Method for evaluating cumulative impacts of projects which involve uncertainty in the baseline environmental conditions

Analysis of cumulative impacts is typically an inexact science. Evaluating cumulative impacts when there is uncertainty in project design data can further complicate the analysis of cumulative impacts. Additionally, a lengthy and expensive effort is often required to obtain baseline data necessary to conduct a quantitatively rigorous analysis of cumulative impacts. Such an extensive effort, would in many cases, only amount to quantifying what is intuitively obvious, adding little substantive value to the decision-making process. Analysts should therefore, carefully weigh the additional value that would be derived before a decision is made to initiate such a study. In many situations, less rigorous approaches may provide decision makers with reliable information that will support the decision-making process. The following discussion outlines such an approach. The approach involves determining the degree to which cumulative impacts would be changed as a result of pursuing an action. This approach combines a quantitative impact analysis of the proposed action with a qualitative analysis of the existing baseline environment. Such an approach is applicable to many different situations where there is uncertainty or incomplete information concerning baseline environmental conditions. The methodology can be applied to the analysis of cumulative impacts for a wide variety of activities that directly or indirectly support environmental remediation projects.