What did the test results for the most recent (October and November) sampling show?

The larger area, Area (#4), shows that many wells contain tetrachloroethylene (PCE), trichloroethylene (TCE) and other related VOCs. Thirty percent of the most recent well tests in this area show PCE or TCE contamination above the federal drinking water standards. To date, 199 wells out of 471 total sampled have contamination above the drinking water standard for public water supplies and another 200 had detectable levels of contamination.

Evaluation of current data show the plume of contamination of TCE, PCE and related chemicals extends from an area of higher concentrations about one block north of Maple Avenue from Lomond on the west, to Woodward on the east southward to 63rd Street. Concentrations drop off to very low levels at Elinore on the west and Lee and Springside on the east. Illinois EPA does not know at this time how far south the plume extends. The commercial/residential area just south of 63rd Street is an area of public water supply connections. No VOCs were detected in two wells that have been tested south of 63rd near 75th and Dunham Road.

Illinois EPA is gathering information from several different areas in our investigation of potential sources of the solvent contamination:

1. Data from private well tests show where elevated levels of contamination exist in the groundwater. Illinois EPA then concentrates efforts upgradient (opposite the flow of groundwater) for source areas.
2. Historical research of known spills and releases of solvents in the area provides information about potential source areas.
3. Illinois EPA sent information requests to area businesses in and near the Ellsworth Industrial Park (north of Maple Ave.) to learn about previous and current solvent use and disposal.
4. The general public is encouraged to provide information to Illinois EPA about solvent use or spills/releases of solvents in the area.

In addition, U.S. EPA has offered their assistance and will work with the Illinois EPA to identify the source(s) of contamination.

According to IDPH, exposure to TCE and PCE at levels much greater than those levels found in Downers Grove area wells can cause nausea, dizziness or headaches.

The health effects of long-term use of well water with low levels of TCE and PCE contamination, as we are seeing here, may pose a slightly increased cancer risk and may lead to impaired immune system function or kidney or liver damage.

There is an updated "Trichloroethylene Health Risk Assessment" by U.S. EPA that is now out for public comment. This draft assessment is available on the Internet at http://www.epa.gov/ncea. You may also telephone the National Center for Environmental Assessment (NCEA's) Technical Information Staff at (202) 564-3261 or fax a request for the assessment to (202) 565-0050.

Since there is no one source of information for all private wells in the state, Illinois EPA depends on numerous sources and efforts. During June and July this year, the Village of Downers Grove provided a list of nearly 850 potential well owners, and DuPage County Public Health provided some additional information that was then cross-referenced. Illinois EPA attempted to contact by telephone the homeowners in the first sampling area (west of Belmont). During August, Illinois EPA, on two occasions, walked the areas of concern both west and east of Belmont and placed door-hangers asking whether residents had a well and wanted it tested for volatile organic compounds. In September, Illinois EPA made a follow-up mailing to homeowners in the area of concern on the east side of Belmont asking them to contact us if they wanted their wells tested in October.

If you or someone you know has a well but has not been contacted by Illinois EPA and wish to have your well tested or to be added to the mailing list for updates about the investigation, feel free to contact Carol Fuller at 217/524-8807.