Congressional District # 04
GRATIOT COUNTY LANDFILLEPA ID# MID980506281
Last Updated: March, 2015
The Gratiot County Landfill site covers 40 acres southeast of St. Louis, Michigan. The area surrounding the landfill is primarily agricultural with some residential development along Jackson Road. A small park is located to the southeast of the site. Approximately 5,300 people live within three miles of the landfill; about 1,500 people are located within one mile. Municipal water wells, serving 4,100 people, are located within three miles of the site. The Pine River is located approximately 1.5 miles west of the site.
The landfill was operated in 1971 by Gratiot County Board of Public Works for the disposal of domestic, commercial and industrial solid waste. Prior to 1977, the Michigan Chemical Corporation, later purchased by Velsicol Chemical Corporation, disposed of various wastes, including 269,000 pounds of polybrominated biphenyls (PBBs) impacted waste at the landfill. In 1977, the state of Michigan discovered elevated levels of contaminants in shallow aquifers and in several nearby ponds. In addition, the State learned that in at least one, and possibly two, places, the wastes were in direct contact with the immediately underlying aquifer. The potential existed for contamination of the deeper aquifer, supplying drinking water for the region.
Site ResponsibilityThe site is being addressed through state and federal actions.
Threats and ContaminantsGroundwater and soil beneath the landfill cover system contain PBBs. Potential health risks include accidental ingestion of or direct contact with contaminated groundwater and soil.
In 1982 Velsicol Chemical Corporation entered into a consent judgment with the United States Environmental Protection Agency (U.S. EPA) and the state of Michigan. The consent judgment covered the Gratiot County Landfill and two other related sites: the Velsicol Chemical Corp. site and the Gratiot County Golf Course site. For the Gratiot County Landfill site, Velsicol agreed to pay cost recovery, to fund certain remedial actions, and to provide clay for the landfill cover system. In 1984 the state of Michigan took action to minimize the migration of contaminants from the landfill. Cleanup actions included: building a slurry wall around the perimeter of the landfill; constructing burial cells inside the landfill to encapsulate the PBB-contaminated waste; excavation, transportation and burial of approximately 20,000 cubic yards of PBB-laden waste from property located across from the site; installing a perimeter fence around the landfill; construction of a clay cap over the entire landfill; and construction of a lagoon to collect surface water runoff in order to control the source of hazardous PBB contamination in the soils and groundwater. The site was included on U.S. EPA's Construction Completion List in July 1995.
The state of Michigan and U.S. EPA have continued to monitor the remedy's effectiveness. In 1992, as part of the five-year review process, the state of Michigan completed an investigation which showed that the slurry wall is ineffective in halting groundwater flow at several locations. Low levels of benzene, chloroethane, 1,1-dichloroethane and 1,2-dichloroethane were detected outside the slurry wall. No PBBs were detected in groundwater samples.
In 1996, as part of a second five-year review, an investigation to determine the extent of contamination outside the slurry wall/landfill began. Based on the investigation's results, the state of Michigan installed a groundwater extraction and treatment system (GETS) to contain contaminated groundwater southwest of the site. Construction of the GETS was completed in 1998. The GETS utilized air stripping as a form of groundwater treatment prior to discharge.
Following the third five-year review in September 2001, the following actions occurred: (1) the state of Michigan evaluated the GETS system and analytical data, determined that the GETS system contained the plume and lowered contaminant levels in the groundwater, and shut down the GETS system in 2005; (2) five methane vents and 22 monitoring points were installed, (3) the landfill cap was evaluated and repaired, (4) the slurry wall was evaluated and monitoring wells have not indicated contamination leaching from the landfill.
The fifth five-year review in 2011 concluded that the remedy continues to be protective of human health and potential exposure pathways continue to be controlled. Continued data collection including groundwater and methane monitoring and implementation of effective institutional controls (ICs) are necessary to ensure that the constructed remedy remains protective in the long-term. MDEQ plans to discuss status of ICs with county during their next meeting in 2015 and expects to have ICs in place in 2016. Methane vents were added in 2013 and 2014 and monitoring has shown a decrease in the concentration of methane. PBBs were not detected in the additional sampling conducted in 2013.
The sixth five-year review is scheduled to be completed in September 2016.
ContactsRemedial Project Manager, U.S. EPA
matthew ohl (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesGRATIOT COUNTY LDFL