JOLIET – The current source of drinking water for many in Will County and the surrounding area could be gone within 15 to 25 years, according to the Illinois State Water Survey.
Walt Kelly, head of the groundwater section of the survey and a groundwater geochemist, gave a presentation Thursday morning to the Will County Board’s Executive Committee about the water supply in the area.
Kelly said after years of withdrawals from the sandstone aquifer that supplies water to much of the Joliet area, the practice is becoming unsustainable.
“Alternative water supplies will be necessary,” Kelly said. “But sandstone aquifers will be an important source of water, and we need to manage them as well as possible.”
Kelly showed a series of maps describing where communities get their water. Most communities outside Chicago rely on groundwater in some form.
He then showed a slide indicating how the amount of water in the aquifer has decreased several hundred feet.
The source of the water that comes through the sandstone aquifer originates from Rockford and farther north. Use of the aquifer dates back to the 1860s.
“We’ve put in thousands of wells since that point, so we’ve pulled out a lot of water,” Kelly said.
The city of Joliet is considering a switch to the Kankakee River, which might take years. Kelly said that although the Des Plaines River runs through Joliet, it isn’t nearly as clean as the Kankakee. The water would have to be fed through pipes across the Des Plaines.
The city also would have to build new treatment plants because treating surface water from the Kankakee is much more difficult than treating groundwater.
However, even if Joliet was removed from aquifer use, Kelly said, it wouldn’t solve the problem for other communities.
The issue is regional and requires a regional solution, he said. He encouraged the county to collaborate with other counties in the area, most of which use deep aquifer water as drinking water, to explore alternatives.
Widespread use of rivers may not be the best solution. During droughts, supply would be limited, and if contaminated consumption would be dangerous, Kelly said. The aquifers still would be a backup in these situations. Other ideas, such as desalination of water from another deep aquifer in the area, might be too costly.