Congressional District # 06
WASTE DISPOSAL ENGINEERINGEPA ID# MND980609119
Last Updated: June, 2015
The Waste Disposal Engineering Site is a 114-acre property located in the City of Andover, Anoka County, Minnesota, approximately 15 miles north of Minneapolis. The site includes a 73-acre landfill that accepted approximately 2.5 million cubic yards of municipal, commercial, and industrial wastes. The landfill operated as a dump from 1963 to 1983. From 1972 until 1974, hazardous wastes including paint sludges, solvents, oils, caustics, and acids were disposed of in an asphalt-lined hazardous waste pit on the site. In 1982, lime sludge, generated by the Minneapolis Drinking Water Treatment Plant, was used to cover the landfill. The area surrounding the site is residential, agricultural, and commercial. Area residents rely on groundwater for their drinking water source but the water supply wells are not impacted by the landfill. The site is bordered by Coon Creek, which discharges into the Mississippi River approximately 11 river miles downstream from the site.
Site ResponsibilityThe site was addressed through federal, state, and potentially responsible parties' (PRP) actions. The site is currently managed by the Minnesota Pollution Control Agency (MPCA) as part of its Closed Landfill Program.
Threats and ContaminantsShallow groundwater beneath the site was contaminated with a wide variety of volatile organic compounds (VOCs). A wide variety of wastes, including hazardous wastes, are present in the landfill. Direct contact and contact with landfill gases were a potential threat to public health until the site was remediated.
In 1974, prior to listing the Site on the National Priorities List (NPL), MPCA ordered an on-site Hazardous Waste Pit to be closed due to the high potential for groundwater contamination. The site was placed on the NPL in 1983. In 1984, EPA and MPCA entered into a Consent Order with potentially responsible parties (PRPs) to complete a remedial investigation and feasibility study (RI/FS). The study was completed in 1987.
In 1987, EPA selected a remedy that required: pumping and treating the groundwater using carbon absorption and discharging the treated water to Coon Creek; installing a cap to completely cover the landfill; installing a clay wall (slurry wall) around the hazardous waste pit; implementing restrictions on land and groundwater use; filling in a wetland and constructing an alternate wetland to replace the lost habitat; and monitoring of the site. Construction of the final site remedy was completed in 1995. At that time, the site was entered into MPCA's Closed Landfill Program for post-closure management and was deleted from the NPL in 1996.
MPCA subsequently made a number of upgrades to the landfill, including installation of an active gas collection and flare system. MPCA has also made upgrades to the groundwater treatment system, including use of aeration treatment for extracted groundwater and discharge of treated groundwater to the Metropolitan Council of Environmental Services rather than to Coon Creek.
Currently, MPCA performs operation and maintenance of the landfill gas, flare, groundwater extraction/treatment system, and landfill cap. Landfill gas is monitored using a network of 20 monitoring probes that surround the landfill. Contaminated groundwater is extracted using a network of 10 wells and is then pumped to an on-site retention basin for treatment. Groundwater that is within acceptable drinking water standards is re-directed to an on-site infiltration basin. Groundwater that contains contaminants which exceeds drinking water standards is treated by aeration until discharge standards are met for the public wastewater treatment system. Operation of the groundwater pump and treat system will continue until established cleanup levels are met.
Beginning in 2007, MPCA operated a Gas-to-Energy system for several years to convert landfill gases to a usable source of energy. More recently, this system was shut down and re-converted to the enclosed flare system, due to contaminant characteristics in the gas which made the system difficult to maintain and costly to operate. From 2009 to 2010, MPCA operated a pilot treatment system in the hazardous waste pit. Currently, MPCA is evaluating the potential for additional actions at the pit. In 2012, MPCA added pre-treatment for PCBs for groundwater extracted near the pit.
EPA's latest Five Year Review of the site was conducted in 2013. It documented that the site currently protects human health and the environment because the remedy was constructed appropriately and groundwater at the site is being contained and treated. Recent remedy enhancements have further increased protection of groundwater at the site.
ContactsRemedial Project Manager, U.S. EPA
leah evison (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesWASTE DSPL ENGINEERING INC