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Regulations for Emissions from Vehicles and Engines

Direct Final Rule for In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emission Measurement Accuracy Margins for Portable Emission Measurement Systems and Program Revisions

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Rule Summary

The U.S. Environmental Protection Agency (EPA) is publishing a Direct Final Rule to adopt final accuracy measurement margins for testing gaseous pollutants with portable emission measurement systems. Also, the rule makes several changes to the program in the early years of in-use testing. First, for particulate emissions (PM), this rule eliminates the first calendar year, i.e., 2006, of the two-year pilot program. Second, due to a delay in developing the final accuracy margin for PM, we are delaying the first year of the fully enforceable PM test program from the 2008 calendar year to the 2009 calendar year. During the 2008 calendar year, we are adding another year of pilot program for that pollutant. Third, and finally, we are extending the normal period for reporting in-test results during the initial years of the program and allowing certain short-term changes in how vehicles are recruited and tested.

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