Methyl t-Butyl Ether (MtBE)
Methyl tertiary butyl ether (MtBE) was added to gasoline to increase the octane rating after lead was removed. In the 1970’s. However, due to widespread groundwater contamination from gasoline spills, MtBE has been replaced in gasoline with ethyl alcohol.. Once MtBeE enters the groundwater due to gasoline spill, it spreads more quickly than other gasoline components since it is more water soluble and more resistant to breakdown in the environment. MtBE is one of a group of approximately 60 compounds associated with petroleum or organic chemical contamination called Volatile Organic Compounds (VOC’s). MtBE is a colorless liquid that had been added to gasoline. Thus its presence in well water would indicate that gasoline contamination exists in the well.
The U.S. EPA has not set a formal health based drinking water standard for MtBE. However, the EPA’s public water supply program has recently made a nonhealth-based recommendation (based upon taste and odor) of MtBE in drinking water to 20 – 40 ug/L. The NH Department of Health and Human Services Bureau of Health Risk Assessment developed a health-based drinking water standard for MtBE of 13 micrograms per liter (ug/L). Studies with animals suggest drinking water with high levels of MtBE may cause stomach irritation, liver and kidney damage, and nervous system effects. Because of the animal studies on MtBE, New Hampshire considers MtBE a possible human carcinogen.
If you have detected MtBE in your drinking water, DES may be able to provide assistance in trying to identify the source of the contamination. You may contact the DES Oil Remediation and Compliance Bureau for assistance at 271-3544.
For more information, please refer to the NH DES fact sheet:
WD-WSEB3-19 MtBE in Drinking Water