EC

/R Incorporated Providing Environmental Technical Support Since 1989

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MEMORANDUM 

TO: Melanie King, EPA OAQPS/SPPD/ESG 

FROM: Bradley Nelson, EC/R, Inc. 

SUBJECT: Summary of the February 23, 2010 Meeting between the U.S. Environmental 

Protection Agency and Exterran to discuss the NESHAP for Existing Stationary 

Spark Ignition Reciprocating Internal Combustion Engines 

1.0 INTRODUCTION 

Exterran requested this meeting with EPA to discuss the national emission standards for 

hazardous air pollutants (NESHAP) for existing stationary spark ignition (SI) reciprocating 

internal combustion engines (RICE), which are to be finalized in August 2010. This meeting 

summary will be available in the docket for this rulemaking (Docket ID No. EPA-HQ-OAR2008-0708). The proposed NESHAP for existing stationary RICE was published in the Federal 

Register on March 5, 2009 (74 FR 9698). The final NESHAP for existing stationary 

compression ignition (CI) RICE was signed on February 17, 2010. 

2.0 ATTENDEES 

Bob Wayland, EPA Jeff Holmstead, Bracewell & Giuliani 

Melanie King, EPA Rebecca Rentz, Bracewell & Giuliani 

Michael Horowitz, EPA (by phone) John Dutton, J-W Power Co. 

Bradley Nelson, EC/R Inc. David O’Leary, Compressor Systems, Inc. 

Kyle Jantzen, Exterran Lewis Sweazy, Compressor Systems, Inc. 

Bill Bowes, Exterran Tom McGrath, IES 

Mike Wasson, Exterran Jeff Panek, IES 

Gerald Meinecke, Exterran Jim McCarthy, IES 

James Harrison, Exterran (by phone) 
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3.0 SUMMARY OF MEETING 

Urban/Rural Distinction

Exterran provided an agenda, which is included as Attachment A to this meeting 

summary. Exterran submitted comments requesting a rural area source subcategory for engines 

less than 500 horsepower similar to what was done in the Oil and Gas rule. Exterran asked if 

EPA could provide any information regarding what direction EPA is headed towards on this 

issue. In the final NESHAP for existing CI engines, EPA determined that it was not appropriate 

to distinguish between stationary existing CI engines at area sources located in urban and rural 

locations. EPA will determine whether a rural area source subcategory is appropriate for 

existing stationary SI engines, and may consider engine size and type as part of this analysis. 

EPA stated that geographical information close to population centers using Urban-1/Urban-2 

(U1/U2) information will be used in the analysis. The U1/U2 definitions are based on the 

definitions of urban/rural for the Urban Air Toxics Program and are defined as follows: 

 U1 counties which include a metropolitan statistical area (MSA) with a population 

greater than 250,000; 

 U2 counties that do not include a MSA with a population greater than 250,000, but the 

Bureau of the Census designates more than 50 percent of the county population as 

“urban.” These counties include areas which comprise one or more central places and 

adjacent densely settled surrounding urban fringe. The urban fringe consists of 

contiguous territory having a density of at least 1,000 persons per square mile; and 

 Rural counties that do not include an MSA with a population greater than 250,000 and 

the Bureau of the Census designates more than 50 percent of the county population as 

“rural.” 

Exterran indicated that it thought that EPA would use the same urban area/urban cluster 

classifications that were used in the Oil and Gas rule and asked whether the decision to use 

U1/U2 categorization was a policy or legal issue. EPA stated that the Urban Air Toxics Program 

definitions clearly distinguishes between urban and rural using the U1/U2 classifications 

Exterran stated that it needed to review the definitions and would provide comments at a later 

date. Exterran also added that it provided a small sample of sites in Texas in earlier comments 

that shows how sparse the populations around these sites are. EPA requested additional 

information on the distance from businesses and residences to these stationary SI engines. 

Work/Management Practices

Exterran stated that it provided a paper to EPA with recommendations for management 

practices for engines at area sources for the final rule. Exterran’s recommendations are included 

as Attachment B to this meeting summary. Exterran stated that SI engines burn cleaner fuel, 

therefore maintenance activities such as oil changes and spark plug replacements are not needed 

every 500 or 1,000 hours of operation. Exterran recommended that the oil change be required 

every 1,440 hours of operation for 4-stroke SI engines. Exterran said that spark plugs can be 
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cleaned and re-gapped a few times before needing to be replaced. In the case of oil changes, 

Exterran indicated that facilities should be allowed to perform an oil analysis. In Exterran’s 

opinion, if the analysis shows that the oil has reached the condemning limits, an oil change 

should be required within 30 days. Exterran indicated that this will reduce waste oil from the 

facilities and still allow the engine to operate efficiently. For inspection of belts and hoses, 

Exterran indicated that the inspection frequency should coincide with the frequency requirements 

of the spark plug replacement and oil change, i.e., every 1,440 hours of operation for 4-stroke SI 

engines. For 2-stroke SI engines, Exterran recommended that the oil change and spark plug 

replacement frequency be extended to 4,320 hours of operation. Exterran stated that these 

engines are low speed, which reduces wear on the engine, and the combustion chamber is sealed 

from the oil, which eliminates oil contamination. Therefore, Exterran indicated that the 

maintenance frequency for 2-stroke engines can be longer than for 4-stroke engines. EPA 

indicated that it will review the information Exterran provided. 

EPA asked for clarification of skip or extended period monitoring that were included in 

Exterran’s recommendations. Exterran stated that the skip or extended period monitoring would 

allow facilities to increase the intervals between inspections based on the maintenance history of 

the SI engine without having to get approval from EPA. Exterran added that the skip or 

extended period monitoring would allow owners/operators to take advantage of premium oils 

and new spark plug technology, which extend the need for replacement. Exterran also added that 

the skip period would reduce the amount of waste oil generated by a facility. For an example, 

Exterran stated that if the oil analysis and spark plug inspection showed the change levels were 

not exceeded after two inspection periods, then the inspection interval could be extended by 

1,440 hours after the next oil change. EPA said it would take Exterran’s recommendations into 

consideration for the final rule and asked for additional information supporting this 

recommendation. 

Crankcase Emissions

Exterran stated that crankcase emissions are the product of diesel fuel combustion and 

asked if EPA plans to require crankcase emission control for stationary SI engines. EPA stated 

that the requirement to use crankcase emissions control was included in the final rule for existing 

stationary CI engines to reduce particulate hazardous air pollutant (HAP) emissions. EPA has 

not reviewed crankcase HAP emissions data from stationary SI engines at this point. 

MACT Floor/Variability

Exterran stated that it has spent approximately $500,000 on testing of stationary SI 

engines, which included testing at different loads and other conditions that may affect emissions. 

Exterran indicated that it could not test for all conditions, such as natural gas composition 

variability or altitude, but believed that the data collected include variability. Exterran thought 

that the maximum achievable control technology (MACT) floor should be derived by identifying 

the top 12 percent of engines and using the highest value from these top 12 percent of engines to 

set the MACT floor. Exterran indicated that this approach will provide a reasonable operating 

scenario as recently approved by the District of Columbia Courts. EPA indicated that it is open 

to ideas for ways to account for variability. EPA suggested that Exterran provide a subset of the 
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data showing the recommended MACT floor calculation and EPA would review the 

recommendation. For engines at high altitudes, EPA stated it could look at data and consider a 

special provision for these engines. 

Cost Analysis

 

Exterran indicated that it believed the control cost estimates in the proposed rule are too 

low and the HAP emission factors are too high. Exterran asked if the control costs were 

calculated based on cost data from vendors. EPA stated that the control costs were calculated 

using costs from both vendors and state collection requests from facilities. EPA also stated that 

additional cost information was received during the comment period, which will be reviewed in 

addition to new data received during the development of the final CI rule. Exterran would be 

willing to provide additional cost information if needed. 

Startup/Shutdown/Malfunction

Exterran reviewed the startup, shutdown and malfunction (SSM) requirements in the final 

rule for stationary existing CI engines and expressed that it had concerns certifying compliance 

with the rule and the issue of credible evidence for stationary SI engines. EPA stated that 

compliance is based on three 1-hour runs, and EPA expects that malfunctioning engines will be 

shutdown. Exterran questioned the scenario where there is a malfunctioning oxidation catalysts 

leading to the engine exceeding the standards and being out of compliance for the period since it 

was last tested. EPA agreed that the engine would be out of compliance for that period, but 

added if there is a malfunction, then the engine should be shutdown. EPA further added that 

certifying compliance means that the engine meets the requirements based on three 1-hour tests. 

EPA stated that if Exterran has alternative suggestions on compliance to please provide 

recommendations to EPA. 

Method 323

Exterran stated that IES will be providing side-by-side testing of three to four engines for 

formaldehyde using Method 323 and Fourier Transform Infrared Spectroscopy. EPA responded 

that this data will be helpful in determining if the Method 323 should be validated. Exterran 

believed that a checklist should be developed to assist the tester in performing Method 323. 
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Attachment A 

Exterran Agenda 

for February 23, 2010 Meeting 
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EPA

Research Triangle Park

SI RICE

February 23, 2010 

1:30 

I. Rural Area Sources Subcategory 

II. Management Practices 

III. MACT Floor/Variability 

IV. Revised Cost Analysis 

V. SSM/Work Practices 
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Attachment B 

Memorandum to Melanie King, EPA 

January 27, 2010 

Management Practices for SI RICE Area Sources < 500 HP