An American International Group Inc. unit is not obligated to provide coverage in a dispute with a construction firm over a San Diego water project, based on exclusions in its policy, says a federal appeals court. Atlanta-based Archer Western Contractors Ltd. was the general contractor for the San Diego County Water Authority’s emergency water storage project, according to Thursday’s ruling by the 9th U.S. Circuit Court of Appeals in San Francisco in Archer Western Contractors Ltd. v. National Union Fire Insurance Co. of Pittsburgh, Pa., a Pennsylvania Corporation.