Soil vapor: SE Hennepin Ave – Minneapolis
The General Mills/Henkel Corp. Superfund Site is at 2010 East Hennepin. The pollutant of concern is trichloroethylene (TCE), a common industrial solvent and degreaser. From 1947 to 1962, TCE and other wastes were disposed of at the site. Chemicals were placed in an “absorption pit” located in the southeast corner of the property. This was common practice at the time. TCE disposal at the site created an area of groundwater contamination (known as a “plume”) that extends about ½ mile southwest.
Below are links to additional information on the site, including historical documents, reports, and maps of the mitigation work since November 2013.
Update on access agreements and mitigation
- Number properties/buildings in total area with sub-slab sample results: 337
- Number properties/buildings over 20 ug/m3: 172
- Number properties/buildings less than 20 ug/m3: 165
- Number of properties/buildings within mitigation area (this number will change based on the data): 176
- Number of properties/buildings with mitigation complete: 152 (86% of 176)
- Number of signed access agreements in the original study area: 189 (97% of the 195 properties)
Draft sampling and monitoring work plan
Beginning in November 2013 General Mills began testing and then mitigating buildings where there was a potential for vapor intrusion. As this first stage of the work, building testing and mitigation moves toward completion, the next stage of the project, soil gas contamination source response is beginning. On June 16, 2014 General Mills submitted a draft plan to the MPCA to begin this additional work. The MPCA reviewed the plan and sent comments back to General Mills. General Mills revised the work plan, which MPCA received on August 20, 2014. The MPCA will review the plan within 30 days and provide approval to proceed or request additional changes. (Older version of the work plan are below under “site information,”)
Next steps in process
Click image for a larger view:
Below is the building mitigation status map. The purpose of the map is to show which buildings are in the mitigation area, where additional investigation is needed and where long-term monitors will be installed. Click image for larger view.
Keeping you informed
The MPCA will continue to communicate with people in the Como SE Minneapolis neighborhood about the vapor study. Sign up online to receive regular updates through GovDelivery. For general questions, contact Cori Rude-Young at 651-757-2680 or at email@example.com.
Maps showing the sampling range, status and mitigation.
History of the former General Mills Inc., research facility.
The Review will assess the groundwater cleanup and ensure that human health and the environment remain protected.
Additional information for property owners
Resources and news.