Water supply for Illinois comes from a variety of sources including surface waters (e.g., rivers, lakes, reservoirs), groundwater from aquifers and private shallow wells. Use of water in Illinois includes residential (both municipal supplies and private wells), agricultural (irrigation and livestock), commercial, and industrial purposes. Illinois water quality is protected by state and federal legislation. Find ongoing monitoring results, and options for testing here.
To find drinking water alerts for public water supplies in your location, start with your local public health department.