Water Resources Research Act Program

Details for Project ID 2008MN235B

Enhanced Degradation of Stormwater Petrochemicals within the Rhizosphere of Raingarden Bioretention Cells

Institute: Minnesota
Year Established: 2008 Start Date: 2008-03-01 End Date: 2009-02-28
Total Federal Funds: $7,000 Total Non-Federal Funds: $14,235

Principal Investigators: Paige Novak

Project Summary: Traditional approaches to stormwater management, such as curb and gutter, fail to provide infiltration or water quality improvements and can act as conduits for pollutants. More municipalities and developers are turning to Low Impact Development (LID), which promotes on site infiltration as alternative stormwater management approaches. Raingardens (small, on-site, vegetated depressions to which runoff is directed) are a popular and promoted Best Management Practice (BMP) for urban stormwater quality. However, there is concern that contaminants present in runoff may accumulate and cause pollution of soil or groundwater. Little research has been done to examine the fate of hydrocarbons in alternative stormwater systems or to understand raingardens as a pollution control device. In order to truly be effective as a pollution control BMP, a raingarden must not only trap and detain, but degrade petrochemicals routed to them. Because most raingardens are vegetated, it is also vital to understand the role of plants in pollution control applications of raingardens. We propose to create simulated raingarden systems in columns and analyze the fate of benzene and toluene (gasoline components), and to determine what effects varying vegetation have upon the degradation capacity of these hydrocarbons. It is our hypothesis that legumes, which possess an enhanced microbial community in the rhizosphere of their roots, will facilitate an environment leading to greater biodegradation of these compounds.