James Laghlin, Managing Editor
Keeping water clean as it flows through an urban area is a major challenge. Water flows off streets, parking lots, yards and the vast expanses of concrete that can be found in industrial and commercial areas. That water is gathered through a network of stormwater drains, ditches and small creeks and typically ends up concentrated in a major stream or river passing through the city.
In most cities, the local wastewater treatment facilities also discharge into that water body, which carries the accumulated mix of polluted waters downstream to the next town - unless it's a coastal community and then it flows into the ocean.
Cleaning up urban waters - and keeping them clean, is a top priority for folks in Tacoma, WA, which was recently named an Urban Clean Water Technology Innovation Partnership Zone. Tacoma has opened the Center for Urban Waters, which will combine the research efforts of the Puget Sound Partnership, the University of Washington Tacoma, Washington State University Puyallup, and the City of Tacoma.
The center will provide space for collaborative research on a local level with potential global implications. The center is developing solutions to restore and protect water in urban settings. Their science is focused in three areas: filtering, decontamination, and regulation.
In filtering, researchers are working on permeable concretes/asphalts that allow water to filter down into groundwater. This is a low tech, low cost, high impact method of reducing storm flows. In decontamination, they are using biochemicals and other clean techniques to remove contaminates from the water. On the regulatory front, they are using genetic "fingerprinting" to identify pollutants in water, which will allow regulators to follow the trail back to the source and use regulatory powers to force changes.
The building that houses the Urban Waters center recently secured LEED Platinum status from the US Green Building Council. In line with its goal of water stewardship, the three-story, 51,000-square-foot building will use 46% less water compared to a traditional buildings through measures like recycling rainwater collected from the roof and wastewater from the lab's pure water system. The recycled water will be used for toilet flushing and to irrigate the landscaping, which is comprised of native and adapted plants.
The property includes a rain garden featuring native plants in the middle of the parking lot that helps collect and filter stormwater runoff. The facility's parking area also is built with pervious pavers which helps pass rainwater through the parking surface and filter into the soil.
I love the idea of this program and hope that it will yield technologies and systems for use across the water landscape. One thing is clear to me: simply collecting stormwater and moving it away from urban centers as quickly as possible is no longer a viable alternative.
Research and focused thought are needed on how to handle this precious resource in an urban setting. This seems like a good place to start. For more information on the program, visit the Center for Urban Waters website: http://www.urbanwaters.org