|Wednesday What's New: Wetlands for Pollution Filtration|
|Written by Heleigh Bostwick Wednesday, 11 April 2012|
Creating wetlands for pollution filtration is not a new idea. In fact, for decades numerous studies have demonstrated that artificially created wetlands work quite well in this way. What’s surprising to me is that it’s not done more often. Or, if it is, it isn’t a topic that you hear about very often in the news, a good enough reason for me to highlight a California community that is doing precisely that for municipal wastewater treatment.
Research has shown that emergent wetlands filled with cattails and rushes filter out many pollutants better than other types of wetlands do and that is exactly what the Town Manager Virgil Koehne set about creating on an unused lot adjacent to “Sewer Treatment Plant #1” in Discovery Bay. Pollutants such as nitrogen and phosphorus are generally taken up and used by the plants; however, heavy metals such as copper, are typically bound up in the sediments. The wetlands will act as a living classroom for students at UC Berkley in exchange for the faculty’s assistance in developing the project.
20,000 gallons a day of primary treated wastewater from the sewage treatment plant is expected to begin flowing through the wetlands in late 2008, eventually returning to the treatment plant for final or tertiary processing. Solar sensors and probes will be installed at strategic locations in the wetlands to monitor water temperature, oxygen levels, salinity, pH, and water clarity. Whether it’s effective enough to treat municipal wastewater remains to be seen, but it’s certainly worth a try.