Anchor QEA is currently assisting Alcoa in developing a comprehensive remedial action plan (feasibility study) to address sediments containing polychlorinated biphenyls (PCBs) within the 8.5-mile-long Grasse River Superfund site in Massena, New York.  As a member of a multi-discipline team, Anchor QEA developed and evaluated remedial alternatives including monitored natural recovery, activated carbon addition, capping (including ice control structures), and dredging.  The development and evaluation of alternatives included consideration of dredge plan designs, sediment dewatering and disposal options, in situ cap designs, construction sequencing and scheduling, and cost estimating.  To facilitate remedial action plan development, Anchor QEA developed mathematical models and assisted in the design and execution of several sediment remediation pilot studies.  The mathematical models were used to assess sediment and cap stability and to quantify the reductions of biota PCB levels associated with different remedial action strategies involving various combinations of natural recovery, sediment dredging, and capping.  Additionally, modeling studies were conducted to assess the impact of ice scour on sediment and cap stability.  The pilot studies on the Grasse River included an in situ capping pilot, a dredging pilot, and an innovative reactive cap pilot study.

Activated Carbon Capping Pilot Study
Anchor QEA assisted Alcoa with the design and implementation of a pilot study involving the placement of activated carbon within the sediments to reduce the bioavailability of PCBs to benthic organisms and fish.  The concept utilizes the sorptive nature of the activated carbon to sequester PCBs, thereby reducing their availability for uptake by fish and biota within the water and sediment.  Anchor QEA led a multidisciplinary team of consultants, the remedial contractor, and academia through the design and construction of the pilot study.  Design work included the conceptual design and fabrication of equipment specifically for the placement of activated carbon sediments.  Anchor QEA served as the construction manager during the successful field implementation, managing and overseeing all aspects of the construction including activated carbon placement, air and water quality monitoring, and sediment sampling.