Discharge of runoff to areas of the site where the water will collect and percolate into the ground is considered infiltration if the volume, rate, or quality of the discharge does not meet Department standards for use of the area as a stormwater treatment buffer. Underdrained swales, underdrained ponds, and similar practices that discharge to surface waters or to buffer strips meeting Department requirements in 06-096 CMR ch. 500, Appendix F for stormwater buffers are not considered infiltration systems, although these may be used to treat runoff prior to discharge to an infiltration area.
06-096 C.M.R. ch. 501, § 2