MFA’s Aquatic Adventures
Characterizing and cleaning up contamination in the aquatic environment can present significant logistical challenges. A sampling of MFA’s recent high adventure aquatic experiences includes:
Work in the navigation channel. Working up to 200 feet below the Willamette river bottom, MFA characterized sediment and groundwater at significant depths. The work required spudding a barge in the channel for hours at a time. Coordination with the Coast Guard was a critical element to implementing this work safely and successfully.
Remedies to accommodate property operations. MFA designed and oversaw construction of a 12-acre sediment cap at an operational barge building facility. Installation of a well-armored, low-profile cap that includes activated carbon and apatite allows for barges more than 3,500 tons, 422 feet long, and 80,000 barrels to continue to launch at this site as they have been for decades without expensive modification to launching infrastructure.
Coordination with collocated and concurrent projects. As the first step in constructing a new riverbank cap over contaminated sediments, MFA was required to coordinate with construction of the new public transit Tilikum Crossing Bridge that would occur in the same four-month work window. MFA devised an approach to remove over 2,000 piles in less than three weeks in order to keep both projects on schedule. Piles were cut with under water hydraulic chainsaws by three diver crews working 14-hour days, seven days per week and supported by two cranes. The piles were efficiently removed by allowing them to float to the surface and removing them in bundles.
Accomplishing these feats in the aquatic environment requires careful planning and foresight, and most importantly, being spry and flexible as the unexpected arises.