California state law used to exempt farms, dairies, and other agricultural operations from getting air permits for pollution from sources such as agricultural dust, diesel irrigation pumps, and livestock waste. This exemption made compliance with the federal Clean Air Act impossible. Earthjustice sued the EPA for allowing California permitting programs to include the exemption, and Earthjustice’s victory led California legislators to strip the exemption from the law.

However, EPA staff recently discovered that it unwittingly approved a provision with the older exemption for agricultural sources back in 1972 as part of a larger state implementation law, and could not find any subsequent action to strip the provision. Unless the EPA or the state take affirmative action to remove the provision, it remains federally-enforceable law.

This suit seeks to compel the EPA to remove the provision.