Wellhead Protection for Water Wells

This chapter provides the necessary design narratives and other related information for the proper establishment of the wellhead protection (WHP) program because the methodology used to delineate a wellhead protection area (WHPA) has legal, economic, and environmental implications during the implementation phase of the program. The WHPA can be determined using analytical methods based on equations that describe groundwater flow and contaminant transport phenomena. The EPA proposes six different methods, including arbitrary fixed radius, calculated fixed radius, standardized variable shapes, analytical methods, hydrogeologic mapping, and numerical flow/transport models, for delineating the WHPA. The chapter presents a case study of 10 water-supply wells installed by the City of Las Cruces in the southern part of New Mexico. The existing methodologies for delineating a WHPA are described and compared.