MAYFLOWER, Ark.—Homeowners whose lives are still in limbo after thousands of gallons of oil streamed into their neighborhood from a ruptured pipeline on March 29 might never know precisely how much of the sticky black goo oil actually spilled.
The working estimate is that 5,000 barrels—210,000 gallons—of Canadian heavy crude oil poured from a 22-foot break in ExxonMobil's Pegasus pipeline on that Good Friday afternoon.
But officials with the U.S. Environmental Protection Agency and Exxon say the actual amount can't be figured until the Pegasus is up and running again. That will allow Exxon to do a mathematical calculation while the line is operating at the same flow as it was when it broke open.
However, that scenario could prove problematic.
It's quite possible that the beleaguered pipeline, which stretches 850 miles across four states from Patoka, Ill., to Nederland, Texas, will never reopen. And, even if it does someday pump oil again, federal regulators have ordered Exxon to permanently reduce its operating pressure.
Karen Tyrone, vice president for operations of ExxonMobil Pipeline Co. told the Arkansas Democrat-Gazette last week that retiring Pegasus "is within the realm of possibilities." The 65-year-old line was manufactured using a welding process that's now known to be defective and with a type of pipe that is inherently brittle and prone to cracking, according to documents filed with federal regulators.
Figuring out an accurate count on barrels spilled is crucial because that number will help determine the size of the fines Exxon will face under the federal Clean Water Act. Civil penalties could range from $1,100 to $4,300 per barrel, depending on whether Exxon is found guilty of negligence or willful misconduct. Penalties for a 5,000-barrel spill could range from $5.5 million to $21.5 million.
The size of an oil spill can be determined in several ways.
Calculations can be made from data that the pipeline operator collected at the time of the spill. A count also can be based on the amount of oil collected during a cleanup, as the EPA's Chicago-based Region 5 is doing in Michigan, where the nation's largest oil pipeline spill occurred in 2010.
In Michigan, the EPA's on-scene coordinator devised a formula to track how much oil was being recovered, whether it was skimmed off the surface of the water or embedded in vegetation, soil, sediments or debris. The agency says more than 1.1 million gallons of oil have been recovered so far in the ongoing cleanup. The Canadian company responsible for that rupture, Enbridge Inc., disputes that figure, claiming only 843,444 gallons spilled.
When asked why the Arkansas and Michigan spills are being handled so differently, an EPA spokeswoman for Dallas-based Region 6, which includes Arkansas, said managers make their own decisions based on the unique factors associated with each cleanup.
"These are two completely different incidents, so to compare the two, we aren't able to do that," EPA spokeswoman Jennah Durant told InsideClimate News. "As far as I know, nobody from our region was involved in the cleanup in Michigan."
Nicolas Brescia, the EPA's Region 6 on-scene coordinator for the Mayflower cleanup, said the agency is keeping tabs on the amount of oil collected, but isn't doing its own tally.
"We are showing the waste collected and disposed of, but it's impossible to figure out the amount of oil in the debris," he said. "You lose some oil to evaporation, some gets absorbed into soil and plants, and some has to biodegrade on its own."
Brescia is confident that the 5,000-gallon estimate provided by Exxon is accurate as possible at this point.
"Until the investigation is done with the Department of Transportation and until they refill that line, we won't know the exact number of barrels lost," Brescia said. "Five thousand is what we're going with because that's the best number we have.
"If we felt maybe that [Exxon] was not 100 percent correct, we could give them an order to answer questions. But we typically don't run into that. There's no value for them to tell us an incorrect number."
Most of the spill site in Mayflower has progressed from the "response" to the "remediation" stage. That means that while the EPA is still involved in the cleanup, the Arkansas Department of Environmental Quality (ADEQ) is directing day-to-day operations on the ground. Brescia, who spent two months in Mayflower after the spill, still makes occasional trips to Arkansas and participates in weekly conference calls.
Philadelphia attorney Andy Levine, a former senior assistant regional counsel for the EPA, said the agency's approach to oil spills can depend on the dynamics of the individuals involved.