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Site Location
SLAPS is a 21.7-acre
property in St. Louis County, approximately 15 miles from downtown St. Louis. SLAPS is
immediately north of the Lambert-St. Louis International Airport and is
bounded by the Norfolk and Western Railroad and Banshee Road on the
south, Coldwater Creek on the west, and McDonnell Boulevard and adjacent
recreational fields on the north and east.
Land use adjacent to the
property is varied. More than two-thirds of the land within a half mile
of the property is used for transportation-related purposes (primarily
the airport). Land adjacent to the property is generally used for
transportation and commercial functions.
Site
History
In 1946, the Manhattan
Engineer District (MED) acquired the 21.7-acre tract of land now known as
SLAPS to store residues from uranium processing at the Mallinckrodt
facility in St. Louis.
The uranium processing,
conducted under a contract with MED/AEC (Atomic Energy Commission),
continued through 1957; the resulting radioactive residues accumulated at
SLAPS. These materials included pitchblende raffinate residues,
radium-bearing residues, barium sulfate cake, Colorado raffinate residues, and
contaminated scrap. Most of the residues were stored in bulk on open
ground. Some contaminated materials and scrap iron were buried at the
western end and in other parts of the property. To limit direct radiation
exposure of the public, the property was fenced to prevent casual entry.
In 1966 and 1967, most of
the stored residues were sold and removed from SLAPS. Onsite structures
were razed, buried on the property, and covered with 1 to 3 feet of clean
fill material. Although these activities reduced the surface dose rate to
acceptable levels, buried deposits of uranium-238, radium-226, and
thorium-230 remained on the property.
In 1973, the tract was
transferred from AEC to the City of St.
Louis by quitclaim deed. The 1984 Energy and
Water Development Appropriations Act (Public Law 98-3060) authorized the
DOE to reacquire the property from the city for use as a permanent
disposal site for the wastes already on the property, contaminated soil
in the surrounding ditches, and the waste from the nearby Hazelwood
Interim Storage Site (HISS).
From 1976 through 1978, Oak
Ridge National Lab (ORNL) conducted a radiological investigation of
SLAPS. This survey indicated elevated concentrations of uranium-238 and
radium-226 in drainage ditches north and south of McDonnell Boulevard. In 1981, the
drainage ditches were designated for remedial action under FUSRAP. In
October 1989, the EPA placed SLAPS on the National Priorities List (NPL),
thus requiring the cleanup to proceed under the guidelines of the Comprehensive
Environmental Response, Compensation and Liability Act (CERCLA).
In 1990, the St. Louis Board
of Aldermen adopted a plan to transfer the SLAPS property to DOE. DOE had
previously stated that the property would be used as a storage site for
contaminated soil from the cleanup of the St. Louis Sites. After the site
was placed on the NPL, DOE worked closely with EPA to determine how the
site would be cleaned up and where the contaminated soil would be stored.
In July 1990, DOE and EPA signed an agreement that established an
environmental review process and schedule for the remediation of SLAPS,
SLDS, and the Latty Avenue
properties. The process required DOE to evaluate alternatives for waste
management, one of which was storage at SLAPS. DOE declined acceptance of
the SLAPS property from the city until the environmental review process
was conducted.
Until 1997, DOE was the lead
agency responsible for the cleanup of SLAPS. In October 1997, Congress
through the Energy and Water Development Appropriations Act transferred
FUSRAP from the DOE to the U.S. Army Corps of Engineers (USACE). Since
that transition was effected, SLAPS has fallen under the responsibility
of the St. Louis District USACE.
Site
Progress
The U.S. Army Corps of
Engineers (USACE) has accomplished a great deal at the St. Louis Airport
Site (SLAPS) since the October 1997 transition of the program. Our
primary goal for SLAPS is to restrict the release of contaminated
materials and minimize their potential impact on human health, wildlife,
and the environment. To accomplish this goal, the USACE invited the
public to participate in setting the interim cleanup standards for the
site.
In 1997 an EE/CA proposing
cleanup of the West End of SLAPS was prepared by the Department of
Energy. Upon receipt of public acceptance of one of the removal action
alternatives, excavation activities began in September 1997 immediately
east of the gabion wall on the bank of Coldwater Creek. In October 1997
FUSRAP was transferred from DOE to USACE under the Energy and Water
Appropriations Act. Work progressed under USACE. Completion of this
removal action resulted in the disposal of 5,100 cubic yards of
contaminated material, which were subsequently shipped by rail in covered
gondola cars to an out-of-state licensed facility.
Cleanup activities continue
to follow CERCLA guidelines and incorporate NCP values. In March 1998
USACE prepared an EE/CA proposing measures to stabilize SLAPS and the
adjacent Ballfields until a comprehensive cleanup could be achieved. The
proposal received public approval, and plans were developed to allow work
to proceed.
Since the approval of the
1998 EE/CA, the following removal actions and environmental documentation
have been performed:
1. In 1998 USACE completed
construction of a 1,200-foot rail spur on SLAPS. A sedimentation basin
was also constructed on the west end of the site to control surface water
and off-site migration of contamination. In all, 10,135 cubic yards of
material were removed from the site for disposal in a licensed,
out-of-state facility.
2. Since 1998, 55,745 cubic
yards of material have been removed from the SLAPS East
End and East End Right-of-Way, encompassing the eastern
third of the site as well as the drainage ditch along McDonnell Boulevard. Although most
of the work on this area is complete, removal actions for the western
portion of the McDonnell
Boulevard drainage ditch remain to be
completed. Contaminated materials excavated to date have been transported
by covered gondola cars for disposal at an out-of-state licensed or
properly permitted facility.
3. Between March and October
2000, 39,995 cubic yards of material were removed from the Radium Pits.
Contaminated materials were transported by covered gondola cars for
disposal at an out-of-state licensed or properly permitted facility.
4. Between December 2001 and
May 2003, 79,000 cubic yards of material were removed from the Phase 1
area. Contaminated materials were transported by covered gondola cars for
disposal at an out-of-state licensed or properly permitted facility.
5. Since December 2002
approximately 24,300 cubic yards of material have been removed from
Phases 2 and 3. Contaminated materials excavated to date have been transported
by covered gondola cars for disposal at an out-of-state licensed or
properly permitted facility.
In accordance with CERCLA
requirements, a five-year review was initiated in January 2003 to ensure
that human health and the environment are being protected by the response
action being implemented. A team led by USACE and including
representatives from EPA and MDNR documented conditions at each site and
the surrounding area. In addition, members of the community were
contacted for their views about the cleanup process to date. USACE
released the draft report documenting the findings of the review in
September 2003.
In early 2000 USACE collected samples from
SLAPS, SLAPS VPs, HISS/Latty Avenue VPs, Futura, and Coldwater Creek.
Analysis of samples of soil and sediment at these sites confirmed the
presence of MED/AEC contamination on these sites. USACE developed cleanup alternatives to
address all of these sites under the same decision document. Cleanup
alternatives were presented to the public for review in the Feasibility
Study (FS) and Proposed Plan (PP) for the
north St. Louis County sites, which
were released in May 2003. Comments on the documents were accepted
through July 14, 2003. The final cleanup remedy is outlined in the
Record of Decision for the North St. Louis
County, Missouri Sites (SLAPS,
HISS/Latty Avenue, and SLAPS VPs).
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