BEST MANAGEMENT PRACTICES TO REDUCE POLLUTION FROM STORMWATER IN HIGHLY URBANIZED AREAS

Catch basin inserts were evaluated in laboratory and field applications to determine their ability to remove particulate pollutants, litter and debris. Three different types of inserts that used different sorbents and screens were used. Laboratory tests with used motor oil showed that the inserts could remove in excess of 80% of free oil and grease. Sand particles that were larger than the screen mesh was completely removed. Field tests showed that median oil and grease, turbidity and total suspended solids concentrations in stormwater were reduced by 30 to 50%. The inserts were more effective in reducing maximum concentrations than low or median concentrations. Some of the inserts plugged after usage and by passed stormwater without creating ponding on the street or reducing flood protection. Large amounts of litter and debris were collected. Catch basin inserts can be used to capture litter and debris while reducing particulate pollutant concentrations while maintaining flood protection.