Radiological survey of Latty Avenue in the vicinity of the former Cotter site, Hazelwood/Berkeley, Missouri (LM001)

A radiological survey was conducted over a proposed construction corridor in the vicinity of the former Cotter site at 9200 Latty Avenue. The survey included gamma exposure rates at the ground surface and at 1 m above the surface throughout the site, sampling of surface soil, sampling of subsurface soil from auger holes, gamma logging of auger holes, and sampling of subsurface water. The results of the survey demonstrated some degree of radioactive contamination in all areas of the construction corridor, extending north and south in some regions onto adjacent private properties. Redistribution of the contamination by flooding, surface runoff, and road and utility line activities was evident. The pattern of contamination ranged from widespread to isolated spots and was found to occur from near the surface to depths of ∼1.8 m. The most highly contaminated region was noted on both sides of Latty Avenue adjacent to the former Cotter site. Concentrations of 230Th in soil from that region were as high as 16,000 pCi/g