The owner of the West Lake Landfill Superfund site in Bridgeton, Mo., is moving forward with installation of an isolation barrier intended to ensure that a nearby underground fire doesn’t come 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 EPA 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 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.
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, 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.