The risk of oil spills on the Columbia River is very low, a new study into vessel traffic and safety has found, but more tethered tug escorts might be needed if new marine terminals increase tanker traffic.
Less than 5 percent of the 1,400 vessels on the lower stretch of the river each year carry bulk oil as cargo, equating to more than 470 one-way trips. Most of the oil traffic carried refined products upriver to terminals in Oregon and Washington state.
The study, issued to the Washington Legislature in November, identified five proposed bulk terminals creating a potential of up to 1,379 additional one-way trips, mostly by tankers. Most of the terminal projects are in Washington state, including coal in Longview, methanol in Kalama and calcium carbonate in Woodland. A methanol refinery has been pitched for Port Westward near Clatskanie.
Opposition has grown fierce against a proposed oil-by-rail terminal by oil giant Tesoro Corp. and transportation firm Savage Cos. at the Port of Vancouver. The terminal could receive up to 300,000 barrels and send out one ship per day bound for West Coast refineries.
The last major oil spill on the Columbia River was March 1984, when the SS Mobil Oil grounded on Warrior Rock near St. Helens, spilling 200,000 gallons of heavy fuel oil. Rudder failure and improper maintenance were determined as the cause.
After the Exxon Valdez struck Alaska’s Bligh Reef in 1989 and spilled 11 million gallons of oil into Prince William Sound, the Oil Pollution Act of 1990 gave shippers 25 years to phase out single-hulled vessels. Tankers now have an outer hull and an inner, redundant layer in case of a failure.
The risk of oil spills is very low, said Brian Kirk of the Department of Ecology. But his department found that, in 2006 figures, a large spill could cost Washington state $10.8 billion and 165,147 jobs.
Nearly 40 percent of the risk of spills came from vessels grounding while powered, while one-third of the risk was from collisions with other vessels. Tankers are at greater risk than articulated tug barges, which are more likely to have redundant propulsion and steering systems that kick in after a failure.
The riskiest place for ships was at river mile 39, near Skamokawa, and the Julia Butler Hansen Refuge for the Columbian White-tailed Deer, because of a turn in the channel and rock hazards. Several groundings have occurred nearby in recent years, most recently the methanol and glycol tanker Argent Cosmos in July. Kirk said the study looked at stationing a tug nearby but found it not to be cost-effective.
“Even though it appears as a spike in the data, we’re still talking about small numbers,” Kirk said. “The risk of anything bad happening on any transit is very low.”
Given the relatively low amount of oil traffic on the river, the work group putting together the report recommended following existing safety rules.
“The big things coming out of the study that there was a lot more safety collaboration than Ecology and legislators were aware of,” said Dan Jordan, a Columbia River Bar Pilot who helps guide ships over the bar and helped in the study.
If traffic increases from a new terminal, however, the report recommends developing new policies to recommend a tug tethered to oil-laden tankers. Oil tankers do not currently require a tug unless there’s a mechanical or other safety issue, said Marine Science Technician Jeffrey Deronde with the Coast Guard. Barges towed by tugs often require a smaller “tag” tug at the stern to assist with steering.
The Department of Ecology was directed to produce the report after the passage by the Washington Legislature of the Oil Transportation Safety Act of 2015. The department contracted risk management consultant DNV GL to conduct the study.
Much of the work was through the Lower Columbia Region Harbor Safety Committee, an industry stakeholder group focused on safe and efficient river transit. The group includes the Coast Guard, regional ports, local governments, Columbia River Pilots, Columbia River Bar Pilots, shippers, oil spill responders, bulk terminal operators, shipping agents, the Merchants Exchange of Portland and other stakeholders in the maritime industry.
“We wouldn’t wait until those tankers actually showed up on the river,” Kirk said. “We think that starting work on that guideline sooner rather than later will help people understand how to best escort tankers on the Columbia River.”