EWG's Tap Water Database — 2021 UPDATE



Stoney Field Mobile Home Park

MTBE was used as gasoline oxygenation additive to boost the octane number. In 2005, MTBE was replaced by ethanol as a gasoline additive. MTBE causes cancers in rats.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20151.40 ppb331.32 ppb - 1.50 ppb
20161.70 ppb331.60 ppb - 1.80 ppb
20172.30 ppb112.30 ppb
20181.34 ppb221.28 ppb - 1.40 ppb
20191.10 ppb440.960 ppb - 1.25 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 13 ppb

The EWG Health Guideline of 13 ppb for MTBE was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date Lab ID Result
2015-04-06L5489130-11.32 ppb
2015-08-07L5755206-41.37 ppb
2015-10-05L5817674-11.50 ppb
2016-01-15L5966601-11.70 ppb
2016-04-08L6125469-11.60 ppb
2016-07-08L6313248-11.80 ppb
2017-01-16L6596778-12.30 ppb
2018-02-1438746951.40 ppb
2018-05-16DWS8723-11.28 ppb
2019-02-1319020710-010.960 ppb
2019-05-0819050207-011.07 ppb
2019-08-1419080810-0011.10 ppb
2019-12-1619121305-0011.25 ppb