Changes

==Provide Runoff Pretreatment==

==Provide Runoff Pretreatment==

[[Pretreatment]] refers to techniques or devices used to retain coarse materials suspended in stormwater runoff, either through filtration or settling, before it enters the BMP rendering it inefficient over time. Proper pretreatment extends the operating phase of the BMP’s life cycle by reducing the rate of accumulation of coarse sediment, thus delaying the need for at times expensive structural repairs like unclogging filter beds, pipes and orifices. Common pretreatment devices include [[vegetated filter strips]], [[Enhanced swales|grass swales]], [[geotextile]]-lined inlet filters/liners, [[check dams]], [[forebays]], eavestrough screens or filters, [[Oil and grit separators]] (i.e., hydrodynamic separators) and manholes containing baffles, filters and sumps. One important consideration for pretreatment is that these devices require frequent (i.e., at minimal, annual) sediment and trash removal maintenance and should be easy to access by inspection personnel.

[[Pretreatment]] refers to techniques or devices used to retain coarse materials suspended in stormwater runoff, either through filtration or settling, before it enters the BMP rendering it inefficient over time. Proper pretreatment extends the operating phase of the BMP’s life cycle by reducing the rate of accumulation of coarse sediment, thus delaying the need for at times expensive structural repairs like unclogging filter beds, pipes and orifices. Common pretreatment devices include [[vegetated filter strips]], [[Enhanced swales|grass swales]], [[geotextile]]-lined inlet filters/liners, [[check dams]], [[forebays]], eavestrough screens or filters, [[Oil and grit separators| oil and grit separators]] (i.e., hydrodynamic separators) and catch basins or manholes containing baffles, filters and sumps. One important consideration for pretreatment is that these devices require frequent (e.g., annual) sediment and trash removal maintenance and should be easy to access by personnel, vehicles and equipment needed to perform inspection and maintenance tasks.

[[File:Oil-grit separator USGS 2002.png|thumb|350px|Example oil-grit separator USGS 2002 (Wikimedia commons)]]

[[File:Oil-grit separator USGS 2002.png|thumb|350px|Example oil-grit separator USGS 2002 (Wikimedia commons)]]