Not later than January 1, 1992, the Administrator shall promulgate regulations under section 7521(a) of this title applicable to urban buses for the model year 1994 and thereafter. Such standards shall be based on the best technology that can reasonably be anticipated to be available at the time such measures are to be implemented, taking costs, safety, energy, lead time, and other relevant factors into account. Such regulations shall require that such urban buses comply with the provisions of subsection (b) of this section (and subsection (c) of this subsection,[1] if applicable) in addition to compliance with the standards applicable under section 7521(a) of this title for heavy-duty vehicles of the same type and model year.
The standards under section 7521(a) of this title applicable to urban buses shall require that, effective for the model year 1994 and thereafter, emissions of particulate matter (PM) from urban buses shall not exceed 50 percent of the emissions of particulate matter (PM) allowed under the emission standard applicable under section 7521(a) of this title as of November 15, 1990, for particulate matter (PM) in the case of heavy-duty diesel vehicles and engines manufactured in the model year 1994.
The Administrator shall increase the level of emissions of particulate matter allowed under the standard referred to in paragraph (1) if the Administrator determines that the 50 percent reduction referred to in paragraph (1) is not technologically achievable, taking into account durability, costs, lead time, safety, and other relevant factors. The Administrator may not increase such level of emissions above 70 percent of the emissions of particulate matter (PM) allowed under the emission standard applicable under section 7521(a) of this title as of November 15, 1990, for particulate matter (PM) in the case of heavy-duty diesel vehicles and engines manufactured in the model year 1994.
As part of the rulemaking under subsection (a), the Administrator shall make a determination as to whether the 50 percent reduction referred to in paragraph (1) is technologically achievable, taking into account durability, costs, lead time, safety, and other relevant factors.
Beginning with model year 1994 buses, the Administrator shall conduct annual tests of a representative sample of operating urban buses subject to the particulate matter (PM) standard applicable pursuant to subsection (b) to determine whether such buses comply with such standard in use over their full useful life.
The Administrator shall establish, within 18 months after November 15, 1990, and in accordance with section 7525(h) of this title, procedures for the administration and enforcement of standards for buses subject to standards under this section, testing procedures, sampling protocols, in-use compliance requirements, and criteria governing evaluation of buses. Procedures for testing (including, but not limited to, certification testing) shall reflect actual operating conditions.
The term “urban bus” has the meaning provided under regulations of the Administrator promulgated under section 7521(a) of this title.
The term “low-polluting fuel” means methanol, ethanol, propane, or natural gas, or any comparably low-polluting fuel. In determining whether a fuel is comparably low-polluting, the Administrator shall consider both the level of emissions of air pollutants from vehicles using the fuel and the contribution of such emissions to ambient levels of air pollutants. For purposes of this paragraph, the term “methanol” includes any fuel which contains at least 85 percent methanol unless the Administrator increases such percentage as he deems appropriate to protect public health and welfare.