The Tri-County Landfill Co./Waste Management of Illinois, Inc. site covers 66 acres in Kane County, Illinois. It accepted municipal, commercial, and industrial waste from 1968 to 1976, with some materials disposed of improperly. A court order closed the landfill in 1981. The site was added to the National Priorities List in 1989, marking it as a priority for federal cleanup.
Investigators found contamination in soil, sediment, and groundwater. EPA identified 32 contaminants of concern. Soil contaminants include metals such as arsenic, lead, chromium, and manganese, as well as pesticides like P,P'-DDT, the solvent benzene, and polychlorinated biphenyls. Groundwater contaminants include arsenic, benzene, trichloroethene, tetrachloroethene, vinyl chloride, lead, mercury, and fluoride. Very low levels of inorganic contaminants, including aluminum, manganese, iron, and lead, remain in soil and groundwater on the site.
Cleanup work ran from 1999 through 2002. Workers excavated and capped contaminated soil, installed a landfill cover to block water infiltration, built a gas collection and treatment system, and set up groundwater monitoring. No contamination was found at locations away from the site. Exposure pathways are under control, and assessments show no unacceptable human exposure risks at this time. Contaminated groundwater migration has been stabilized, with no unacceptable discharge to surface water.
The site has achieved "Sitewide Ready for Anticipated Use" status. All cleanup goals for current and reasonably anticipated future land uses have been met. Land-use restrictions prohibit interference with the cap and limit groundwater use. These restrictions have been in place since 2013. One business currently operates on-site, employing 10 people and generating about $1,090,000 in annual sales. The sources differ on the date of the most recent five-year review: one states it was completed in July 2019, while another states it was completed on August 27, 2024. Operation and maintenance continue under EPA oversight, and the site has not yet been deleted from the National Priorities List.
Community members can review site records at the Gail Borden Public Library in Elgin, Illinois. Questions can be directed to the Community Involvement Coordinator or Remedial Project Manager assigned to the site.
