| Abstract: | Natural attenuation has recently been recognized by the U.S. Environmental Protection Agency (EPA) as an appropriate remedy for sites contaminated with chlorinated solvents. Because natural attenuation does not require active remediation, it is considerably less expensive than other groundwater remedies. However, as laid out in EPA's recently released guidance, careful, systematic evaluation of natural attenuation must be conducted to ensure that the remedial approach is appropriate for a given site. The guidance requires that data be collected to demonstrate that natural attenuation is occurring and a fate-and-transport model must be conducted to estimate the extent to which a contaminated plume will ultimately migrate. Finally, the proponent of natural attenuation must be prepared to conduct long-term groundwater monitoring to verify that natural attenuation is controlling plume migration and that human health and the environment are not adversely affected. |
