Investigation of the influence of geomorphic factors on the deposition of radionuclide contamination in the receiving stream of the former Weldon Spring Uranium Feed Materials Plant (presently, the Weldon Spring Site Remedial Action Project) St. Charles County, Missouri

“The primary objective of this study is to determine whether recognition of geomorphic forces within a fluvial system can lead to more effective scoping and execution of a characterization study. This investigation was designed to evaluate whether the contaminant occurrence data could be statistically correlated with sediment deposit type, to provide a predictive tool for guiding investigations into fluvial systems. The data set used for this study was generated by the Department of Energy under their Weldon Spring Site Remedial Action Project, from their investigations of the Southeast Drainage; a naturally occurring stream segment contaminated with radioactive wastes from operation of the Weldon Spring Uranium Feed Materials Plant in the 1950’s and 1960’s. The investigation mapped and categorized the sediment deposits from which contaminant data had been collected and conducted statistical analyses of those data to determine the sediment category with the highest concentration occurrence. The investigation, under the methods developed and used, concluded that there was a slight trend toward the highest occurrence in what were defined as Margin Deposits, however, the degree of overlap of the categorical data sets prevented a strong conclusion. It was concluded that the data set available for statistical analysis was not sufficiently representative of the sediment categories to effectively distinguish a strong correlation.Other significant observations and recommendations were made during the course of this investigation regarding the general occurrence of contaminants in a fluvial system. The presence of radioactive contaminates provided ample opportunity to observe, through field instrument readings, the physical locations, boundaries, and three-dimensional occurrence of contaminates, and provided insight into the nature of original emplacement and rework of contaminates in an ephemeral stream system. The mapping and conceptual modeling of the stream erosion and sedimentation processes generated an understanding into the temporal nature of contaminant movement through sediment transport. These observations can provide future investigators with guidelines for proper scoping of a data collection effort in a fluvial geomorphic environment” --Abstract, pages ii-iii.