A Method to Enable a Dynamic Spill Response Regime through the Use of Numerical Modeling
Aurelien Hospital, Jim Stronach, and M.W. (MAC) McCARTHY
On behalf of the Trans Mountain Expansion Project, a framework of numerical models was used to simulate the transport and fate of a number of hypothetic diluted bitumen spills in coastal BC. In addition to providing the required information for permit applications, the modeling framework also demonstrated its value with respect to establishing a dynamic spill response regime.
Dilbit Crude Oil, Properties, Weathering Behavior, and Spill Countermeasures
E. Taylor, G. Challenger, J. Rios, M.W. McCARTHY, C. Brown, and J. Morris
Diluted bitumen (dilbit) crude oil represents a range of oils produced from bitumen extracted from oil sands in Alberta, Canada. As these reserves are increasingly in demand, more transportation options are being sought to deliver the product to refineries both in North America and abroad. This paper provides a review of dilbit oil properties, applicable countermeasures, and potential fate, behavior and effects for spills to land, freshwater, and marine settings and compares these oils to other oil commodities that have been transported and used over the past decades.
Spill Response Plan Evaluation Using an Oil Spill Model
Aurelien Hospital, James A. Stronach, M.W. McCARTHY, Mark Johncox
Numerical simulation was used to evaluate the effectiveness of an oil spill response plan for the southwest coast of Canada. The plan was part of the permitting process for a proposed terminal expansion that would result in an increase in tanker traffic. The purpose of this response evaluation was to point the way to the development of a risk-informed enhanced oil spill response capacity that would be capable of managing large spills in coastal British Columbia. Mitigation inputs such as deployment time, storage capacity and speed were based on existing and proposed equipment. Results confirmed the need to reduce the time to first response due to the effects of currents on the floating oil and the close proximity of shorelines along the proposed shipping route. In addition, results validated the need to upgrade availability of early on-water storage capacity, which could be met by a large fast storage vessel, enabling the spill response to be more efficient and to obtain a much higher recovery rate.
Dilbit Crude Oil Weathering on Brackish Water: Meso-scale Tests of Behavior and Spill Countermeasures
Elliott Taylor, Greg Challenger, Jose Rios, Jim Morris, MAC McCARTHY, and Colin Brown
Oil weathering and countermeasures testing was conducted with Cold Lake Blend and Access Western Blend dilbits from May 13 through May 26, 2013 at the Kinder Morgan/Trans Mountain Pipeline pump station in Gainford, Alberta. Based mostly on visual observations, both dilbits exhibited properties that one would expect of a heavy “conventional” crude oil. In no instance was any oil observed to have sunk. Densities increased as oil weathered, approaching—and in some cases exceeding—values of 1000 kg/m3. Viscosities increased rapidly with weathering exceeding 10,000cP within 24 hours for both dilbits exposed to moderate agitation. Visual observations of the oil’s surface in the various tanks showed that a crust formed as the oil weathered. Chemical analyses of the weathered oils and water column showed that concentrations of BTEX diminished rapidly, although TPH values in the water column were variable and dependent on the degree of surface agitation. Countermeasures tested included dispersant application, burning, shoreline cleaners, and skimmers. Visual observations of the dispersant test revealed that Corexit 9500 was marginally effective on 6-hour weathered oil and not particularly effective for more weathered dilbit. The test burn on 6-hour weathered oil was effective with a sustained burn and an estimated 70% oil combusted. Estimates show that approximately 50% of 24-hour weathered oil was burned, but only after sustained effort to ignite. The 72-hour weathered oil was not successfully ignited. Tests with Corexit 9580 found the cleaning agent to be effective on oils weathered up to 5 days and applied to granite tile. Observers noted that the time oil weathers on water before being placed on the tile was less important than the time the weathered oil was exposed to air. The three brush skimmers tested all effectively recovered dilbit throughout the oil weathering tests.
The Critical Interval between Obsolescence and Abandonment: Hunting for a Pro-Active Solution to Commercial Vessel Scrapping
M.W. (MAC) McCARTHY and Devon Grennan
At some point in a ship’s life it will travel a timeline between economic obsolescence and scrap. Ending service in a scrap yard may well be a benchmark for responsible vessel ownership. However some commercial vessels, particularly those intermediate sized ships of marginal value and utility, may have a difficult time arriving at the scrap yard and subsequently make a course deviation into abandonment; once abandoned they become environmental threats usually harboring hazardous and noxious substances and impacting habitat. Abandoned vessels often pose latent economic threats typically as a navigational hazards and attractive nuisances. Solving the problem of an abandoned vessel often falls to the resource trustee who for lack of staff and funds may find it more expedient to ignore the case.
No coherent path to the scrap yard exists for the responsible owner of an obsolete vessel and that path may even be inconsistent at best to a resource trustee trying to proactively mitigate a derelict. Both parties face a series of permit hurdles across multiple agencies many of which lack an incentive to coordinate across jurisdictions. For the obsolete vessel owner the path of least resistance is to pass that vessel down to a marginal operator who may be the least capable entity to initiate responsible vessel recycling. For the resource trustee, the path of least resistance maybe inaction until the vessel becomes an emergency response.
No healthy ship recycling industry exists in the United States. Shipyards shy away from self-performance or leasing space to a subcontractor for liability reasons. A permit applicant desirous of proactively scrapping a ship upland would nominally face an uncoordinated battery of federal, state and local permit requirements that could further be subdivided according to special disciplines. In short, lack of a regulatory champion willing to address policy inconsistencies and barriers for the proactive disposal of derelict, abandoned and obsolete vessels threatens to channel these ships toward more costly emergency actions.Read More
Intertidal Zone Oil Recovery from the Buried Derelict S.S. Catala
M.W. (MAC) McCARTHY and Devon Grennan
In the spring of 2006 a beachcomber discovered black oil within the shipwreck of the Catala, setting-off an effort to remediate the wreck before the winter storm season created a catastrophic persistent oil release. 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 inflow. 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.