Apr 5, 2015

This study evaluated the efficiency of a bioretention system installed in Daly City, California, for a large suite of pollutants, including some that have been rarely evaluated in such systems. Water quality improvements (concentration or load reductions) were demonstrated for total Hg, polychlorinated biphenols (PCBs) and dioxins ranging between 18 and 100%, and a suite of more conventional pollutants [sediment, cadmium, copper, nickel, lead, zinc, and polycyclic aromatic hydrocarbons (PAHs)] ranging between 20 and 90%. The balance of evidence suggests that such systems, when designed and functioning correctly, can be highly effective in treating pollutant concentrations and loads in stormwater runoff in semiarid environments.

Nicole David
Associated Staff: 
Programs and Focus Areas: 
Clean Water Program