Evaluating the Effects of Waterjet Delivered Amendment on Benthic Organism

The remediation of contaminated sediments is regularly performed through the addition of remediation amendments. The delivery of these amendments is typically executed through mechanical mixing methods, which can be devastating to the benthic communities living in these areas. This research combines the efforts of Missouri University of Science and Technology's Environmental, Mining, and Geological Engineering departments, in order to test the effects of a less invasive amendment delivery system on benthic organisms. A custom waterjet nozzle combined with a pressurized amendment vessel and a standard pressure washer are currently being investigated as a means to deliver remediation amendments into contaminated sediments. The functionality of this system and its delivery efficiency are both being assessed in other ongoing research projects. The purpose of this research was to investigate the effects that this waterjet delivery system would have on benthic organisms. The waterjet delivery system was tested on a benthic organism surrogate as a means to evaluate the newly developed delivery systems impacts on these creatures, and Styrofoam coupons were used as the surrogate. The coupons were placed in different environments and the exiting stream from the waterjet delivery system was passed over each. The variables examined in this analysis included water pressure, distance from the jet to the surrogate, depth of surrogate burial in sand and/or water, and different nozzle degree angles. For animals capable of burrowing at least an inch, like mollusks, would be safe from harm unless the waterjet was being operated within two inches of the sediment.