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February 23, 2010Client Alert

EPA Announces New Hazardous Air Pollutant Emission Standards for Existing Stationary Diesel Engines

On February 17, 2010, the United States Environmental Protection Agency (“EPA”) set toxic air emission standards for certain existing diesel powered engines. The types of engines covered by the rule are typically found in power plant, chemical and manufacturing facilities and generate electricity for compressors and pumps. The rule will go into effect in mid-April, 60 days after publication in the Federal Register.

The rule regulates the emissions of hazardous air pollutants (“HAPs”), including formaldehyde, acetaldehyde, acroline methanol and other toxic pollutants known or suspected to cause cancer and other serious health effects, from reciprocating internal combustion engines (“RICE”), also known as compression ignition (“CI”) engines.

The following diesel engines are covered by the rule:

  • Engines used at stationary “area” sources of hazardous air pollutants that were constructed or reconstructed before June 12, 2006;
  • Engines used at major sources of hazardous air pollutants, that were constructed or reconstructed before June 12, 2006 and that have a rating of 500 horsepower (“HP”) or less or;
  • Engines used at major sources of hazardous air pollutants for non-emergency purposes, that were constructed or reconstructed before December 19, 2002 and have a rating of greater than 500 HP.

“Area sources” are sources that are stationary, i.e., not mobile, such as cars or trucks, and are not “major sources.” “Major sources” of HAPs are stationary sources that emit, or have the potential to emit, any single HAP at a rate of 10 tons per year (“tpy”) or more, or any combination of HAP at a rate of 25 tpy.

Among the requirements imposed on facilities using these stationary diesel engines will be installation of emissions control equipment to limit toxic emissions and burning of ultra-low sulfur fuel in non-emergency engines rated at 300 HP or greater, and performing emissions tests to demonstrate performance and compliance.

The rule also requires that these engines comply with emissions standards during startup and shutdown and during any malfunction.

EPA estimates there are more than 900,000 of these engines in use at industrial, agricultural, utility and other facilities. EPA further estimates that when the rule is fully implemented in 2013, air toxic emissions will be reduced by 1000 tpy, fine particulate matter emissions by 2800 tpy, carbon monoxide emissions by 14,000 tpy, and volatile organic compounds (“VOCs”) emissions by 27,000 tpy.

EPA did not address stationary spark ignition RICE in this rule, but intends to do so in a future rule package planned for August 2010.

EPA’s final rule is posted at:

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