Changes

*The filter strip should have a flow path length of ≥ 5 m; however, some pollutant removal benefits are realized ≥ 3 m.

*The filter strip should have a flow path length of ≥ 5 m; however, some pollutant removal benefits are realized ≥ 3 m.

===Pretreatment===

===Pretreatment===

*A [[gravel diaphragm]] at the top of the slope is always recommended.  

*A [[level spreader]] or [[gravel diaphragm]] at the top of the slope is always recommended.  

*When filter strip slopes are greater than 5%, a series of [[level spreaders]], [[check dams]] or gravel diaphragms should be used to help maintain sheet flow.  

*When filter strip slopes are greater than 5%, a series of [[level spreaders]], [[check dams]] or gravel diaphragms should be used to help maintain sheet flow.  

*Filter strips should drain continuously as sheet flow until reaching a [[swales|swale]], [[bioretention]] facility, or other LID practice.

*Filter strips should drain continuously as sheet flow until reaching a [[swales|swale]], [[bioretention]] facility, or other LID practice.