Drift River dike withstands Redoubt

OIl terminal survives flooding sparked by eruption heat

March 24, 2009 

The evacuated Drift River oil terminal, its tanks holding 6 million gallons of Cook Inlet crude oil, survived the first violent flood this week from the eruptions of nearby Redoubt volcano, government and industry officials said Tuesday.

Overflights and one on-the-ground visit Tuesday showed that some mud-saturated floodwater lapped over a protective dike early Monday morning when the Drift River rose 25 feet from the melting effect of hot ash and rock on Redoubt's ice fields, the officials reported. But the powerful river, which elsewhere scoured off the bark and limbs from mature standing trees, skirted harmlessly around the tank farm before receding.

"The system worked as it is supposed to," said Coast Guard Cmdr. Joseph Losciuto, the federal on-scene coordinator in the event of an oil spill.

But he and his state counterpart, Gary Folley of the Alaska Department of Environmental Conservation, said in interviews that they remain concerned about what the volcano may yet do and whether the earth-filled containment structure will retain enough strength to hold back the next flood.

"Our biggest concern is the structural integrity of the dike itself," Folley said. "Whenever an earthen dam encounters any kind of flow of water, it's going to weather and wear."

At a Tuesday press conference at the Alaska Volcano Observatory, a scientist sounded a note of warning: Redoubt is likely to erupt for months, while the source of potential floodwater is almost immeasurable.

"There's a lot of glacier up there," said geophysicist Stephanie Prejean.

The risks spurred a demand from the environmental organization Cook Inletkeeper that the crude in two partially filled tanks be immediately drained into tankers and hauled away to safety. The oil is about a third of what was spilled in Prince William Sound by the Exxon Valdez 20 years ago Tuesday.

"From our perspective, it's just common sense -- you don't leave that much oil at the base of an erupting volcano," Bob Shavelson, the group's executive director, said from Homer. "I think they're planning to do nothing. That's the cheapest thing to do."

But Lana Johnson, a spokeswoman for the terminal's operator, Cook Inlet Pipeline Co., said the oil could remain safely in the tanks. Keeping the tanks partially filled could prevent another problem if the dike is breached: buoyant tanks breaking from their foundations and floating away, a disaster that occurred in New Orleans during Hurricane Katrina flooding, she said.

Either the state or federal government could order the tanks to be drained if an oil spill were imminent, but the Coast Guard's Losciuto said that's unlikely for now. Draining the tanks below their normal working level would require a long startup period when operations resumed, potentially risking some Cook Inlet production. Unless the dike was weakened, there would be no reason to expect it to fail, he said.

"We're comfortable leaving the limited amount of product in those tanks," Losciuto said. "It's definitely better than having the damage and loss of the facility if the tanks were moved off their foundations."

An engineer from the firm that designed the dike plans to fly to the terminal today to examine its integrity, said Folley from the DEC. If repairs are necessary, heavy equipment has been parked inside the dike and is available.

The Drift River oil terminal is one of several on the west side of Cook Inlet connected by pipeline to offshore production platforms. Four of Drift River's seven 11-million-gallon tanks are operational. They are filled with oil from the platforms, then drained by tankers that deliver the oil to the Tesoro refinery in Nikiski on the other side of the Inlet.

But the facility was built in a floodplain downriver from an ice-encrusted volcano that tends to erupt every two decades. During the last eruptive phase, from 1989 to 1990, the tank farm was flooded, though none of the 37 million gallons then stored was spilled.

In response, Cook Inlet Pipeline Co., itself operated by Chevron Pipe Line Co., surrounded the tank farm with a 25-foot-tall dike made of earth and gravel and protected on the river side with concrete armor. The project, completed in August 1990, was untested until a series of eruptions began Sunday night.

Folley said the designers thought they had built the dike five feet above a projected 100-year flood. "It was considered to be an engineering marvel for the year," he said.

Eleven workers were evacuated by helicopter Monday morning. Some returned Tuesday and found parts of the facility outside the dike devastated by the flood. Part of the airstrip near a hangar was covered in 40 inches of mud, Folley said. But the workers were also able to start the generator that powers the facility, he said.

With the facility shut down, Chevron is storing its production at tank facilities at Trading Bay and Granite Point, also on the west side of the Inlet, said spokeswoman Roxanne Sinz.


Find Richard Mauer online at adn.com/contact/rmauer or call 257-4345.

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