MPCA and MDH News Release
November 7, 2013
MDH and MPCA alert Minneapolis neighborhood of possible vapor intrusion
Media availability at MPCA at 2 p.m., 520 Lafayette Road North—experts from MPCA and MDH
On Wednesday, Nov. 6, the Minnesota Department of Health (MDH) and Minnesota Pollution Control Agency (MPCA) sent letters to owners, occupants and renters of residences in the Como neighborhood of southeast Minneapolis. The letter was sent to alert them of an ongoing investigation of potentially harmful vapors that may be intruding into homes and buildings.
The letters informed residents of potential health concerns, but stressed that more investigation and testing need to take place in their residences and buildings to evaluate actual risk and determine the correct response. Residents were also given contact information for sources at MDH who can talk to them about health risks, and contacts at the MPCA for details on the history of the pollution causing the vapor release.
There are two informational open house-community meetings scheduled for residents in the area of concern in southeast Minneapolis. Both meetings are planned for Tuesday, Nov. 12, at Van Cleve Recreation Center at 901 15th Ave. SE in Minneapolis. There will be early afternoon and early evening sessions from 12:30-3 p.m. and 5-7:30 p.m. During the first hour agency representatives will be available to answer questions, followed by presentations at 1:30 and 6 p.m. Additional community informational meetings are being planned.
The soil vapor in question is trichloroethylene, commonly known as TCE. It was used as an industrial solvent at a former General Mills research facility at 2010 E. Hennepin Ave in Minneapolis in the 1940s until the early 1960s. During that time waste TCE was disposed of in a pit on the property. The contaminated site has been known for more than 30 years. General Mills, under the oversight of the MPCA, pumped and treated groundwater at the site to remove the TCE for 25 years.
Based on extensive groundwater testing over many years, data demonstrated that TCE concentrations in the groundwater significantly declined and the groundwater plume has stabilized. With approval from the MPCA, the treatment systems were shut down in September 2010. Drinking water in the area was never a health issue as this area is served by city water and there were no wells that drew from the contaminated plume.
Soil vapor testing was required as the next step in the process. In October 2013, data showing TCE in soil gas samples taken on public rights-of-way in the areas prompted this alert to residents.
At the open houses, residents and property owners will be informed of the testing locations and procedure, as well as the potential health risks of TCE. Environmental testing at the properties will be performed in the method approved by the MPCA. Testing will begin as soon as testing and mitigation plans are approved and access agreements are signed by property owners.
If TCE levels in the soil beneath any building or home are above the safe level set by MPCA and MDH, General Mills has agreed to install vapor ventilation systems, which work like radon mitigation systems. Such systems are a proven solution for both radon and vapor intrusion problems; homes with existing radon mitigation systems may already be effectively reducing TCE.
MPCA and MDH are asking for public assistance in this process. To ensure quick response times, officials with the MPCA and MDH encourage all residents and property owners to cooperate by allowing access for tests inside their residences.
There is no cost to residents or property owners for testing or mitigation. Vapor intrusion mitigation systems will be offered and installed at no cost in affected homes. Access agreements will be available at the public meetings.
A map of the study area is available on the MPCA website at: http://www.pca.state.mn.us/.
More information is also available at Trichloroethylene (TCE) and Your Health.
Media availability at MPCA at 2 p.m., 520 Lafayette Road North—experts from MPCA and MDH###