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Many of the physical and chemical properties of soil are affected by texture. The [[filter media]] component of [[bioretention]], [[swales]] and [[green roofs]] must meet very specific design specifications related to texture in order for the BMP to achieve drainage and water treatment performance targets. If the media texture is too fine (i.e., contains more silt- and clay-sized particles than specified) it may have low permeability and [[Drainage time|drain too slowly]] or retain too much water for excessively long periods of time. If the media texture is too coarse (i.e., contains more [[sand]] and gravel-sized particles than specified) it will have high permeability and may drain too quickly to provide adequate treatment of run-off, and may not retain enough water between storm events to sustain healthy vegetation cover.  

Many of the physical and chemical properties of soil are affected by texture.  

 

The [[filter media]] component of [[bioretention]], [[swales]] and [[green roofs]] must meet very specific design specifications related to texture in order for the BMP to achieve drainage and water treatment performance targets. If the media texture is too fine (i.e., contains more silt- and clay-sized particles than specified) it may have low permeability and [[Drainage time|drain too slowly]] or retain too much water for excessively long periods of time.  

 

If the media texture is too coarse (i.e., contains more [[sand]] than specified) it will have higher permeability and may drain too quickly to provide adequate treatment of run-off, and may not retain enough water between storm events to sustain healthy vegetation cover.  

==Testing==

==Testing==