Maximum Utility for Minimum Cost: Simple Structural Methods for Stormwater Quality Improvement

Stormwater runoff is characterized by the United States Environmental Protection Agency as "one of the greatest remaining sources of water pollution" in America. Thus, efforts to implement stormwater quality improvement regulations are accelerating across the United States, compelling municipalities and land developers to maximize the usefulness of stormwater infrastructure as never before. With simple modifications to current designs, common catch basins and other stormwater structures can be more effectively utilized as pollution control devices, rather than merely as a way to move stormwater. Future systems must drain runoff which can not be infiltrated to areas where it can be appropriately managed, and simultaneously, reduce the environmental impact of the ultimate discharge to the receiving waters. Adding a deep sump to catch basins, a common feature in some areas of the country, has been shown to remove some sediments and gross particles. As an additional benefit, these structures allow the use of an outlet hood or baffle, which can drastically reduce the discharge of floatable debris and trash, and aid in the removal of free oil and grease. This "cleaner" runoff can also extend the service life of a traditional stormwater detention facility, such as a pond, or a retention facility, such as a groundwater recharge area. This paper addresses a group of low-cost components which comprise the SNOUT Stormwater Quality Control System, manufactured by Best Management Products, Inc. (BMP, Inc.) The applications include a deep sump catch basin with an outlet hood, a structure with an outlet hood and flow restrictor, structures configured to bypass high flows, and outlet controls which can accommodate extreme flow conditions while retaining captured pollutants.