EPA's Final Standards for Internal Combustion Engines: Good News for Residential, Institutional and Commercial Facilities

April 27, 2010
MGKF News Flash

On March 3, 2010, the U.S. Environmental Protection Agency ("EPA") published final rules that would affect a broad category of existing internal combustion engines, including emergency generators. The proposed version of the rule was published on March 5, 2009 and was the subject of significant comment from engine owners and operators. The rule has been finalized 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 existing compression ignition engines at area (non-major) sources of hazardous air pollutants ("HAPs"), as well as existing engines located at major sources of HAPs.

Whereas EPA previously proposed to limit emissions of HAP for emergency stationary engines at area sources by applying stringent emission standards for carbon monoxide ("CO"), EPA significantly modified its proposal in two ways. First, EPA has determined that existing emergency internal combustion engines located at residential, institutional and commercial facilities are not subject to Subpart ZZZZ. As a result of this determination, Subpart ZZZZ will not apply to existing units at a broad range of facilities including office buildings, hotels, hospitals, colleges and universities. Second, EPA established Management Practices standards for emergency engines located at other area sources, in lieu of emission standards included in the original proposal. The Management Practices include:

  • Changing the oil and filter annually or every 500 hours of operation, whichever comes first;
  • Inspecting the air cleaner every 1,000 hours of operation or annually, whichever comes first; and
  • Inspecting all hoses and belts every 500 hours of operation or annually, whichever comes first, and replacing as necessary.

The final rule establishes emission limits for other engine types at area and major sources of HAP. For example, non-emergency engines with a rating between 300 and 500 horsepower, at both area and major HAP facilities, would be subject to a CO emission standard of 49 ppmvd or 70 percent reduction (from the originally proposed 4 ppmvd or 90 percent reduction). Non-emergency engines with a rating greater than 500 horsepower, at both area and major HAP facilities, would be subject to a 23 ppmvd or 70 percent reduction standard for CO (from the originally proposed 4 ppmvd or 90 percent reduction).

Facilities with internal combustion engines subject to Subpart ZZZZ should carefully evaluate the final rule to determine the standards applicable to facility engines, as well as the feasibility of meeting proposed emission limits or Management Practices. The effective date of the final rule is May 3, 2010.