April 27, 2009

VIA E-MAIL

Mr. Jaime Pagan

Energy Strategies Group

U. S. Environmental Protection Agency

D243-01

Research Triangle Park, NC 27711

Re: EMA Recommendations Regarding Emergency CI Engines Greater Than 

30 Liters/Cylinder and Definition of Installed

Dear Mr. Pagan:

At the meeting held between EPA and EMA at your offices on February 9, 2009, one of 

the topics discussed was the need to revise the New Source Performance Standards (NSPS) for 

Compression Ignition (CI) engines as the regulation applies to engines with a displacement 

greater than 30 liters per cylinder (l/cyl). When finalized in 2006, the NSPS required owners and 

operators of large engines used in emergency back-up applications to meet the same emissions 

standards as engines used in non-emergency, prime power applications. That regulatory 

approach is in contrast to the regulation of engines less than 30 l/cyl where the NSPS recognized 

that emergency engines cannot use aftertreatment to meet emissions limits due to the potential

degradation of critical engine performance parameters during emergency operations or natural

disasters.

To correct the above discrepancy, EMA requested that you consider revising the CI 

NSPS to apply the same approach to emissions control for emergency engines larger than 30 

l/cyl as you do for engines less than 30 l/cyl. That approach would assure that the emissions 

limits for emergency engines greater than 30 l/cyl would not trigger the need for aftertreatment.

After that meeting, you requested that EMA provide a proposal for the emission limits for 

large emergency-only engines. EMA has the following recommendation for a revised set of 

emission limits for emergency engines larger than 30 l/cyl. In the United States, the predominant 

market for such engines is likely to be nuclear power installations, but other application such as 

flood control or government/public safety operations centers also are possible. 
Mr. Jaime Pagan

April 7, 2009

Page 2

EMA recommends that owners and operators of stationary CI engines greater than 30 

l/cyl that are used only in emergency back-up applications meet the following emissions limits 

using the referenced test methods and conditions.

FUEL

Low Sulfur Fuels should be used for all tests, i.e., fuel less than 500 ppm sulfur

PM

0.40 g/kw-hr, US EPA Methods 5B or 17 

NOx

IMO Tier II or Tier I levels, determined by IMO curve and installation date. NOTE: 

IMO Tier III is aftertreatment forcing and would not apply.

TEST CONDITIONS

All tests to be run at factory test bed or certification site and steady load conditions at 

85% and 100% of nameplate rated load and at a constant rated speed.

For PM tests, average test results from three, 0.5 hour or longer values at each load 

condition with the result compared directly to the emission standard.

For NOx tests, average test results from three, 0.5 hour or longer values at each load 

condition. Include corrections for ambient humidity and temperature as stipulated in Section 

5.12.4 IMO MEPC58 revised Marpol Annex VI, October 2008. Compare the results directly 

with the NOx emissions standard specified by the IMO curves.

If emissions compliance measurements are to be performed at the site, the allowances 

stipulated in Sections 6.3.11.1, 6.3.11.2, and 6.3.11.3 of the same document should be applied in

addition to the corrections stated in Section 5.12.4.

LABELING

Similar to requirements for other CI emergency engines in the NSPS, EMA proposes that 

engines larger than 30 l/cyl that are destined for emergency operations be specifically labeled by 

the manufacturer with the phrase “FOR EMERGENCY USE ONLY”.

By adopting the above emissions standards for emergency engines larger than 30 l/cyl, 

EPA will be revising the currently applicable PM and NOx standards so that regulatory 
Mr. Jaime Pagan

April 7, 2009

Page 3

emissions limits can be met without the use of aftertreatment that may adversely affect 

emergency engine performance. Moreover, this will rectify the inconsistent treatment of large 

emergency engines in the current CI NSPS and will allow the continued use of engines greater 

than 30 l/cyl for emergency applications without increasing the likelihood of safety performance 

degradation or failure during emergency operations.

Secondly, as we discussed during our February 9th 2009 meeting, EMA requested that 

EPA clarify the term “installed” as it applies to stationary engine installations. This term drives 

significant industry activity toward compliance with the emissions standards. Thus, EMA 

requests that EPA define this term in the rule making package:

“Installed” means a stationary engine that is delivered to the owner/operator and is 

permanently affixed to its mounting position where it is intended to be operated.

Finally, as we also discussed at our February 9th meeting, EMA would like to open a 

discussion with appropriate EPA staff on alternative test methods relative to PM measurements 

of stationary diesel engines. EMA does not believe that EPA Test Method 5, currently required 

in the NSPS, is the most appropriate method for larger stationary engines. You mentioned that 

one of the EPA staff, Mr. Ron Myers, could be available to discuss such alternative test methods. 

EMA requests confirmation of Mr. Myers availability and contact information to begin these 

discussions.

EMA would be pleased to discuss these issues with you further, and look forward to 

seeing a final resolution through a corrective rule-making process. 

Please do not hesitate to call me at 312-827-8734.

Respectively submitted,

Joseph L. Suchecki

Joseph L. Suchecki

Director, Public Affairs