The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Ground Water Vulnerability Assessment: Contamination Potential Under Conditions of Uncertainty
Box 1.1President's Water Quality Initiative
The President's Water Quality Initiative was launched in 1989 in response to the widespread concern that agricultural activities contribute to the contamination of the Nation's ground waters. The goal of the initiative is to relate agricultural activities to ground water quality and to develop and implement farm management strategies that protect ground water. The USDA was directed to achieve this goal in a manner that maintains productivity and profitability, and minimizes regulation. Research, education, technical assistance, cost-sharing, and data collection programs have been implemented to achieve these objectives. The Initiative will extend through 1995; it is led by the USDA and involves eight principal USDA agencies, state agricultural experiment stations and cooperative extension services, the U.S. EPA, the U.S. Geological Survey, the National Oceanic and Atmospheric Administration, and state universities.
As part of the initiative, the USDA developed a ground water vulnerability index for use in setting priorities in program management and to provide insight on the impact of policy development. A description of the USDA Ground Water Vulnerability Index for Pesticides and its applications is presented in the national level case study in Chapter 5.
situations are relatively obvious. For example, ground water contamination is likely to occur in areas having shallow water tables and sandy soils with high recharge rates. Such relatively obvious situations, however, are found on land that comprises only a small fraction of the area of the United States. Efforts to protect against future contamination must focus on the much larger areas where relative vulnerability to contamination is more difficult to distinguish. Given this understanding, resource managers have sought to identify areas where contamination is more likely to occur than in other areas. Thus the concept of ground water vulnerability to contamination was developed.
Ground Water Vulnerability to Contamination
As illustrated in Box 1.3 the concept of ground water vulnerability to contamination has different meanings for different people. In its broadest context, ground water vulnerability refers to whether or not an underlying aquifer will become contaminated as a result of activities at the land surface. For the purposes of this report, ground water vulnerability to contamination is defined as: