LOS ANGELES – A federal judge ruled that a Southern California clean-air agency could impose its anti-smog rules on state and local public fleet vehicles, according to the Associated Press. Last year, the U.S. Supreme Court ruled that the South Coast Air Quality Management District (SCAQMD) could not enforce rules requiring private fleets to use engines that burn cleaner fuels. The higher court sent the case to a lower court to determine whether the regulations could be applied to public fleets. The U.S. District Court Judge Florence-Marie Cooper wrote, "The court has concluded that the fleet rules are constitutional as applied to state and local governments." In 2000, SCAQMD imposed standards, which regulate air quality in all or major parts of Los Angeles, San Bernardino, Riverside, and Orange counties. The rules required private and public operators to buy cleaner-burning models when they replace or add vehicles to their fleets.