Description: Various modeling programs have been used to determine the wellhead protection areas throughout Kentucky. Systems using wells will have a WHPA-1, which represents a 400' minimum radius around the well or a 6-month time of travel for groundwater to the source. WHPA-2 generally represents a 10-year time of travel or the hydrologic boundary if there was not sufficient information to model the protection area. WHPA-3 will generally be the hydrologic boundary. Water suppliers using abandoned underground mine works will have the entire mined out area delineated as a WHPA-1. Systems that are using a spring or a well in karst areas will have the entire basin delineated as WHPA-1. This is due to the highly sensitive nature of the entire recharge area for these types of aquifers. Systems that use wells may have delineations that change if new wells are added or old wells are abandoned. Different modeling programs have been used to establish wellhead protection areas. These areas may change if a system decides to change the way they have modeled the aquifer being used.