sediment removal in sand filters
The following discussion is an example of what the Colorado Stormwater Center teaches participants at BMP Inspection and Maintenance workshops.
It is recommended that sediment be removed from sand filters once the sediment has penetrated about 2 inches below the surface. Stormwater sediment is easily identifiable by its black color. If you dig a small hole in the sand filter, you can measure the depth of black sediment to determine if removal is needed. If so, the sediment should be removed manually using a flat shovel or other lightweight equipment. Operating heavy machinery on sand filters is not recommended as it can compact the sand, reduce infiltration rates and potentially damage the underdrain.