Wellhead protection is an approach to preventing contamination of groundwater that supplies public wells started in Europe in the 1960s and 1970s and has been part of European Union legal directives for many years. The concept comprises several steps that have now also been defi ned in law in the United States (Safe Drinking Water Act, Section 1428), which include the following basic measures:
1. Defi ne the zone of principal recharge to existing and future wells 2. Identify potential sources of contamination within the zone 3. Specify and implement management measures to control the potential sources of
While simple in concept, this approach is challenging to carry out, since it involves defi ning a protection area around wells and the participation of existing land users in that area whose practices may be incompatible with preventing contamination of groundwater. The concept of wellhead protection is also complementary to the current understanding that once groundwater is found to be degraded, it is diffi cult, time-intensive and costly, and perhaps nearly impossible in some hydrogeologic settings, to treat and restore it to its previous quality in the foreseeable future. A conceptual wellhead protection area is depicted in Exhibit CS4.1.