Wednesday, May 26, 2010

Gulf spill lessons: Laud EPA for dispersant decision

By Linda Pilkey-Jarvis, Spill Preparedness Section Manager, Spill Prevention, Preparedness, and Response Program

We all should thank the U.S. Environmental Protection Agency (EPA) for showing leadership on the chemical dispersant controversy in the Gulf. As manager for Ecology’s oil spill preparedness program, I have learned a lot from the Deepwater Horizon oil spill response and their experience with dispersants.

More than 700,000 gallons of dispersants applied

The EPA regulates the approval of these products. More than 715,000 gallons of dispersants have been used so far in the Gulf – including 85,000 gallons that was applied underwater. Last week, EPA required British Petroleum (BP) to identify and use a less toxic, more effective product on the spill.

Less toxic, more effective dispersants needed

The Gulf brand, Corexit EC9500A, is on the EPA’s list of approved products but apparently has been banned in Great Britain for decades due to a limited toxicity test that produced negative results. The testing criteria in the United States are different than Britain’s.

This is something that should be looked at once the response is done. There may not be sufficient quantities of other, less toxic dispersants available in the quantities needed for this incident. However, BP should have been searching for that from the start.

Short- and long-term environmental impacts unknown

Dispersants are used to break up the oil and move it from the water’s surface down into the water column. The oil will more quickly dilute in the water. Dispersants and the dispersed particles are toxic. The decision to use dispersants is a trade off – removing oil from the surface and avoiding shoreline impacts – with the increased exposure to plankton or other water column organisms. The Deepwater Horizon underwater application is a new technique, the short and long term impacts are truly unknown.

BP, other companies reluctant to release information about toxicity

Because the chemical formula is proprietary, BP and other companies are reluctant to publicize the chemical composition to help address the question of toxicity. It’s a bad thing that BP initially refused to comply with the EPA’s directive. There was simply no call for it.

Washington State’s Corexit sent to aid Gulf spill response

Corexit is the same brand of dispersant we stored here in Washington before it was shipped to the Gulf to aid the response there. Our local cache was an earlier version of the product (Corexit 9527) which had a different chemical formula.

Valid answers – or maybe not

The Deepwater Horizon response is sure to answer a lot of questions about dispersants that have gone unanswered for years. However, because Washington’s waters are so different, including being much colder, the answers may not all directly apply here.

Dispersants have limited use here

In Washington, there are areas off the coast where dispersant use has been pre-approved, and in the deepest areas of Puget Sound there are areas with conditional approval – which means the decision will be made during the spill. All other areas in Washington have been disapproved for its use. We have never had to use dispersants on spill here yet.

Sharing lessons learned from the Gulf

We intend to keep blogging about the lessons learned from the Gulf and how they apply here in Washington. You can send us an email if there is a topic you want to hear about.

No comments: