The Department of Toxic Substances Control (DTSC) operates the state-owned Stringfellow Pretreatment Plant site in Riverside County. The Stringfellow Pretreatment Plant site includes groundwater monitoring and extraction wells and three treatment facilities used to filter and clean the contaminated groundwater. The DTSC also leases ten facilities (450,405 square feet) throughout California that include space for offices, specialized fieldwork, sample and field equipment storage, two environmental chemistry laboratories, and an information center for the Stringfellow Pretreatment Plant site.