||Robert S. Kerr Environmental Research Lab., Ada, OK. ;ManTech Environmental Technology, Inc., Ada, OK. ;Coast Guard, Elizabeth City, NC.
A detailed characterization of the underlying and adjacent soils of a chromeplating shop was performed to provide information on the extent of soil and aquifer contamination at the site on the potential for off-site migration and environmental impact. Intact, moist cores were obtained from more than 40 different locations, resulting in more than 200 discrete samples for total metal analysis, selective extraction tests, and adsorption-reduction experiments, to assess the chemical speciation and distribution of chromium on the contaminated soils and its leaching potential. Surface analytical techniques were also used to determine chemical speciation and to further elucidate mineral fractions responsible for retention of the chromium on the soils and sediments. Adsorption and reduction capacities of the saturated aquifer sediments were variable and low, while the unsaturated soils' reduction capacities were much greater and were correlated with depth (decreasing capacity with increasing depth). The soils' adsorption and reduction capacities were eventually overwhelmed, however, and permitted the passage of Cr(VI) into the underlying ground water. (Copyright (c) 1994 AEHS).