Analysis of ground-water level time-series for hydrogeologic conceptualization, Hanford Site, Washington

Abstract

Evaluations of natural ground-water level variations may be used to infer hydrogeologic characteristics of an area. This study analyzes ground-water level time-series by statistical and analytical methods in a section of the Hanford Site near Richland, Washington. Advantages of such passive methods of analysis may include relative simplicity, low cost, and avoidance of disturbances typically associated with stress testing of aquifers. Seasonal variations of the Columbia River stage are shown to affect ground-water levels in two hydrostratigraphic units. Seasonal ground-water withdrawals for irrigation in the upper Cold Creek Valley influence water levels In several wells west of the Cold Creek barrier. Vertical connectivity of the hydrostratigraphic units is also considered by studying the effects of surface waste water disposal activity on the underlying units. Estimates of the vertical hydraulic conductivity through a basalt flow interior are obtained.