Document 2RJj0RYo34Kmy9zjmMKNBLZVa

August 25, 2017 VIA EMAIL AND U.S. M ATT, Mr. Allan Timm Site Remediation Unit 1 Site Remediation and Redevelopment Section Remediation Division MINNESOTA POLLUTION CONTROL AGENCY 520 Lafayette Road North St. Paul, MN 55155-4194 Mr. Timothy J. Grape, PG Project Manager Site Remediation & Redevelopment Section Remediation Division MINNESOTA POLLUTION CONTROL AGENCY 520 Lafayette Road North St. Paul, MN 55155-4194 Re: Southeast Hennepin Groundwater and Vapor Intrusion Site Dear Messrs. Timm and Grape: I enclose a supplemental report by Geosyntec and GSI based on the soil and groundwater sampling data collected by the MPCA in April 2017. These investigation results demonstrate that the TCE plume originates within the Southeast Hennepin Area Groundwater and Vapor State Superfund Site ("the Site."). In particular, these results demonstrate that there is a significant TCE release on the Sears property at 2600 Winter Street NE which, according to publicly available information, has been owned by Sears since 1964. The TCE concentrations measured in groundwater at the southwest boundary of the Sears site were significantly higher than TCE concentrations measured at the northeast (up gradient) boundaries of the Sears site. There is much more TCE leaving the Sears property on its southwest boundary than what is entering the Sears property on the up gradient, northeast boundary of the Sears property. In addition, the TCE on the northeast boundary of the Sears property shows that there are TCE sources up gradient of the Sears property. One General Mills Boulevard Golden Valley, Minnesota 55426 Sierra Club v. EPA 18cv3472 NDCA Tier 1 ED 002061 00115367-00001 Mr. Allan Timm Mr. Timothy J. Grape Page [ PAGE \* MERGEFORMAT J August 25, 2017 These results fully explain the continuing presence of TCE in groundwater and soil vapor. The new data provide no evidence that the General Mills/Henkel site is an ongoing source of TCE in groundwater. No additional response actions are necessary to address impacts associated with the historical activities at the General Mills/Henkel site. No up gradient investigation will alter these findings and conclusions as to the General Mills/Henkel site. Accordingly, General Mills reiterates its demand that MPCA do two things: 1. Demand that those parties responsible for the up gradient TCE sources, including Sears, investigate and remediate those releases; and 2. De-list the General Mills/Henkel site from the Minnesota Permanent List of Priorities (PPL) and cooperate with U.S. EPA to de-list the General Mills/Henkel site from the National Priority List (NPL). We would be pleased to discuss this matter further. Sincerely, Larry Deeney Senior Technical Leader - Global Environment cc: Hans Neve (via email only) (w/encl.) Carmen Netten (via email only) (w/encl.) Ann Cohen (via email only) (w/encl.) Mary Sands (via email only) (w/encl.) Michael Kavanaugh (via email only) (w/encl.) Thomas McHugh (via email only) (w/ end.) Delmar Ehrich (via email only) (w/encl.) Sierra Club v. EPA 18cv3472 NDCA Tier 1 ED 002061 00115367-00002