AMAZONIA, Mo. (AP) – Twenty years after cleanup work wrapped up on a former northwest Missouri landfill, most people have either forgotten the site or never knew it existed.

The St. Joseph News-Press reports that Wheeling Disposal began operating a landfill in the 1970s in a rural area near Amazonia. Before its closure in 1986, the landfill accepted waste such as pesticides, heavy metals, paint, solvents and leather tanning sludge.

The Environmental Protection Agency put the site on the Superfund list in 1989, shortly after it earned the agency’s highest-possible score for toxicity. Superfund status brought federal funds to aid in a cleanup and containment project, which was completed in 1994.

A report released earlier this year shows chemicals remain isolated in the former landfill and have not leaked into groundwater.