CHAPTER 3 

 THE RESOURCE -BASED APPROACH 



Groundwater is very likely our most threatened resource and yet it is 

 not receiving adequate protection or the overall management attention it 

 demands. Programs at the federal, state and local levels of government 

 designed to protect groundwater tend to focus on individual sources of 

 potential contamination, rather than on the resource itself. While 

 controlling pollution at the source is still important, regulatory 

 programs must never lose sight of the resource that is being protected as 

 new programs are being designed to meet that goal. Rather than attempting 

 to control all sources on an equal basis (no matter what contaminants are 

 involved, or where the land-use activity is located) regulatory programs 

 need to differentiate among the potential contamination sources and their 

 relative threat to the protected resource. 



Historically, water-quality protection in the United States began with 

 the "dilution is the solution to pollution" philosophy. This concept, 

 however, does not work well in its application to groundwater because once 

 contaminants mix with the groundwater, they are difficult to locate, 

 monitor, and recover. Until the source of contamination is stopped, 

 contaminants continue to mix with groundwater and move away from their 

 point of entry in the direction of groundwater flow. 



The "contaminate and remediate" approach to groundwater management 

 followed. There were few no regulatory activities focusing on prevention 

 of contamination at the source through land-use controls. Regulatory 

 efforts were limited to monitoring programs and construction standards for 

 land-disposal sites and clean-up activities. 



In the early to mid-seventies, the relationship between land use and 

 groundwater quality and the value of prevention as opposed to remediation 

 began to be recognized. However, the understanding of what prevention 

 might involve was still undeveloped. Because it was believed that aquifer 

 material was capable of cleansing groundwater over short distances, 

 prevention was focused on bacterial contamination and easily protected by 

 the 400 feet radius around public -supply wells. 



As hydrologists tracked contaminants to sources more distant than the 

 400 foot protection radius to public-supply wells, water management 

 officials began to investigate the need to protect entire aquifers or 

 watershed basins. However, where this ambitious approach was attempted, 

 it soon proved both economically and politically infeasible. 



In searching for ways to streamline and reduce the process for identi- 

 fying areas in need of intensive protection, hydrologists refined 

 hydrologic concepts for identifying the aquifer areas that directly supply 

 a public-water-supply well. These concepts led to the identification of 

 the "zone of contribution" to pumping wells. The approaches used for 

 defining zones of contributions under various types of hydrogeologic 

 conditions include both analytical tools and computer models. Today, 



