Assessing the value of hydrogeologic information for risk‐based remedial action decisions

Remedial action decisions for groundwater contamination are made under conditions of uncertainty regarding both human exposure levels and chemical potency. The value of groundwater monitoring in reducing exposure uncertainty can be estimated within a decision‐analytic framework. The value of information from a particular monitoring strategy will depend on the expected accuracy of the strategy in estimating exposure, prior uncertainty about exposure and potency, the costs and efficiencies of the alternative remedial actions, and values assumed for the discount rate and the cost per unit risk. The proposed framework for assessing the value of hydrogeologic information at a groundwater contamination site consists of three steps: (1) determine a probability distribution for average lifetime exposure; (2) estimate the value of perfect exposure information in reducing the expected opportunity losses of decision making; and (3) compare hydrogeologic monitoring costs with the expected value of the sample information provided.