Sand Filter Media Coefficient of Permeability Values
Coefficient of Permeability (k, ft/day)
Notes:
Coefficient of permeability, k, values for sand were computed by the City of Austin staff based on field observation and actual performance of previously installed sand filters. The values ranged form approximately 0.5 to 2.7 ft/day, with an average value of 1.5 ft/day. These values are substantially lower than those quoted in textbooks but allow for clogging associated with accumulated sediments. In an appropriately sized sedimentation basin, a value of k = 3.5 ft/day is recommended for sand filters. Other media k values are presented in this slide.