Regional stormwater treatment system.. Super-sized LID

Regional stormwater treatment facilities are an alternative solution to parcel based low impact development (LID) when trying to meet water quality treatment goals in urban settings.  Urban retrofit projects are challenging due to many site constraints (i.e. narrow median strips, lack of green or open spaces, and areas built on structure) . Our design team needed to look beyond parcel scale approaches and identified larger sites to provide regional treatment. Capture In ZhenJiang, China, we designed a system called the Waterfall Treatment System (WTS) that is only 2000m2 but capable of treating runoff from a surrounding 120 ha area. This high-performance system contains a gravity pre-filter bay, followed by dispersion weirs and four engineered media filter beds. Under drains collect the filtered water at an infiltration rate of 100 cm/hr. Construction ImageCurrently under construction, the system is designed to removal 80% total suspended solids, 50% total phosphorus, 60% dissolved zinc, and 30% dissolved copper. This type of system should be added to your suite of tools when addressing stormwater water quality improvements in urban settings.