INTERTIDAL ZONE OIL RECOVERY FROM THE BURIED DERELICT S.S. CATALA

摘要

Built in Scotland as a Union Steamship Company tramper in 1925, the S.S. Catala plied the coast of British Columbia for decades before ending her sailing career as a floating hotel in Ocean Shores, Washington. In 1965 a fierce Pacific storm capsized the 229' riveted steel-hulled vessel at her moorings transforming a real estate developer's dream into a local attractive nuisance. The casualty occurred at Damon Point, a land spit that has since become a State Park and is one of the coast's richest migratory waterfowl habitats as well as the nesting ground for two federal and state-listed threatened birds. Multiple salvage efforts had failed before the derelict's superstructure was cut away and the hull buried in the mid-80's. In the spring of 2006 a beachcomber discovered black oil within the Catala's rusted remains setting-off a Washington State Department of Ecology driven effort to remediate the wreck before the winter storm season created a catastrophic persistent oil release. Time was short: site access could not begin until August when the threatened birds vacated the spit; the contractor had to withdraw by the end of September when the site became vulnerable to ocean storm surges. Regulatory compliance was complicated: Ecology had to win fast-track permits from five separate agencies before they could authorize their contractor, Global Diving & Salvage, to begin work. Engineering was challenging: heeled over and buried in the intertidal zone, the Catala's keel was 26' below grade; a robust sheet pile cell had to be constructed to provide worker safety from unstable soils and manage water in-flow. Despite these conditions the project team was able to safely remove over 30,000 gallons of bunker oil from the ship delivering to the State of Washington a striking example of the benefits of a pro-active derelict vessel response. This case study will discuss the technical and managerial process by which this intertidal site was remediated.