SPRINGFIELD , Ill. – Residents who obtain their drinking water from private wells in the Island Lake area are advised to have the water tested for possible groundwater contamination, the Illinois Department of Public Health announced today.

Routine testing of the city’s municipal water wells by the Illinois Environmental Protection Agency (Illinois EPA) revealed the presence of methyl tertiary butyl ether (MTBE), indicating that the contamination could also be present in the area’s private wells.

Although the contaminants were found in Island Lake’s source water, the water provided by the city meets U.S. Environmental Protection Agency drinking water standards.

The area potentially affected by contamination is located in McHenry County, east of the Fox River, south of West Burnett Road and south of Griswald Lake, west of Island Lake and north of Cotton Creek. The area extends into Lake County and is located west of the Northern Court and Fern Drive Loop, south of East Burnett Road, and north of Island Lake and Cotton Creek. Persons with private wells in this area are encouraged to have their water tested by a private laboratory.

A list of private laboratories approved for testing can be obtained by calling Patti Nomm, McHenry County Health Department, at 815-334-4585 or Larry Mackey, Lake County Health Department, at 847-356-6222. Once samples have been analyzed, residents can call the health departments for an explanation of the test results.

MTBE has been used since the 1980s as an additive in unleaded gasoline. Animal studies suggest that drinking elevated levels of MTBE may cause gastrointestinal irritation and can adversely affect the nervous system.

This information has been compiled from historic data and is provided to the public to ensure full disclosure of state records.