EPA Proposes Standards for Existing Internal Combustion Engines

May 4, 2009
by CAROL McCABE and MICHAEL NINES
MGKF Special Alert

On March 5, 2009, EPA published proposed rules that would affect a broad category of existing internal combustion engines, including emergency generators. EPA estimates that more than one million engines will be affected. The rule is proposed as an amendment to 40 CFR Part 63, Subpart ZZZZ, National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal combustion Engines, and would affect all existing engines at area (non-major) sources of hazardous air pollutants (HAPs), as well as existing engines located at major sources of HAPs.

EPA proposes to limit emissions of HAP through emission standards for carbon monoxide (CO) for most diesel-fired internal combustion engines. EPA anticipates that the control technologies necessary to meet these standards will also result in reductions of nitrogen oxides (NOx) and particulate matter emissions. EPA also proposes to require that use of ultra-low sulfur diesel fuel for diesel-fired compression ignition engines greater than 300 horsepower with a displacement less than 30 liters per cylinder.

The proposal covers a wide variety of engine types, and identifies specific emission limits or work practice standards for engine categories. For example, at major sources of HAP, all compression ignition engines with a rating between 50 and 300 horsepower would be subject to a CO emission standard of 40 ppmvd, including during periods of startup or malfunction. At area HAP sources, these engines would be subject to specific work practice, inspection and maintenance standards. Engines with a rating greater than 300 horsepower, at both area and major HAP facilities, would be subject to a CO emission standard of 4 ppmvd or 90% reduction, with a 40 ppmvd standard during startup or malfunction. Emergency compression ignition engines with a rating between 300 and 500 horsepower located at major HAP sources would be subject to a 40 ppmvd standard for CO. Likewise, emergency compression ignition engines with a rating greater than 500 horsepower located at area HAP sources would be subject to a 40 ppmvd standard for CO, including during startup and shutdown. Smaller emergency engines would be subject to specific work practice, inspection and maintenance standards.

A primary goal of the proposed rule is to achieve significant reductions from large, existing engines at area HAP sources that were not previously subject to federal emission standards. EPA anticipates that add-on controls may be necessary to achieve the proposed emission limits. Such controls may include non-selective catalytic reduction, oxidation catalyst or diesel particulate filters. In addition, the proposed rule includes performance testing requirements for all engines subject to emission limits.

The proposed amendment to Subpart ZZZZ is potentially significant for many owners and operators of internal combustion engines. Particularly affected will be large emergency and non-emergency engines, such as those serving hospitals, data centers, industrial plants or other facilities which rely on these engines. These facilities should carefully evaluate the proposed rules, and determine the feasibility of meeting the proposed emission limits. EPA is accepting comment on the proposal until June 3, 2009.

If you have questions or would like additional information regarding this ruling, please contact Carol McCabe at cmccabe@mgkflaw.com or 484-430-2304 or Michael Nines at mnines@mgkflaw.com or 484-430-2350.