kerr-mcgee (residential areas)

ADJACENT TO PLT AT 258 ANN STREET

The Kerr-McGee Residential Areas site is one of four National Priorities List (NPL) sites in the West Chicago, Illinois area contaminated with radioactive thorium wastes. The radioactive waste originated from a nearby facility known as the Rare Earths Facility (REF). The REF, operated by Lindsay Light and Chemical Company and its successors from 1932 until 1973, produced non-radioactive elements known as rare earths and radioactive elements such as thorium, radium, and uranium along with gas lantern mantles for private entities and the United States government's use in federal atomic energy programs. The REF produced these elements by extracting them from monazite sands, bastnasite (rare earth ore), and other ores, using an acid leaching process. Production of these elements resulted in the generation of radioactive mill tailings that contained residual levels of thorium, radium, and uranium as well as certain other insoluble metals. Kerr-McGee purchased the REF in 1967 and maintained operations until closing the facility in 1973. Over several decades before the health risks associated with radioactive materials were generally recognized, the mill tailings were available for use as free fill material by residents and contractors. Winds also may have spread some of the mill tailings stored on the REF to nearby properties. As a result of the windblown contamination and the use of the tailings as fill material, the soil at many properties in the West Chicago area became contaminated with radioactive materials. Approximately 15,000 people live within three miles of the Site. Drinking water in the area is obtained from municipal or private wells and is not impacted by site contaminants.