The Trump administration has escalated its fight with California over environmental regulations. Environmental Protection Agency Administrator Andrew Wheeler sent a letter Monday to the California Air Resources Board threatening to withdraw billions of dollars in federal highway money unless the state clears a backlog of air pollution control plans. “California has the worst air quality in the United States, with 82 nonattainment areas and 34 million people living in areas that do not meet National Ambient Air Quality Standards,” Wheeler wrote. California’s population, topography, weather and other factors do worsen air pollution there, but the state also is widely recognized as a leader in improving air quality. Under the Clean Air Act, states that don’t meet federal air quality standards are required to submit “State Implementation Plans.” Wheeler says California represents a disproportionate share of the backlog of such plans. “Since the 1970s, California has failed to carry out its most basic tasks under the Clean Air Act,” said Wheeler. He then laid out the penalties for failing to meet federal requirements, which include losing federal highway dollars. California is expected to receive about $8 billion in fiscal years 2019 and 2020. To view the full article visit NPR.