Kirtland Air Force Base has faced a lot of criticism for how it has handled a decades old fuel spill that threatens Albuquerque’s drinking water supply. The base is now showing off what officials there are calling a monumental pump and treat system that’s cleaning the groundwater.
More than 15 years ago the Air Force discovered they had an aviation gas leak on their hands. On Saturday, Oct. 24, dozens of people climbed onto a bus headed to the site where that spill happened.
State environmental regulators have estimated that as much as 24 million gallons of fuel may have seeped into the ground over decades.
When the bus pulled onto the base where a team of cleanup experts are waiting to answer questions, the first thing people wanted to know was what caused the leak.
Wayne Bitner, an environmental restoration specialist with the Air Force, explained that in the 1950’s aviation gas was brought in on a railcar. The train ran directly over the underground pipe that was used to transfer the fuel.
“What we figure happened,” Bitner said, “was the train was coming in with a full load of fuel, and every time it goes over the track it’s just putting pressure on the pipe, bouncing it into the rock that’s underneath, and over time it just beat a hole, or holes, into the pipe.”
Adria Boudour is the chief scientist working on the cleanup for the Air Force Civil Engineer Center.
“It probably started with a drip-drip,” Boudour said, “and then that drip-drip became a leak-leak and then that leak-leak became super saturated.”
The Air Force began sucking vapors out of the soil around the spill site and burning them off several years after it was discovered. But the effectiveness of that approach was questioned by many people in the community.
The Air Force ran those vapor extraction units for over a decade, but only a fraction of the contamination was pulled out of the ground.
And the lack of treatment of the contaminated groundwater, not just the soil, has long been a bone of contention for locals.
For now the base has stopped suctioning the vapors out of the earth.
Boudour wants to boost oxygen levels in the soil to spur naturally occurring microbes to gobble up the toxins in hotspots of contamination.
That is an approach critics of the Air Force’s clean up efforts have been suggesting for years.
“Microbes love to eat this as a hydrocarbon,” Boudour said “it’s like kids and a candy store. And they’re indigenous.”
The most dangerous contaminant from the spill is ethylene dibromide, or EDB.
“EDB is actually a known carcinogen,” Boudour said. “That puts it in a different class. It’s also very soluble in water, so it kind of transports with it.”
So far a plume of EDB has spread more than a mile from where the spill happened, moving towards Albuquerque’s drinking water wells in the groundwater hundreds of feet below the earth’s surface.
This summer, months behind deadline, the Air Force finally started a pump and treat project. They pull water contaminated with EDB out of the aquifer and then treat it to the point that EDB is no longer detectable. Their hope is to pull the plume of contamination back towards the spill site and away from the city’s drinking water wells.
Dennis McQuillan with the New Mexico Environment Department said so far they’ve pumped about 13 million gallons of contaminated water out of the aquifer and recovered 5 milligrams of EDB.
“That’s a really small amount,” McQuillan said, “but it’s really toxic stuff. When you consider a little bit of EDB goes a long way, that was some very important five milligrams of contamination."
McQuillian said two more extraction wells will be running by the end of the year and they might build more in the future.
The treated water is used to keep the base’s golf course green, but some will also be injected back into the aquifer.
Boudour said she hopes they’ll only need to pump and treat for 10 years.
So far the cleanup has cost $100 million but Boudour said in order to finish the job, that number could more than double.