A new study states that diluted bitumen, a raw material used as a feedstock in oil refineries, turns into a “heavy, viscous, particle-laden residue” after days of exposure, say, in ocean water after an incident like the Refugio Oil Spill. That’s not unlike the type of oil found on the beach and in the water by the people who attempted to restore the shore this past May.
The heavy crude that befouled Refugio may not literally be diluted bitumen, explained UCSB geochemist David Valentine, but it has characteristics that are more like diluted bitumen than the lighter oils to which current spill response is tailored. For instance, heavy crude tends to sink — instead of floating on the surface as medium and light crudes do — and it is very sticky. Valentine is among the authors of the paper and also a scientist researching the aftermath of Refugio, which gave a first-hand case study of spill response.
The study advises that federal agencies widen their response protocols to deal with heavy crudes and that the agencies and local government increase coordination, share lessons learned, improve planning, and conduct joint exercises. The study points out that the Pipeline and Hazardous Materials Safety Administration (PHMSA) could benefit from these approaches but is hampered by its lack of authority to respond to spills. The checklist PHMSA uses to approve spill response plans for pipelines might determine completeness, which is all it is required to do, but the method is a weakness, the study states. Because the agency does not use field staff, as Coast Guard and Environmental Protection Agency do, to examine the adequacy of rupture plans, the paper expresses concern that pipeline response plans lack the strategies needed for unique terrain, for instance environmentally sensitive areas, in a bitumen spill.