Geosynthetic Filters for Water Quality Improvement of Urban Storm Water Runoff

Suspended solids in highway storm water runoff create a wide range of water quality problems; their removal lessens the deleterious impact of storm water runoff on aquatic ecosystems. In this study, three geotextiles were tested in a laboratory setup with influent suspensions having a hydraulic loading rate, total suspended solids (TSS) concentration, and particle size distribution similar to those reported for urban highway storm water runoff. Results indicated that after a short ripening period, a geotextile with an apparent opening size of 150 mu m can effectively remove suspended solids to below a target concentration of 30 mg/L. The results also showed that the change in hydraulic conductivity of the geotextile filter system can be related to suspended solids captured via a power function, which may be used to predict the flow rate through the filter during its life span. New retention criteria specifically for storm water filtration are introduced for geotextiles. DOI: 10.1061/(ASCE)EE.1943-7870.0000565. (C) 2012 American Society of Civil Engineers.