The former Gold Eagle dry cleaning business was located in the area of 66th St. E and 16th Ave. S in Richfield, Minn. The business operated until about 1995, when it closed and an environmental investigation of the property was conducted prior to redevelopment. A dental clinic now operates out of the former dry cleaner site building.
This is a largely residential area, although there are a number of businesses in the area, including the Appleseed Montessori School and Childcare Center next door.
What's the problem?
An investigation in the area last fall found elevated concentrations of tetrachloroethene (PCE) in soil vapors and groundwater underneath the site. The source of the PCE contamination is likely the former Gold Eagle dry cleaner.
Groundwater contaminated with PCE or other chemicals can release vapors that can rise through the soil and seep through basement and foundation cracks into homes and other buildings, where it could be inhaled by people. This problem is referred to as vapor intrusion.
Testing of soil vapor under the foundations of several nearby homes the Appleseed Montessori School and Childcare Center showed that PCE vapors are likely present beneath buildings at elevated levels. A work plan has been developed that includes more sampling so that the extent of the area of concern is better defined.
When chemical vapors enter buildings through the foundation, the amount in indoor air is usually not high enough to affect most people’s health. The possible health effects from breathing PCE depends on the amount in indoor air and how long people breathe it.
Long-term exposures to PCE may increase the risk of certain types of cancer based on studies in workers or animals breathing very high levels of these contaminants (thousands of times greater than what may be found at vapor intrusion sites). At high levels, PCE can also cause neurological effects such as vision changes or delayed reaction time.
For more information regarding health and vapor intrusion, please visit the Minnesota Department of Health website.
What's being done?
On October 15, a sub-contractor working for the MPCA installed a vapor intrusion mitigation system in the lowest level of the Appleseed Montessori School and Childcare Center. Immediately following the installation of the mitigation system, testing indicated that the system was operating as designed to prevent PCE vapors from entering the indoor air of the daycare.
The MPCA requires that all mitigation systems undergo confirmation sampling within 30 days of installation to show that systems are working and that the indoor air contamination is below levels that would require additional action. Two confirmation sampling events were conducted after the mitigation system was installed. The final round of confirmation sampling indicated that the vapor mitigation system is operating as planned.
The MPCA’s contractors are also in the process of installing and verifying multiple vapor mitigation systems in nearby homes where elevated soil gas levels were detected.
Minnesota Department of Public Health