In some cases, vulnerability assessments can be used to identify or predict the existence of potential for ground water contamination in a particular geographical or jurisdictional area. Therefore, these assessments often take the form of a map of existing levels of contamination or areas where contamination is known to have the potential to occur. In these cases, the assessment documents the problem needing to be resolved and provides the justification and rationale for further discussion, action, and/or policy development.
Another potential use of a vulnerability assessment in the policy development stage is to analyze proposed alternative policies that seek to respond to a particular ground water quality problem. A program manager faced, say, with a problem with the use of the herbicide atrazine in a particular region might need to examine several alternative policies—from education and technical assistance to regulation of usage rates to an outright ban on use. Various analytical tools could then be used by the policy analyst to determine the impacts of each of these options on a variety of factors including atrazine use, productivity, and ground water quality. For example, the predicted effectiveness of a policy that is implemented only in more vulnerable areas (versus all areas) can be estimated through the use of vulnerability assessments.
Vulnerability assessments can also be used to guide various program-level management decisions. As stated above, assessments can document the level of severity and need to resolve a ground water contamination problem. Further, an assessment can highlight the need for financial or human resources to be directed toward the control of a particular ground water contaminant or contamination problem.
Vulnerability assessments also can give managers information they need to allocate resources to areas for particular purposes. These purposes could vary from providing the greatest benefit or protection with the least expenditure to preventing the worst possible contamination problem. For example, vulnerability assessments could be used to establish routine ground water monitoring programs, to establish databases, or to ensure compliance with standards or other protection requirements. More vulnerable areas would be monitored more closely than less vulnerable areas to identify incidences of contamination. Similarly, allocation of personnel to compliance programs could be based on vulnerability assessments. Assigning additional personnel to supervise land use regulations or mitigation plans in more vulnerable areas recognizes the need for closer control of activities in areas more susceptible to contamination.
In each of these instances, vulnerability assessments serve as a tool to