Lenexa, Kan. -- A March 2013 aerial survey of the West Lake Landfill at Bridgeton, Mo., has determined that radiologically-contaminated wastes buried there in the 1970s remain contained within secure, fenced areas of the Superfund site, and do not pose public health risks, according to a report issued today by EPA Region 7.
Region 7 requested the survey, which was conducted March 8 by EPA’s Airborne Spectral Photometric Environmental Collection Technology (ASPECT) Program, to gather data to help inform future decisions about the Superfund site. An ASPECT airplane with a pilot, co-pilot, technician and scientific equipment on board flew multiple low-altitude passes over the site and adjacent residential and industrial properties to identify surface areas that emit gamma radiation.
“The results of the ASPECT survey are consistent with previous studies that indicate the site’s radiological wastes remain contained inside Operable Unit 1,” EPA Regional Administrator Karl Brooks said. “The site is securely fenced and clearly marked with warning signs. Under these conditions, this material poses no health risks to the public. A person would have to illegally trespass onto the site to be exposed to elevated levels of radiation.”
Previous radiation screening surveys of the site, performed in 1994 and 1995, used ground-based detection equipment. Due to the overgrowth of small trees and heavy vegetation on significant portions of the site since those surveys, Region 7 chose instead to conduct an aerial survey using the ASPECT airplane.
The ASPECT survey is part of EPA’s work to update information collected through prior investigations. The 200-acre site encompasses several inactive areas of closed sanitary and demolition fills, including two areas where leached barium sulfate waste from World War II-era nuclear weapons manufacturing was buried in the 1970s; and the separate Bridgeton Sanitary Landfill.
EPA added the West Lake Landfill Site to the Superfund National Priorities List (NPL) in 1990. In 2008, the Agency signed a Record of Decision (ROD) which selected a remedy of containing the radiologically-contaminated material in place, constructing an engineered protective earthen cap for the landfill, installing and operating a system of groundwater monitoring wells around the site’s perimeter, institutional (or land use) controls, and long-term maintenance of the remedy.
After the ROD was signed, EPA continued to receive public comments about the selected remedy. In response to those comments, in 2010 EPA tasked the four Potentially Responsible Parties (PRPs) – the U.S. Department of Energy, Cotter Corporation, Bridgeton Landfill LLC and Rock Road Industries LLC – to conduct a Supplemental Feasibility Study (SFS). This study further evaluated EPA’s selected remedy, and alternatives involving excavation of the radiologically-contaminated landfill material and disposal of it at a permitted off-site facility or in a new, secured on-site disposal cell.
Because the estimated costs for each alternative remedy outlined by the SFS exceeded a $25 million threshold, Region 7 was required to consult with EPA’s National Remedy Review Board (NRRB). In 2012, the NRRB suggested additional groundwater sampling, a more detailed study of a partial excavation remedy, and a more detailed analysis of potential treatment technologies for use on the radiologically-contaminated landfill material. EPA Region 7 has tasked the PRPs to perform the additional sampling and analyses.
Region 7 requested the March 2013 ASPECT survey to gather additional data as it reconsiders the final remedy selected for the site. EPA also tasked the PRPs to conduct four seasonal rounds of groundwater sampling. The first round of groundwater sampling was made public in January. The second round was completed in April, and the results from that sampling analysis are currently being reviewed. The third and fourth rounds of groundwater sampling are expected to be completed by the end of 2013.
Region 7 will hold a public meeting next month to further discuss the results of the ASPECT survey, the second round of groundwater sampling, and plans for further investigation of West Lake Landfill. The meeting will be held from 6:30 p.m. to 8:30 p.m. on Tuesday, June 25, in the auditorium at Pattonville High School, 2497 Creve Coeur Road, Maryland Heights, Mo., 63043.
Full text of the ASPECT survey report and results of previous groundwater sampling at the site are available online.