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Fact Sheet 1

Fact Sheet #1

August 2001

Downers Grove, Illinois


During the spring of 2001, the Illinois EPA began a groundwater investigation just east of I-355 near Downers Grove. This investigation is in response to citizen concerns related to recent private well sampling in neighboring Lisle. Results of a few samples in Downers Grove in May showed some solvent contamination in scattered wells. Consequently, Illinois EPA decided to initiate a separate investigation in Downers Grove to identify contaminated wells and potential sources.

The Illinois EPA collected samples from private water wells in unincorporated Downers Grove during the week of July 16, 2001. The results from theses samples constitute the first phase of the Downers Grove Groundwater Investigation. In this first round of sampling, approximately 160 wells, in three areas were analyzed for levels of solvent-type chemicals, known as volatile organic chemicals (VOCs).

What areas were sampled in the first round of the Downers Grove Groundwater Investigation?

  1. Area 1) Elmore and Inverness generally bound the main study area on the north, Belmont on the east, 59th Street on the south and Walnut on the west.
  2. Area 2) A second area is north of Burlington between Granville and Edwards, and generally extends about one block north and south.
  3. Area 3) The third area tested is bounded by 63rd on the north, Main on the east, 67th on the south and Saratoga on the west.

What did the test results for the July sampling show?

The larger, main area (#1) shows that some wells contain tetrachloroethylene (PCE), trichloroethylene (TCE) and other related VOCs. Some wells in this area show PCE or TCE above the federal drinking water standards.

Sample results from the two smaller areas mentioned above (#2 and #3) were well below the drinking water standard or the chemicals of concern were not detected.

Do you know the source of the contamination?

No, we do not have enough information yet to identify the source(s) of contamination. We are conducting an area-wide investigation to determine the nature and extent of contamination and possible source(s) of contamination.

What are the levels of VOCs in the main study area?

Of the approximately 100 samples in this area (#1), 34 results were greater than the federal drinking water standards for public water supplies, which are five parts per billion for both PCE and TCE. (Although these standards are not enforceable for private wells, Illinois EPA and Illinois Department of Public Health (IDPH) use them as a comparison level regarding the safety of private water wells). Other VOCs were detected at lower levels.

Should well owners drink the water?

The Illinois Department of Public Health recommends that owners of wells containing TCE and PCE at or greater than the standards not use their wells as a source of drinking water.

If contamination is found in my well, will the state force me to change over to a public water supply?

Neither Illinois EPA nor Illinois Department of Public Health would "force" a citizen to abandon a private well. IDPH will advise residents of any well contamination and make recommendations about changes in water use. Private wells are the domain of the well owner.

What adverse health effects are related to exposure to TCE or PCE?

Exposure to levels of TCE and PCE much greater than those levels found in Downers Grove area wells can cause nausea, dizziness or headaches. Exposure to low levels over long periods may lead to impaired immune system function and may increase the risk of kidney or liver cancer or other damage.

How can I reduce my exposure to TCE or PCE?

If your water contains TCE or PCE, you can greatly reduce your exposure by using another source of drinking water or by using water filtration equipment designed to remove VOCs. Since VOCs evaporate into the air, you can reduce your exposure by running the bathroom exhaust fan during baths and showers. Exposure to TCE or PCE from other water uses should be very small.

Should I install a filter system to remove this type of contamination?

Activated carbon or activated charcoal filtration whole-house systems effectively remove volatile organic chemicals such as PCE and TCE. A homeowner should look for systems that are ANSI-approved or NSF (National Sanitation Foundation)-approved. A source of information about water filtration systems is Water Quality Association of Lisle, 630-505-0160 at

Where can I obtain information about connecting to the Downers Grove water supply?

Residents can obtain packets of information containing a pre-annexation agreement and Downers Grove water distribution specifications. Please call Dave Conley at 630-434-5462 or pick up the information at the Public Works Facility at 5107 Walnut.

What is the next step of the investigation?

The Illinois EPA is scheduling another round of testing of additional wells in the Downers Grove area in mid-September. In addition, an investigation is ongoing to try to determine the source or sources of the contaminants in these wells. The Illinois EPA will place notices on residents' doors in the proposed second study area on Wednesday, August 22, 2001 asking residents to contact the Agency if they want their wells tested.

For more information, you may contact:

Community Relations Coord.

Illinois EPA


Public Information Officer

Illinois EPA


Remedial Project Mgr.

Illinois EPA, State Sites Unit