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MEMORANDUM 

TO: Jim Eddinger, U.S. Environmental Protection Agency, OAQPS/SPPD 

FROM: Eastern Research Group 

DATE: November 2011 

SUBJECT: Estimated Impacts from the Proposed Amendments to the NESHAP for Area 

Sources: Industrial, Commercial, and Institutional Boilers 

1.0 INTRODUCTION 

This memorandum describes the estimated cost and emissions impacts of the proposed 

amendments to the promulgated March, 2011 Area Source Industrial, Commercial, and 

Institutional Boiler NESHAP (76 FR 15554). The methodology used to estimate the impacts for 

the March, 2011 rule is documented in the memorandum “Revised Methodology for Estimating 

Impacts from Industrial, Commercial, Institutional Boilers at Area Sources of Hazardous Air 

Pollutant Emissions” located in the docket1. Cost, emissions, and secondary impacts were 

assessed for the proposed reconsideration amendments to the March, 2011 rule. Since the 

methodology specified in the promulgation memorandum did not change, only the impacts of 

the proposed amendments are presented in this memorandum. 

This memorandum is separated into the following sections: 

1.0 Introduction 

2.0 Summary of Impacts Methodology 

3.0 Summary of Results 

4.0 References 

 
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2.0 SUMMARY OF IMPACTS REVISIONS

This section discusses the impacts analysis for the proposed reconsideration 

amendments of the promulgated March, 2011 Area Source Boiler NESHAP. The area source 

model units developed for the promulgated March, 2011 rule were used for the impacts 

analyses for the proposed reconsideration amendments

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. 

2.1 Proposed Changes in Regulatory Requirements for Area Sources 

The promulgated rule required all new area source boilers to perform an initial boiler 

tune-up. This provision is being proposed to be deleted from the final rule. For the 

promulgated rule, the cost of this initial tune-up was estimated to be $6,477 per boiler in 

capital costs and $2,875 per boiler in annual costs. Total cost savings are estimated to be $111 

million in capital cost and $30 million in annual costs. It was also assumed that the boiler tuneup would provide a one percent reduction in all pollutant emissions. Without the tune-up, 

emission reductions would normally be assumed to decrease. However, since it is likely that 

manufacturers would conduct a tune-up as part of installation and startup of any new sources, 

there is no change in the estimated emission reductions for new area source boilers. 

2.2 Proposed Changes in Emission Level Requirements for Area Sources 

The numeric emission level requirements for mercury (Hg) from coal combustion at 

both existing and new area source boilers have changed. It was determined that the test data 

used to establish these emission limits for the promulgated March, 2011 rule was a utility 

boiler and thus not subject to the provisions of the Industrial, Commercial, and Institutional 

Area Source Boiler NESHAP. The numeric emission limits were re-determined based on the 

next best-performing area source boiler; this unit served as the basis of the emission limit 

calculations for both existing and new area source coal-fired boilers. As a result, the Hg 

emission limit for coal combustion at existing and new area source boilers increased from 4.8E06 pounds per million British thermal unit of heat input (lb/MMBtu) to 2.2E-05 lb/MMBtu. As 

discussed in section 2.3, other changes were made to the procedures for estimating impacts 

that, combined with the revisions to the Hg limits, result in negligible changes to the emission 
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reductions estimates for Hg. This change in the mercury emission limit will not change the 

estimated costs because the technology basis (i.e., fabric filter) has not changed. 

The limits for CO were also revised based on revisions to the MACT floor methodology3, 

resulting in a CO limit of 420 ppm. The revised limit is similar to the limit finalized in the 

promulgated rule, 400 ppm, and has negligible impacts on the estimated costs and emission 

reductions.

2.3 Major Source Data and Analysis Changes that Affect Area Sources 

EPA performed a review of test reports for the top performers from the March, 2011 

Major Source NESHAP. Numerous data corrections and new data submissions were received 

after the promulgation of the March, 2011 Major and Area Source NESHAPs. A summary of 

these data corrections and new data submissions is provided in other memoranda4,5. As a 

result of these changes, baseline emission factors for CO, Hg, and organic HAPs increased at 

major sources since promulgation of the March, 2011 rules. Since the area source model units 

utilize the major source baseline emission factors, the overall baseline emissions of these 

pollutants have changed. Without the initial tune-up requirement for new area source boilers, 

CO reductions would likely be decreased. However, as stated earlier, it is likely that 

manufacturers would conduct a tune-up as part of installation and startup of any new sources. 

The combination of changes has an overall effect of negligible impact on the estimated 

emission reductions for CO, Hg, and organic HAPs from existing and new area sources. The 

methods used to develop baseline emission factors for major and area source units are detailed 

in another memorandum6. 

3.0 SUMMARY OF RESULTS

Table 1 summarizes the cost impact changes discussed in section 2.0 of this 

memorandum. The table also provides a comparison to the impacts estimated for the 

promulgation of the March, 2011 Rule. As shown in Table 1, capital costs for existing area 

source boilers were unchanged as a result of this analysis. Annual costs were revised after 

correcting for a spreadsheet reference error discovered in the calculation of costs for the 
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promulgated Match 2011 rule. The change in annual costs for existing area source shown in 

Table 1 is the corrected annual costs of the promulgated March 2011 rule. The changes 

discussed in section 2.0 did not result in increased annual costs. Capital and annual costs for 

new area source boilers decreased due to the elimination of the initial tune-up provision in the 

proposed rule. As discussed in section 2.0, the revisions to the impacts analysis do not result in 

net changes to the emission reductions for Hg, CO, or organic HAP for the reconsideration. 

Table 1 – Summary of Changes to Cost Impacts since Promulgated Rule 

Source 

Total Capital Investment ($2008) Total Annual Costs ($2008) 

Promulgated Rule Reconsideration Promulgated Rule Reconsideration 

Existing Sources 2,100,370,929 2,100,370,929 586,995,677 598,829,342 

New Sources 619,756,216 508,933,671 264,869,374 234,624,437 

4.0 References

1. Gibson, G., S. McClutchey, and A. Singleton, ERG. Revised Methodology for Estimating 

Impacts from Industrial, Commercial, Institutional Boilers at Area Sources of Hazardous 

Air Pollutant Emissions. February, 2011. 

2. Gibson, G., and A. Singleton, ERG. New Unit Analysis for the Industrial, Commercial, and 

Institutional Boilers National Emission Standards for Hazardous Air Pollutans – Area 

Source. April, 2010. 

3. Eastern Research Group. Revised MACT Floor Analysis for the Industrial, Commercial, and 

Institutional Boilers National Emission Standards for Hazardous Air Pollutants – Area Source. 

November, 2011.

4. Gibson, G., B. Long, and A. Singleton, ERG. Revised Methodology for Estimating Cost 

and Emissions Impacts for Industrial, Commercial, Institutional Boilers and Process 

Heaters National Emission Standards for Hazardous Air Pollutants – Major Source. 

November, 2011. 

5. Gibson, G., and A. Singleton, ERG. Handling and Processing of Corrections and New Data 

in the EPA ICR Databases – Revised November 2011. November, 2011. 
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6. Gibson, G., and A. Singleton, ERG. Revised Development of Baseline Emission Factors 

for Boilers and Process Heaters at Commercial, Industrial, and Institutional Facilities. 

November, 2011.