How to you test whether or not a bioswale designed to infiltrate stormwater run-off from Highway I-95 will perform as expected? You simulate the runoff event by directing water from a fire hydrant down the storm drains to mimic a big rainstorm. Add a little dye, and you can visually track flow. This is a part of a project sponsored by PennDOT, supervised by AECOM, with researchers from both Temple and Villanova, as well as help from the Philadelphia Water Department.
Here is a link to a video of the dye emerging. The dye emerges at just after the 50 second mark.
Where’s the geophysics? Well, we placed a 28-electrode electrical resistivity line along a 27 m section of the floor of the bioswale and collected time-lapse, electrical resistivity tomography data to monitor infiltration. More about this in a later post.