A coalition of community groups is suing the Central Valley Regional Water Quality Control Board, saying the agency is breaking state law by allowing pollution from dairy farms to penetrate groundwater supplies used for drinking water.
Last year, the board issued a permit that requires existing dairies to regulate some of their own pollution.
The community groups say those guidelines still don't apply to any new dairies, and don't require enough protections at waste lagoons. They say the rules also don't regulate solid manure discharged offsite.
The groups claim that means the permit isn't strict enough to meet state clean water laws.
The coalition of community groups called AGUA and the Environmental Law Foundation filed the suit jointly Friday in Sacramento Superior Court.