The Gratiot County Landfill covers 40 acres southeast of St. Louis, Michigan. It accepted domestic, commercial, and industrial solid waste starting in 1971. Michigan began revoking its operating license in 1976 after permit violations. By that point, the landfill had released hazardous chemicals into the surrounding soil and groundwater, including roughly 269,000 pounds of polybrominated biphenyls, also known as PBBs. EPA added the site to its National Priorities List, which identifies the most serious contaminated sites in the country, in September 1983.
PBBs are the main contaminant of concern at the site. They have been found in solid waste, soil, and groundwater within the landfill area. Groundwater and surface water at the site still contain PBBs. People could face health risks from accidentally swallowing or coming into direct contact with contaminated groundwater or surface water. Methane moving from the buried waste toward occupied structures has also been a concern.
EPA and the Michigan Department of Environmental Quality completed the long-term remedy in 1995. The cleanup includes a slurry wall around the landfill perimeter, burial cells to contain PBB-contaminated waste, excavation and burial of contaminated soil from nearby properties, a clay cap over the entire landfill, fencing, and a lagoon to collect surface water runoff. Hydraulic controls and a vertical well reinjection system also help manage groundwater. Institutional controls restrict residential development and other land uses that are incompatible with current contamination levels.
The most recent five-year review, completed in September 2011, confirmed that the cleanup actions protect human health and the environment in the short term. EPA assessments show that human exposure is currently under control across the entire site, with no unacceptable exposure pathways identified. Contaminated groundwater migration is stabilized, and there is no unacceptable discharge to surface water. Ongoing work includes groundwater and methane monitoring, methane collection system improvements, and routine operation and maintenance. The site has not been deleted from the National Priorities List and has not yet achieved sitewide ready-for-anticipated-reuse status, meaning some cleanup goals or required land-use restrictions still need to be fully met.
Community members who want to learn more or ask questions can contact EPA's Community Involvement Coordinator or Remedial Project Manager.
