Urban Stormwater Infiltration: Assessment and Enhancement of Pollutant Removal

Overview of Problem: Urban stormwater contains a variety of organic and inorganic chemical “pollutants”. Thus, discharge of stormwater to surface water, a common practice, raises concern over the impact on water quality of the receiving waters (lakes and streams). One alternative is treatment of stormwater in municipal wastewater treatment plants, but large variations in stormwater loadings creates problems with plant capacity. Infiltration through soil is another alternative for stormwater disposal. Adsorption, degradation, and other processes may remove pollutants, allowing “clean” water to recharge the groundwater system. However, if pollutants migrate into the groundwater, infiltration may be an unacceptable method of stormwater management. Availability of sites for infiltration is another important limitation.