Baltimore Ecosystem Study Institute of Ecosystem Studies

2015 BES Annual Meeting Presentation and Poster Abstracts

Getting the ‘N’ out of Stormwater: Harnessing Microorganisms for Sustaining Water Quality and Development
Peralta, Ariane
Co-Authors: Eban Z. Bean & Ariane L. Peralta

Abstract: Urbanization increases impervious surfaces; increasing runoff that transports pollutants such as sediments, nutrients, and metals. If untreated, these pollutants migrate into local waterways leading to impairment of natural water resources. Nitrogen reduction in these stormwater control measures (SCMs) is promoted by designing systems to facilitate conversion of nitrogen species into gaseous forms of nitrogen (N2 & N2O) through the microbial process of denitrification. Two SCMs that are most credited with nitrogen removal are stormwater wetlands and bioretention with internal water storage. Since virtually all nitrogen transformations are microbially-mediated, varying environmental conditions directly impacts microbial process rates. However, from an engineering perspective, denitrification is a “black box” process. It is assumed that when nitrogen enters systems with anaerobic conditions, sufficient carbon and nutrient resources along with optimal temperatures, denitrification activity occurs optimally. This approach does not account for the variation in activity influenced by the microbial community adapted to a particular location within the built environment. Our goal is to take an interdisciplinary approach to expand our understanding of effects of carbon and nutrients on microbial community structure, their role in driving nitrogen removal rates, and how SCMs designs can be optimized to enhance nitrogen removal. Here, we present baseline water quality conditions prior to construction of stormwater retrofits in Greenville, NC. We plan to examine sediment characteristics and nitrate removal potential at the molecular level through examining the dynamics of microbes carrying out nitrogen removal processes. We are applying a social-ecological- technology systems approach to modify SCMs for enhanced stormwater management.