Science Inventory

Rain Garden Research at EPA's Urban Watershed Research Facility

Citation:

STANDER, E., M. BORST, T. O'CONNOR, AND A. A. ROWE. Rain Garden Research at EPA's Urban Watershed Research Facility. Presented at Denitrification in Managed Landscapes, Narragansett, RI, May 12 - 14, 2009.

Impact/Purpose:

To inform public

Description:

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.

URLs/Downloads:

FOR_FURTHER_INFORMATION[1].PDF   (PDF,NA pp, 5 KB,  about PDF)

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Record Details:

Record Type: DOCUMENT (PRESENTATION/POSTER)
Product Published Date: 05/14/2009
Record Last Revised: 07/15/2009
OMB Category: Other
Record ID: 209550

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