The South Macomb Disposal Authority site covers 159 acres in Macomb Township, Michigan and includes two adjacent landfills that accepted municipal waste from 1968 through 1975. Although no hazardous waste was reportedly dumped there, hazardous chemicals are present in the soil and groundwater. Leachate from the landfills entered the McBride Drain and flowed into the North Branch of the Clinton River. The site was first assessed in 1984 and added to the National Priorities List (NPL) in 1986.
EPA identified 25 contaminants of concern in groundwater at the site. These include volatile organic compounds such as benzene, toluene, vinyl chloride, and dichloromethane, metals including arsenic, cadmium, chromium, mercury, and lead, and ketones such as acetone and methyl ethyl ketone. Contamination has reached subsurface soils, three aquifers, and residential drinking water wells. The biggest health risks involve drinking or directly contacting contaminated groundwater, as well as potential soil ingestion and landfill gas migrating into nearby buildings.
A removal action was completed in 1990. A remedy was first selected in 1991 and revised in 2002. The updated cleanup plan included an engineered cap, vertical extraction wells, pumping, onsite treatment, drainage controls, ambient air monitoring, and institutional controls. Construction of all remedial work finished in October 2005. However, cleanup results did not meet required performance standards in 2006, and the State of Michigan approved additional leachate collection and groundwater extraction methods. Human exposure to contamination is currently under control across the entire site. Physical construction is complete sitewide. However, whether contaminated groundwater migration is stabilized remains uncertain due to insufficient data, and cleanup goals for current and future land uses have not all been achieved.
Operation and maintenance activities are estimated to begin between April and June 2027, with remedial action completion estimated between March and May 2028. A final Record of Decision from the state is estimated between December 2027 and February 2028. The site has not been deleted from the NPL, and no five-year review has been completed. Continued monitoring is underway to determine whether the additional remedial actions are achieving compliance or whether further steps are needed.
Community members with questions can contact the EPA's Community Involvement Coordinator or Remedial Project Manager.
