Aquifer maps for county planners in Lake County, Illinois: three-dimensional geologic mapping, and aquifer sensitivity classification for the Antioch Quadrangle

Lake County is located in the northeast corner of Illinois (Fig. 1). Adjacent to the Chicago metropolitan area, it contains some of the most rapidly growing communities in the state. Many of these communities rely heavily upon groundwater resources. Accurate maps of the sands and gravels within the thick Quaternary sediments are needed by agencies of local government for infrastructure planning, resource development (potential aquifers, recharge areas, building aggregate, etc.), land use planning, and environmental protection.