(04/22/2011)

Paul Quinlan, E&E reporter

One word could describe U.S. EPA’s oversight of BP PLC’s decision to
pour 1.84 million gallons of oil-dispersing chemicals into the Gulf of
Mexico during the Deepwater Horizon oil spill: uncertain.

Responding to growing public unease last year over BP’s strategy of
fighting a massive chemical spill with more chemicals, EPA flexed its
regulatory muscle. The result was not confidence-inspiring: a shoving
match between the world’s largest environmental regulator and one of
the world’s largest oil companies that showed how little the regulators
understood about oil dispersants.

One year later, scientists say little has changed.

Decision making about the use of dispersants to combat the oil pouring
out of the Macondo well 5,000 feet below the Gulf surface were driven
more by politics, circumstances of supply and availability, and
educated guesswork than by informed science, experts say.

Some questions posed during the spill have been answered. For example,
the chemical constituents of the dispersant used has been published by
EPA and shown in rudimentary tests to be no more toxic or less
effective than competing alternatives.

But since the Obama administration has resumed issuing drilling permits
in the Gulf of Mexico, the most important questions remain unanswered:
How much did dispersants — as opposed to simple physics –contribute
to keeping oil underwater and out of Louisiana’s marshes? How effective
was underwater injection of the dispersants onto the wellhead? And what
long-term effects will the lingering chemicals and the dispersed oil
have on the Gulf of Mexico ecosystem?

“There are so many data gaps and uncertainties with the use of
dispersants and their effects,” said Carys Mitchelmore, an
environmental chemist and toxicologist at the University of Maryland’s
Center for Environmental Science and co-author of a 2005 National
Research Council report on oil dispersants. “Why hasn’t there been the
funding available to look into some of these things?”

After last year’s spill began, regulators seemed confused. Twenty days
after the rig explosion, on May 10, EPA told BP to monitor and assess
its use of oil dispersants. Ten days later, the agency ordered the oil
giant to switch from Corexit-brand dispersant to one of several others
believed to be “less toxic and more effective.” BP declined and
defended its choice. EPA criticized the company’s response as
“insufficient” and ordered BP to “significantly scale back” dispersant
use. BP did not (Greenwire, June 24).

EPA Administrator Lisa Jackson now defends her agency’s call to allow
BP to fight the spill using dispersants. “The chemicals helped break up
the oil,” Jackson told The New York Times in a recent interview.”It
was the right decision to use them.”

If that is the case, then on what basis did EPA decide to order BP to
ramp down dispersant use on May 26, two months before the well was
capped? EPA officials declined to comment. But other experts have
speculated.

“My view is that I think EPA was responding a bit to public concern and
pressure,” said Ron Tjeerdema, an environmental toxicologist and oil
dispersants expert at the University of California, Davis.Tjeerdema
was one of 50 scientists, engineers and spill responders that the
National Oceanic and Atmospheric Administration assembled during the
spill to decide whether to continue using dispersants. The panel
concluded that dispersant use should continue.

At that point, questions lingered over whether a better alternativet o
Corexit existed. A table listing 19 dispersants alongside crude
measures of the toxicity and effectiveness of each — part of the
National Contingency Plan (NCP) Product Schedule on file at EPA —
indicated that two Corexit formulas, 9500A and 9527A, might be among
the most toxic and least effective formulas in breaking up South
Louisiana crude oil (Greenwire, May 13).

The table became the basis of EPA’s decision, under pressure from
Congress and the public, to order BP to switch to one of the listed
alternatives. Mitchelmore said she later found problems and
inconsistencies in the testing methods that produced the data listed in
the NCP product schedule table’s toxicity and effectiveness ratings.

By then, EPA had already ordered BP to switch to something other than
Corexit. Upon BP’s refusal, EPA launched its own tests to see if a
better alternative existed. The results came back two months later on
Aug. 2, around the time the well was capped. To the agency’s chagrin,
BP was shown to be right. EPA’s tests showed Corexit 9500A was no more
toxic or less effective than any of the competing products, all of
which were stockpiled in vastly smaller and ultimately insufficient
quantities (E&ENews PM, June 30).

From the early days of the spill, BP’s purchase of Corexit represented
a third of the world’s supply. After the spill, in November, the
federal government’s Oil Budget Calculator report said of dispersant
use: “… were it a spill by itself, it would be one of the larger
spills in U.S. waters.”

But the scarcity of Corexit alternatives made the decision about
whether to switch to some other brand “a moot choice,” according to
Tjeerdema.

“The oil industry generally only stockpiles one at a time,” he said.
Tjeerdema recalled chuckling to himself over news reports that BP began
dispersing oil using Corexit 9527, an older formula that dates back to
the 1980s, before switching to 9527A.

“Right away, I understood they were getting rid of their old stockpile
that they hadn’t used for 20 years,” Tjeerdema said.”They’re kind of
efficient in wanting to get the most out of their stockpiled
dispersants.”

Breaking up is hard to do

Dispersants are frequently compared to dish soap — and in fact, share
some of the same ingredients. The chemicals break up oil — which
otherwise tends to cluster and float — into tiny droplets that can
sink and diffuse into the water column, so that bacteria and marine
organisms can more easily consume them.

Given the shortage of equipment available during the Deepwater Horizon
spill to burn, skim or otherwise dispose of the oil at the surface, the
question becomes one of environmental tradeoffs: Should the oil be
sunken with dispersants, at possible risk to deepwater marine
ecosystems, or be allowed to surface on its own and float onto beaches
and into marshes?

Tjeerdema, who served on the NOAA panel that recommended continued
dispersant use for the spill last June, stands by the group’s consensus
that dispersing the oil was “less environmentally harmful” than
allowing crude to migrate into the coastal marshes and wetlands along
the Louisiana coast, which act as nurseries for economically important
fish and shellfish and can be almost impossible to clean.

“If you take dish detergent and squirt it to your aquarium, it will
certainly kill your fish,” Tjeerdema said. “If you can put 2 million
gallons of dispersant into the environment in a way that it will mix
and bind with the oil to reduce overall toxicity, maybe that’s nots uch
a bad thing.”

But the chemicals do not just disappear. In the most comprehensive
study on the fate of oil dispersants used in the Gulf spill, Liz
Kujawinski, an associate scientist of marine chemistry at the Woods
Hole Oceanographic Institution, found that a key ingredient in the
dispersants — dioctyl sodium sulfosuccinate, or DOSS — remained
trapped in the underwater plume of oil that had spread 180 miles from
the well by September, even as it became almost undetectably dilute.

“There was sort of a public perception that the dispersant was just
going to go away,” Kujawinski said. “We concluded that dilution was
really the primary process.”

But Kujawinski reserves judgment on whether or not dispersing the oil
was a good idea. For one, she says, not enough data exists to show what
effect, if any, dispersants sprayed deep underwater had on breaking up
the oil gushing from the wellhead. She and other researchers note that
simple physics may have done more to keep the oil trapped in underwater
plumes.

Rather than second-guess the response, Kujuawinski says research should
be devoted to answering the most important questions: Did dispersants
play a significant role in breaking up the oil at the wellhead and
should sinking the oil have been the goal at all?

“We need to take a step back and say it’s happened and then say whether
or not it did what it’s supposed to do,” she said, noting that
responders had limited equipment for skimming and burning oil that rose
to the surface.

“The known negative impact of swamping the marsh with oil –that’s a
known problem,” Kujawinski said. “The big question is whether or not
they caused a different problem.”

Answers may not be forthcoming soon. As dolphins and sea turtles
continue to wash up mysteriously on the Gulf Coast, only $40 million of
the $500 million BP has committed to Gulf research has been disbursed
so far because of organizational delays. EPA has proposed additional
research into oil dispersants toxicity and effectiveness in 2012,
although the agency has come on the chopping block and already faces
$1.6 billion in cuts under the budget deal approved last week –likely
the first of many such spending fights.

For now, the puzzle surrounding dispersants remains unsolved, said Lisa
Suatoni, senior scientist with the Natural Resources Defense Council.

“In the end, we would hope that the government and BP would have a will
to put together that puzzle, and it’s not all clear from the research
that’s coming out that they do have that will,” she said. “It’s a
little discouraging if the interest in oil spill response research
lasts only as long as the oil spill response.”

Special thanks to Richard Charter