The City of Lancaster purchases its water from DWU also known by Dallas Water Utilities. DWU uses and treats surface water from 7 sources: the Trinity River and Lake Ray Roberts, Lewisville, Grapevine, Ray Hubbard, Tawakoni and Fork. A Source Water Susceptibility Assessment for your drinking-water sources(s) is currently being updated by the Texas Commission on Environmental Quality and will be provided to us this year. The report will describe the susceptibility & types of constituents that may come into contact with your drinking water source based on human activities and natural conditions. The information contained in the assessment will allow us and/or the system(s) from which we receive water to focus on source water protection strategies. For more information on source water assessments and protection efforts follow this link.