By: Devin H. Mannix, Daniel B. Abrams, George S. Roadcap, Daniel R. Hadley, and Walton R. Kelly
"Sandstone aquifers in Illinois have been important sources of water for municipalities and industries since the mid-1800s, and remain important in Will, Kendall, Kane, and McHenry Counties (Figure 1a). Long-term withdrawals have resulted in declining groundwater levels (also known as heads), with the greatest declines of over 900 feet in Will County, locally exceeding 1,100 feet when wells are pumping.
Multiple factors have contributed to large declines in the sandstone aquifers. First, the aquifers are hundreds of feet below the land surface, overlain by material that impedes the vertical movement of water, which prevents rainfall from replacing water withdrawn from the aquifers. Second, both municipal and industrial demands are increasingly concentrated along a fault zone, which further impedes the movement of water and exacerbates drawdown. With demands projected to increase in the coming decades, the future availability of water from the sandstone is in jeopardy."
