The Red Oak City Landfill covers 40 acres near Red Oak, Iowa, and operated from 1962 to 1974. The EPA found contaminated water seeping from the landfill into the East Nishnabotna River in 1984. The site was added to the National Priorities List (NPL) in 1989, largely because the Red Oak public water supply sits about 2.3 miles away. The site has since been deleted from the NPL after cleanup goals were met.
Thirty-five contaminants of concern have been identified across soil, groundwater, and surface water. Heavy metals and metalloids in soil include arsenic, cadmium, chromium, lead, mercury, nickel, selenium, and thallium, along with a range of other metals such as copper, zinc, and manganese. Organic compounds found in soil include polycyclic aromatic hydrocarbons, naphthalene, tetrachloroethene, and several phthalates. Groundwater and leachate contain volatile organic compounds (VOCs) such as trichloroethene, tetrachloroethene, toluene, 1,2-dichloroethene, and acetone.
The EPA selected a cleanup plan in 1993 that called for a clay cap over the landfill, river bank stabilization, site fencing, deed restrictions, and groundwater and surface water monitoring. A major flood in 1993 led to modest changes to the cap and bank stabilization design, documented in a 1996 Explanation of Significant Differences. Construction work started in 1997, and a Certificate of Completion was issued in November 2002. The site was deleted from the NPL in September 2005. Today, the city of Red Oak uses the landfill cover to produce hay, and the site is part of the EPA's Return-to-Use Initiative.
Human exposure is currently under control, and groundwater migration is stabilized. Waste remains in place beneath the cap, so groundwater and surface water monitoring continues. The most recent Five-Year Review, completed in July 2022, confirmed that the remedy protects human health and the environment. The next Five-Year Review is scheduled between July and September 2027. Deed restrictions and zoning limitations remain in effect to prevent residential or other incompatible uses.
Community members with questions can contact the EPA's Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the Iowa Department of Natural Resources.
