General Mills used this Minneapolis property for food and chemical research from 1930 to 1977, disposing of waste in an on-site pit from 1947 to 1962. That practice contaminated soil and groundwater with trichloroethene, a chemical that poses an unacceptable risk to human health at the levels found here. Henkel Corporation bought the property in 1977, and a private investment group later transformed the buildings into a business incubator. As of December 2024, 24 small businesses operate on the site and employ 113 people.
The site was added to the National Priorities List in 1984, and a groundwater pump and treat system ran from 1985 to 2010. That system removed several contaminants, but trichloroethene remains in the groundwater. A second phase of remedial action began in November 2013 and is estimated to wrap up between December 2027 and February 2028. Starting in 2013, General Mills also installed vapor mitigation systems in several hundred nearby homes to address the risk of contaminated air seeping indoors.
The Minnesota Pollution Control Agency (MPCA) completed its most recent five-year review in 2021. That review found that soil remedies are protective of human health, but the groundwater remedy is not protective because of ongoing vapor intrusion risks to buildings at and near the site. Human exposure has not been brought under control. Investigators also found additional groundwater and vapor contamination sources northeast of the site, now called the Southeast Hennepin Groundwater and Vapor site, which MPCA continues to investigate.
Institutional controls restrict the property to industrial and commercial uses. Soil deeper than four feet below ground cannot be disturbed without prior authorization, and groundwater cannot be dewatered or used for supply wells without MPCA approval. The MPCA oversees cleanup under an EPA Enforcement Deferral Pilot Agreement, and EPA will continue monitoring to confirm that contaminated groundwater stays contained in the original area.
The EPA held community interviews in March and April 2023 to develop a Community Involvement Plan, which has since been released. The plan serves as a guide for residents and stakeholders as cleanup continues. Anyone with questions can contact the EPA's Remedial Project Manager or the MPCA at vaporinfo.pca@state.mn.us.
