Just because a landfill is closed doesn't mean hazardous materials don't get out.
The Olmsted County Sanitary Landfill in Oronoco is one of three superfund sites in Olmsted County. The former landfill occupies 52 acres of a 304-acre property according to an Environmental Protection Agency profile on the site.
From 1970 to 1987, the landfill accepted mixed materials including asbestos, electroplating sludge paint and solvents. From 1987 until its final closure in 1993, the landfill accepted only demolition debris and ash from Rochester Public Utilities.
Waste disposal there contaminated groundwater with hazardous chemicals and the EPA listed the landfill a superfund site and placed it on its National Priorities List. The Minnesota Pollution Control Agency took over monitoring and cleanup of the site when the MPCA instituted its closed landfill program and the EPA removed the site from its national priorities list the following year.
The other two Olmsted County superfund sites being monitored by the MPCA include the former Capri beauty salon in Byron and Clothing Care Cleaners site, 612 11th Ave. N.W., where environmental investigations found chemicals used in dry cleaning in ground water at the site.
Former wood treatment plants, pesticide manufactures, dumps and dry cleaners have contaminated parts of Minnesota with hazardous waste. Even with state and federal aid, it can take years to clean them up.