Dispersants, Alaska are bad mix, RCAC says

Wesley Loy

For Petroleum News

The executive director of the Prince William Sound Regional Citizens’ Advisory Council is reiterating his organization’s skepticism about the use of dispersants to respond to oil spills in Alaska waters.

Mark Swanson writes in the July issue of the council’s newsletter, The Observer, that until dispersants are shown to be effective and environmentally beneficial, the council “does not recommend their use and advocates for mechanical cleanup options with booms and skimmers that physically remove the spilled oil.”

The nonprofit, congressionally mandated council monitors the Valdez oil terminal and associated tanker traffic.

The unprecedented extent to which dispersants were applied during the 2010 BP Deepwater Horizon disaster in the Gulf of Mexico has heightened public attention and research, Swanson writes.

He notes the U.S. Environmental Protection Agency is slowly working through potential new regulations pertaining to the agency’s list of authorized dispersants. There’s also an “ongoing update of the Alaska Regional Response Team’s Dispersant Usage Guidelines.”

Swanson, who formerly headed the U.S. Coast Guard’s marine safety office in Valdez, says dispersants “simply do not seem like the best option for our local waters.”

“Council research has shown that dispersant effectiveness is significantly decreased in the cold and low salinity waters of Prince William Sound,” Swanson writes.

He continues: “Our research indicates that the underwater mixing depth available for dispersion in deep coastal Alaskan waters is reduced, in warmer months, to a shallow freshwater lens of glacial runoff and snow melt water sitting atop the denser saltwater. Council-funded laboratory studies have also shown that chemically dispersed oil is more toxic than naturally dispersed oil. These studies have demonstrated that key local species like herring, salmon and cod are adversely affected when exposed to far lower hydrocarbon concentrations than previously suspected, in the parts per billion realm rather than parts per million. Actual experience with dispersed oil in Alaskan waters is relatively limited and includes only small dispersant applications trialed during the Exxon Valdez oil spill in 1989.”

Swanson adds: “Other groups are becoming galvanized around the issue of dispersants. Dozens of coastal Alaska Native tribal councils have signed resolutions opposing the use of dispersants in their subsistence waters.”

Read Swanson’s full column online at http://tinyurl.com/l3mhgpx.