Slide 32 of 52
Notes:
The principles of Darcy�s Law are used for sizing the sand filter bed area as derived by the City of Austin, TX, Environmental and Conservation Services Department. The primary design parameter for filtration basins is surface area. The necessary surface area is a function of the water quality volume, permeability of the filter medium, the bed depth, the hydraulic head (height of water above the bed), and the time for water to filter through the bed. The equation in this slide can be used to size all types of filter media.