St. Louis Downtown Site

 Home
 BEMR Contents
 U.S. Map

MISSOURI FUSRAP SITES

The Missouri Sites within the Formerly Utilized Sites Remedial Action Program (FUSRAP) are the St. Louis Downtown Site, Latty Avenue Properties, the St. Louis Airport Site, and the St. Louis Airport Site Vicinity Properties (see map). FUSRAP was established in 1974 under the provisions of the Atomic Energy Act to identify, investigate, and clean up or otherwise control previously decontaminated Manhattan Engineer District and Atomic Energy Commission sites where residual radioactive contamination exceeds current guidelines and other sites assigned to the U.S. Department of Energy by Congress.

FUSRAP encompasses 46 sites in 14 states and is funded through the Oak Ridge Operations Office. For a general discussion of FUSRAP and associated costs, see the overview of the program presented in the Tennessee section of this report. All costs for waste management activities, program management, and relevant landlord activities attributable to the Department of Energy are provided for within the scope of environmental restoration. No FUSRAP sites have either current or planned nuclear material and facility stabilization activity needs. Funding for all sites is 100 percent nondefense.

In addition to their geographical proximity, the St. Louis sites are linked by historic origin of contamination (uranium processing and recovery operations for the Manhattan Engineer District and Atomic Energy Commission at St. Louis Downtown Site during the 1940s and 1950s, with subsequent storage of residues at Latty Avenue Properties and the St. Louis Airport Site and migration of contaminants from processing and storage sites to vicinity properties). A Federal Facilities Agreement negotiated between the Department of Energy and the Environmental Protection Agency for the St. Louis sites was signed in June 1990. The agreement covers remedial action at all four sites and establishes responsibilities and interactions of the two agencies in the Department of Energy's remedial action activities and procedural and documentation requirements under the Comprehensive Environmental Response, Compensation, and Liability Act. The Department is preparing a Remedial Investigation/Feasibility Study-Environmental Impact Statement addressing all four St. Louis sites; the draft documents are currently under review. The Record of Decision documenting the final remedy for the sites as a group will be issued in 1998. Other documentation that addresses these sites collectively includes a remedial investigation report, a draft feasibility study, and a work plan and ancillary planning/scoping documents that include a field sampling plan, a quality assurance project plan, and a community relations plan.

Although the Department of Energy is the lead agency for remedial action at the St. Louis sites, the Department's plans and activities are subject to oversight by Environmental Protection Agency Region VII and are being coordinated with appropriate Missouri State agencies, including the Missouri Department of Natural Resources. The Department also provides for the participation of federal and state legislators, local and county officials, and the general public in the decisionmaking process regarding options for remedial action and waste disposal.

Future use of these sites and the final cost of their remediation depend on the Record of Decision that will document the remedial alternative selected for implementation. The scenario used for the Baseline Environmental Management Report cost estimate assumes implementation of the lowest-cost protective option for cleanup of these sites, which includes excavating all accessible soils and sediments contaminated above guidelines at the St. Louis Downtown Site and vicinity properties, St. Louis Airport Site, St. Louis Airport Site Vicinity Properties, the Latty Avenue Properties, and Coldwater Creek, and consolidating and capping of waste from all St. Louis sites at St. Louis Airport Site. A final cleanup strategy for the St. Louis FUSRAP sites will be determined after public review of the final Remedial Investigation/Feasibility Study-Environmental Impact Statement and the Record of Decision. The cost for cleanup at the St.Louis sites could range from $350 to 400 million for the "onsite disposal cell" remedial option to $950 to 1,000 million for the "complete excavation and offsite disposal" remedial option.

ST. LOUIS DOWNTOWN SITE

The St. Louis Downtown Site is an operating industrial facility that produces various chemical products. The site occupies nearly 18 hectares (45 acres) in an industrial area on the eastern border of the city, about 60 meters (200 feet) west of the Mississippi River.

FACILITY MISSION

Contamination at the St. Louis Downtown Site originated from industrial-scale processes to recover uranium from high-grade uranium ore from the Belgian Congo. From 1942 to 1957, Mallinckrodt Chemical Works conducted a variety of uranium processing and recovery operations for research, development, and production programs under contract to Manhattan Engineer District and the Atomic Energy Commission. By 1957, the company had processed more than 45,000 metric tons (50,000 tons) of natural uranium products at its facilities. Mallinckrodt, Inc. currently owns the site.

During closeout of operations in 1957, government­owned buildings were either dismantled or transferred to Mallinckrodt as part of a settlement. Of the 60 buildings involved in the operations within the Mallinckrodt facility, fewer than 20 remain, and Mallinckrodt has constructed a number of new buildings on site. The St. Louis Downtown site was one of the first sites designated for inclusion in FUSRAP. The Department's present objective at the site is to eliminate or reduce the potential for exposure to radioactive and chemical contaminants.

The primary contaminants at the site are uranium and thorium. Based on chemical characterization data, several metals (antimony, arsenic, beryllium, lead, nickel, and thallium) are also present at concentrations above background. The potential for contaminant transport is limited. Impervious materials (e.g., buildings) cover most contaminated soils; however, in areas where there is no soil cover, contaminants may be released to air as particulates or as gaseous emissions (e.g., radon gas). Contaminants on building surfaces may also be released to air. Soil contaminants could reach ground water through infiltration of surface water, although this release mechanism is currently limited because surface water cannot penetrate the soil cover. In areas with no soil cover, contaminant migration via surface runoff and erosion is also possible.

Potential exposure routes are inhalation and ingestion of exposed contaminants. Because the site is currently an operating industrial plant, potential receptors could include plant employees and recreational users of the Mississippi River and the contaminated city property adjacent to the plant.

FUTURE USE

Metropolitan St. Louis is a diverse hub of transportation, commerce, and industry. Land use within 1.6 kilometers (1 mile) of the St. Louis Downtown Site includes a variety of public, agricultural, industrial, commercial, and residential activities.

Future use after site cleanup has not yet been determined, but this report assumes that it will continue to be Industrial/Commercial. Future use of the St. Louis Downtown site depends on the Record of Decision that will document the remedial action alternative selected for implementation. The Record of Decision will involve input from the Environmental Protection Agency, state and local agencies, and stakeholders. The Department expects environmental restoration activities to be completed within the next one to two decades.

ENVIRONMENTAL RESTORATION

Environmental restoration of the St. Louis Downtown Site will include disposition of approximately 188,000 cubic meters (246,000 cubic yards) of contaminated waste and will require approximately 15 years. Cleanup will be conducted under the Comprehensive Environmental Response, Compensation, and Liability Act protocol for remediation of low-level radioactive contamination at FUSRAP sites and the Atomic Energy Act of 1954, as amended. As required by the Comprehensive Environmental Response, Compensation, and Liability Act, other federal and state laws are incorporated in the development of remediation goals for the site. Key regulators include Environmental Protection Agency Region VII, the Missouri Department of Natural Resources, and local governments, as appropriate. Final cleanup alternatives will be developed and evaluated as required under the Comprehensive Environmental Response, Compensation, and Liability Act and the National Environmental Policy Act. Interim removal actions will be initiated if necessary, and environmental impacts will be documented in an engineering evaluation/cost analysis report and a categorical exclusion report as required under the National Environmental Policy Act.

ASSESSMENT

Radiological and chemical characterization and surveys conducted at the St. Louis Downtown Site from 1987 through 1990 included walkover gamma scans; collection and analysis of systematic and biased soil samples; collection and analysis of ground-water samples for radioactive and chemical constituents; collection of surface soil samples and analysis for uranium, radium, thorium, and various chemical parameters; downhole gamma logging; and radiological surveys of building surfaces. Because the site is an operating plant, final characterization in the buildings to delineate the final boundaries of the contaminated areas will be performed immediately before remedial action begins.

Assessments of contamination are documented as required by the Comprehensive Environmental Response, Compensation, and Liability Act and the National Environmental Policy Act regulatory process. In addition to the Remedial Investigation/Feasibility Study­Environmental Impact Statement and Record of Decision for the St. Louis sites, environmental documentation includes a site designation; planning documents (preliminary engineering evaluation of remedial action alternatives, field sampling plan, characterization plan, quality assurance plan, health and safety plan, and community relations plan); design engineering reports and work plans; site surveillance and maintenance reports for construction and closure and post­closure plans; and final reports (post­remedial action report, verification report, and certification docket). The environmental surveillance program, including monitoring of air and external gamma radiation, will be maintained throughout remedial action and any necessary interim removal actions. Since 1984, environmental surveillance data have consistently indicated that the St. Louis Downtown Site is making no significant contribution to offsite radioactivity.

Surveys of buildings revealed that most residual surface contamination was on walls and floors; the highest exposure readings were near cabinets formerly used to store radiation sources. Beta­gamma measurements were above guidelines at several locations within buildings. Surveys of the roofs of several buildings also detected residual radioactive contamination that exceeds guidelines.

Building surveys showed that uranium­238 is the primary radioactive contaminant in 15 of the 17 onsite buildings found to contain residual radioactivity above current guidelines. Radium­226 is the primary contaminant in Buildings K1E (Plant 1) and 101 (Plant 6). Both buildings, as well as Building 25 (Plant 1), also had radon concentrations exceeding current guidelines for habitable structures. Building K1E, which is used for storage, also showed widespread beta­gamma activity above guidelines for uranium on walls and roofs. Although beta-gamma measurements were above current guidelines in some buildings, little removable contamination was found, and average gamma exposure rates did not exceed guidelines. Several additional buildings had roof contamination [Building 116B (Plant 6) and Buildings 704­708 (Plant 7)]. Elevated beta­gamma activity was detected on most interior surfaces in Building 116 (Plant 6); Building 100 (Plant 6E); and Buildings 700, 704-707, and 708 (Plant 7). Surveys found contamination primarily on walls and floors in Building 25 (Plant 1); Buildings 50, 51, 51A, 52, and 52A (Plant 2); and Building 117 (Plant 6).

The primary soil contaminants that exceed guidelines at the St. Louis Downtown Site are radium­226, uranium­238, and thorium­230. In general, radionuclide concentrations exceeding current guidelines for soil were found near or beneath buildings, as expected, based on previous radiological surveys and site operations. Two exceptions were Plant 5 and the municipal vicinity property, which were not associated with Manhattan Engineer District and Atomic Energy Commission activities but exhibited radioactive contamination above guidelines. Thorium-230 was the primary contaminant at Plant 5; the maximum depth of contamination was 3 meters (10 feet). At the city properties, the primary contaminants were uranium­238, radium­226, and thorium­230, which were distributed across the entire area; the maximum depth of contamination was 12.8 meters (42 feet).

Most elevated radioactivity in soil at Plant 1 was found near Building K1E. Radium­226 was the primary contaminant, and contamination was found to depths greater than 3 meters (10 feet). At Plant 2, most of the radioactivity exceeding guidelines was found near or beneath Buildings 51, 51A, 52, and 52A. The primary contaminants were uranium­238 and thorium­230; contamination was detected to depths greater than 7 meters (23 feet). Soil at Plants 6, 7, and 10 exceeded guidelines across the entire plant area. The primary contaminant at Plant 6 was uranium­238; the maximum depth of contamination was 6 meters (20 feet). At Plant 7, primary contaminants were uranium­238, radium­226, thorium­232, and thorium­230; contamination extended to depths greater than 6 meters (20 feet). At Plant 10, uranium­238 and thorium­230 were the primary contaminants, and the maximum depth of contamination was 2.1 meters (7 feet). Soil at Plant 6E showed little residual radioactivity.

Chemical characterization identified several metals in site soils; metals exceeding maximum expected background concentrations with the greatest frequency in discrete samples were thallium, selenium, cadmium, lead, and zinc. Samples from isolated onsite areas also failed the hazardous waste criterion for Extraction Procedure toxicity­lead.

Sediment from 35 of 84 manholes surveyed at the St. Louis Downtown Site showed residual radioactivity exceeding guidelines; therefore, portions of the stormwater sewer and sanitary sewers will require remedial action. Radionuclide concentrations in ground water were all near background except for elevated uranium levels in one well near Building K1E (Plant 1), which suggested that uranium in this area may be leaching into the ground water. Ground-water monitoring for chemical indicator parameters detected 16 metals and 10 organic compounds; however, results of volatile organics analysis of soil samples generally indicated low concentrations, and metals detected most frequently in soil were not found at elevated levels in ground water.

REMEDIAL ACTION

One area of the site (Plant 10) is currently undergoing an interim removal action; appropriate Comprehensive Environmental Response, Compensation, and Liability Act and National Environmental Policy Act documentation (including an Engineering Evaluation/Cost Analysis report and a categorical exclusion report) was prepared and submitted for public review before the removal action began. In September 1995, approximately 9,200 cubic meters (12,000 cubic yards) of contaminated material were shipped by rail car to Envirocare of Utah for disposal.

The Department of Energy is currently engaged in a comprehensive environmental review process for the St. Louis Downtown Site. It selected Building 116 as a temporary storage facility for contaminated soils and rubble generated during Mallinckrodt plant expansion and maintenance activities. The Department will select a final cleanup strategy after public review of the final Remedial Investigation/Feasibility Study­Environmental Impact Statement and the Record of Decision.

The scenario used for the Baseline Environmental Management Report cost estimate for the St. Louis sites assumes excavation of accessible soils from the St. Louis Downtown Site, vicinity properties in the downtown and airport areas, the Latty Avenue Properties, and Coldwater Creek sediments and consolidation and capping at the St. Louis Airport Site. The cost estimate assumes a total waste volume of 188,000 cubic meters (246,000 cubic yards) of low-level waste at the St. Louis Downtown Site to be transferred to the St. Louis Airport site and includes decontamination of 17 buildings at this site.

FUNDING ESTIMATE

The following table presents estimated funding information for the St. Louis Downtown Site.