Insurer Associated Aviation Underwriters has settled a lawsuit filed by residents alleging their water supply was contaminated by an industrial solvent released by one of the company's insureds. The insurer insured both the City of Tucson and the airport from 1960 to 1972. The suit alleged that trichloroethylene or TCE from airport degreasing operations caused the contamination. Litigation has been going on for over 15 years with other defendants entering into previous settlements. Hughes Aircraft Co. had previously settled its liability for $85 million.