The St. Paul Port Authority's Beacon Bluff redevelopment project features a state-of-the-art storm water treatment system.
In St. Paul, 163 acres worth of storm water runoff that previously flowed directly into the Mississippi River will now filter through a state-of-the-art treatment system thanks to a collaborative effort organized by the St. Paul Port Authority. The new system is part of Beacon
Bluff, a larger Port Authority redevelopment project to economically revitalize the 46-acre parcel of land that once served as 3M's East Side campus.
When construction of a new roadway on the Beacon Bluff property necessitated storm water runoff improvements to meet the city's updated watershed criteria, the Port Authority recognized a larger opportunity to help St. Paul improve outdated systems in an adjacent residential
neighborhood by diverting its runoff into a new, supersized system.
A team effort between the Port Authority, the City of St. Paul, the Capitol Region Watershed District, civil engineering firm Loucks Associates and the University of Minnesota has made that system a reality. It features the SAFL Baffle, a specialized baffle or metal grate
named for and engineered by the U of M's St. Anthony Falls Laboratory. The patent-pending innovation traps about 90 percent of sediment from storm water runoff and stores it in a sump, where it can be periodically removed. Because contaminants often attach themselves to sediment,
its removal will help prevent those contaminants from entering the river.
The system also can retain more than 1 million gallons of water, greatly reducing the risk of flooding. Ten-foot-wide metal reservoir tanks are surrounded by 7,000 cubic yards of recycled rubber tire chips, creating more void space for the water to infiltrate than traditional
fillers like gravel or sand. Real-world infiltration and water quality data also will be tracked to gauge the system's effectiveness -- a rarity among U.S. storm water systems. Monte Hilleman, Port Authority vice president of redevelopment, says the data will help fine-tune
watershed requirements for future systems. He adds that more proven efficiencies within those systems will facilitate more densely built environments.
"A more sophisticated understanding and regulation of these infiltration rates will allow for more developable square footage on any given parcel of land," Hilleman says, "which in my mind is more jobs, more tax base and more good things for the city of St. Paul."
-- Andrea Lahouze