Dry municipal solid waste (MSW) samples were compacted in Plexiglas columns to densities of 160, 320 and 480 kg m(-3). The columns were set-rip as constant head permeameters. Wafer flowed continuously through the columns under hydraulic gradients of 2-4 ..0 m m(-1). Hydraulic conductivities were calculated according to Darcy's equation. Hydraulic conductivity was found to be time-dependent The temporal variation was attributed to varying degrees of saturation clue to gas formation and relative movement of fine particles in the columns. The average hydraulic conductivities at 160, 320 and 480 kg m(-3) were 9 . 6 x 10(-2), 7 . 3 x 10(-4) and 4 . 7 x 10(-5) cm s(-1), respectively.