Control of Air Pollution from New Motor Vehicles: Proposed Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control Requirements

概要

EPA published a Notice of Proposed Rulemaking (NPRM) on May 13, 1999, proposing a major program designed to significantly reduce the emissions from new passenger cars and light trucks, including pickup trucks, minivans, and sport-utility vehicles (the ``Tier 2 program''). The proposed program combines requirements for cleaner vehicles and requirements for lower levels of sulfur in gasoline. A supplemental notice was published on June 30, 1999, clarifying the May 13, 1999, proposal in light of a May 14, 1999, ruling by a panel of the Court of Appeals for the District of Columbia regarding the recently promulgated national ambient air quality standards (NAAQS) for ozone and PM. Our supplemental notice also provided additional modeling information not included in the May 13, 1999, proposal regarding 1-hour ozone levels for areas where the 1-hour ozone standard currently applies. In light of the uncertain status of the 8-hour ozone standard resulting from the Court of Appeals' ruling, EPA recently issued a Notice of Proposed Rulemaking on October 20, 1999, proposing to rescind our earlier findings that the 1-hour ozone standard is no longer applicable in certain areas that have attaine