This DTSC approved site remedy was installed in Southern California at a former military testing facility with high levels of TCE (20 ug/l) and DCE on a groundwater plume that transitioned between 25 and 3 feet below ground surface, and high concentrations of salts. In the spring of 2015, Intrinsyx installed over 300 trees, half of which consisted of our new variety of salt and boron tolerant poplar trees for placement in zones with the highest salt concentrations. All the trees were inoculated with our PDN3 endophyte upon installation, as well as a follow-up re-inoculation in the spring of 2018.
Trees are established, and the tree tissue sampling and lab analyses all indicate that trees are engaging the TCE plume, even in areas with a depth to groundwater contamination at 20 feet bgs. Groundwater monitoring wells indicate that downgradient TCE concentrations are decreasing. Overall, the trees are having a positive impact on groundwater plume TCE concentrations and we expect in future seasons to continue to see accelerated TCE degradation in groundwater.