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Congressional District # 14


EPA ID# ILD980824015
Last Updated: May, 2015

Site Description

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.

Site Responsibility

This Site is being addressed through federal and potentially responsible party (PRP) actions.

In January 2009, Tronox (formerly Kerr-McGee) filed for Chapter 11 bankruptcy and ceased work on the Site. In May 2010, an interim agreement was reached with Tronox that provided funding for work through 2010.

On February 14, 2011, a bankruptcy settlement agreement was reached with Tronox that provided for the creation of the West Chicago Environmental Response Trust (Trust) to address remaining Tronox environmental responsibilities in West Chicago, including the Residential Areas Site. The February 14, 2011 bankruptcy settlement agreement provided initial funding for the remaining cleanups in West Chicago but the bulk of the funding to complete the environmental cleanups relies on Department of Energy (DOE) reimbursement payments to the Trust pursuant to Title X of the Energy Policy Act of 1992.

Threats and Contaminants

Mill tailings containing residual levels of thorium, radium, and uranium as well as certain other insoluble metals were used as fill material by residents and contractors and wind may have spread some of the mill tailings stored on the REF to nearby properties. As a result, the soil at many properties in the West Chicago area became contaminated with radioactive materials. Due to the insolubility of the contaminants, groundwater in the area is not adversely impacted by the site contamination. People who are exposed to elevated levels of radiation in the soils may suffer adverse health effects.

Cleanup Progress

Prior to the Residential Areas Site's listing on the NPL, Kerr-McGee conducted cleanup actions in the mid-1980s at approximately 120 residential properties in the West Chicago area with the excavations subsequently backfilled with clean fill and restored.

Following the Site's listing on the NPL in 1990, Environmental Protection Agency (EPA) established cleanup standards for site soils and began field investigations to identify contaminated properties. The study area for the site includes more than 2,170 properties in and around the City of West Chicago. EPA began testing properties in September 1993 to determine which ones were contaminated with radioactive thorium mill tailings.

In November 1994, EPA decided to conduct a non-time-critical removal action at the site and its decision in an action memorandum which selected excavation of contaminated soil and offsite disposal as the selected removal action. EPA simultaneously issued a unilateral administrative order to Kerr-McGee to conduct the removal action and the cleanup of contaminated properties began in May 1995. The cleanup consists of digging up the contaminated soil at each property; hauling the contaminated soil away for disposal at a licensed, permanent disposal facility; backfilling the excavated areas with clean soil; and restoring and landscaping the property as needed.

On September 29, 2003, EPA issued a record of decision (ROD) documenting the ongoing removal action is eliminating existing and potential future risks to human health and the environment at the site and selecting no further action after the ongoing removal action is completed as the remedy for the Site. The removal action will continue until all testing is complete and all identified contaminated properties are cleaned up.

As of September 2006, Kerr-McGee (now known as Tronox) had completed the cleanup of all 676 known contaminated properties and had removed 110,883 cubic yards of contaminated soil from the site. EPA completed investigations in the study area at all but three properties where access had not yet been granted by the property owners.  EPA subsequently gained access to these remaining properties to complete sampling activities and no additional contamination was found.

As part of the ongoing removal action, EPA evaluated the properties that were part of the mid-1980s Kerr-McGee cleanup to determine whether any residual contamination was left behind and covered with clean backfill soil. Any low-level residual contamination, if buried under clean soils, may have gone undetected during EPA's investigation activities. EPA carefully analyzed all available file data and excavation information for each property that was part of the 1980s cleanup project and conducted additional sub-surface investigations where file documentation indicated elevated levels may have been left in areas and were not subsequently cleaned during the EPA directed removal action. Any residual contamination left behind during the 1980s cleanup and not detected by EPA initial gamma surveys did not create unacceptable exposures at the surface but may present unacceptable exposures if the materials were uncovered in the future. Any soils exceeding EPA's cleanup standards discovered were cleaned up as part of the ongoing removal action.

EPA determined that 40 properties involved in the mid-1980s cleanup required additional sampling to determine if contamination remained on the property above the cleanup criteria. A total of 15 properties were identified with contamination remaining above the cleanup standards.

EPA routinely receives inquiries from general public in regards to the status of specific properties. In some cases EPA receives new information and determines additional sampling efforts are warranted. If any contamination is present above the cleanup standard and if so, the properties will be cleaned up by the West Chicago Environmental Response Trust.

In January 2009, Tronox (formerly Kerr-McGee) filed for Chapter 11 bankruptcy and ceased work on the site. EPA immediately began attempting to negotiate a settlement of environmental claims with Tronox that would fund the cleanup of any remaining properties in need of additional cleanup. In May 2010, an interim agreement was reached with Tronox that provided funding to complete the cleanup of 10 properties identified with residual contamination and cleanup of these properties was completed by the end of 2010. Five additional properties were cleaned up in 2011 and 2012. To date, all but one of the properties identified with contamination have been cleaned up and restored. Cleanup of the remaining property will happen once an adequate funds become available.

The DOE payments, mandated by Title X of the Energy Policy Act of 1992, reimburse the Trust for 55.2% of the eligible cleanup costs which are audited and approved by DOE. The Trust uses these DOE reimbursements to fund remaining cleanups in West Chicago. DOE audits the Trust’s submitted claims annually and Title X states that DOE shall reimburse the Trust in the amount of the audit and approved claims. Unfortunately, DOE only partially reimbursed the Trust’s audited and approved claims in 2012 and has failed to reimburse any audited and approved claims in 2013 or 2014. Due to the lack of funding the Trust was forced to cease efforts on the Site until adequate funding was received.  In April 2015, the Trust received partial reimbursement for past claims.  EPA plans to work with Trust to utilize a small portion of these funds to cleanup the known remaining contaminated property.

Community Involvement

The local community has been very involved in site issues for more than two decades. The Thorium Action Group (TAG), a very active and vocal community group, fought hard for the removal of the thorium materials from the West Chicago and DuPage County area. EPA participated in regular meetings of the West Chicago Intergovernmental Forum, which includes representatives of state and federal regulatory agencies, local community representatives, members of TAG, the PRP, and other interested stakeholders.  As the cleanup of the sites in West Chicago began to reach completion, these meetings were held less often and are now held on an "as needed" basis.  Minutes of these meetings since 2007 other documents relating to the cleanup of the Kerr-McGee sites in West Chicago can be found at http://www.epa.gov/region5/cleanup/kerrmcgee/index.htm.  Throughout the bankruptcy process, the local communities were involved in the negotiations and were a party to the bankruptcy agreement.  

Property Reuse

The Residential Areas Site is already being used for residential and other purposes.  Future use of the properties at the site is expected to remain the same as current use.


Remedial Project Manager, U.S. EPA
david seely (seely.david@epa.gov)
(312) 886-7058

Community Involvement Coordinator, U.S. EPA
janet pope
(312) 353-0628




Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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