When designed as a stand alone water quality BMP (i.e., not pretreatment to another BMP) the vegetated filter strip should be designed with a pervious berm of [[sand]] and gravel at the toe of the slope for shallow ponding of runoff. | When designed as a stand alone water quality BMP (i.e., not pretreatment to another BMP) the vegetated filter strip should be designed with a pervious berm of [[sand]] and gravel at the toe of the slope for shallow ponding of runoff. |