Remediating nutrient and bacterial contaminated stormwater via bioretention : a comparative anlysis of three filter designs

Abstract

Urbanization and the development of impervious surfaces have impacted waterways and associated riparian ecosystem functions. Surfaces such as rooftops, parking lots, and roadways generate large volumes of stormwater that can transport contaminants (e.g. nitrates, pathogens, motor oils, and heavy metals) throughout urban watersheds. Thus, urban planning and development is critical for remediating contaminated stormwater. Bioretention techniques, a watershed protection method, utilize landscape designs of planned slopes, basins, and filter materials to remediate urban runoff from impervious surfaces. This study tested the efficacy of three filter designs to filter two common pollutants nitrates (used in fertilizers) and <italic>E. coli<italic> (an indicator for pathogens) and to release filtrate for non-potable re-use. Results indicated that while there was no statistical difference between the performances of these filters, implementing bioretention techniques using a sandy loam filter design is a viable and economic best management practice for capturing, filtering, and utilizing stormwater from impervious surfaces.