ALBUQUERQUE, N.M. — Environmentalists call it the largest threat to a city's drinking water supply in history, as much as 24 million gallons of jet fuel - or twice the size of the Exxon Valdez oil spill - seeping into an underground aquifer and steadily toward this drought-stricken city's largest and most pristine water wells.
But more than 12 years after the toxin-laden plume from a 40-year underground pipe leak was discovered at Kirtland Air Force Base, estimates of its size and its threat to the water supply of New Mexico's largest city keep growing, less than half a million gallons have been pumped out of the ground, the Air Force is two years away from finalizing a cleanup plan and local officials are still arguing about whether the spill is something they need to get involved with.
"We're pretty soon going to be swimming in this stuff, " Albuquerque Bernalillo County Water Utility Board member Rey Garduno said at a recent hearing held shortly after the New Mexico Department of Environment acknowledged the size of the spill could be as much as 24 million gallons, or three times previous estimates.
He called the spill a "traveling tsunami."
Although no one can really say how soon the plume might hit well fields, other board members remain confident the cleanup is in good hands.
"The good news is that Uncle Sam owns this, not some defunct railroad company," said board member Wayne Johnson, noting top Pentagon officials have assured state and local officials they would take full responsibility for cleanup.
Still, in a state where the nuclear bomb was developed and officials and environmentalists have fought for years for federal funding to clean up radioactive waste at Los Alamos National Laboratory and Kirtland's neighbor, Sandia National Laboratory, Uncle Sam's word is little reassurance to some.
"We are really running out of time on this," said Dave McCoy, executive director of the watchdog group Citizen Action New Mexico. "If this was above ground and you could see it, there would be squawking about it all the way to Canada."
The spill was first discovered in 1999 when the Air Force noticed a pool of fuel coming up out of the ground at its old aircraft fuel storage center, which dates back to the 1950s. Air Force officials say the fuel was leaking from an underground pipe for at least 40 years as tests on elements in the plume - which contains the cancer-causing Benzyne and other harmful toxins - show it dates back to at least the 1970s.
While fuel tanks now have gauges and modern technology that allow officials to more closely monitor how much fuel goes in and out, Kirtland civil engineer Brent Wilson says the leak dates back to the days when "the way to measure was to take a long stick and dip into the tank."
Initially, the Air Force estimated the spill to be about 100,000 gallons. But as more than 130 monitoring wells have been dug around the site, estimates on the size and severity of the spill have continued to grow.
In 2007, fuel was found 500 feet down in the aquifer that provides Albuquerque half of its drinking water. This spring, the state geologist who initially estimated the spill at 8 million gallons told McCoy he now thinks it could be as much as 24 million gallons. And a new report from the Air Force indicates rising groundwater levels have further exacerbated the problem, swamping some of the spill beneath the water table.
State and Air Force officials first tried to downplay the new size estimate, then conceded that while it is not an official calculation, nobody really knows the spill's size or when it might reach two of the city's key wells in the Ridgecrest field, the closest of which is 2 miles from the original spill site but less than two-thirds of a mile from what is now estimated to be the plume's leading edge.
"It is simply not knowable," says Jim Davis, head of the resource protection division at NMED, which has been designated by the U.S. Environmental Protection Agency to oversee cleanup.
It is also unclear, McCoy says, whether plans for essentially sucking the contamination out of the ground and water could cause the rest of the plume to travel in a new direction -- toward some of the city's nearly 100 other wells -- or at a faster rate.
It is exactly those types of questions and uncertainties, Air Force officials say, that are behind what the public perceives to be slow action on their part.
"Everyone is very concerned that when we do spend a dollar there is something that comes out of it and that we are not making it worse," said Wilson.
But he emphasizes the Air Force has already committed some $50 million and has hired one of the world's foremost experts on spill remediation, The Shaw Group. "We own this problem," he said.
A full cleanup plan is due to the state in 2014. But short-term efforts call for increasing the use of so-called soil vapor extraction, or SVE, technology that sucks the fuel from the ground and then burns it off.
The Air Force has four small SVE units operating near the source of the original leak, but they have pulled only an estimated 400,000 gallons from the ground since the first was put in place in 2004. Two larger units with 10 times the capacity are set to come on line later this year. And two other technologies are being studied for sucking and burning off the contaminants from water that has been trapped below the groundwater, Davis said.
Complicating matters is the erratic movement of the plume.
"We can't just stick a straw in it," Wilson said.
He said he was unsure if Shaw has ever dealt with a similarly complex spill of such magnitude. Requests for comment from Shaw, sent through base officials and separately by email and a phone call from The Associated Press, were not answered. The EPA also was unable to say if there has ever been a comparable spill that has been successfully cleaned up.
Bruce Thomson, director of the University of New Mexico Water Resources Program and a Kirtland-area resident who has followed the spill since it was discovered, said he believes other spills have been remediated from such depths, but on smaller scales or involving different types of contaminants.
While the New Mexico spill poses a "very real threat," Thomson said he believes any contaminants in the water supply would initially show up in very low concentrations, giving officials time to respond.
Still, he criticized the Air Force for waiting so long to start measuring the extent of contamination.
"Before they could develop (a remediation) plan they really did need to delineate the plume," he said. "That should have been done many years ago. That is being done now. And as they sink more (monitoring) wells they discover it is worse than they thought."
Associated Press writer Susan Montoya Bryan contributed to this report.