Stay up to Date
MacKenzie Elmer's biweekly environmental news roundup (Mondays)
Monday, Feb. 25, 2008 | Nearly every drop of fuel consumed by San Diego’s cars, trucks and passenger planes is first piped from Los Angeles to an industrial site that sits in Mission Valley north of Qualcomm Stadium. More than a dozen rust-streaked white tanks along Interstate 15 store the fuel, which then gets trucked to the region’s gas stations.
The 10.5-acre depot, owned by Houston-based Kinder Morgan Energy Partners, has served as the region’s fuel warehouse since 1962. And sometime in the ensuing years — no one is exactly sure when — fuel began seeping out from the tanks there. It crept nearly a mile south, beneath Qualcomm Stadium’s parking lot and down into a groundwater aquifer the city hopes to tap for drinking water.
Recovering the ‘Lost Resource’
Much about the plume is unknown: Its exact volume, what caused it or when it started. But the sprawling streak of fuel is one of the region’s largest pollution plumes and narrates a decades-long story that highlights the challenges of removing contaminants from the environment, the often-slow regulatory process that governs cleanups and arid San Diego’s increased focus on finding every drop of water it can.
Ronald Reagan was still president when the leaking fuel was first discovered. The city estimates as much as 300,000 gallons of gasoline may have seeped beneath the surface. The pollution itself is not unusual. Thousands of gas stations across the country have leaked stored gasoline into the ground.
But the Mission Valley depot, which can hold 26 million gallons of fuel, was built atop an ancient streambed composed of gravel and sand — porous soil that allowed the fuel to seep freely. And the gasoline stored there contained MTBE, methyl tertiary butyl ether, a chemical that was first added to gasoline in 1979 to help it burn cleaner.
Without the MTBE, bacteria in the soil would have contained the leak, says Dave Huntley, a geological sciences professor at San Diego State University. Toxic chemicals in gasoline such as benzene are typically devoured by bacteria.
“It’s like a moving buffet,” Huntley says. “And the bacteria are sitting at the edge of it. At the leading edge, they love it, they can keep up with it.”
But they don’t eat MTBE. And MTBE dissolves in water. So by the time the leak was discovered in 1987, the groundwater around the plume had been contaminated.
Kinder Morgan, which bought the property in 1998, is responsible for cleaning up that toxic mix. The pollution should have been removed before Kinder Morgan made the purchase, but the cleanup was delayed as the previous owners — Shell Oil, Mobil Oil, Powerine Oil and Santa Fe Pacific Pipeline Partners — argued about who was responsible. The regional board, the county’s water pollution cop, initially set a 1996 deadline for completion when it ordered the cleanup in 1992. That was pushed back to 1999, and again to 2010 (the deadline for soil to be clean) and 2013 (the deadline for groundwater to be clean).
That’s much sooner than when Kinder Morgan once estimated it would finish cleanup: 2034.
Kinder Morgan won’t say how much it has spent on cleanup, as vapor extraction wells — giant straws that allow the gas to evaporate — have been dug throughout the city-owned Qualcomm Stadium parking lot.
Company spokeswoman Emily Thompson says the cleanup is on time and has reduced the plume’s size by 95 percent. John Serrano, a deputy city attorney, disputes that, saying the city believes as much as a third of the pollution, 100,000 gallons of gasoline, may remain.
The gasoline has dissolved in an aquifer that could supply water for 2,000 to 5,000 families a year. And the city wants to begin tapping that water supply by 2010 — not 2013. It has sued Kinder Morgan, aiming to expedite the cleanup process.
The lawsuit demonstrates the importance being given to region’s miniscule groundwater resources. San Diego County gets 2 percent of its water from the ground, importing about 90 percent. The City Council authorized spending as much as $500,000 on an outside law firm, Los Angeles-based Tatro Tekosky Sadwick, to pursue litigation. The two sides are still arguing pretrial motions in U.S. District Court and expect to continue doing so through the summer.
Before World War II, the aquifer beneath Qualcomm Stadium provided much of the city’s water, Serrano says. Ken Weinberg, director of water resources at the San Diego County Water Authority, describes the Mission Valley aquifer as “the lost resource.”
After the war, importing water from the Colorado River became cheaper, Weinberg says, and the pumping stopped. But as the region’s water sources face increasing pressures from drought, climate change and the Endangered Species Act, the equation is shifting back, he says, at the same time that the filtration technology that converts salty groundwater into drinking water has gotten less expensive.
“This is a natural storage place,” Serrano says. The aquifer “could hold a tremendous amount of water. It could make a big difference. It’s a reserve and resource we want to have protected.”
But some question the city’s pursuit of groundwater from a source near a gasoline tank farm. Even if the pollution is cleaned up, the tanks that caused it will remain. And tanks and pipes are just as likely to leak today as they were 20 years ago, says John Robertus, executive officer at the regional water board.
“If the city is that focused on having pristine water in the aquifer — yet the city is acknowledging the tank farm is going to stay there in perpetuity — it doesn’t make sense to me,” Robertus said. “My concern is that it could be re-contaminated by a future spill from the same site. People are improving their management methods, but every year those facilities are another year older.”
Huntley, the SDSU hydrologist, says he believes gasoline companies are more environmentally minded than they once were — if only because it can be cheaper to prevent pollution than to clean it up.
The days have ended, Huntley says, when gas levels in storage tanks were measured by jamming a rod down into the tank like a massive dipstick to see where gasoline wetted the rod. That process punched holes in the bottoms of many gasoline tanks, he says.
Thompson, the Kinder Morgan spokeswoman, says routine inspections, which include pipeline pressure testing, ensure the tank farm runs safely. But she offers no guarantee about the site’s long-term integrity. “You’re asking me to predict the future, and who can do that?” she says.