Summary

EPA Signs Explanation of Significant Differences

The U.S. Environmental Protection Agency (EPA) Region 7 has issued an Explanation of Significant Differences (ESD) for the Parkview Well Superfund Site, Operable Unit 02 (OU02). Under the Superfund law, EPA issues an ESD for a site cleanup change that differs from the original decision document but does not alter the overall remedy.

This ESD memorializes a change to the OU02 Record of Decision (ROD) selected remedy to add a source control performance objective for the in-situ chemical oxidation (ISCO). Source control ISCO injections will target the contaminant of concern, tetrachloroethene (PCE), for concentrations in groundwater greater than 2,000 micrograms per liter (µg/L). Specifically, once groundwater values for PCE are equal to or less than 2,000 µg/L, the source control remedy will be considered complete and ISCO injections will no longer be needed. Setting and using this source control measure for PCE will ensure that residual source mass is addressed to a level that will allow for restoration of the groundwater in a reasonable time frame. This change does not alter the fundamental cleanup approach adopted in the OU02 ROD or 2011 ESD.

EPA has assessed the ability of the public to access this ESD through an internet-based repository and has determined that the local community has this ability. The Administrative Record for this site will be available on EPA’s website (see Site Documents & Data).

Questions, comments, or requests for site information can be submitted to: