The owner of the West Lake Landfill Superfund site in Bridgeton, Mo., is moving forward with installation of an isolation barrier intended to prevent a nearby underground fire from coming into contact with nuclear waste material.
The West Lake Landfill, which contains waste from the former uranium production facility at Mallinckrodt Chemical Works in St. Louis, is adjacent to the Bridgeton Landfill, where an underground fire has been burning since 2010. At the state’s request, owner Republic Services agreed to build a barrier separating the two landfills in 2013, but those plans stalled because the Environmental Protection Agency didn’t have a full grasp of the extent of radioactive contamination at the site. Last month, Missouri Attorney General Chris Koster denied Republic Services’ appeal against building a heat extraction barrier at the Bridgeton site, and the company has now reached a settlement agreement with EPA Region 7 that sets installation into motion.
Work will include installation of a heat extraction system in the “Neck” area between the North and South Quarry portions of the Bridgeton Landfill; temperature monitors; an ethylene vinyl alcohol cover over the North Quarry portion of the Bridgeton Landfill; and use of inert gas injection, among other measures.
“We expected the EPA to assume jurisdiction,” Republic Services spokesman Russ Knocke said in a statement this week. “We have been ready to put these protective measures in place for some time, and we remain committed to working with the EPA on the implementation of an isolation barrier.”
According to the EPA, the heat extraction system is designed to ensure waste temperatures in the Neck remain below levels that would indicate a subsurface reaction (or smoldering event) while also preventing the spread of a potential reaction from the South to the North Quarry. Inert gas injection, according to the EPA, isolates, contains, inhibits, and extinguishes independent subsurface reactions. The ethylene vinyl alcohol cover, which is an extension of an existing cover in the South Quarry, is meant to prevent oxygen intrusion and collection of landfill gases, reduce landfill odors, and prevent surface water infiltration.
The agreement dictates that Republic Services submit plans for the heat extraction system, inert gas injection, and environmental monitoring within 30 days of the settlement. Work plans for the ethylene vinyl alcohol cover are due within 60 days, and completion of that cover will be required within four months of the start of construction. The total cost of EPA oversight associated with the project is estimated at $728,000.
Environmentalist Ed Smith, with the Missouri Coalition for the Environment, said in an interview Monday that the process surrounding the isolation barrier is “just a delay in what needs to be done, and that’s the removal of the radioactive waste. We’ve wasted years now trying to figure out where this barrier is going to be located.”
EPA spokesman Ben Washburn said in an interview Tuesday that the agency expects to propose a final cleanup remedy at the West Lake site by the end of 2016. “We’re still on schedule to do that. We’re going through some data validation interpretation right now,” he said.
According to Smith, the EPA has not properly tested the North Quarry for material.
“The fact that the state of Missouri and the EPA are advancing these plans fairly rapidly in succession of one another probably means things aren’t so great at the landfill,” Smith said. “One of the things we have a hard time getting is a thorough update on the status of the fire from the state of Missouri or the EPA.”
Washburn said the distance from the most southern known portion of radiologically impacted material (RIM) to temperature monitoring probes in the Neck is about 700 feet.
“But what’s important to note given that distance is that there’s no indication that the subsurface reaction has reached up into the Neck or progressed past the Neck into the North Quarry,” he said. “The data (from a recent study, Phase I D) indicates that that reaction is still in the southern quarry of the landfill, but between the southernmost point of RIM to that temperature monitoring probe in the Neck is 700 feet. … The testing was designed to determine the extent of RIM, and we’ve completed that testing, and we feel pretty confident in the data.”
The U.S. Senate in February passed legislation that would transfer remediation authority of the site from EPA to the Army Corps of Engineers’ Formerly Utilized Sites Remedial Action Program, which residents and lawmakers have long requested. Members of the House have introduced companion legislation.
