MTBE in southern California water

Methyl tertiary butyl ether (MTBE) is a common fuel oxygenate used in motor vehicle fuels to control emissions and boost octane. It is more water-solu ble than other fuel constituents and does not adsorb well to substrates suc h as soil. It can contaminate groundwater supplies through leaking undergro und fuel storage tanks and pipelines, and through spills, urban storm runof f, and precipitation. It can also contaminate open water reservoirs through exhaust from motorized watercraft. The Metropolitan Water District of Sout hern California surveyed six reservoirs that supply drinking water in South ern California. Recreation on these reservoirs ranged from none at all to h igh activity with personal watercraft. It was found that motorized watercra ft can contribute a significant amount of MTBE to the water supply.