The Wissahickon Creek, between Morris Road and Lafayette Ave., will be tested with non-toxic dyes tomorrow, which will turn it’s water bright green. Scientists from The Academy of Natural Sciences of Drexel, and Temple University, will track the tracer dye’s movements down the Wissahickon.  This test is the first of several in the month of September, and are meant to evaluate the creek’s ecosystem and overall health. The tests are being conducted in consultation with the Pennsylvania Department of Environmental Protection and are funded through a grant from the National Science Foundation.