Evaluating Sediment Removal Efficiency of Catch Basin Inserts (CBIS) as a Post-Construction Water Quality Tool For Ohio Roadways

Abstract

Urban areas produce large amounts of stormwater runoff due to the land being covered with impervious materials such as concrete and asphalt. Stormwater inlets, or catch basins, are a commonly used method for collecting stormwater runoff and directing it away from streets and sidewalks via a storm sewer system before eventually discharging into local bodies of water. However, typically these stormwater systems only redirect the runoff without providing a means for removing potentially harmful pollutants (i.e, trash, debris, sediment, metals, and chemicals). These pollutants are then often discharged directly into local lakes, rivers, and streams, potentially harming native aquatic wildlife. Post construction stormwater practices are commonly used to treat runoff from urban areas by reducing the total runoff volume, lowering peak flow rates, and/or treating the runoff for potentially harmful pollutants carried in the runoff. However, some post construction stormwater practices in urban areas are often not viable options because of their large land, construction, and maintenance requirements. Catch basin inserts (CBIs) are one type of post-construction BMP that are easy to install into existing catch basins and require no additional land use while still providing a means of removing pollutants from stormwater runoff before entering the municipal separate storm sewer system (MS4). However, limited data is available to demonstrate the expected performance of various CBIs to ensure that these practices meet the pollutant removal standards set forth by the USEPA. This study, conducted at the Auburn University – Erosion and Sediment Control Test Facility (AU-ESCTF) evaluated the sediment removal capabilities of eight different proprietary CBI products for potential use as a post-construction stormwater tool for Ohio Department of Transportation projects. CBIs were tested using different flow rates and soil types and analyzed for both initial performance and longevity.