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Clearing the Air in California's Central Valley

Threatened with lawsuits from Earthjustice and clean-air advocates, in October 2001, the EPA redesignated the San Joaquin Valley a "severe" ozone region, a change in status from "serious" that reflects the smog problem as well as the lack of progress in solving it. The reclassification means that the 25,000-square-mile valley becomes one of the 11 most polluted regions in the nation. Concentrations of ozone and airborne particulate matter from Stockton to Bakersfield rival pollution found in Los Angeles and Houston.