Western States Petroleum Assn. v. Superior Court

Opinion

MOSK, J.

We granted review to determine whether evidence not contained in the administrative record is admissible in a traditional mandamus action to show that a quasi-legislative administrative decision was a “prejudicial abuse of discretion” within the meaning of Public Resources Code section 21168.5, a provision of the California Environmental Quality Act (CEQA) (Pub. Resources Code, § 21000 et seq.), either because the agency “has not proceeded in a manner required by law” or because the decision was not supported by “substantial evidence.” We conclude that the substantial evidence…