Illinois American Water knows just how important water is to daily life. When you need it, you expect it to be there — and you expect it to be clean and safe. Customers are the number one priority, and IWA is proud to deliver clean, safe, reliable and affordable water and wastewater services. In Illinois IWA serves about 1.3 million people. To ensure your water is of the highest quality, IWA strictly follows regulations that are set by local authorities as well as federal standards.