Fig. 2From: Application of denitrifying wood chip bioreactors for management of residential non-point sources of nitrogenSix distinct zones in a modified bioretention unit. Top to bottom shows regions of stormwater ponding, mulch, top soil, nitrification, denitrification (IWSZ) and drainage layers. Wood chips are contained in the denitrification (IWSZ) zoneBack to article page