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Rain Garden Research of EPA's Urban Watershed Research Facility (Poster)
STANDER, E., M. BORST, T. O'CONNOR, AND A. Rowe. Rain Garden Research of EPA's Urban Watershed Research Facility (Poster). Presented at Denitrification Research Coordination Network Workshop: Managing Denitrification in Human Dominated Landscapes, Narragansett, RI, May 12 - 14, 2009.
To inform the public
Rain gardens are vegetated depressions designed to capture and infiltrate stormwater runoff from impervious surfaces such as roofs, parking lots, and roads. The potential benefits compared to traditional curb and gutter drainage systems include peak flow attenuation in receiving waters, increased groundwater recharge, stream baseflow maintenance, and filtration and transformation of environmental stressors, such as heavy metals and nutrients, commonly found in runoff. These structures are quickly gaining popularity as green infrastructure components of low impact development planning. Background Few studies have quantified the ability of rain gardens to effectively manage chemical stressors. These studies indicate that the gardens function well in removing heavy metals and phosphorus, but the results for nitrogen have been mixed (Davis 2007). A nitrogen species of particular interest is nitrate, which is known to contribute to algal blooms and hypoxia in receiving waters. Current rain garden design, which typically includes rapidly draining sandy soils with low levels of organic matter, is not conducive to nitrate removal through denitrification. Compost is often mixed in with the sandy media to increase adsorption of heavy metals and phosphorus and increase organic matter content, but without the proper conditions for nitrate removal, compost may be a nitrate source in rain garden effluent. Alternative carbon sources should be considered. EPA’s rain garden research in Edison, NJ, studies enhancements of rain garden design to promote increased nitrate removal through denitrification and plant uptake while maintaining high levels of heavy metal and phosphorus removal.
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Rain Garden Research of EPA's Urban Watershed Research Facility Exit
Record Details:Record Type: DOCUMENT (PRESENTATION/POSTER)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
WATER SUPPLY AND WATER RESOURCES DIVISION
URBAN WATERSHED MANAGEMENT BRANCH