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Fact Sheet

September 2014

Update on the West Lake Landfill Superfund Site, Bridgeton, Missouri


The West Lake Landfill Superfund Site is located on a 200-acre parcel about one mile north of the I-70 interchange within the city limits of Bridgeton, Mo., in northwestern St. Louis County.

Two areas of the site were radiologically-contaminated in 1973 when soils mixed with leached barium sulfate residues were used as daily and intermediate cover in the landfill operations.

The site is divided into two operable units (OUs), each with identifying areas. OU-1 consists of radiological areas 1 and 2 and the Buffer Zone/Crossroad Property; OU-2 consists of the other landfilled areas, which did not receive any of the radiologically-contaminated soil – this is known as the Bridgeton Landfill.

EPA issued its initial Record of Decision for the site in 2008, which is now under reevaluation.


1. Feasibility Study
EPA is currently conducting the Supplemental Supplemental Feasibility Study (SSFS) to inform the forthcoming proposed final remedy for the site. Key activities of the SSFS include reevaluation of the volume of radiologically-impacted material (RIM) located in the landfill, evaluation of partial excavation alternatives, and evaluation of the extent and movement of contamination in the groundwater.

2. Subsurface Smoldering Event
There is a subsurface smoldering event (SSE) occurring on the Bridgeton Landfill side of the site. Bridgeton Landfill is managed under Missouri Department of Natural Resources (MDNR) authority and work related to the SSE is being conducted by Republic Services. Republic has an extensive network of gas extraction wells and temperature monitoring probes to monitor the event, and currently has plans to expand its monitoring network. EPA maintains routine communication with MDNR to stay informed about the SSE. All current data suggest the SSE remains distant from the areas containing known RIM.

3. Isolation Barrier
To ensure that the public remains protected from the SSE potentially impacting the RIM, EPA is partnering with the U.S. Army Corps of Engineers to oversee the development of plans for an isolation barrier, which will isolate the SSE from the RIM. Once a barrier alignment has been chosen, design work will begin in earnest, with construction of the isolation barrier anticipated to begin in approximately 18 months.

Pre-construction activities have already begun, which include the installation of an off-site air monitoring system and the installation of a wind-blown debris barrier.

4. Off-Site Air Monitoring Network
EPA has set up its own off-site air monitoring network to monitor air quality during construction of the isolation barrier. A total of five monitors have been placed around West Lake Landfill. This is in addition to the on-site air monitoring being conducted by the PRP’s contractor. The off-site air monitoring will include particu­late matter, including sampling for alpha, beta, and gamma radiation and related constituents, and vola­tile organic compounds. The on-site and off-site air monitoring will provide a robust air monitoring network to ensure that work on the isolation barrier does not pose a threat to those living and working in the areas around the landfill.


EPA will review the detailed plans for the isolation barrier alignment alternatives as they are submitted by the Potentially Responsible Parties (PRPs) in mid-October.

EPA will review the bird mitigation plans when they are submitted by the PRPs, and will coordinate that review with the St. Louis Airport Authority and the Federal Aviation Administration.

The U.S. Geological Survey is currently preparing a report regarding groundwater data. EPA expects to receive this in the near future. This report is a vital next step in reevaluation of the site.

EPA continues to press toward selection of a final remedy. We expect to approve work plans very soon for the next stages of Feasibility Study work that must be completed to support a new Proposed Plan and Record of Decision.  


Additional site information, including documents, correspondence, and past issues of the West Lake Update, are available on the EPA Region 7 West Lake Landfill website: www.epa.gov/region7/cleanup/west_lake_landfill.

The Administrative Record and other related documents for the West Lake Landfill Superfund Site are available for review at the following locations:

St. Louis County Library
Bridgeton Trails Branch
3455 McKelvey Road
Bridgeton, Missouri 63044

EPA Region 7 Records Center
11201 Renner Blvd.
Lenexa, Kansas 66219


If you have questions about this Fact Sheet, or need additional information about the West Lake Landfill Superfund Site, please contact:

Ben Washburn
Community Involvement Coordinator
Office of Public Affairs
U.S. EPA Region 7
11201 Renner Blvd.
Lenexa, KS 66219
(913) 551-7364
Toll-free: (800) 223-0425

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