You are here:
ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM: Stormwater Source Area Treatment Device - Arkal Pressurized Stormwater Filtration System
Citation:
NSF International. ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM: Stormwater Source Area Treatment Device - Arkal Pressurized Stormwater Filtration System. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-04/084, 2004.
Impact/Purpose:
to inform the public
Description:
Performance verification testing of the Arkal Pressurized Stormwater Filtration System was conducted under EPA's Environmental Technology Verification Program on a 5.5-acre parking lot and grounds of St. Mary's Hospital in Milwaukee, Wisconsin. The system consists of a water storage tank, two separate filtration processes, pumps and other ancillary equipment. The filtration system was designed to remove 80 percent of suspended solids greater than five microns in diameter from runoff collected in parking lot storm drains, and discharge the treated water to the municipal storm sewer. 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 82 percent of the suspended sediment loading, and that the system was capable of treating particles smaller than five microns in size. The testing also verified that parameters that commonly bind to particulate matter, such as total phosphorus, total Kjeldahl nitrogen (TKN) and total zinc, were removed from the runoff. The system required a total of eight O&M events during the 16-month verification period. Maintenance consisted primarily of cleaning and disinfecting the filter devices, which would develop microbial growth during long dry periods. A total of 84 hours of staff time and $260 in direct costs were used to maintain the system. An estimated 78 kilowatts of electricity were required to power the system for each storm event.