Ground-Water Geology of the Shallow Aquifers in Dupage County, Illinois

137 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1960.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Groundwater geology in western Illinois, south part, a preliminary geologic report

"Replacement for fig. 6, p. 10": leaf inserted.Bibliography: p. 28

Ground-Water Resources of DuPage County, Illinois

A rapidly increasing development of ground-water resources in DuPage County, Illinois, has resulted from the municipal and industrial growth in the Chicago metropolitan region. Evaluation of the ground-water resources of DuPage County provides a basis for their development and management. Ground-water supplies are withdrawn from four principal geohydrologic units: 1) glacial drift aquifers, 2) Silurian dolomite aquifer, 3) Cambrian-Ordovician aquifer, and 4) the Mt. Simon aquifer. The glacial drift and Silurian dolomite aquifers receive recharge chiefly from precipitation that falls within the county limits. Relatively impermeable shales of the Maquoketa Formation separate these aquifers from the deeper Cambrian-Ordovician aquifer. Eecharge to the Cambrian-Ordovician aquifer occurs in the areas of Kane, McHenry, Kendall, Boone, and DeKalb Counties where the Maquoketa Formation is appreciably dolomitic, relatively thin, or absent. The water moves southeastward from these recharge areas through the aquifer toward a deep cone of depression centered near Summit in Cook County. The total potential yield of the glacial drift and Silurian dolomite aquifers is calculated to be 41 million gallons per day (mgd); the calculated potential yield of the Silurian dolomite aquifer (38 mgd) is limited by recharge. Full development of the underlying Silurian dolomite aquifer is assumed in estimating the potential yield of the glacial drift aquifers (3 mgd), and the yield of the glacial drift aquifers is considered as supplemental to the yield of the Silurian dolomite aquifer. Practical sustained yields of the deeper Cambrian-Ordovician and Mt. Simon aquifers are calculated to be 4.3 mgd and 2.1 mgd respectively. Water levels in wells in the Cambrian-Ordovician aquifer in some areas have declined as much as 635 feet since 1864, and the average decline over the county during the 96-year period (1864 to 1960) was about 480 feet. Total withdrawals from the Cambrian-Ordovician and Mt. Simon aquifers in 1960 (8.8 mgd) exceeded the calculated total practical sustained yield of these aquifers (6.4 mgd). The Silurian dolomite aquifer is the most heavily developed source of ground water in DuPage County and yielded 68 percent of the 29.3 mgd pumped from all aquifers in 1960. The calculated practical sustained yield of this aquifer (35 mgd) exceeded total withdrawals in 1960 and nonpumping water levels were not critical in any pumping center in the county. Extrapolation of pumpage graphs shows that the practical sustained yields of some pumping centers will be exceeded within 2 to 5 years and the practical sustained yields of all pumping . centers will be exceeded by 1985. Extrapolation of the pumpage growth curve for the county shows that total ground-water withdrawals from wells will exceed the potential yield of the Silurian dolomite aquifer by about 1977