A solid-waste district in Vermont has sued its insurer in an effort to recover $500,000 paid to 451 customers whose plants were damaged by herbicide-tainted compost. The district said it had been unaware of the contamination. It acquired its product-liability coverage through the Vermont League of Cities and Towns, which has rejected the district's claim based on a pollution-exclusion clause. "The nature of insurance coverage was open and known to [the Chittenden Solid Waste District], its agents and attorneys. As such there could not be any misrepresentation as to the coverage," according to the league's court filing.