A geosynthetic clay liner (GCL) was exhumed from a composite liner (geomembrane over-lying GCL) in a landfill cell that had been exposed to the atmosphere for 12 yr because a leachate collec-tion system had not been placed and the cell was never filled with waste. GCL samples were exhumed from locations along the top, middle, and toe of eastern and southern slopes, as well as from an anchor trench. Hydraulic conductivity of the GCL was less than 5.0 x 10-11 m/s or greater than 10-6 m/s, depend-ing on sampling location. GCL samples exhumed from the top of slope had low hydraulic conductivities and contained bentonite with relatively high swell index (≥ 20 mL/2 g), whereas samples exhumed from the toe had high hydraulic conductivities and low swell index (≤ 10 mL/2 g). Hydraulic conductivity of GCLs exhumed from mid-slope and from an anchor trench varied. Five of six GCL samples with low hy-draulic conductivity had exhumed gravimetric water contents < 20%, suggesting that these GCL samples may have remained relatively dry during the exposure period.
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