Ballard Marine Construction, under the direction of the United States Coast Guard (USCG), and “unified command” among both the Washington and Oregon Department of Ecologies, took on a massive and carefully engineered project to prevent more than 32,000 gallons of bunker oil from escaping into the Columbia River from the Liberty Ship Davy Crockett. This ship was left to rest on the shore of the river near the Port of Camas. After an initial failed removal attempt by a private contractor, the SS Davy Crockett needed emergency mitigation.
Scope of Work
Ballard removed 4,450,000 pounds of steel, and another 824,822 pounds of debris, including wire, bricks, and oiled sorbent materials, and one point six million gallons of oil and/or otherwise contaminated water. All recovered materials were taken off-site for proper disposal. As per the USCG regulations, zero discharge of the contaminated water from inside the containment was allowed into the river. Prior to reintroduction of this water, it underwent a multistep treatment process on-site, then was sent off to local municipal wastewater to undergo further treatment.
The operation involved stabilizing the vessel and containment of the pollution threat. When local dry-docking facilities were unavailable for deconstruction, an in-river cofferdam containment was installed around the derelict vessel. Abnormally heavy spring runoff from the snow caused near-record river levels and high river currents. This led to zero visibility and created a challenging environment for many commercial divers involved in the operation. To further mitigate these record currents, a deflection, or shear wall, was installed to lessen the impact on the cofferdam.
The final process of this large-scale mitigation project was the remediation of the site back to its former state. Diver dredgers processed over nine million gallons of water and removed 100 cubic yards of contaminated sediment from within the containment area. Once finished, Ballard was able to complete this massive undertaking while ensuing no lost-time accidents, and no marine life harm.
Client: U.S. Coast Guard, Portland
Location: Camas, WA
Diver Depth: 40ft