CGRS Environmental Services and RPI Group Approved Installer, Vista Geoscience, were a bit surprised at what happened recently at a Denver hydrocarbon site they were remediating with Trap & Treat® BOS 200® injections. In late 2011, PCE contamination was also discovered (most likely coming from an upgradient dry cleaner). The client stated “The data shows that the BOS 200® injections have worked very well, even on the chlorinated solvents.” How can that be?!Comingled plumes are somewhat rare, but they’re out there. Scott Noland, President of Remediation Products, Inc., explains: “Enhanced anaerobic bioremediation of fuel hydrocarbons encompasses a multitude of metabolic pathways, some of which can cause reductive dechlorination of solvents through a co-metabolic mechanism. Not that anyone would do this on purpose, but toluene will actually degrade vinyl chloride.”