West Lake Update April 28, 2016 ¦** EPA Reaches Agreement with Bridgton Landnll for Installation of Components of Isolation Bar- rier System EPA Region 7 has finalized an Administrative Settlement Agreement and Order on Consent (Settlement) requiring Bridgeton Landfill, LLC to start work on several critical components of the isolation barrier system at the West Lake Landfill Superfund Site. These actions will be implemented in the North Quarry portion of the Bridgeton Landfill as a Time Critical Removal Action to prevent the subsurface reaction in the southern portion of the Bridgeton Landfill from potentially reaching Operable Unit 1. In December 2015, EPA announced its deci- sion to proceed with construction of an isolation barrier system. The Enforcement Action Memo- randum that accompanies the Settlement outlines important steps in the implementation of that decision. These actions include the installation of a Heat Extraction System (HES) within the "Neck" area between the North and South Quarry por- tions of the Bridgeton Landfill, use of inert gas injection, installation of an ethylene vinyl alcohol (EVOH) cover over the North Quarry portion of the Bridgeton Landfill, installation or additional temperature monitoring probes (TMPs), and other environmental monitoring. EPA is working in close coordination with the Missouri Department of Natural Resources, which remains the lead agency for the Bridgeton Landfill or Operable Unit 2 of tne West Lake Landfill Site. The Settlement will initiate needed actions in the North Quarry while the state continues its efforts to require Bridgeton Landfill to address the ongo- ing subsurface reaction in the South Quarry. The HES is designed to ensure waste tempera- tures in the Neck area remain below levels that could indicate the presence of a subsurface reac- tion and prevent tne potential spread of the reac- tion from the South to the North Quarry. Inert Gas Injection is designed as a rapid deploy- ment measure to isolate, contain, and inhibit and/ or extinguish any independent subsurface reaction that may occur in the Neck area or in the North Quarry. The Settlement requires Bridgeton Land- fill to maintain the materials necessary for inert gas injection on site, so as to facilitate implementa- tion within seven days if certain triggers are met. Bridgeton Landfill will be required to place an EVOH cover over the North Quarry. This cover will be an extension of the existing EVOH cover in the South Quarry. The EVOH cover will assist in prevention of oxygen intrusion, collection of landfill gasses, reduc- tion or odors emanating from the landfill, and prevent surface water infiltration. The Settlement further requires Bridgeton Landfill to install additional North Quarry Subsurface TMPs. The TMPs will monitor landfill temperatures that could be a Erecursor to, or indicative of, a subsurface reaction in the forth Quarry. Measurement of landfill temperatures and landfill gas composition will be used to assess the perfor- mance of the HES. The Settlement also requires the installation of two sulfur dioxide (S02) air monitors for a period of one year. These monitors will be operational within 30 days of EPA's approval of the work plan. The location and type of monitor will be determined after consultation with, and approval by, EPA and MDNR. Work plans for the HES, Inert Gas Injection, and envi- ronmental monitoring will be submitted within 30 days of the Settlement. The work plan for the EVOH cover will be submitted within 60 days. The Settlement further requires completion of the HES within four months of the con- struction start date. The protection of human health and the environment remains EPA's top priority at the West Lake Landfill Superfund site, ana this Settlement demonstrates EPA's commitment to protecting the community and on-Site workers. EPA continues to work on the technical and legal details of the remaining portions of the isolation barrier system and will provide tnese details to the public when they are available. The Settlement and Enforcement Action Memo- randum are available on EPA's West Lake Landfill website: www3.epa.gov/region07/cleanup/west_lake_landfill Community Inquiries Ben Washburn 913-551-7364 Washburn.Ben@epa.gov Find Us On www.facebook.com/WestLakeLandfillSuperfundSite www.twitter.com/WestLakeSite www, scr ib d. com / epare gion 7 ------- |