Re: Oil spill | Guest column

By Lovel Pratt

Washington State’s shorelines are not treated equally when it comes to dispersant use in the event of an oil spill. On the outer coast, a “no dispersant use zone” applies to marine waters that are both less than three nautical miles from the coastline and 60 feet or less in depth. A “no dispersant use zone” also applies to all marine waters south of a line drawn between Point Wilson and Admiralty Head. North of that line, including San Juan County, a “case-by-case authorization zone” applies to marine waters both within three nautical miles of the coastline or an island shoreline and greater than 60 feet in depth.

SJC shorelines are not afforded the same three nautical mile buffer from dispersant use as is the state’s outer coast and Puget Sound. Furthermore, 60-foot depths often occur very close to our shores (see the dispersant policy map, search “dispersant” at

The Friday Harbor Laboratories’ review on dispersant use in SJC assumes that a decision to use dispersants will be based on a formal environmental assessment that utilizes best available science; however, conflicting priorities may prevent that. The responsible party (the owner or operator of the source of the spill) has a significant decision-making role in a spill response. The incident commander position is shared by the federal and state on-scene coordinators and a responsible party representative. The responsible party’s prioritization of cost and corporate reputation could conflict with best available science in the decision-making process. The use of dispersants may cost less than traditional spill response tactics. Dispersants can make an oil spill “disappear” below the water’s surface, potentially reducing the visual images that can cause negative publicity for the responsible party.

The FHL review makes an important recommendation to investigate and stockpile dispersants that are less toxic and more effective than the dispersant currently stockpiled (Corexit 9500).

The review also points out that “much information on dispersant efficacy is based on laboratory tests and may not apply precisely to real-world spills.” Alaska addresses this: when dispersants are approved for use, Alaska requires a dispersant application field test to determine the dispersant’s effectiveness under existing site-specific environmental conditions.

If SJC remains a “case-by case authorization zone,” I recommend some additional conditions for dispersant use in the event of an oil spill: 1) Decisions to use dispersants are based on best available science; 2) The least toxic and most effective dispersants are used; 3) A dispersant application field test is required to determine the dispersant’s effectiveness in existing site-specific conditions; and 4) Compensation for the costs associated with environmental damages that can result from dispersant use is addressed.

The FHL review of dispersant use concludes that SJC should remain “case-by-case,” which could be applied to all marine waters in Washington state. In any case, SJC’s shorelines should be afforded the same considerations and protections as all other shorelines in Washington state. I thank FHL for initiating this community discussion before a major spill occurs.

Pratt consults on vessel traffic, oil spill prevention and response issues.