Mariposa County no longer needs to clean its air to meet ozone standards

US environmental regulators have decided that Mariposa County, California, has met its clean air targets for ozone. This means the county no longer has to implement special measures to reduce air pollution.

Counties that fail to meet air quality standards face mandatory actions, like requiring cleaner fuels or stricter emissions controls on factories and cars. These actions can be expensive and politically unpopular. This decision means Mariposa County avoids those requirements, even though the air quality data used to make the decision excluded some pollution events.