The Site is a former wood treating facility which treated wood with pentachlorophenol (“PCP”) on a 13.5 acre parcel from 1959 to approximately 1982. Sludge from the pressure treating process was deposited in lagoons on the northern edge of the Site. EPA has information that these lagoons caught fire sometime in the early 1970s, and that sludge from the wood treating operation was burned in an on-site boiler used to steam the wood before treatment. Water from the lagoons went through an on-Site treatment system, then into the city sewers. A ground water diversion, interception and collection system designed to capture water carrying leachate from the Site was constructed in the late 1970s. Water from this system was pumped to a treatment facility prior to being discharged into the city sewers. The lagoons were closed in 1978-1979 and were backfilled with soil. In 1975, Sentinel began manufacturing hog houses and later, in 1980, outdoor wood furniture made with lumber treated with copper chromated arsenic (“CCA”). Although the CCA lumber was treated off-Site, the sawdust and scrap wood from the manufacturing was burned on Site. Sentinel ceased operations in the late 1980s.