The Philadelphia Industrial Chemical Corporation (PICCO) operated a hydrocarbon resin manufacturing plant on its property. It sold the property to a third party, Gould, who later sold the property to the Philadelphia Electric Company (PECO) (plaintiff). PECO had a full opportunity to inspect the condition of the property when it made the purchase. Subsequently, Hercules (defendant) succeeded PICCO’s interest in the property, assuming all liabilities. The Pennsylvania Department of Environmental Resources (PDER) then found resinous materials like those that were used by PICCO seeping into the Delaware River from the property. The PDER ordered PECO to clean up the pollution. PECO did so at an expense of $400,000. PECO brought a suit for private and public nuisance against Hercules. The district court found in favor of PECO and granted an injunction requiring Hercules to stop any further pollution. Hercules appealed.