The Sweetwater Union (Calif.) High School District alleges in a lawsuit that it was bilked of $1.8 million through a kickback scheme between a former employee and a paving contractor. The suit contends that the district's plumbing supervisor signed off on inflated invoices and bills for incomplete work from a paving company that had contracts with Sweetwater from 1998 through 2005. The supervisor approved payment of the bills in exchange for kickbacks, the suit asserts.