Ladera Ranch CA Drinking Water Source is Robert B. Diemer Water Treatment Plant in Yorba Linda CA, It Sits on Top of 2 Old Shell Oil Wells that were plugged and capped in the 1950's. Ladera Ranch, California gets its drinking water primarily from imported supplies provided by the Metropolitan Water District of Southern California (MWD) via the State Water Project's California Aqueduct and the Colorado River Aqueduct, alongside local sources managed by the Santa Margarita Water District. Robert B. Diemer Water Treatment Plant operated by the Metropolitan Water District of Southern California. Metropolitan Water District treatment facility is at 3972 Valley View Ave Yorba Linda CA. The more I dig into the mystery of the multiple Ewing sarcoma cancer cases and the old Shell oil wells under Ladera Ranch CA and possible water contamination, the more bizarre it gets. Today I discover that the water source for Ladera Ranch, the Robert B. Diemer water treatment plant, was built in 1...