Sand filters are pressure vessels filled with sand and are designed to remove solids down to 75 – 100 micron in size. The filters have an automated backwash sequence that can be determined by time or pressure and the backwash water should be filtered as well to keep the solids from re-entering the treatment system. The sand filter protects the downstream enhanced treatment technology that can be harmed by a large volume of solids. This technology is a very good first step BMP for sites with heavy solids.
(last updated March 13, 2013)