Source: http://www.stltoday.com, October 20, 2016
By: Bryce Gray

A letter from Missouri Department of Natural Resource officials has outlined numerous sources of groundwater contamination at Bridgeton Landfill and has requested that the site’s operator, Republic Services, pursue “corrective measures” to mitigate the impact of an underground fire smoldering within the landfill, while continuing environmental monitoring efforts.

Based on sampling conducted at the site, the state found “statistically significant evidence of contamination” affecting groundwater at and around the landfill.

The letter dated Oct. 14 was addressed to Erin Fanning, a lead environmental manager of the site, and identified contaminants such as dichloroethane, benzene, toluene, and xylenes, that exceed allowable safety thresholds.

The samples were collected by environmental consulting firms on behalf of Republic Services and sent to the Department of Natural Resource’s Solid Waste Management Program for analysis.

The site has been under increased public scrutiny ever since the 2010 detection of the underground fire within the landfill — referred to as a “subsurface smoldering event” by landfill officials, since the reaction is taking place in the absence of oxygen.

The “smoldering event” not only exacerbated odor issues at the landfill, but more notably sparked concerns about its proximity to radioactive waste in the adjacent West Lake Landfill.

Republic Services has spent approximately $200 million in its ongoing efforts to fight the fire, which includes the installation of pipes that send cooling fluids through the landfill to control temperature.

The landfill’s operators say that odor concerns peaked in 2013 and 2014 but have since been curbed by mitigation efforts. The spread of the fire, they say, has also been slowed to a rate of about six inches per day and is confined to one of the parts of the landfill farthest away from the known radioactivity at West Lake.

Knocke said in a statement: “After years of intensive ground water monitoring, there has been no evidence of off-site, downgradient impacts attributable to the landfill. As important, federal regulators have been clear that no one will ever drink or use the groundwater at the site. It will never be a public water source. The landfill is in a managed state. With the cooling barrier in the neck area now fully operational, more than $200 million in new treatment and monitoring infrastructure, and the EPA nearing completion of its permanent remedy for West Lake, these test results are unlikely to affect any regulators’ plans. In addition, MDNR’s letter will not change the ongoing, comprehensive groundwater monitoring regime and liquids management processes at the site.”