The Maxey Flats Project is a former commercial facility utilized for the disposal of low-level radioactive waste.
The United States has been disposing of low-level nuclear waste in shallow land burial facilities since the early 1960s. A total of six commercial low-level radioactive waste disposal facilities have operated in the United States with only two remaining in operation today. One of the four that is no longer in operation is the Maxey Flats Disposal Facility, currently known as the Maxey Flats Project (MFP). The MFP is located in northeastern Kentucky on the southern border of Fleming County approximately nine miles northwest of the city of Morehead.
The MFP consists of the original 280 acres and approximately 550 acres of buffer zone area. The restricted area consists of approximately 60 acres of which more than 55 are covered with a geomembrane liner.
From 1963 to 1977, the commonwealth of Kentucky, under authorities granted by the U.S. government, licensed private operators to dispose of low-level radioactive wastes from military ships and facilities, hospitals, universities, corporations, etc., at the Maxey Flats Project. During commercial operation, an estimated 5 million cubic feet of material were disposed that contained approximately 242,000 kilograms of source material (consisting of uranium and thorium or ores containing them), 2.4 million curies of byproduct materials, and 431 kilograms of special nuclear material (plutonium and enriched uranium). To assure proper closure and management, the commonwealth of Kentucky has maintained the site since the time commercial operations were discontinued.
The commonwealth of Kentucky is obligated to control access, conduct environmental monitoring and provide site maintenance and monitoring. This is accomplished by a series of U.S. Environmental Protection Agency (EPA)-approved work plans. These work plans include:
- Interim Maintenance Plan (IMP)
The purpose of the IMP is to establish the initial procedures that may be used to conduct oversight of the MFP subsequent to Certification of Completion of the Initial Remedial Phase (IRP) by the EPA.
- Performance Standard Verification Plan (PSVP)
The PSVP provides a program for long-term monitoring that does not rely on data from a single collection event.
- Quality Assurance Project Plan (QAPP)
The QAPP provides the quality assurance measures that will be implemented in order to ensure the precision and accuracy of data. This data will be routinely assessed and reported for all environmental monitoring and measurement data.
- Health and Safety Plan (HASP)
The HASP’s objective is to provide for health and safety of the environment and workers, thus mitigating adverse or potential impacts on public health and safety.
- Operation and Maintenance Summary (O&M)
The O&M has been prepared to identify the O&M tasks the commonwealth of Kentucky should perform during the Interim Maintenance Period. The O&M also provides details for the activities needed to maintain elements of the IRP Remedial Action upon issuance of the Certificate of Completion.
· Commonwealth Monitoring and Maintenance
The commonwealth will also be obligated to periodically replace the impermeable cap and any other site structures that deteriorate over time. Upon verification that the ground surface has fully settled, an elaborate final cap will be constructed. Monitoring and maintenance will then continue into perpetuity.
The remedial investigation and feasibility study was conducted from March 1987 through September 1991 under an Administrative Order by Consent.
The record of decision was issued in September 1991. Meanwhile, between December 1988 and November 1989, EPA Emergency Response solidified 286,000 gallons of tanked leachate (radioactive contaminated trench water) because of significant leakage from the metal tanks; then from March 1991 to September 1992 EPA Emergency Response disposed of the solidified leachate blocks in an underground on-site trench and installed 30 acres of a temporary above-ground plastic, impermeable liner to prevent infiltration of rain into the waste trenches.
After lengthy negotiations lasting from June 1992 until June 1995, two consent decrees (one for the 50 de maximis parties and one for the 306 de minimis parties) arranged for cost allocation and for the performance of the remedial design (RD) and remedial action (RA). After the required public comment periods, the U.S. District Court activated the decrees in April 1996; the RD for the first of two major cleanup phases (1. Leachate removal and disposal and 2. Building demolition, on-site disposal, and other items) began immediately thereafter.
Construction of Phase I and Phase II of the reinforced concrete bunkers (for disposal of solidified radioactive leachate and other contaminated materials) has been completed. Approximately 900,000 gallons of leachate were removed from within the landfill since current dewatering operations began in September 1998. Landfill dewatering operations were discontinued during early fall 2000.
Construction of an interim cap to prevent water infiltration with a perimeter drainage system that includes the groundwater interceptor channel has been completed. To verify the drainage system does not negatively impact erosion rates, erosion monuments have been installed for monitoring the rate of erosion.
The completion of the Initial Remedial Phase was declared in October 2003 by EPA.
Remedial work completed at the Maxey Flats Waste Disposal Site has been under the guidance of the EPA Region IV headquartered in Atlanta, Ga., and has been completed in accordance with the consent decree signed in 1996. International Technology Corporation and Shaw Environmental Group performed the remedial construction.
Department of Energy's Legacy Management Web Site
US EPA Region IV Web Site on the Maxey Flats Project
Maxey Flats Project: An in-depth exploration of Kentucky's prominent Superfund site – PDF.
