U.S. EPA Promulgates Final Air Toxics Standards for Compression Ignition RICE

On March 3, 2010, U.S. EPA promulgated final National Emissions Standards for Hazardous Air Pollutants (NESHAP) for existing compression ignition (CI) stationary Reciprocating Internal Combustion Engines (RICE) that were not previously regulated by the existing, so called, RICE MACT (i.e., 40 CFR Part 63, Subpart ZZZZ).  The RICE MACT rule was originally promulgated in 2004.  The March 3, 2010 final rule sets limits on emissions of carbon monoxide (CO) and formaldehyde (CH2O) for the following units: 

1. CI RICE located at area sources of air toxics emissions,
2. CI RICE with site ratings of less than or equal to 500 brake horsepower (bhp) located at major sources of air toxics emissions that were constructed or reconstructed before June 12, 2006, and
3. CI RICE with site ratings of greater than 500 bhp located at major sources of air toxics emissions that were constructed or reconstructed before December 19, 2002. 

RICE affected by the March 3, 2010 final rule are typically located at power plants and chemical and manufacturing facilities, and are used to generate electricity in periods of utility power outages or to power pumps and/or compressors.  However, many other types of facilities use emergency generators that will now be covered by the rule.  For example, information technology (IT) and/or business sector companies utilizing emergency generators to power servers in times of utility power outages will also be affected as well as hospitals, municipalities (e.g., sanitary pumping stations, wastewater treatment plants), detention centers,  and other operations that rely on back-up power generation.

The March 3, 2010 final rule is the result of revisions to the rule originally proposed on February 25, 2009.  The February 25, 2009 proposed revisions originally included requirements and emission standards affecting both CI RICE and spark ignition (SI) RICE.  However, U.S. EPA has only promulgated those portions of the proposed revisions that affect CI RICE.  U.S. EPA projects that final emission standards for existing SI RICE that burn gasoline, natural gas, and landfill gas will be promulgated by August 10, 2010.