Size of Exxon spill remains disputed

Federal scientists say the Gulf of Mexico oil leak is much bigger than initially estimated, eclipsing Alaska's Exxon Valdez disaster as the largest oil spill in U.S. waters.

But in Alaska, plenty of oil spill watchdogs remain skeptical that Exxon Mobil Corp.'s tanker spill in Prince William Sound in 1989 was limited to 11 million gallons.

Judging by the amount of oil that landed on 1,300 miles of Alaska coastline, "there's no reason to believe 11 million gallons," said Walt Parker, who headed the Alaska Oil Spill Commission created in the Exxon Valdez aftermath.

At one time, state lawyers pushed to verify the size of the spill, which killed thousands of birds and otters, hundreds of seals and eagles and damaged the livelihoods of many fishermen. But the state's interest in the matter ended after it settled its pollution case against the oil company in 1991.

Riki Ott, a Cordova activist, writer and fisherman, says a better estimate of the Exxon oil spill is 30 million gallons. She cites calculations made in 1991 by a marine surveyor the state hired to investigate the spill's size.

But 11 million gallons has become the official number. The Coast Guard accepted it. The number has been used in media accounts and scientific journals for the past 21 years. Lawyers for oil-spill class-action plaintiffs didn't challenge it, saying it was immaterial to their case.

If the Exxon Valdez instead spilled 30 million gallons, it may still top the Gulf leak.

Federal scientists' calculations on May 27 put the volume of the Gulf oil leak between 500,000 gallons and 1 million gallons per day, much larger than the ballpark estimate BP and the Coast Guard had provided in previous weeks. Unless the well can be sealed off, officials expect it to continue leaking until August. That's when BP is expected to finish drilling a relief well capable of stopping the flow.

"Practically every aspect of responding to an oil spill is contingent on knowing the scope of the problem they are dealing with," said Jeff Short, a former federal scientist who studied the aftermath of the Exxon spill. He now works for the environmental group Oceana.

Knowing the flow rate is important for environmental, legal and financial reasons, National Oceanic and Atmospheric Administration administrator Jane Lubchenco said last week.

The Gulf gusher has leaked between 23 million to more than 46 million gallons of oil, according to federal estimates.


The size of the Exxon spill came from Exxon and its contractors. It never received a complete investigation from state or federal regulators.

Many records from the state's case against Exxon are now housed in a special archive, on the University of Alaska Anchorage campus, devoted to the oil spill.

The records from the case show that just weeks before the 1991 settlement, the state-hired investigator, Texas marine surveyor Jim Murchison, told the Alaska Department of Law that the 11 million gallon estimate provided by an Exxon contractor company called Caleb Brett had "serious deficiencies."

Caleb Brett used some simple math: it subtracted the volume of oil removed from the damaged Exxon Valdez from the nearly 54 million gallons of oil the tanker was carrying before grounding on Bligh Reef.

But Murchison was certain that the Exxon Valdez's damaged oil tanks were holding seawater, not just crude oil, and wanted the state to get records that would prove him right or wrong. The tanks on the ship had "large holes" in them, and seawater would have forced its way into them when the oil gushed out, he wrote in a memo to a state attorney in September 1991.

Murchison wasn't the first to question the spill size, according to press accounts at the time. Salvage boat captain Nikki Hennessy, who responded to the spill, publicly disputed the 11 million figure in 1989, based on his observations at the scene and his belief that seawater had filled the tanks. Hennessy believed Exxon pumped large amounts of seawater into three tankers that came to remove oil from the disabled ship, and the company counted the seawater as oil.

Murchison calculated the size of the Exxon spill at 25 million gallons, at minimum.

"In time, all of the oil cargo in the damaged tanks would have spilled into the sea, the oil cargo in the forward tanks would have gone rather quickly. This loss would have been caused and accelerated by the pumping action due to the up to 20 feet, or more, of diurnal tide action, the reported 15 foot seas and the rolling of the vessel due to the tides and 'Ground effect' causing the vessel to slowly roll and list or heel between two and five degrees," he wrote.

He continued, "In addition errors were noted in the calculations of the oil on board the (tanker) on March 25, 1989. Most of the water cuts or soundings are questioned because of the large holes in the vessel, apparently the method used to differentiate between oil and water was providing inaccurate results which resulted in grossly underestimating the water and overestimating the oil."

"If there is any way possible we need the actual shore tank figures, for actual oil received ashore," Murchison wrote to a state attorney.

"Just between you and me it looks like a giant conspiracy to understate the amount lost to the sea and overstate the amount recovered from the vessel," he wrote in a memo to the attorney.

The civil case was settled on Oct. 9, 1991 and the state dropped the investigation.

State officials later said they were more concerned about how much oil landed on the beaches. Also, using the amount of barrels spilled to calculate a fine would have resulted in a lower payment than what the state received through the settlement, they said.

Exxon officials in recent years have ridiculed the theory that seawater was counted as oil when the oil was pumped off.

"What's in it for us to distort a figure like that?" an Exxon spokesman told the Daily News in 2004.

Exxon spokesman Alan Jeffers recently said the company doesn't have any better numbers to offer for the spill now than it did 21 years ago.


The debate over the size of the Gulf of Mexico spill mushroomed in recent weeks.

University professors and other researchers did their own math, came up with much bigger numbers and aired their findings in the national media.

After the complaints, the Coast Guard commander in charge of the spill response assigned federal scientists to study the matter. Shortly after that, they published the estimate that the well was spilling 500,000 to 1 million gallons a day.

Findlay Abbott is an Exxon Valdez class-action plaintiff who has tried unsuccessfully for years to get the 11 million gallon figure reconsidered for that case. He said recently he understands the difficulty of calculating the size of the Gulf leak, thousands of feet under water. But he remains outraged that government officials never verified the size of the Exxon spill, which he believes could be easily determined using the records that Murchison had requested.

"The evidence is overwhelming but people don't care. I just had a weird feeling that no one wants to know," Abbott said.

Abbott is still typing up legal filings. Though his previous motions in the class-action case have failed, he filed one just a few weeks ago, in which he claimed the plaintiff attorneys had opposed his efforts to "bring truth to the record and show the full reprehensibility of Exxon's behavior."

Find Elizabeth Bluemink online at or call 257-4317.

More Gulf oil spill coverage and photos