385

4 Regulatory Impact Analysis For EPA’s Proposed RCRA Regulation Of Coal Combustion Residues (CCR) 

Generated by the Electric Utility Industry. Prepared by US Environmental Protection Agency Office of Resource 

Conservation & Recovery (ORCR) (formerly Office of Solid Waste) 1200 Pennsylvania Avenue NW (Mailstop 

5305P) Washington DC, 20460 USA. Available at http://www.regulations.gov/ docket number EPA-HQ-RCRA2009-0640-0003, Appendix H.

Base Reduction Policy

Plant Name Unit ID Hg Controls Existing Controls Hg lbs/Tbtu Required, % Hg lbs/Tbtu

Big Brown 1 ACI Cold-side ESP + Fabric Filter + SNCR 9.09 55.98 1.01

Big Brown 2 ACI Cold-side ESP + Fabric Filter + SNCR 9.09 55.98 1.01

Lewis & Clark B1 ACI Wet Scrubber 7.68 47.92 0.75

Martin Lake 1 ACI Cold-side ESP + Wet Scrubber 5.41 26.09 0.56

Martin Lake 2 ACI Cold-side ESP + Wet Scrubber 5.41 26.09 0.56

Martin Lake 3 ACI Cold-side ESP + Wet Scrubber 5.41 26.09 0.56

Monticello 3 ACI Cold-side ESP + SNCR + Wet Scrubber 6.30 36.53 0.96

R M Heskett B1 Cold-side ESP 7.81 48.77 0.45

R M Heskett B2 Cold-side ESP + Cyclone 4.76 16.00 0.75

Leland Olds 1 Cold-side ESP 7.68 47.93 0.77

Leland Olds 2 Cold-side ESP 7.81 48.77 0.78

Milton R Young B1 Cold-side ESP + SCR + Wet Scrubber 4.21 4.93 0.75

Milton R Young B2 Cold-side ESP + SCR + Wet Scrubber 4.21 4.93 0.75

Stanton 1 Cold-side ESP 7.81 48.77 0.78

Stanton 10 Fabric Filter + Dry Scrubber 7.51 46.76 0.75

Limestone LIM1 Cold-side ESP + Wet Scrubber 6.75 40.76 1.13

Limestone LIM2 Cold-side ESP + Wet Scrubber 6.75 40.76 1.13

Dolet Hills 1 Cold-side ESP + Wet Scrubber 8.33 51.98 1.35

Coal Creek 1 Cold-side ESP + Wet Scrubber 4.21 5.07 0.76

Coal Creek 2 Cold-side ESP + Wet Scrubber 4.21 5.07 0.76

Laramie River Station 1 Cold-side ESP + Wet Scrubber 5.31 24.71 0.56

Laramie River Station 2 Cold-side ESP + Wet Scrubber 5.31 24.71 0.56

Antelope Valley B1 Fabric Filter + Dry Scrubber 7.51 46.76 0.75

Antelope Valley B2 Fabric Filter + Dry Scrubber 7.51 46.76 0.75

Twin Oaks Power One U1 Fabric Filter 5.82 31.33 1.35

Twin Oaks Power One U2 Fabric Filter 5.82 31.33 1.35

Pirkey 1 Cold-side ESP + Wet Scrubber 7.59 47.27 1.35

Coyote B1 Fabric Filter + Dry Scrubber 7.64 47.66 0.75

Great River Energy Spiritwood Station 1 Cold-side ESP + Fabric Filter + SNCR + Dry Scrubber 7.68 47.92 0.75
Based on these key assumptions, EPA projects an average reduction cost of $27,017 per 

pound of Hg removed. Unit by unit costs are provided in Table 2.

Table 2 – Unit by unit cost estimates for achieving an emission rate of 4 lb/TBtu Hg

Plant Name Unit ID Capacity 

(MW)

Heat Rate 

(Btu/kWh)

Existing PM 

Controls

(Base to 

Policy) Hg 

remv'd (lbm)

(2007$) unit 

S/lbm Hg

Total 

Cost

Big Brown 1 575 11001

Cold-side ESP + 

Fabric Filter + 

SNCR

-396 3954 1565723

Big Brown 2 575 10931

Cold-side ESP + 

Fabric Filter + 

SNCR

-393 3980 1565723

Lewis & Clark B1 52.3 13787 Wet Scrubber -31 22920 704682

Martin Lake 1 750 11512 Cold-side ESP + 

Wet Scrubber -332 32175 10671737

Martin Lake 2 750 11202 Cold-side ESP + 

Wet Scrubber -323 32174 10383770

Martin Lake 3 750 10784 Cold-side ESP + 

Wet Scrubber -311 32309 10038209

Monticello 3 750 11246

Cold-side ESP + 

SNCR + Wet 

Scrubber

-359 29249 10487787

R M Heskett B1 29.37 11985 Cold-side ESP -17 38871 652353

R M Heskett B2 75.5 11386 Cold-side ESP + 

Cyclone -22 53992 1206545

Leland Olds 1 221 11404 Cold-side ESP -109 25792 2812406

Leland Olds 2 448 11021 Cold-side ESP -217 23822 5176973

Milton R Young B1 250 10661

Cold-side ESP + 

SCR + Wet 

Scrubber

-64 51542 3272935

Milton R Young B2 455 10661

Cold-side ESP + 

SCR + Wet 

Scrubber

-116 49018 5665257

Stanton 1 130.3472 10990 Cold-side ESP -77 26601 2050240

Stanton 10 57.35278 10320 Fabric Filter + 

Dry Scrubber -31 30538 935770.1

Limestone LIM1 831 10102 Cold-side ESP + 

Wet Scrubber -372 29034 10797351

Limestone LIM2 858 10108 Cold-side ESP + -384 28982 11134608
Wet Scrubber

Coal Creek1 554 11219 Cold

-side ESP + 

Wet Scrubber

-162 48056 7781365

Coal Creek2 560.3 10818 Cold

-side ESP + 

Wet Scrubber

-158 47982 7576786

Laramie River 

Station

1 565 11312 Cold

-side ESP + 

Wet Scrubber

-235 34742 8170580

Laramie River 

Station

2 570 10953 Cold

-side ESP + 

Wet Scrubber

-230 34737 7980115

Antelope Valley B1 450 10988 Fabric Filter + 

Dry Scrubber

-264 22315 5888636

Antelope Valley B2 450 11206 Fabric Filter + 

Dry Scrubber

-269 22269 5993120

Twin Oaks Power 

One U1 152 9497 Fabric Filter

-50 38215 1900963

Twin Oaks Power 

One U2 153 10364 Fabric Filter

-55 37778 2064287

Coyote B1 427 11639 Fabric Filter + 

Dry Scrubber

-228 22122 5043515

Pirkey1 675 10693 Cold

-side ESP + 

Wet Scrubber

-349 26185 9140141

Great River Energy 

Spiritwood Station

1 99 8937

Cold-side ESP + 

Fabric Filter + 

SNCR + Dry 

Scrubber

-46 11694 535381.6

Dolet Hills1 650 10674 Cold

-side ESP + 

Wet Scrubber

-351 27064 9500464

Total-5948 1.61E+08

Average 27016