Natural Systems Data Package for the Active Trenches of the Low-Level Burial Grounds, Hanford Site, Washington

Abstract

This document summarizes the available information regarding the natural system (vadose zone and saturated zone) at the active trenches of the 200 West Area and 200 East Area Low-Level Burial Grounds (LLBGs). This information is relevant for developing the natural system fate and transport model for the update of the active trenches performance assessment. This document presents a description of the major features, events, and processes of the natural system at the active trenches of the 200 West Area and 200 East Area LLBGs that involves the geologic features or framework, and the vadose zone and groundwater flow and transport system. The description of the geologic features includes the following items: • Geologic setting • Major structural features • Major hydrostratigraphic units • Geologic framework The discussion concerning vadose zone flow and transport at the active trenches of the 200 West Area and 200 East Area LLBGs includes the following topics: • Vadose zone features, events, and processes relevant to the development of the vadose zone conceptual model • Hydrogeologic units and conditions • Factors affecting moisture movement • Flow and transport properties of major units The discussion concerning the groundwater flow and transport system in the vicinity of the active trenches of the 200 West Area and 200 East Area LLBGs includes the following topics: • Saturated zone features, events, and processes relevant to the saturated zone conceptual model • Hydrogeologic units • Groundwater flow conditions • Flow and transport properties