The Ottawa Radiation Areas site covers 16 contaminated areas spread across Ottawa, Illinois and surrounding locations in LaSalle County. Two companies, Radium Dial Company and Luminous Processes, Inc., processed radium-based paint for glow-in-the-dark clock and watch dials at this location from 1918 to 1978. That work left radioactive waste in soils, groundwater, surface water, and sediment throughout the city. EPA added the site to the National Priorities List in October 1992.
The main contaminants are radium-226 and radon. Radium-226 shows up in soil and other media across several areas of the site. Radon has been detected in soil and in some buildings in the Ottawa area. EPA determined that these contaminants pose unacceptable risk to human health or the environment. Human exposure is not currently under control, meaning an unsafe level of contamination exists and people could reasonably be exposed. Groundwater migration is under control, and monitoring continues to confirm contaminated groundwater stays within the original area.
EPA has completed cleanup at 15 of the 16 areas. Early removal actions between 1986 and 1994 relocated one home, installed radon reduction systems in several buildings, and removed about 32,000 cubic yards of radioactive soil to a disposal facility in Utah. A larger cleanup from 1995 to 1997 excavated over 40,000 tons of contaminated soil. Remedies at the remaining area, the NPL-8 landfill, have not yet been fully put in place. New remedial action at the NPL-8 Conservation Area started in September 2024 and is estimated to run through early 2028. A 2021 five-year review found that remedies at seven areas protect human health and the environment, and that the NPL-8 landfill remedy is expected to be protective once fully implemented. Several site areas have returned to productive use under institutional controls that prevent incompatible land uses like residential development.
EPA is now conducting the site's fourth five-year review, with completion targeted for November 22, 2026. This review checks that cleanup continues to protect people and the environment, including verifying that radon reduction systems in buildings are working. EPA finalized a Community Involvement Plan in January 2024 to keep affected residents informed as cleanup continues. Community interviews are being conducted as part of the five-year review process. Anyone who wants more information or wants to participate in a community interview can contact EPA's Community Involvement Coordinator. Site records are available for public review at the Reddick Library at 1010 Canal Street in Ottawa.
