Travelers Casualty and Surety Co. v. Ribi Immunochem Research, Inc.

Ribi Immunochem Research, Inc. (Ribi) (defendant) poured toxic waste into a landfill monthly for three years, assuming that it would evaporate, but the waste migrated into the groundwater. Ribi eventually settled lawsuits with property owners, the state, and the federal government for remediation costs. Ribi held a comprehensive general-liability insurance policy with Travelers Casualty and Surety Co. (Travelers) (plaintiff) that excluded coverage for damages arising from the discharge of hazardous waste, except for discharges that were sudden and accidental. Ribi made insurance claims for defense costs and indemnification for the lawsuits. Travelers denied the claims and brought an action in state district court for a declaration that the policy did not cover the claims. Ribi counterclaimed, alleging breach of contract and other claims. Travelers moved for summary judgment. The district court granted summary judgment for Travelers, and Ribi appealed. Ribi argued on appeal that the exception for sudden and accidental discharge did not have a temporal requirement, but required only that the migration of waste was unexpected. Travelers argued that it was the discharge, not the migration, of waste that must have been sudden and accidental, and that the phrase sudden and accidental did not encompass the gradual migration of waste after intentional disposal.