§7554 Urban Bus Standards

Summary

The EPA must write rules by January 1, 1992 that apply to city buses sold for the 1994 model year and later. Those rules must make buses cut their soot (particulate matter) emissions to 50% of the level allowed by the heavy-duty diesel standard that was in place on November 15, 1990 for 1994 model-year heavy-duty diesel vehicles. If cutting to 50% is not possible, the EPA can raise the allowed level but not above 70% of that November 15, 1990 level. The EPA must decide whether 50% is doable when it makes the rules, looking at durability, cost, safety, time needed, and other factors. Starting with 1994 buses, the EPA will test some buses each year to see if they meet the soot limit over their full useful life. If the tests show they do not, the EPA must require that all new city buses bought or put into service in metro areas that had 750,000 or more people in 1980 be able to run on, and be run only on, low-polluting fuels. The EPA will set the pass-fail rate and a five-year phase-in that begins three years after the decision, reaching 100% in the fifth year. The EPA can extend this to smaller metro areas if there would be a big health benefit. The EPA must also set retrofit rules within 12 months after November 15, 1990 for buses in covered areas whose engines are replaced or rebuilt after January 1, 1995, and must set testing and enforcement procedures within 18 months after November 15, 1990. “Low-polluting fuel” means methanol, ethanol, propane, natural gas, or similar fuels (methanol means at least 85% methanol unless the EPA sets a different percentage).