Story behind cancer cluster in Ladera Ranch CA appears to link to old oil wells found underground and possible benzene vapors in the sewer system, any usable drinking water has to be piped in. There does not appear to be a link from the old oil wells underground to the Ladera Ranch drinking water, they are totally separate. The drinking water for Ladera Ranch is stored in underground concrete lined reservoirs. There is no major usable drinking-water aquifer directly beneath Ladera Ranch or in South Orange County, so there is no connection from the old oil wells to the water, there is no  aquifer  water supply underground. Like most of South Orange County, Ladera Ranch does not rely on local groundwater for its primary drinking supply; water is imported via major regional pipelines. Ladera Ranch, California gets its drinking water imported and piped in from regional water agencies via the Santa Margarita Water District (SMWD) with chloramine and the sulfites in the water. Benz...