Remediation of PCE Contamination in Multi-Tenant Commercial Plaza
When this property owner decided to sell, this multi-tenant commercial plaza in the greater Boston area required remediation of tetrachloroethylene (PCE) contamination in groundwater associated with a historical operator. Contamination had been identified during due diligence, and it was very important to implement a time-effective remediation strategy with minimal disruption to various operating businesses.
Wilcox & Barton, Inc. chose a combined remedial approach to treat the PCE contamination. This included liquid activated carbon (PlumeStop®), an enriched, microbial consortium (BDI Plus®), and an engineered, hydrogen release compound (HRC®). We chose this approach because it combines the fast-acting capabilities of PlumeStop with the reductive dechlorination process enhanced by HRC and BDI.
High traffic at this multi -tenant site created challenges for the remediation team. Specifically, the operational hours of the various businesses required injections to be performed at night to maximize safety and minimize disruption, while the quick timeline called for the remediation team to complete the injections during the winter. As a result, the injection project was completed over ten days from 10pm to 7am in freezing conditions. Winter weather challenged the remediation team because they needed to prevent the remediation fluid, water supply, and equipment from freezing. Although the work was being done at night, snow plows and other vehicles commonly used the large parking lot, so visibility and traffic control were vitally important. Heaters were incorporated to keep the injection fluids in liquid form, and warming and rest facilities were provided for the injection team. Additionally, the driller provided lighting and traffic control. The injections covered a relatively large area and lasted for two weeks. The application event was successfully completed.
There have been four quarters of post-injection monitoring. In the first month following the injections, all but one residual monitoring well in the treatment area experienced drastic reductions of PCE to Non-Detect (ND) levels. Concentrations of residual PCE in the remaining monitoring well are decreasing towards ND and currently barely exceed the drinking water standard. Overall, the combined remedy was considered extremely effective in reducing the PCE contamination in the groundwater at a fast rate.