Borehole Data Package for Calendar Year 2001 RCRA Wells at Single-Shell Tank Waste Management Area U

This document provides information on the construction of three new RCRA wells at Waste Management Area U in September 2001. These wells were constructed to the specifications and requirements described in Washington Administrative Codes 173-160 and 173-303. Grab samples for geological description and archive were collected every 5 ft throughout the wells. Borehole and drill cuttings were monitored regularly for organic vapors and radionuclide contaminants. At well 299-W18-40, beta-gamma activity was found to be slightly above background at 120 ft below ground surface. All other measurements were below background. Cesium-137 was found at the ground surface and at 3 ft below ground surface (bgs). No other manmade contamination was found. At well 299-W19-44, no radionuclide contamination was found, but several intervals of high carbon monoxide were detected. Cesium-137 was detected at 3 ft bgs at 0.4 pCi/g. At well 299-W19-45, no radionuclide contamination was found, but several intervals of high carbon monoxide were detected. Cesium-137 was detected near the surface at 0.4 pCi/g. No other manmade radionuclide was detected. At well 299-W19-45, samples for geological description and archive were collected every 5 ft throughout the well. No contamination was noted. Cesium-137 was detected near the surface at 0.4 to 1.4 pCi/g. No other manmade radionuclide was detected