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Regulatory

Announcement

 Printed on Recycled Paper

United States

Environmental Protection

Agency

Air and Radiation EPA420-F-99-004

January 1999

Office of Mobile Sources

A National Emission Control Program

EPA intends to propose a national program to control emissions of oxides

of nitrogen (NOx), hydrocarbons, and carbon monoxide from large

nonroad SI engines. These engines are used in a variety of industrial

equipment, including forklifts, airport ground-service equipment, generators, and compressors. Emissions from large nonroad SI engines account

for approximately 2 percent of total mobile source NOx emissions nationwide.

The results of an EPA study completed in 1990 demonstrated the need for

control of air pollution in the nonroad engine and vehicle arena. EPA

published this finding in conjunction with the first rulemaking to set

emission standards for nonroad engines, which was completed in June

1994. In September 1997, the Agency issued a proposal for more strinProposed Finding on Emission

Standards for New Large

Spark-Ignition Nonroad Engines

The U.S. Environmental Protection Agency (EPA) is proposing a finding

that spark-ignition (SI) engines rated above 19 kilowatts (25 horsepower)

contribute to air pollution in ozone or carbon monoxide nonattainment

areas. EPA intends to propose a national program to control emissions

from this currently unregulated source to help reduce the harmful health

effects of ozone and carbon monoxide.
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gent emission standards for diesel

engines used in most nonroad applications. EPA has subsequently finalized

emission standards for nonroad SI

engines rated at or below 19 kilowatts,

which consist predominantly of residential and commercial lawn care equipment.

Many of the engines that would be

affected by these new emission standards have counterpart engine models

used in highway applications. While

highway engines have seen extensive

technological developments, the

nonroad engine designs have changed

little to reflect these improvements.

Shifting toward these technologies that have been developed for cars and

trucks, such as electronically controlled closed-loop injection systems

with three-way catalytic converters, there is a great potential to dramatically improve engine performance and fuel economy in addition to the

anticipated emission reductions.

Health and Environmental Benefits

If the standards are implemented as discussed, the resulting emission

reductions would translate into significant, long-term improvements in

air quality in many areas of the U.S. Application of basic automotive

emission control technologies would reduce NOx and hydrocarbon

emissions by 70 to 90 percent. The emission standards being considered

are part of an overall program designed to ensure that engine emissions

are controlled throughout a lifetime of field operation, not just in the

laboratory. Overall, the program would provide much-needed assistance

to states facing ozone and carbon monoxide air quality problems that are

causing a range of adverse health effects for their citizens, especially in

terms of respiratory impairment and related illnesses.
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Public Participation Opportunities

EPA desires full public participation in the rulemaking process. The

Agency solicits comments from all interested parties. Wherever applicable, full supporting data and detailed analysis should also be submitted

to allow EPA to make maximum use of the comments. Commenters are

especially encouraged to provide specific suggestions for changes to any

aspects of the proposal that they believe need to be modified or improved.

EPA will accept comments on the proposed finding for 30 days after

publication in the Federal Register. For instructions on submitting

written comments, please see the Federal Register notice, which is

available from the EPA Air and Radiation Docket by calling 202-260-

7548; please refer to Docket No. A-98-1. In addition, the proposed

finding and related documents are available electronically via the EPA

Internet server at:

http://www.epa.gov/oms/nonroad.htm

There will also be an opportunity for oral and written comment when

EPA publishes a subsequent Notice of Proposed Rulemaking.

For More Information

Document information is also available electronically at the Internet site

given above, or by writing to:

U.S. Environmental Protection Agency

Office of Mobile Sources

2000 Traverwood Drive

Ann Arbor, MI 48105

734-214-4278