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Rain Garden Research at EPA’s Urban Watershed Research Facility: Promoting Nitrate Removal through Rain Garden Design
Citation:
STANDER, E. K., M. BORST, AND T. OCONNOR. Rain Garden Research at EPA’s Urban Watershed Research Facility: Promoting Nitrate Removal through Rain Garden Design. Presented at EPA SCIENCE FORUM, 2008, WASHINGTON, DC, May 20 - 22, 2008.
Impact/Purpose:
to present information
Description:
Rain gardens are designed to infiltrate stormwater, capture suspended solids, sorb heavy metals and phosphorus, and transform nutrients through biological processes. Most studies have found a low capacity for stormwater nitrate removal. Research at the Urban Watershed Management Branch in Edison, NJ, involves manipulating rain garden design to promote nitrate removal. Manipulations including rain garden size, vegetation type, organic matter content, and saturation at depth will be tested for enhancement of nitrate removal via denitrification. Sandy media amended with organic carbon-rich newspaper will be added to large, outdoor rain garden mesocosms located at EPA’s Urban Watershed Research Facility. Mesocosms will be planted with turf grass or herbaceous plants; some will include a deep saturated zone. Stormwater will be added to the mesocosms, and effluent nitrate concentrations will be measured. Denitrification and plant uptake of nitrate will be measured using nitrogen stable isotopes. This research will contribute to an understanding of nitrate removal mechanisms in rain gardens for application to national guidelines for design, construction, and maintenance.