News Releases - 2001

More Results Received from Illinois EPA Water Well Sampling in Downers Grove

Springfield, Ill. -- Results have been received by the Illinois EPA for the third round of residential well sampling in the Downers Grove area conducted in October and November. Of the 173 samples collected, 54 private wells contained levels of trichloroethylene (TCE) and tetrachloroethylene (PCE) contamination at or above the federal drinking water standard of 5 parts per billion.

Since July 2001, 471 private wells in unincorporated Downers Grove have been analyzed for the presence of TCE and PCE, as part of the ongoing groundwater investigation. Of these, 199 have been above the drinking water standard and another 200 had detectable levels of the contaminants, but were not above the drinking water standard.

For purposes of notification of residents, TCE and PCE results were combined since they are similar chemicals that affect the body in the same way. Both chemicals are cleaning solvents commonly used by a host of commercial, industrial and government facilities for many years.

"We will use this data to develop an understanding of the extent of the contamination in the groundwater 100 to 200 feet beneath Downers Grove, where many of these private water wells are located," said Illinois EPA Director Renee Cipriano. "This will aid us in trying to find a source or sources of this contamination." Toward that goal, the Illinois EPA has asked the U.S.EPA to assist in the investigation. On-scene coordinator, Steve Faryan has been assigned to the project. The U.S.EPA investigation will focus on properties at and near the Ellsworth Industrial Park.

Illinois EPA has conducted some sampling in that area. Preliminary results indicate that contamination in this area already may have passed vertically through the soil layer near where it was released and entered the bedrock layer, where the private water wells are located. This suggests that the contamination is not from a recent spill, but has had time to migrate through the soils down into the bedrock layer.

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 and southward to 63rd Street to the south. Concentrations drop off to very low levels at Elinor on the west and Lee and Springside on the east.

Illinois EPA does not plan to collect additional private well samples in the area, except in select areas for scientific corroboration. An area that may be needed to provide complete data to define the contamination plume is a small area just east of Belmont and north of Maple Street "If there are residents in this area using private wells, they may be at risk for contamination," said Cipriano. "If a resident in this area has a well, we would like to collect a sample." An area north of 83rd Street, near Woodward, will also be sampled.

According to the Illinois Department of Public Health, the health effects of long-term use of well water with low levels of TCE and PCE contamination may pose a slightly increased cancer risk. No studies were found that definitively associated an adverse health effect in animals or humans exposed to the levels of TCE and PCE found in the drinking water, but human studies were limited. The standard of 5 parts per billion for TCE and PCE in drinking water is protective of public health; therefore, prudent public health practice supports the decision to reduce the individual exposures of affected residents.

Throughout the investigation, affected residents have been provided information about their sample results. Residents with levels of contaminants above the federal drinking water standard were notified that the Illinois Department of Public Health recommends they find an alternative source of drinking water. In addition, a mailing list is maintained by the Agency and interested persons are regularly notified of activities relating to the investigation. Anyone interested can contact Carol Fuller at 217/524-8807 to be added to the mailing list.

Related Information

• Downers Grove Groundwater Investigation Fact Sheets