A cross-sectional profile of the site stratigraphy (Fig. 1A) was constructed
by interpretation of well log data (visual and texturally based documentation of
well cuttings during well installation) and sediment core data. Throughout our
field area, a silt-clay aquitard overlying the sand aquifer was observed at all drill
locations; the upper silt/clay unit ranges in thickness from 5 to 22 m, is typically
orange colored at the surface, and is green to grey at its base. Below the upper
clay/silt unit, a distinct transition to sand-rich sediments is observed. The aquifer
sand unit extends from an average depth of 15 m to the maximum depth of drilling
(60 m), and this unit is characteristically fine to course grained and is grey in
color. Depth to bedrock is constrained to 60 m. For modeling purposes, the
stratigraphy of our site is idealized as a 12 m clay cap overlying a 48 m grey sandy
aquifer (Fig. 1B).