Sediment Removal Testing Using the New Jersey Laboratory Protocol (New) for Filtration Manufactured Treatment Devices

A study of a Filterra bioretention system was conducted under the new State of New Jersey laboratory testing protocol (released January 25, 2013) for stormwater filtration manufactured treatment devices (MTDs). This was one of the first studies conducted under the new protocol and serves as a test case for the testing process, adjusting to the problems encountered, and how the results can be evaluated and applied to field installations.The testing first evaluated the treatment performance (removal efficiency of sediment) of the MTD based using the new protocol's required particle size distribution (PSD). A total of 27 test runs were conducted using an influent suspended sediment concentration (SSC) of 200 milligrams per liter (mg/L) at a maximum treatment flow rate (MTFR). The MTD had an average SSC removal efficiency of 90%. Three scour tests were also completed to ensure that previously captured sediment will not be released or discharged. The three scour tests determined that at the MTD's maximum allowable flow rate (250 gallons per minute [gpm]), and anticipated 6-month, 12-month, and 24-month sediment loads, the system had an average effluent SSC concentration of less than 2 mg/L, well below the maximum allowable effluent SSC concentration of 20 mg/L.With a greater movement towards Low Impact Development (LID) Best Management Practices (BMPs), this study shows how LID BMPs can be evaluated using MTD testing protocols and can be directly compared to other MTD's under the New Jersey laboratory protocol.