The U.S. Radium Corp. site sits on a 2-acre property in Orange, New Jersey. The plant processed carnotite ore from 1917 to 1926 to extract radium for medical use and luminous paint. That work left the facility and nearby residential and commercial properties contaminated with radium-226 and other radioactive materials. EPA added the site to the Superfund National Priorities List (NPL) in September 1983 and has been managing cleanup ever since.
The main contaminants are radium-226 and radium-228, found in soil, debris, groundwater, and air. Radon and radon decay products are present in soil gas and air near High and Alden Streets. Uranium isotopes (uranium-234, uranium-235, and uranium-238) and thorium isotopes (thorium-230 and thorium-232) have been found in groundwater and soil. The site also contains cadmium and vanadium pentoxide in soil. Radium-226 emits ionizing radiation and decays into radon gas, raising cancer risk through radiation exposure, inhalation of radioactive dust, or ingestion of radioactive particles.
Cleanup is organized into three operable units (OUs). OU1 covers the satellite area and nearby properties, where contaminated material was excavated and sent off-site for disposal starting in 1997. OU2 addresses High and Alden Streets, where cleanup included radon mitigation systems, gamma radiation shielding, containment, and off-site disposal across eight phases running through June 2016. OU3 covers groundwater, where a 2006 investigation concluded that no active cleanup was needed, though monitoring continues. EPA signed a Preliminary Close-Out Report in September 2006 confirming that construction was essentially complete. The site reached sitewide readiness for anticipated reuse in August 2018.
Current status is that all cleanup goals for existing and reasonably anticipated future land uses have been met. Human exposure is under control, with no unacceptable exposure pathways in place. Groundwater near the southeast corner of the High and Alden Street property remains slightly above cleanup goals in a limited area, but no one drinks or uses that groundwater, so it poses no unacceptable risk. Annual groundwater monitoring continues. EPA completed its fourth Five-Year Review (FYR) on January 30, 2026, confirming that all remedies remain protective of human health and the environment. The site has not yet been deleted from the NPL.
Community members can review site records at the EPA Superfund Records Center at 290 Broadway, 18th Floor in New York City, or at the Orange Public Library in Orange, New Jersey.
