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ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT STORMWATER MANAGEMENT INC., STORMFILTER SYSTEM WITH ZPG MEDIA
Citation:
NSF International. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT STORMWATER MANAGEMENT INC., STORMFILTER SYSTEM WITH ZPG MEDIA. U.S. Environmental Protection Agency, Washington, DC, 600/R-04/125, 2004.
Description:
Verification testing of the Stormwater Management, Inc. StormFilter Using ZPG Filter Media was conducted on a 0.19 acre portion of the eastbound highway surface of Interstate 794, at an area commonly referred to as the "Riverwalk" site near downtown Milwaukee, Wisconsin. The system consists of an inlet bay, flow spreader, cartridge bay, overflow baffle, and outlet bay, housed in a 12 foot by 6 foot pre-cast concrete vault. The system was designed to remove sediments, metals, and stormwater pollutants from wet weather runoff. The verification challenge included collecting influent and treated effluent samples during 15 qualified storm events. A qualified storm event was defined as a minimum of 0.2 inches of rainfall, where representative sample aliquots are collected throughout the duration of the event and composited into a flow-weighted composite sample. The influent and effluent sampling areas were equipped with automated samplers and flow monitoring devices to collect and monitor the flows entering and exiting the system. The verification testing concluded that the system was capable of removing approximately 46 percent of sediment as determined by the total suspended solids (TSS) analytical procedure and 92 percent of sediment as determined by the suspended sediment concentration (SSC) analytical procedure. The primary difference between these two procedures is that the SSC analytical procedure is more likely to measure larger sediment particles as compared to the SSC analytical procedure. Particle size analysis conducted on stormwater samples showed the runoff entering the StormFilter contained a large proportion of coarse sediment, while the effluent contained a larger proportion of fine sediment. The StormFilter also removed total and dissolved phosphorus, total copper, and total zinc from stormwater consistent with its performance claim. The system was cleaned and equipped with new filter cartridges before the start of verification testing, and after the completion of the 15-month verification period. Maintenance consisted of replacing the filter cartridges and vacuuming sediments from the sediment chamber. Approximately 570 pounds (dry weight) of sediment was removed from the StormFilter's sediment collection chamber during the maintenance event at the end of the testing period.