Lawrence Todtz Farm is a 13-acre former municipal and industrial landfill near Camanche, Iowa, listed on the EPA's Superfund National Priorities List in 1986. The site operated from 1958 to 1975. DuPont disposed of cellophane process waste in a 2.5-acre section called the impoundment, which spread contamination into groundwater and soil. Corteva AgriScience took on liability for the site in June 2019 after spinning off from DowDuPont.
The EPA identified 34 contaminants of concern across groundwater and soil. Groundwater contains organic compounds such as benzene, toluene, xylene, tetrachloroethene, tetrahydrofuran, carbon disulfide, and several ketones. Heavy metals found in groundwater include arsenic, lead, chromium, nickel, beryllium, cobalt, vanadium, antimony, and barium. Soil contamination includes arsenic, lead, benzene, toluene, xylene, carbon disulfide, tetrahydrofuran, and cresol compounds. Arsenic and lead were detected above background levels in the impoundment.
Physical cleanup construction wrapped up in September 1991. The work included placing a two-foot soil cover over the impoundment, installing a groundwater monitoring system, and fencing off the site. New private domestic wells were also installed for water supply. An environmental covenant filed with Clinton County in 2007 bans residential, agricultural, and food chain uses on the property and prohibits new water supply wells. The site is listed on Iowa's Registry of Hazardous Waste Disposal Sites, requiring state approval for any change in use or ownership transfer. The city of Camanche also passed an ordinance in 2009 prohibiting new wells within city limits except for monitoring purposes.
The EPA's 2020 Five-Year Review found the remedy currently protects human health because institutional controls prevent exposure to contamination. There are no current unacceptable human health risks at the site. However, the remedy is only short-term protective. Groundwater migration data is insufficient for EPA to confirm whether contamination is stable or poses no unacceptable discharge to surface water. Additional groundwater characterization and evaluation are needed to determine whether further response actions are required for long-term protection. Corteva continues monitoring groundwater and surface water. The most recent Five-Year Review was completed in September 2025, and the site has not yet been deleted from the National Priorities List.
Community members with questions can contact the EPA's Community Involvement Coordinator or Remedial Project Manager. The administrative record for the site is available for public review and dates back to 1990.
