Redmond Bioretention Research

Nutrient export from bioretention systems is a known issue. To investigate alternative bioretention soil mixes (BSMs) that do not exhibit similar pollutant export, Herrera and the City of Redmond implemented this monitoring project to evaluate the treatment performance of six new bioretention swales. The systems were designed with different BSM blends. We were responsible for the experimental design, producing the monitoring plan, selecting, programing, and installing the monitoring equipment, conducting the monitoring, and reporting on the results. This project represents the largest full-scale bioretention monitoring project in Washington to date.  The results have been used by the City and Ecology to improve bioretention design and refine BSM specifications.