Superfund legislation has established two types of liability for past and current releases of hazardous substances. The first is associated with cleaning up old and abandoned hazardous waste sites, the second with residual liability arising after cleanup. Damage claims associated with injuries to natural resources are a concern under the second type of liability.

Contingent valuation (CV) measures what is called passive use value or existence value. The CV method has been used to measure the benefits of environmental policy actions. CV measures of economic value rely on choice. In CV studies, choices are posed to people in surveys; analysts then use the responses to these choice questions to construct monetary measures of value. The specific mechanism used to elicit respondents' choices can take a variety of forms, including asking survey respondents whether they would purchase, vote, or pay for a program or some other well-defined object of choice....

Contingent valuation (CV) measures what is called passive use value or existence value. The CV method has been used to measure the benefits of environmental policy actions. CV measures of economic value rely on choice. In CV studies, choices are posed to people in surveys; analysts then use the responses to these choice questions to construct monetary measures of value. The specific mechanism used to elicit respondents' choices can take a variety of forms, including asking survey respondents whether they would purchase, vote, or pay for a program or some other well-defined object of choice....