EU001 is located in Saginaw County, Michigan, and is contaminated with hazardous substances, pollutants, or contaminants (specifically dioxins and furans) that have or may have come to be located from The Dow Chemical Company (“Dow”) Midland Plant property, with an address of 1000 East Main Street, 1790 Building, Midland Michigan, 48667 (the “Midland Plant”). Dow’s Midland facility is a 1,900-acre chemical manufacturing plant. Dioxins and furans are byproducts from the manufacture of chlorine-based products. Past waste disposal practices, emissions and incineration at Dow have resulted in on and off-site dioxin and furan contamination.
As part of Dow’s GeoMorph sampling and analysis in 2007, several transects were placed across the Tittabawassee River to collect soil and sediment for analysis. As part of their actions under their operating license requirements, Dow submitted analytical data from the samples that had been analyzed to MDEQ in the fall of 2007. Based on the analytical results, MDEQ identified several areas where sample results indicated that potential risk to public health may be present due to higher contaminant concentrations in residential or high public use areas.
In February, 2008, MDEQ, U.S. EPA, and MDCH met to evaluate data previously provided by Dow to determine the need to conduct further assessment of properties in the floodplain. The team determined that additional assessment, including sampling, would be necessary. The purpose of the sampling was to determine if there was substantial risk to those people accessing or living on the properties. During the discussions, it was decided that MDEQ would lead the effort to prioritize area to be further assessed. These areas would be called “exposure units.” MDEQ recommended that EU001 (the Riverside Boulevard area) would be given first priority. MDCH supported this program.
EU001 is subject to periodic, almost annual, flooding and erosion. This is particularly true during high stream flow events. EU001 flooding results in the deposition of contaminated soil and sediment from upstream locations. This may result in an increase in the amount and/or level of dioxin contamination at EU001 in the future. Flooding and erosion of EU001 also may result in the spread of dioxin contamination to other locations within the flood plain, as well as to downstream locations.
The response actions will mitigate threats to public health, welfare, and the environment presented by the presence of an uncontrolled release of dioxin and furans (hazardous substances) that pose a high risk of direct contact to humans and wildlife in soils and dust located within the EU001. Due to the contaminated nature of the soil, the continuing release of contamination into the environment and the food chain, and potential exposure to the public, this removal action is classified as time-critical. The removal actions for EU001 include excavation and disposal of contaminated soil at the surface, excavation and/or containment of remaining contaminated soil below the excavated areas (if necessary), air monitoring, backfilling and restoration of the impacted areas, removal of highly contaminated soils from and paving of the Riverside Blvd and driveways, and the cleanup of the residential interiors contaminated with dioxin.
Excavation and disposal activities will be conducted in a manner as protective as possible of existing structures and to preserve mature trees. The response activities will require approximately 75 on-site working days to complete.
