E

C

/R Incorporated Providing Environmental Technical Support Since 1989

501 Eastowne Drive, Suite 325  Chapel Hill, North Carolina 27514

Telephone: (919)484-0222  Fax: (919) 484-0122

 

MEMORANDUM

DATE: August 8, 2010

SUBJECT: Impacts Associated with NESHAP for Existing Stationary SI RICE

FROM: Bradley Nelson and Tanya Parise, EC/R, Inc.

TO: Melanie King, EPA OAQPS/SPPD/ESG

1.0 PURPOSE

The purpose of this memorandum is to provide an estimate of the cost impacts and the 

emission reductions of the National Emission Standards for Hazardous Air Pollutants (NESHAP) 

for existing spark ignition (SI) stationary reciprocating internal combustion engines (RICE). The 

regulation applies to existing stationary SI RICE that are less than or equal to 500 horsepower 

(HP) located at major sources and all existing SI RICE at area sources of hazardous air pollutants 

(HAP) emissions. Impacts discussed in this memorandum include emissions reductions and total 

costs associated with the regulatory requirements that will be promulgated under 40 CFR part 63, 

subpart ZZZZ. Costs associated with the final rule include the capital and annual cost of 

purchasing and operating air pollution control equipment, recordkeeping, reporting, and 

performance testing. 

The total capital cost associated with the NESHAP for existing stationary SI RICE is 

estimated to be $383 million in the year 2013. The total annual cost of the NESHAP is estimated 

to be $253 million in the year 2013. The NESHAP for existing stationary SI RICE is estimated 

to reduce HAP emissions in the year 2013 by 6,000 tons per year (tpy). 
2

2.0 ENGINE POPULATION

The existing population of SI engines in the U.S. was estimated using information 

obtained from the Power System Research’s (PSR) North American Engine PartsLink Database 

provided by the U.S. EPA Office of Transportation and Air Quality. The number of affected SI 

engines was estimated using population and engine sales information from PSR.1,2 In addition to 

the PSR data, EPA received SI engine population data from the U.S. Department of Agriculture 

(USDA) that provided a summary of SI engines used as irrigation sets by fuel type and engine 

size from the National Agriculture Statistics Service (NASS). This NASS estimates were used in 

lieu of the information from PSR for irrigation sets. According to USDA, the majority of 

irrigation sets are located at area sources. Therefore, it was assumed that 95 percent of existing 

SI engines that are irrigation sets are located at area sources. It was also assumed that 95 percent 

of existing SI engines used for gas compression are located at area sources, based on information 

from the natural gas transmission industry.

3

 For all other industries and applications, it was 

assumed that 60 percent of existing SI engines are located at area sources. The number of 

affected SI engines is presented in Table 1.

Table 1. Number of Affected Enginesa

Size Range

(HP) Major Sources Area Sources

25-50 55,842 91,709

50-100 14,955 39,447

100-175 23,679 48,539

175-300 5,104 17,393

300-500 3,148 12,499

500-600 N/A 6,250

600-750 N/A 1,071

>750 N/A 11,411

Total 102,729 228,318

a

Engines subject to this rule are existing SI engines constructed before 6/12/2006 that are less 

than or equal to 500 HP and located at major source and existing SI engines constructed before 

6/12/2006 and located at area sources.

 

1 Memorandum from Tanya Parise, Alpha-Gamma Technologies, Inc. to Jaime Pagán, EPA Energy Strategies 

Group, Existing Population of Stationary RICE, June 26, 2008.

2 Memorandum from Tanya Parise, EC/R to Melanie King, EPA. Existing Population of Stationary RICE 

Attachments. February 10, 2010.

3 Letter from the American Petroleum Institute to EPA. Support for Use of Management Practices in the 

National Emission Standards for Hazardous Air Pollutants Standards for Reciprocating Internal Combustion 

Engines at Area Sources in Rural Locations. November 2009.
3

3.0 COST IMPACTS

The cost impacts associated with the final rule include the annual and capital costs of 

controls, costs associated with keeping records of information necessary to demonstrate 

compliance, costs associated with reporting requirements under the General Provisions of 40 

CFR part 63, subpart A, costs of purchasing and operating equipment associated with continuous 

parametric monitoring, and the cost of conducting performance testing to demonstrate 

compliance with the emission standards. The following sections describe how the various cost 

elements were estimated. 

Control Costs

For certain engines, the final rule sets emission standards based on the use of oxidation 

catalyst and non-selective catalytic reduction (NSCR). For engines that will need to add control 

technology to meet the emission standards, the following equations were used to estimate capital 

and annual control costs:

HAP Control Technology

Capital Cost

($2009)

Annual Cost

($2009)

Oxidation Catalyst (4SLB) $12.8 x HP + $3,069 $1.81 x HP + $3,442

NSCR $24.9 x HP + $13,118 $4.77 x HP + $5,679

The above control cost equations were calculated using retrofit cost data received from industry

groups, vendors, and manufacturers of engine control technology. Documentation for how these 

control cost equations were developed is presented in a memorandum available from the 

rulemaking docket.

4

The final rule emission standards are shown in Table 2. Engines not shown in Table 2

are not subject to numerical emission standards in the final rule, but must meet work practice or 

management practices instead. For engines located at major sources of HAP, it is expected that 

owners and operators of existing non-emergency 2SLB engines between 100 HP and 500 HP, 

existing non-emergency 4SRB engines between 100 HP and 500 HP, and landfill/digester gas 

engines will be able to meet the emission limitation without adding any aftertreatment controls. 

Therefore, no control costs were attributed to these engines. 

Existing non-emergency 4SLB engines between 100 HP and 500 HP at major sources 

and existing non-emergency 4SLB engines greater than 500 HP at area sources are expected to 

use an oxidation catalyst in order to meet the emission standards. Costs estimated for these 

engines include the cost of installing and operating an oxidation catalyst for reducing HAP 

emissions. It was assumed that 5 percent of the existing population of 4SLB engines already 

have add-on controls for HAP reduction, which is based on information available from the RICE 

Population Database.

 

4 Memorandum from Bradley Nelson, EC/R to Melanie King, EPA OAQPS/SPPD/ESG, Control Costs for Existing 

Stationary SI RICE, June 29, 2010.
4

Existing non-emergency 4SRB engines greater than 500 HP at area sources are expected 

to use NSCR in order to meet the emission standards. Costs estimated for these engines include 

the cost of installing and operating NSCR for reducing HAP emissions, assuming that 20 percent 

of the existing population already have add-on controls for HAP reduction. The percentage of 

existing 4SRB engines currently operating with add-on controls used to estimate impacts is 

based on information from different sources, including information from different EPA Regional 

Offices, the RICE Population Database, and control technology vendors.

Table 2. Final Emission Standards

Subcategory

Applicable Standard 

(except during periods of 

startup)

Aftertreatment Required to 

Meet Standard

2SLB Non-Emergency

100≤HP≤500

at major sources

225 ppmvd CO at 15% O2 None

4SLB Non-Emergency

100≤HP≤500

at major sources

47 ppmvd CO at 15% O2 Oxidation Catalyst

4SRB Non-Emergency

100≤HP≤500

at major sources

10.3 ppmvd CH2O at 15% O2 None

Landfill/Digester Gas 

Non-Emergency 100≤HP≤500

at major sources

177 ppmvd CO at 15% O2 None

4SLB Non-Emergency >500 HP

at area sources

47 ppmvd CO at 15% O2 or 

93% CO reduction Oxidation Catalyst

4SRB Non-Emergency >500 HP

at area sources

2.7 ppmvd CH2O at 15% O2

or 

76% CH2O reduction

NSCR
5

Performance Testing

Existing stationary SI RICE subject to numerical emission standards under the final rule 

must conduct an initial performance test to demonstrate that the standards are being met. 

Owners and operators of SI engines that are not subject to any numerical emission standards are 

not subject to any testing requirements, which includes existing stationary SI engines less than 

100 HP at major sources and existing stationary emergency SI engines less than or equal to 500 

HP at major sources, as well as existing stationary SI engines at area sources (except nonemergency 4SLB engines greater than 500 HP and non-emergency engines 4SRB greater than 

500 HP). The following non-emergency existing stationary SI engines are subject to testing 

under the final rule:

 2SLB 100≤HP≤500 located at major sources,

 4SLB 100≤HP≤500 located at major sources,

 4SRB 100≤HP≤500 located at major sources,

 Landfill/digester gas 100≤HP≤500 located at major sources, 

 4SLB >500 HP located at area sources, and

 4SRB >500 HP located at area sources.

The cost of conducting carbon monoxide (CO) performance testing for 2SLB and 4SLB 

engines is based on the cost of portable analyzer testing and is estimated to be $1,000 per day. It 

was assumed that 2 engines could be tested each day using the portable analyzer, therefore the 

costs per engine was estimated to be $500. The testing costs are based on information previously 

obtained from engine testing firms and summarized in the memorandum “Portable Analyzer 

Testing Costs.” 5 The cost of conducting formaldehyde performance testing for non-emergency

4SRB engines was estimated to be $2,000 per day, with two engines being tested per day. 

Therefore the testing cost was estimated to be $1,000 per engine for formaldehyde testing. 

Recordkeeping

Recordkeeping costs were calculated assuming 1 hour per year for each existing SI

engine. The costs are attributed to the requirement of following the manufacturer’s emissionrelated operation and maintenance (O&M) requirements or the owner/operator’s own 

maintenance plan. It is expected that the majority of owner/operators are already following some 

type of O&M requirements and minimal to no additional burden is expected. A technical labor 

rate of $73 per hour was used to estimate the cost and is based on technical labor rates obtained 

from the Bureau of Labor Statistics.

6

 All costs were converted to 2009 dollars for purposes of 

presenting costs associated with the rule in present day terms. The recordkeeping cost for 

emergency SI engines is estimated to be 1 hour per year to record the number of hours the 

emergency engine is operated.

 

5 Memorandum from Bradley Nelson, Alpha-Gamma Technologies, Inc. to Sims Roy, 

EPA/OAQPS/ESD/Combustion Group, Portable Emissions Analyzer Cost Information, August 31, 2005. 

6

http://www.bls.gov/news.release/ecec.toc.htm
6

Reporting

Certain non-emergency engines affected by this rule will be subject to reporting 

requirements such as reading instructions, training personnel, submitting an initial notification, 

submitting a notification of performance test(s), and submitting semi-annual compliance reports. 

It is estimated that a total of 14 hours will be needed, where 4 hours are expected to be used for 

reading the rule, 4 hours are estimated to be used for training, and 6 hours are expected to be 

used for preparing and submitting notifications and compliance reports. Owners and operators of 

SI engines that are not subject to any numerical emission standards are not subject to any

reporting requirements. This includes existing emergency SI engines less than or equal to 500 

HP located at major sources, existing SI engines less than 100 HP located at major sources, and 

existing SI engines at area sources (except non-emergency 4SLB greater than 500 HP and nonemergency 4SRB greater than 500 HP). The following non-emergency existing stationary SI 

engines are subject to reporting requirements under the final rule:

 2SLB 100≤HP≤500 located at major sources,

 4SLB 100≤HP≤500 located at major sources,

 4SRB 100≤HP≤500 located at major sources,

 4SLB >500 HP located at area sources, and

 4SRB >500 HP located at area sources.

Monitoring

The cost of monitoring includes the purchase of a continuous parametric monitoring 

system (CPMS). Existing non-emergency 4SLB greater than 500 HP at area sources and 

existing non-emergency 4SRB engines greater than 500 HP at area sources that have add-on 

controls are required to use a CPMS to monitor the catalyst inlet temperature and pressure drop 

across the catalyst to ensure those parameters do not exceed the operating limitations. The cost 

of purchasing and operating a CPMS was obtained from vendor quotes received for previous 

rulemaking and adjusted to current a cost of $568.

7

 It is estimated that 30 hours per year is 

necessary to operate and maintain the CPMS and that 6 hours per year (or 0.5 hours per month) 

is needed to record information from the CPMS. There are no costs associated with monitoring 

for emergency engines.

Summary of Costs

The total costs estimated for the final rule requirements include the purchase, installation, 

and operation of aftertreatment controls and monitoring equipment, performance testing, and the 

costs associated with recordkeeping, notification, and reporting requirements. The total 

estimated costs associated with the final rule in the year 2013 are presented in Table 3 through 

Table 7. 

 

7

Part A of the Supporting Statement for Standard Form 83 Stationary Reciprocating Internal Combustion Engines, 

November 17, 2003.
7

Table 3. Summary of Major Source and Area Source Costs for the SI RICE NESHAP1

Size Range 

(HP)

Capital 

Control 

Cost

Annual 

Control 

Cost

Initial Test Recordkeeping Reporting

Monitoring 

- Capital 

Cost

Monitoring 

- Annual 

Cost

Total 

Annual 

Costs

Total Capital 

Costs

Major Sources

25-50 $0 $0 $0 $4,060,795 $0 $0 $0 $4,060,795 $0

50-100 $0 $0 $0 $1,087,540 $0 $0 $0 $1,087,540 $0

100-175 $48,502,361 $37,071,061 $15,971,384 $1,721,899 $5,725,314 $0 $0 $60,489,657 $48,502,361

175-300 $13,225,919 $8,382,568 $3,442,648 $371,157 $1,234,097 $0 $0 $13,430,470 $13,225,919

300-500 $10,934,795 $5,562,872 $2,123,326 $228,919 $761,155 $0 $0 $8,676,272 $10,934,795

500-600 $0 $0 $0 $0 $0 $0 $0 $0 $0

600-750 $0 $0 $0 $0 $0 $0 $0 $0 $0

>750 $0 $0 $0 $0 $0 $0 $0 $0 $0

Total $72,663,076 $51,016,500 $21,537,358 $7,470,310 $7,720,566 $0 $0 $87,744,734 $72,663,076

Area Sources

25-50 $0 $0 $0 $6,668,944 $0 $0 $0 $6,668,944 $0

50-100 $0 $0 $0 $2,868,511 $0 $0 $0 $2,868,511 $0

100-175 $0 $0 $0 $3,529,711 $0 $0 $0 $3,529,711 $0

175-300 $0 $0 $0 $1,264,799 $0 $0 $0 $1,264,799 $0

300-500 $0 $0 $0 $908,913 $0 $0 $0 $908,913 $0

500-600 $75,474,331 $26,628,053 $3,655,719 $454,493 $1,264,260 $2,821,013 $13,003,822 $45,006,347 $78,295,345

600-750 $15,222,363 $5,052,207 $652,400 $77,882 $225,620 $503,438 $2,320,662 $8,328,771 $15,725,801

>750 $210,754,181 $62,143,967 $6,951,011 $829,795 $2,403,874 $5,363,896 $24,725,562 $97,054,209 $216,118,077

Total $301,450,875 $93,824,227 $11,259,129 $16,603,048 $3,893,754 $8,688,347 $40,050,046 $165,630,205 $310,139,222

Grand 

Total $374,113,951 $144,840,727 $32,796,487 $24,073,358 $11,614,321 $8,688,347 $40,050,046 $253,374,939 $382,802,298

a Costs are presented in 2009 dollars.
8

Table 4. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP1

NAICS

Major Source Area Source Total (Major + Area)

Capital Cost Annual Cost Capital Cost Annual Cost Capital Cost Annual Cost

Electric Power Generation (2211) $52,905,258 $63,062,494 $120,301,416 $65,334,028 $173,206,675 $128,396,522

Natural Gas Transmission (48621) $1,484,494 $1,462,530 $140,977,276 $67,467,484 $142,461,771 $68,930,015

Crude Petroleum & NG Production (211111) $4,561,236 $6,138,383 $732,943 $1,258,072 $5,294,179 $7,396,454

Natural Gas Liquid Producers (211112) $4,561,236 $6,138,383 $732,943 $1,258,072 $5,294,179 $7,396,454

National Security (92811) $5,878,362 $7,006,944 $13,366,824 $7,259,336 $19,245,186 $14,266,280

Hydro Power Units (335312) $0 $25,248 $0 $37,872 $0 $63,120

Irrigation Sets (335312) $3,025,050 $3,230,856 $34,027,819 $22,445,211 $37,052,869 $25,676,067

Welders (333992) $247,440 $679,896 $0 $570,130 $247,440 $1,250,027

Total $72,663,076 $87,744,734 $310,139,222 $165,630,205 $382,802,298 $253,374,939

a Costs are presented in 2009 dollars.
9

Table 5. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP – by Size1

NAICS

Major Source Area Source Total (Major + Area)

Capital Cost Annual Cost Capital Cost Annual Cost Capital Cost Annual Cost

Electric Power Generation (2211)

25-50 hp $0 $2,758,459 $0 $4,137,688 $0 $6,896,147

50-100 hp $0 $606,144 $0 $909,215 $0 $1,515,359

100-175 hp $33,868,173 $42,238,648 $0 $1,803,548 $33,868,173 $44,042,196

175-300 hp $10,603,849 $10,767,847 $0 $446,361 $10,603,849 $11,214,209

300-500 hp $8,433,236 $6,691,397 $0 $264,820 $8,433,236 $6,956,217

500-600 hp $0 $0 $26,390,293 $15,169,876 $26,390,293 $15,169,876

600-750 hp $0 $0 $5,325,628 $2,820,584 $5,325,628 $2,820,584

>750 hp $0 $0 $88,585,495 $39,781,934 $88,585,495 $39,781,934

Total Electric Power Generation 2211 $52,905,258 $63,062,494 $120,301,416 $65,334,028 $173,206,675 $128,396,522

Natural Gas Transmission (48621)

25-50 hp $0 $102 $0 $1,934 $0 $2,036

50-100 hp $0 $4,872 $0 $92,571 $0 $97,443

100-175 hp $301,721 $376,291 $0 $203,518 $301,721 $579,809

175-300 hp $643,157 $653,104 $0 $342,928 $643,157 $996,032

300-500 hp $539,617 $428,162 $0 $214,637 $539,617 $642,799

500-600 hp $0 $0 $19,975,323 $11,482,372 $19,975,323 $11,482,372

600-750 hp $0 $0 $9,808,436 $5,194,789 $9,808,436 $5,194,789

>750 hp $0 $0 $111,193,518 $49,934,735 $111,193,518 $49,934,735

Total Natural Gas Transmission (48621) $1,484,494 $1,462,530 $140,977,276 $67,467,484 $142,461,771 $68,930,015

Crude Petroleum & NG Production (211111)

25-50 hp $0 $388,115 $0 $582,173 $0 $970,288

50-100 hp $0 $66,698 $0 $100,047 $0 $166,744

100-175 hp $4,549,775 $5,674,246 $0 $242,285 $4,549,775 $5,916,531

175-300 hp $1,037 $1,053 $0 $44 $1,037 $1,096

300-500 hp $10,424 $8,271 $0 $327 $10,424 $8,598

500-600 hp $0 $0 $32,184 $18,500 $32,184 $18,500
10

Table 5. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP – by Size1(cont’d)

600-750 hp $0 $0 $0 $0 $0 $0

>750 hp $0 $0 $700,760 $314,697 $700,760 $314,697

Total Crude Petroleum & NG Production (211111) $4,561,236 $6,138,383 $732,943 $1,258,072 $5,294,179 $7,396,454

Natural Gas Liquid Producers (211112)

25-50 hp $0 $388,115 $0 $582,173 $0 $970,288

50-100 hp $0 $66,698 $0 $100,047 $0 $166,744

100-175 hp $4,549,775 $5,674,246 $0 $242,285 $4,549,775 $5,916,531

175-300 hp $1,037 $1,053 $0 $44 $1,037 $1,096

300-500 hp $10,424 $8,271 $0 $327 $10,424 $8,598

500-600 hp $0 $0 $32,184 $18,500 $32,184 $18,500

600-750 hp $0 $0 $0 $0 $0 $0

>750 hp $0 $0 $700,760 $314,697 $700,760 $314,697

Total Natural Gas Liquid Producers (211112) $4,561,236 $6,138,383 $732,943 $1,258,072 $5,294,179 $7,396,454

National Security (92811)

25-50 hp $0 $306,495 $0 $459,743 $0 $766,239

50-100 hp $0 $67,349 $0 $101,024 $0 $168,373

100-175 hp $3,763,130 $4,693,183 $0 $200,394 $3,763,130 $4,893,577

175-300 hp $1,178,205 $1,196,427 $0 $49,596 $1,178,205 $1,246,023

300-500 hp $937,026 $743,489 $0 $29,424 $937,026 $772,913

500-600 hp $0 $0 $2,932,255 $1,685,542 $2,932,255 $1,685,542

600-750 hp $0 $0 $591,736 $313,398 $591,736 $313,398

>750 hp $0 $0 $9,842,833 $4,420,215 $9,842,833 $4,420,215

Total Natural Gas Liquid Producers (211112) $5,878,362 $7,006,944 $13,366,824 $7,259,336 $19,245,186 $14,266,280

Hydro Power Units (335312)

25-50 hp $0 $22,688 $0 $34,032 $0 $56,721

50-100 hp $0 $2,560 $0 $3,840 $0 $6,399

100-175 hp $0 $0 $0 $0 $0 $0

175-300 hp $0 $0 $0 $0 $0 $0

300-500 hp $0 $0 $0 $0 $0 $0

500-600 hp $0 $0 $0 $0 $0 $0
11

Table 5. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP – by Size1(cont’d)

600-750 hp $0 $0 $0 $0 $0 $0

>750 hp $0 $0 $0 $0 $0 $0

Total Hydro Power Units (335312) $0 $25,248 $0 $37,872 $0 $63,120

Irrigation Sets (335312)

25-50 hp $0 $32,913 $0 $625,338 $0 $658,251

50-100 hp $0 $65,825 $0 $1,250,677 $0 $1,316,502

100-175 hp $1,222,348 $1,524,449 $0 $824,505 $1,222,348 $2,348,954

175-300 hp $798,634 $810,986 $0 $425,827 $798,634 $1,236,813

300-500 hp $1,004,068 $796,683 $0 $399,376 $1,004,068 $1,196,060

500-600 hp $0 $0 $28,933,107 $16,631,556 $28,933,107 $16,631,556

600-750 hp $0 $0 $0 $0 $0 $0

>750 hp $0 $0 $5,094,712 $2,287,931 $5,094,712 $2,287,931

Total Irrigation Sets (335312) $3,025,050 $3,230,856 $34,027,819 $22,445,211 $37,052,869 $25,676,067

Welders (333992)

25-50 hp $0 $163,908 $0 $245,862 $0 $409,771

50-100 hp $0 $207,394 $0 $311,091 $0 $518,485

100-175 hp $247,440 $308,594 $0 $13,177 $247,440 $321,771

175-300 hp $0 $0 $0 $0 $0 $0

300-500 hp $0 $0 $0 $0 $0 $0

500-600 hp $0 $0 $0 $0 $0 $0

600-750 hp $0 $0 $0 $0 $0 $0

>750 hp $0 $0 $0 $0 $0 $0

Total Welders (333992) $247,440 $679,896 $0 $570,130 $247,440 $1,250,027

Total $72,663,076 $87,744,734 $310,139,222 $165,630,205 $382,802,298 $253,374,939
12

Table 6. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP – by Number of Engines

1

NAICS

Number of Engines Total (Major + Area)

Major Area Total Capital Cost Annual Cost

Electric Power Generation (2211)

25-50 hp 37,933 56,900 94,833 $0 $6,896,147

50-100 hp 8,336 12,503 20,839 $0 $1,515,359

100-175 hp 16,534 24,802 41,336 $33,868,173 $44,042,196

175-300 hp 4,092 6,138 10,230 $10,603,849 $11,214,209

300-500 hp 2,428 3,642 6,070 $8,433,236 $6,956,217

500-600 hp 0 2,107 2,107 $26,390,293 $15,169,876

600-750 hp 0 363 363 $5,325,628 $2,820,584

>750 hp 0 4,677 4,677 $88,585,495 $39,781,934

Total Electric Power Generation 2211 69,323 111,132 180,455 $173,206,675 $128,396,522

Natural Gas Transmission (48621)

25-50 hp 1 27 28 $0 $2,036

50-100 hp 67 1,273 1,340 $0 $97,443

100-175 hp 147 2,799 2,946 $301,721 $579,809

175-300 hp 248 4,716 4,964 $643,157 $996,032

300-500 hp 155 2,952 3,107 $539,617 $642,799

500-600 hp 0 1,595 1,595 $19,975,323 $11,482,372

600-750 hp 0 668 668 $9,808,436 $5,194,789

>750 hp 0 5,871 5,871 $111,193,518 $49,934,735

Total Natural Gas Transmission (48621) 619 19,899 20,519 $142,461,771 $68,930,015

Crude Petroleum & NG Production (211111)

25-50 hp 5,337 8,006 13,343 $0 $970,288

50-100 hp 917 1,376 2,293 $0 $166,744

100-175 hp 2,221 3,332 5,553 $4,549,775 $5,916,531

175-300 hp 0 1 1 $1,037 $1,096

300-500 hp 3 5 8 $10,424 $8,598

500-600 hp 0 3 3 $32,184 $18,500
13

Table 6. Summary of Major Source and Area Source NAICS Costs for the SI RICE NESHAP – by Number of Engines1(cont’d)

600-750 hp 0 0 0 $0 $0

>750 hp 0 37 37 $700,760 $314,697

Total Crude Petroleum & NG Production (211111) 8,479 12,758 21,237 $5,294,179 $7,396,454

Natural Gas Liquid Producers (211112)

25-50 hp 5,337 8,006 13,343 $0 $970,288

50-100 hp 917 1,376 2,293 $0 $166,744

100-175 hp 2,221 3,332 5,553 $4,549,775 $5,916,531

175-300 hp 0 1 1 $1,037 $1,096

300-500 hp 3 5 8 $10,424 $8,598

500-600 hp 0 3 3 $32,184 $18,500

600-750 hp 0 0 0 $0 $0

>750 hp 0 37 37 $700,760 $314,697

Total Natural Gas Liquid Producers (211112) 8,479 12,758 21,237 $5,294,179 $7,396,454

National Security (92811)

25-50 hp 4,215 6,322 10,537 $0 $766,239

50-100 hp 926 1,389 2,315 $0 $168,373

100-175 hp 1,837 2,756 4,593 $3,763,130 $4,893,577

175-300 hp 455 682 1,137 $1,178,205 $1,246,023

300-500 hp 270 404 674 $937,026 $772,913

500-600 hp 0 234 234 $2,932,255 $1,685,542

600-750 hp 0 40 40 $591,736 $313,398

>750 hp 0 520 520 $9,842,833 $4,420,215

Total Natural Gas Liquid Producers (211112) 7,702 12,347 20,050 $19,245,186 $14,266,280

Hydro Power Units (335312)

25-50 hp 312 468 780 $0 $56,721

50-100 hp 35 53 88 $0 $6,399

100-175 hp 0 0 0 $0 $0

175-300 hp 0 0 0 $0 $0

300-500 hp 0 0 0 $0 $0
14

500-600 hp 0 0 0 $0 $0

600-750 hp 0 0 0 $0 $0

>750 hp 0 0 0 $0 $0

Total Hydro Power Units (335312) 347 521 868 $0 $63,120

Irrigation Sets (335312)

25-50 hp 453 8,599 9,052 $0 $658,251

50-100 hp 905 17,199 18,104 $0 $1,316,502

100-175 hp 597 11,338 11,935 $1,222,348 $2,348,954

175-300 hp 308 5,856 6,164 $798,634 $1,236,813

300-500 hp 289 5,492 5,781 $1,004,068 $1,196,060

500-600 hp 0 2,310 2,310 $28,933,107 $16,631,556

600-750 hp 0 0 0 $0 $0

>750 hp 0 269 269 $5,094,712 $2,287,931

Total Irrigation Sets (335312) 2,552 51,063 53,615 $37,052,869 $25,676,067

Welders (333992)

25-50 hp 2,254 3,381 5,635 $0 $409,771

50-100 hp 2,852 4,278 7,130 $0 $518,485

100-175 hp 121 181 302 $247,440 $321,771

175-300 hp 0 0 0 $0 $0

300-500 hp 0 0 0 $0 $0

500-600 hp 0 0 0 $0 $0

600-750 hp 0 0 0 $0 $0

>750 hp 0 0 0 $0 $0

Total Welders (333992) 5,227 7,840 13,067 $247,440 $1,250,027

Total 102,729 228,319 331,047 $382,802,298 $253,374,939
15

4.0 EMISSION REDUCTIONS

The emissions reductions associated with the final rule are based on requiring emission 

standards that are based on applying add-on controls to existing non-emergency 4SLB engines 

from 100 HP to 500 HP at major sources, non-emergency 4SLB engines greater than 500 HP at 

area sources, and non-emergency 4SRB engines greater than 500 HP at area sources. Baseline 

emissions were calculated using the existing stationary SI engine emission factors

8

and control 

efficiencies presented below assuming 2,800 hours per year (hrs/yr) for non-emergency

operation and 50 hrs/yr for emergency operation. It was also assumed for purposes of estimating 

reductions associated with the final rule that 5 percent of existing 4SLB engines and 20 percent 

of existing 4SRB engines are currently operating with add-on controls that reduce HAP 

emissions. In addition, the Engine Manufacturers Association (EMA) has indicated that about 5 

percent of stationary SI engines are used for emergency operation. These engines are 

predominantly 4SRB engines, according to EMA.9To calculate the tpy emissions reductions 

associated with the final rule, the following general equation was used:

EFpollutant (lb/hp-hr) x (hp) x (hrs/yr) x (ton/2,000 lb) x (# of engines) x (% reduction)

Emission Factors:

Engine HAP

(lb/hp-hr)

CO

(lb/hp-hr)

NOx

(lb/hp-hr)

VOC

(lb/hp-hr)

2SLB 5.96x10-41.06x10-24.18x10-23.07x10-3

4SLB 5.41x10

-4

3.92x10-31.15x10-22.78x10-3

4SRB 2.43x10-41.93x10-21.47x10-21.25x10-3

The emission factors were derived using data available in EPA’s Emissions Database for 

stationary engines and emissions data received following the proposed rule and are presented in a 

memorandum available from the rulemaking docket.

Control Efficiencies:

Technology HAP CO NOx

4SLB Ox. Catalyst 71% 94% N/A

4SRB NSCR 76% 49% 97%

The control efficiencies are based on the average percent reduction observed during EPA’s 

testing program at Colorado State University. The results from this testing are available from 

www.regulations.gov as Document ID Number EPA-HQ-OAR-2002-0059-0665.

 

8 Memorandum from Bradley Nelson, EC/R to Melanie King, EPA OAQPS/SPPD/ESG, Emission Factors for 

Existing Stationary SI RICE, August 3, 2010.

9 Letter from Joe Suchecki, EMA to Sims Roy, EPA. EMA Response to Questions on Proposed SI NSPS. 

September 19, 2005. 
16

Based on the above assumptions and the existing population of engines shown in Table 1 of this 

memorandum, the HAP, CO, NOx, and VOC baseline emissions and reductions were calculated. 

The estimated reductions as a result of the final rule are shown in Table 7. 

Table 7. Summary of Emissions Reductions for the SI RICE NESHAP

Engine Size 

(HP)

Emission Reductions (tpy)

HAP CO NOx VOC

Major Sources

25-50 0 0 0 0

50-100 0 0 0 0

100-175 744 7,124 0 3,826

175-300 277 2,653 0 1,424

300-500 288 2,755 0 1,480

500-600 N/A N/A N/A N/A

600-750 N/A N/A N/A N/A

>750 N/A N/A N/A N/A

Total 1,308 12,532 0 6,730

Area Sources

25-50 0 0 0 0

50-100 0 0 0 0

100-175 0 0 0 0

175-300 0 0 0 0

300-500 0 0 0 0

500-600 1,005 20,698 20,632 5,170

600-750 220 4,533 4,519 1,132

>750 3,475 71,557 71,328 17,874

Total 4,700 96,789 96,479 24,177

Grand Total 6,008 109,321 96,479 30,907