CitiesGoGreen - December 2008 - (Page 22)

What is a point source? The EPA defines a “point source” as: “Any discernible, confined, and discrete conveyance, including but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock concentrated animal feeding operation (CAFO), landfill leachate collection system, vessel or other floating craft from which pollutants are or may be discharged. This term does not include return flows from irrigated agriculture or agricultural stormwater runoff.” What is green infrastructure? According to the Environmental Protection Agency: “Green infrastructure is an approach to wet weather management that is cost-effective, sustainable, and environmentally friendly. Green infrastructure management approaches and technologies infiltrate, evapotranspire, capture and reuse stormwater to maintain or restore natural hydrologies. At the largest scale, the preservation and restoration of natural landscape features (such as forests, floodplains and wetlands) are critical components of green stormwater infrastructure. By protecting these ecologically sensitive areas, communities can improve water quality while providing wildlife habitat and opportunities for outdoor recreation. On a smaller scale, green infrastructure practices include rain gardens, porous pavements, green roofs, infiltration planters, trees and tree boxes, and rainwater harvesting for nonpotable uses such as toilet flushing and landscape irrigation.” nology popular in Europe for 50 years and cost-competitive with other techniques— have become a favored approach. LEED and the National Association of Home Builders are showing more municipalities how to encourage sustainable development techniques. The EPA’s Stormwater Pollution Prevention Plan (SWPPP) is another guideline for developers and builders interested in sustainable developments. A well-designed Stormwater Pollution Prevention Plan is important in LID, Coffman says. having a smaller footprint—such as a green roof—may be best. There are many low-energy stormwater management options, but what will municipal officials embrace? Coffman says developers will push sustainable technologies if local regulations encourage innovation, creativity and sustainability. Learning in Portland, Oregon Portland, OR is a pioneer in sustainable stormwater management and consistently tops lists of the most sustainable U.S. municipalities. The municipality of 568,000 has embraced a variety of sustainable stormwater methods, including green roofs, rain gardens, porous pavement, vegetated swales and landscaping, downspout disconnection and rain barrels. “Portland is a water community with a reputation for being a progressive city,” said Dean Marriott, Portland’s Director of Environmental Services. “That attracts Low energy, low cost Overall, low energy approaches mean low costs. Until recently, traditional stormwater management approaches have centered on pipes, basins and ponds, Howe says. However, sustainable designs can be expensive if they require adding a lot of plants or are improperly maintained. John Moll is a founding member of the Stormwater Equipment Manufacturers Association (SWEMA). He contends improper maintenance of green approaches cause problems in the long run. “No one thinks of cleaning out a constructed wetland, a pond or a bioswale,” he said. “If a bioswale is catching lots of cancer-causing metals and other terrible stuff, where is it going? It’s going downstream of influent. It’s going to leach back out unless there’s a maintenance program.” SWEMA promotes the idea that manufactured, proprietary devices have an important place in the systematic treatment of run-off. The organization calls for independent, third-party testing of all stormwater technologies, proprietary or otherwise, utilizing the same standards and protocols. There are occasions—especially in developed and urban areas—where the footprint of a green infrastructure approach may be too large or inappropriate in some other way. Stormwater management equipment alone or in combination with a natural approach A partial list of green infrastructure methods and approaches • Low Impact Development (LID): A comprehensive stormwater management and site-design approach that mimics predevelopment hydrology by using design techniques that infiltrate, filter, evaporate, and store runoff close to its source as opposed to costly large-scale systems. • Preserving existing vegetation: Deep, established root systems easily take up stormwater and allow it to infiltrate into the ground. • Green roofs: Vegetated rooftops with a shallow soil layer can support 22 December 2008 http://cfpub.epa.gov/npdes/glossary.cfm?program_id=0#P http://cfpub.epa.gov/npdes/home.cfm?program_id=298 http://cfpub.epa.gov/npdes/home.cfm?program_id=298 http://citiesgogreen.com

Table of Contents Feed for the Digital Edition of CitiesGoGreen - December 2008

Citites Go Green Contents In Motion We’re Taking Steps 10,000 Rain Gardens in Kansas City Chicago Center for Green Technology Connecticut’s ‘One Thing’ Green Infrastructure for Stormwater Management Philadelphia The Economics of What Matters New Context: New Possibility

CitiesGoGreen - December 2008

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