Evaluate amendments to the default bioretention mixture (60% sand : 40% compost) for reduction of nutrients, bacteria, chemical toxicants, and toxicity to aquatic organisms.
Replicate installations (n = 3 per treatment) of bioretention amended with plants and/or fungi were constructed at the WSDOT ‘Ultra-urban stormwater testing facility’ in Seattle, WA where they treated stormwater from I-5 and the surrounding watershed over 2 years. Hydrology, chemistry, and toxicology was monitored for one storm per quarter.
Field Test: Feb 2017-Feb 2019
Saturated hydraulic conductivity (Ksat)
Soil temperature & moisture
Total suspended solids
Dissolved organic carbon
Total organic carbon
Total and dissolved metals (As, Cd, Cu, Cr, Ni, Pb, Zn)
Polycyclic aromatic hydrocarbons (PAHs)
Biological & chemical oxygen demand
Nutrients (ortho-P, total P, nitrate+nitrite, ammonia, total Kjeldahl N)
Zebrafish (Danio rerio) embryo survival and sublethal morphometrics (length, eye area, pericardial area)
USFWS Environmental Contaminants Division
SAM (Stormwater Action Monitoring)