Once the Maine Department of Environmental Protection receives a complaint about possible MTBE contamination of well water, an initial water sample is tested.

If the sample is found to contain MTBE or other gasoline compounds, additional samples are taken from the well and home faucets.

Samples are also taken from neighboring homes and the department looks for likely sources of the contamination, such as underground or above-ground storage tanks, fuel spills, and even automobile accidents where a gas tank might have ruptured.

If a source is found, the DEP conducts a remediation, typically removing the contaminated soil, to clean up the site.

To address contamination of well water, a granular-activated carbon filter treatment system is installed within the home and quarterly testing is done. The filter system remains in the home until a full year of clean tests results are attained.

If, after a year, test results continue to have MTBE, a replacement water supply is offered, typically in the form of a new well.

If clean water cannot be found, other options include connecting to public water, if available, and as a last resort, long-term treatment, typically a permanent granular-activated carbon filter treatment system.

More information is available online at a DEP Web site dedicated to MTBE: www.maine.gov/dep/rwm/homeowner/mtbe.

Source: Maine Department of Environmental Protection