State Water Resources Research Institute Program

Project ID: 2008MN235B
Title: Enhanced Degradation of Stormwater Petrochemicals within the Rhizosphere of Raingarden Bioretention Cells
Project Type: Research
Start Date: 3/01/2008
End Date: 2/28/2009
Congressional District: Fifth
Focus Categories: Water Quality, Non Point Pollution
Keywords: Alternative Stormwater Management, Raingardens, Phytoremediation, Biodegradation, Low-Impact Development
Principal Investigator: Novak, Paige
Federal Funds: $ 7,000
Non-Federal Matching Funds: $ 14,235
Abstract: 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.

Progress/Completion Report, PDF