West Lake Landfill site, Bridgeton Missouri
• National Priority Listing (NPL) for West Lake
o West Lake Landfill was listed on the NPL in 1990 (See 55 FR 35502-25512, Aug.
o The NPL listing package was primarily based on radioactive contamination;
however, the narrative summary mentions that there are other chemical
contaminants in the landfill.
o NPL listings are based on data of a sufficient nature to list the site but are not
inclusive of all contaminants that may present an unacceptable risk and do not
define the areal of extent of contamination.
• As noted in a 2012 HRS listing: The HRS does not require scoring all
pathways if scoring those pathways does not change the listing decision. The
HRS is a screening model that uses limited resources to determine whether a site
should be placed on the NPLfor evaluation and possible Superfund response. A
subsequent stage of the Superfund process, the remedial investigation (RI),
characterizes conditions and hazards at the site more comprehensively.
• For the West Lake site, Operable Unit (OU) 1 deals with landfills that contain RIM (and
other chemicals) and OU2 deals with the other non-RIM landfills at the NPL site.
• OUI had a Record of Decision (ROD) signed in 2008. Subsequent to the signature of the
ROD, concerns were raised by the Missouri Coalition for the Environment and others
regarding EPA’s decision to cap the Site and leave RIM in place. As a result, the Agency
chose to more thoroughly explore other potential alternate remedies, including full and
partial excavation. That has been the primary focus of work over the last few years,
including the NRRB consultation and ongoing work supported by OSRTI, ORD, and
• OU2 (non-RIM landfills) had a separate ROD signed in 2008 for the non-radiation
portion of the site.
o The ROD for OU2 (non-RIM landfills) states: “For areas operated under state
permit, i.e., the Former Active Sanitary Landfill and the Closed Demolition
Landfill, the terms of their respective permits dictate the appropriate closure and
post-closure care requirements. Successful completion of these requirements
would eliminate the need for further CERCLA action at these units. Consistent
with EPA’s policy on coordination between the Resource Conservation and
Recovery Act and CERCLA actions, these regulated units are deferred to the state
o The OU2 ROD indicates that the Former Active Sanitary Landfill, also known as
the Bridgeton Landfill, is part of the OU2 area The OU2 ROD requirements
• Installation of landfill cover meeting state sanitary landfill requirements
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• Groundwater monitoring consistent with requirements for sanitary
• Surface water runoff control
• Gas monitoring and control consistent with sanitary landfill requirements
• Institutional Controls
• Surveillance and maintenance of the remedy
o Because of the deferral, all of the activities and issues related to the Bridgeton
Landfill have been lead and managed by the State. This includes management of
the off-gassing, which has been an issue of significant community interest.
• The following maps are attached (please note the “North” arrows as the orientation can
vary from one map to the next):
o West Lake Landfill OU-2 map
• Shows the the overall boundaries and state permit coverages
o West Lake Site Layout for OU-1, which shows Radiological Areas 1 and 2
o West Lake Site vicinity map
• There also has been some recent discussion regarding a recent flyover.
o Based on discussions with the Region, in February 2015, a local fire department
official conducted a flyover using an infrared camera that supposedly indicated
that the North Quarry of the Bridgeton Landfill may have elevated temperatures.
Immediately north of the North Quarry is where RIM was found during 2014
sampling associated with locating an isolation barrier between the RIM and the
SSE. This could have led to the conclusion that the subsurface smoldering event
may have migrated to the radiation contamination areas.
o However, it appears that the State and the Region have determined that the data
from that flyover are not credible, due to concerns with the overall process,
o Thus, the Region and the State are no longer addressing the flyover. The Region
continues coordination with the state on review of the data from the temperature
probes and gas extraction wells to evaluate the possible movement of the SSE.
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