Santa Clara County officials and advocates are rejoicing as the federal government agrees to reassess the use of leaded aviation gasoline nationwide. During a news conference Wednesday, County Counsel James Williams announced the Environmental Protection Agency approved a petition from the county and several environmental organizations to evaluate whether leaded fuel used by airplanes is a threat to public health and welfare. Leaded fuel for cars was banned in the U.S. more than two decades ago, but it is still used by some airplanes, including those at the Reid-Hillview and San Martin airports in Santa Clara County. "Today is a...