Biofiltration has become common in Minnesota’s urban landscape because it is one of the most robust stormwater treatment practices available to designers. Stormwater professionals and practitioners, however, still face challenging decisions while designing these practices and often feel as if they are guessing when selecting media components and designing these practices. In particular, the most commonly used and recommended biofiltration media mixes have been shown to export phosphate, potentially contributing to water quality impairments. This increases environmental risk and uncertainty when attempting to implement TMDL recommendations.
Thus, the objectives of this research are to 1) identify which local and sustainable biofiltration media are effective for filtration rate, supporting plant growth and microbial function, and that do not release phosphate, and 2) document local sources, simple tests or metrics, and/or design specifications that can be used by practitioners to reliably and repeatably obtain a biofiltration practice that functions as expected. This presentation will cover results from Phase 1 (completed June 2020) and an introduction to Phase 2 (initiated May 2020).
Speaker(s)
Andy Erickson, Jessica Kozarek, St. Anthony Falls Lab, University of Minnesota; Laura Lewis, Environmental Engineering, University of Minnesota