The Illinois Environmental Protection Agency and the United State Environmental Protection Agency require that all water plants disinfect the water. The Chicago Water Department uses chlorine for this purpose adding a minimal amount assuring the water remains safe as it travels from the treatment plant to homes.
If you are sensitive to chlorine in your water, a carbon filter will remove all chlorine. Carbon filters must be consistently maintained to minimize bacteriological contamination of your water. Alternatively, fill a pitcher with tap water and place it in the refrigerator overnight, usually by the next day the chlorine will have evaporated out of the water. If your immune system is compromised in any way, ask your doctor about any precautions you should take when drinking bottled or tap water.