With oil dissipating, lawmakers focus on questions about chemical used in Gulf spill cleanup

Lawmakers focus on chemical used in Gulf cleanup

WASHINGTON — Lawmakers pressed scientists Wednesday to explain what effects a chemical used to get rid of oil will have on the Gulf’s ecosystem, even as a new report by the Obama administration characterized the effort as remarkably successful.

BP applied nearly 2 million gallons of a chemical dispersant to the oil as it spewed from the broken underwater well. The aim was to break apart the oil into tiny droplets so huge slicks wouldn’t tarnish shorelines and coat marine animals, and to make the oil degrade more rapidly.

A report released Wednesday by the National Oceanic and Atmospheric Administration shows that 9.6 percent of the estimated 172 million gallons of oil released into the Gulf of Mexico was dispersed by the chemicals.

Sen. Sheldon Whitehouse, D-R.I., called use of the chemicals a “grand experiment.” He said it was unclear whether it would limit damage from the spill, or cause greater harm.

Paul Anastas, the assistant administrator for the Office of Research and Development at the U.S. Environmental Protection Agency, said that while the effects of such a large quantity of dispersants are unknown, tests so far have not found dispersants near coasts or wetlands. Laboratory tests conducted by the EPA comparing the chemicals to oil alone and to mixtures of oil and dispersants also show that they are not more toxic.

“When you look at all of the tools to combat this tragedy … dispersants have shown to be one important tool in that toolbox,” Anastas told lawmakers.

But several independent scientists testifying before the panel Wednesday faulted the EPA testing.

“A laboratory experiment … doesn’t help us understand much of the environmental chemistry or its effects on other parts of the ecosystem,” said Ronald Kendall, director of the Institute of Environmental and Human Health at Texas Tech University.

David Smith, a professor of oceanography at the University of Rhode Island, told senators the EPA tests were not done under conditions similar to what existed in the Gulf, and that the organisms used in the EPA’s research had no relevance to the deep sea where the chemical was applied.

The chemical — Corexit 9500 — was on a federal list of preapproved dispersants, but in May the EPA directed BP to use less of the toxic chemical because its long-term effects were unknown.

While Corexit was used in previous oil spills, BP for the first time applied the chemical beneath the water surface, where the oil was coming out of the well. Typically, dispersant is applied to oil pooled on the surface. And never before had such a large amount of the dispersant been used.

On the Net:

EPA Dispersant Studies: www.epa.gov/bpspill