STATEMENT OF WORK
Independent Technical Review for Operable Unit 1 at the West Lake Landfill Site
1. BACKGROUND INFORMATION
The West Lake Landfill Site is on a parcel of approximately 200 acres located in
the northwestern portion of the St. Louis metropolitan area. It is situated approximately
one mile north of the intersection of Interstate 70 and Interstate 270 within the limits of
the city of Bridgeton in northwestern St. Louis County. The Missouri River lies about 1.5
miles to the north and west of the Site.
The Site consists of two radiologically contaminated landfill cells comprising
Operable Unit 1 (OU-1) and the Bridgeton Sanitary Landfill (Former Active Sanitary
Landfill) and several inactive areas with sanitary and demolition fill that have been
closed comprising OU-2. Land use at the site and the surrounding areas in Earth City is
Other facilities which are not subject to this response action are located on the
200-acre parcel including concrete and asphalt batch plants, a solid waste transfer station,
and an automobile repair shop.
The Site was used agriculturally until a limestone quarrying and crushing
operation began in 1939. The quarrying operation continued until 1988 and resulted in
two quarry pits. Beginning in the early 1950s, portions of the quarried areas and adjacent
areas were used for landfilling municipal solid waste (MSW), industrial solid wastes, and
construction/demolition debris. These operations were not subject to state permitting
because they occurred prior to the formation of the Missouri Department of Natural
Resources (MDNR) in 1974. Two landfill areas were radiologically contaminated in
1973 when they received soil mixed with leached barium sulfate residues.
The barium sulfate residues, containing traces of uranium, thorium, and their longlived
daughter products, were some of the uranium ore processing residues initially
stored by the Atomic Energy Commission (AEC) on a 21.7 acre tract ofland in a then
undeveloped area of north St. Louis County, now known as the St. Louis Airport Site
(SLAPS), which is part of the St. Louis Formerly Utilized Sites Remedial Action
Program managed by the U.S. Army Corps of Engineers (USACE)
In 1966, residues associated with the production and refining of uranium
materials were purchased by Continental Mining and Milling Company of Chicago,
removed from the SLAPS, and placed in storage at the Hazelwood Interim Storage Site
(HISS) on Latty Avenue under an AEC license. In 1967, Commercial Discount
Corporation, which obtained possession of the HISS property and residuals, began drying
residue and shipping them to Cotter Corporation in Canon City, Colorado (DOE 1987).
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In 1969, residues remaining at the HISS were sold to Cotter Corporation in Canon City.
In 1970, Cotter Corporation dried and shipped some of the remaining residues from the
HISS to Canon City (DOE 1994). In December 1970, an estimated 10,000 ton of
Colorado raffinate and 8,700 tons ofleached barium sulfate remained at the Latty
Reportedly, 8,700 tons of leached barium sulfate residues were mixed with
approximately 39,000 tons of soil and then transported to the West Lake site in 1973.
According to the landfill operator, the soil was used as cover for municipal refuse in
routine landfill operations.
The geology of the landfill area consists of Paleozoic-age sedimentary rocks
overlying Pre-Cambrian-age igneous and metamorphic rocks. The Paleozoic bedrock is
overlain by unconsolidated alluvial and loess deposits of recent (Holocene) age. Alluvial
deposits of varying thickness are present beneath Areas 1 and 2. The landfill debris varies
in thickness from 5 to 56 feet in Areas 1 and 2, with an average thickness of
approximately 30 feet in Area 2. The underlying alluvium increases in thickness from
east to west beneath Area 1. The alluvial thickness beneath the southeastern portion of
Area 1 is less than 5 feet (bottom elevation of 420 ft/amsl) while the thickness along the
northwestern edge of Area 1 is approximately 80 feet (bottom elevation of 370 ft/amsl).
The thickness of the alluvial deposits beneath Area 2 is fairly uniform at approximately
100 feet (bottom elevations of 335 ft/amsl).
A subsurface oxidation event (SSE) is ongoing in the South Quarry Landfill
portion of the Bridgeton Sanitary Landfill. The South Quarry cell is connected to the
North Quarry cell which is adjacent to Operable Unit 1, Area 1, one of the locations on
site that received the radiologically contaminated soils in 1973. Pursuant to an order
from the Missouri Attorney General, the site owner is required to install a subsurface
barrier between the North Quarry cell and OU-1 Area 1 to prevent the SSE from
migrating into the radiologically contaminated materials.
As a follow-up to EPA R7 consultation with EPA’s National Remedy Review
Board (NRRB) in February 2012, the following evaluations are being conducted to assess
the Remedial Alternatives for OU-1: 1) partial excavation evaluation; 2) alternative
landfill cap designs; 3) evaluation on the use of waste treatment technologies, including
apatite; 4) recalculation of RIM volumes for a full excavation scenario; 5) groundwater
fate and transport modeling; and 6) recalculation of discount rate. These evaluations will
be contained in a forthcoming Supplemental Feasibility Study (SSFS) Amendment or
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II. OBJECTIVE AND SCOPE
This will be an interagency agreement. The EPA is requesting assistance from
the US Army Corps of Engineers (US ACE) to conduct an Independent Technical Review
(ITR) of specific documents associated with Operable Unit-1 at the West Lake Landfill
and being developed in response to National Remedy Review Board (NRRB) comments.
The technical support may consist of performance of specific tasks which USEP A
contractors have neither the expertise or cannot provide at reasonable cost to EPA.
III. WORK ASSIGNMENT TASKS
USACE shall furnish personnel and services required to conduct an ITR of
reports prepared by the Responsible Parties in response to the recommended NRRB
Tasks included in this scope are:
1. Project Planning and Support
2. Independent Technical Reviews
3. Community Relations Support
TASKl PROJECT PLANNING AND SUPPORT
This task includes work efforts related to project initiation, management, and
support. Activities required under this task include the following, as applicable:
1.1 US ACE shall participate in a scoping meeting with EPA to discuss the work
1.2 USACE shall provide proposed level of effort and costs for the support activities
to be performed. Based on EPA’s review of the scope, level of effort and cost
estimate, USACE may be called upon to participate in negotiations with EPA on
the proposed level of effort and to revise the level of effort as a result of these
1.3 The USACE shall perform site-specific project management including:
1.3 .1 Establishment and maintenance of necessary work assignment files,
schedules, and project documentation
1.3.2 Provide monthly reporting and invoices. These documents shall contain
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narrative of specific task and subtask activities sufficient enough for the
EPA Remedial Project Manager (RPM) to evaluate the work assignment
1.3.3 Monitor costs and performance
1.3.4 Coordinate staffing and other support activities to perform the work
assignment tasks in accordance with the Statement of Work (SOW)
including USACE subcontractors, if utilized.
1.3.5 Attend necessary work assignment meetings
1.3 The USACE shall accommodate any external audit or review mechanism that
EPA may require. Level of effort for this work will be determined at a later date
and this IA will be amended to include this task and associated cost.
TASK2 INDEPENDENT TECHNICAL REVIEWS
This task includes the work required to conduct the ITR and documents the
2.1 US ACE shall coordinate and prepare a review plan and assist EPA in preparing
the reviewer’s charge statement.
2.2 US ACE shall perform an ITR of reports prepared by the Responsible Parties
(RPs) in response to the NRRB consultation with EPA on the Supplemental
Feasibility Study dated December 28, 2011. The purpose of the ITR is to
provide an independent assessment of the RP’ s work products to ensure the
scientific and technical components have been applied in a sound manner to meet
established regulatory requirements. The ITR will be conducted by qualified
individuals who are independent of those who performed the work, and who are
collectively equivalent in technical expertise (i.e., peers) to those who prepared
The reports prepared in response to the NRBB recommendations will include:
2.2.1 Up to four ITR reports to address the following:
• The RP’ s evaluation of a partial excavation alternative;
• The RP’s recalculation of RIM volumes to address alternate excavation
• The RP’ s evaluation of up to three alternative landfill cap designs;
• The RP’ s evaluation on the use of up to five waste treatment technologies,
including apatite and soil sorting;
• The RP’s results of groundwater fate and transport modeling; and
• The RP’ s recalculation of all alternatives using a 7% discount rate.
2.2.2. A Supplemental Feasibility Study Addendum or equivalent document.
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2.2.3 A Revised Proposed Plan, if required. If a Revised Proposed Plan is
required, the level of effort for the ITR will be determined at a later date and this
IA will be amended to include this task and associated cost.
2.2.4 An Amended ROD, if required. If a Revised ROD is required, the level of
effort for the ITR will be determined at a later date and this IA will be amended
to include this task and associated cost.
2.3 USACE ITR team will review historical documents for familiarity and
understanding of the site. Historical documents will not be the subject of the
ITR. Historical documents to be reviewed include, but may not be limited to the
• OUI Site Characterization Summary Report
• OUI Remedial Investigation Report
• OUI Baseline Risk Assessment
• QUI Feasibility Study
• OUI Supplemental Feasibility Study
• OUI Record of Decision
• EPA Radiological and Infrared Survey Report (ASPECT) (May 20I3)
• MDNR Radiological Survey Report (May 20 I3)
• Radiation Management Corporation Radiological Survey (I982)
• NRC Radioactive Material in West Lake Landfill (I988)
2.4 US ACE shall prepare an ITR report for each of the documents reviewed. The
letter report will contain USACE’s technical evaluation and, to the extent
practicable, shall be written in terms understood by the general public. The letter
report will be submitted to EPA as a “final” product. The number of days
allotted for completion of the ITR will be jointly determined and agreed upon by
EPA and USACE based upon the size and nature of the document to be
reviewed, but shall be no less than 45 calendar days for any review.
2.5 The USACE ITR will focus exclusively on the scientific and technical aspects of
the documents and whether the scientific and technical components have been
applied in a sound manner to meet established regulatory requirements. It will
not address grammatical, editorial, or formatting aspects of the document.
2.6 The US ACE ITR team shall participate in one technical meeting with EPA and
the RPs for each of the documents reviewed. The purpose of these meetings will
be to provide clarification on any comments. These meetings will be conducted
in the St. Louis area. If not able to be accomplished via an in-person meeting,
the meeting shall be accomplished by phone and internet (Web Meeting).
2. 7 EPA shall furnish US ACE with the following:
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2.7.1 Background documents, data, and other information necessary to ensure
the ITR’ s completeness;
2.7.2 Notification, at least 30 days in advance, of submittal of a document for
2.7.3 A tentative schedule identifying anticipated document submittal dates,
review times, and meetings.
TASK 3 COMMUNITY RELATIONS SUPPORT
This task includes efforts related to community relations support to EPA.
Activities required under this task include the following:
3.1 Upon issuance of this IA, USACE shall attend two community meetings to inform
the public ofUSACE’s support to EPA under this IA and answer questions. For
the initial public meeting after IA release, USACE will prepare a Power Point
presentation or other visual aids, as required to communicate the ITR process to
the public. For the second public meeting after the IA release, USACE shall
attend to answer any remaining public questions regarding the IA scope.
3.2 Upon completion of the review of each document, US ACE staff shall attend a
community meeting and present a description of the work accomplished by
US ACE and the findings of the ITR. The presentation will be provided via Power
Point, or via other means, if required. An electronic file of the Power Point
presentation shall be furnished to EPA at the meeting. USACE shall furnish 50
paper copies of the PowerPoint presentation for distribution to the public.
3.3 USACE staff shall be available to participate in pre- and post-meeting public
availability sessions for the meetings at which the USACE reviews are presented.
USACE shall provide necessary public availability session displays and
information packets (up to 50 handouts of Power Point presentation).
3.4 EPA, as lead agency, shall be the central point of contact for all project
stakeholders. If requested by EPA, US ACE shall provide written responses to
written questions received by EPA from the community regarding USACE’s
scope of work for the ITR effort.
TASK4 WORK ASSIGNMENT CLOSE-OUT
This task includes efforts related to work assignment close-out. Activities
required under this task include the following:
4.1 Upon notification by EPA, the USACE shall begin all internal procedures
necessary to close out the work assignment including any file duplication,
distribution, storage, or archiving per the contract requirements.
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4.2 The USACE shall return documents identified to EPA or other document
repositories as directed.
IV. WORK ASSIGNMENT PERIOD OF PERFORMANCE
August 1, 2014 to December 30, 2016
V. STATUTORY AUTHORITY
The statutory authority for entering into this IA is Section 105(a)(4) of the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) of 1980 (42 U.S.C. 9601 et seq., Public Law 96-510, December 11,
1980), as amended by the Superfund Amendments and Reauthorization Act
(SARA) of 1986 (Public Law 99-499, October 17, 1986), and Executive Order
VI. SCHEDULE OF DELIVERABLES/MILESTONES
1.3.2 Monthly Reports/Invoices
2.2 ITR Reports
VII. EPA CONTACTS
Project Manager Dan Gravatt
Project Officer Ina Square
Per agreed upon schedule
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