fcSz) West Lake Update May 19,2015 EPA Directs PRPs to Perform Additional RIM Characterization This Summer EPA Region 7 has reviewed and approved the Phase ID Work Plan Addendum submitted by the Potentially Responsible Parties (PRPs) in April 2015. The purpose of the Phase ID investigation is to build on previous work conducted at the site to identify the extent of radiologically impacted material (RIM) in the southwestern and western portions of Operable Unit 1 (OU1) Area 1, and to assist EPA in evaluating potential locations for an isolation barrier. Contractors began mobilizing at the site on May 11th. Contractors under EPA oversight will use Gam- ma Cone Penetrometer Testing (GCPT) to screen for gamma radiation. Once these locations and depths are established, contractors will use a sonic drilling rig to drill soil borings to collect soil core samples from GCPT locations that have elevated gamma readings. The borings will be visually inspected and scanned for gamma radiation to identify the locations where soil samples will be collected for laboratory analysis. The samples will be analyzed for the fol- lowing isotopes: Radium-226, Radium-228, Thorium-230, Thorium-232, Uranium-234, Uranium-238, Actinium-227, Potassium-40, Prot- actinium-231, Scandium, and Lead-210. Consis- tent with EPA quality control practices, laboratory analytical reports and data will be subjected to data validation in accordance with the Multi- Agency Radiation Laboratory Analytical Protocol. In addition to the investigation work described above, EPA Region 7 sent a letter to the PRPs on April 20, requesting additional RIM characteriza- tion at Area 1 and Area 2 of the West Lake Landfill Site. Hie purpose of this planned additional char- acterization is to better define the extent of the RIM in OU1 Areas 1 and 2 to support a thorough evaluation of full and partial excavation remedy options. EPA has worked closely with its Office of Re- search and Development (ORD) and the U.S. Army Corps of Engineers to review existing data from Areas 1 and 2 to define the appropriate scope of this additional sampling effort. The additional samples required by this work will be collected using the same GCPT sampling and confirmation sonic coring that will be used for the Phase ID work described above. This additional character- ization will be planned and implemented concur- rently with the upcoming Phase ID work in order to maximize the speed and efficiency with which both events can be completed. EPA expects the work to last through the sum- mer. The Phase ID Work Plan Addendum and the April 20 letter to the PRPs are now available at this website: www.epa.gov/region7/cleanup/ we st_lake_lan dfill Community Inquiries Ben Washburn 913-551-7364 Washburn.Ben@epa.gov Find Us On www.facebook.com/eparegion7 www.twitter.com/eparegion7 www.scribd.com/eparegion7 www.epa.gov/region7/cleanup/west_lake_landfill The GCPT direct push rig in action during characterization work at the West Lake Landfill Superfund Site in Bridgeton, Mo., in 2013 Community Advisory Group Meeting The next Community Advisory Group (CAG) meeting will be held June 8 at 6:30 p.m. at the Operating Engineers Local 513 Offices, 3449 Hol- lenberg Drive, Bridgeton, Mo. 63044. ------- |