The Mobil gas station at Harbor Boulevard and Gisler Avenue in Costa Mesa is long gone, replaced with an urgent care center. There’s a credit union next door and a restaurant nearby. Palm trees and plants screen slate-and-stucco buildings from nonstop traffic. And kids from a neighborhood middle school laugh and jostle each other on their way home to the tidy houses down the block.
The Orange County Water District sees a threat beneath this suburban neighborhood: a mile-long plume of the now-banned gasoline oxygenate methyl tertiary butyl ether, or MTBE, tainting the soil and groundwater at concentrations up to 77 times the state drinking water standard.
The district traces the pollution to a 1987 leak from buried gas tanks at the Mobil station. It’s fighting ExxonMobil’s bid to end cleanup and monitoring there under California’s Low Threat Underground Tank Closure Policy.
“The company’s consultants didn’t even know this plume was there,” said Roy Herndon, the water district’s chief hydrogeologist. “One of the key criteria in the low-risk closure policy is that a plume is stable and decreasing. If a plume hasn’t even been delineated, then how can it be shown to be stable and decreasing?”
In a written statement, ExxonMobil spokesman Todd Spitler noted that the Orange County Health Care Agency continues to monitor the site.
“ExxonMobil’s goal is the same as the community's — to remediate as quickly and safely as possible,” Spitler wrote.
Herndon suspects the plume of subterranean pollution is heading toward a district drinking-water well.
“Every week, we’re getting new notices of sites being proposed for closure under this policy. And the question in my mind is how well investigated these sites have been,” he said.
It’s a question other water suppliers and regulators across the state are asking as well. Some of the most vocal skeptics are in Alameda and Santa Clara counties, which rely heavily on groundwater.
Problems in Santa Clara and Alameda counties
Local regulators once had broad discretion to judge what was appropriate for a site. In principle, though, most of California’s groundwater was to be considered potentially suitable for drinking, and pollution was supposed to be cleaned up.
Then, in August 2012, the State Water Resources Control Board started closing cases where there are still additives and petroleum in the ground, but where regulators believe they are stable and far enough from municipal wells that the pollution won’t pose an immediate threat.
That approach puts a statewide policy ahead of the cherished local authority of city, county and regional water officials.
In August state regulators closed down a site, despite objections from the Santa Clara County Department of Environmental Health, the Santa Clara Valley Water District and San Jose City Hall.
The gas station where the leak occurred is about 300 feet from a well in a city park that includes community gardens and an organic farm. Irrigation water comes from city pipelines, but officials have considered switching to the well. The three agencies asked for more studies to measure the contaminant plume. State officials refused.
That leaves volunteer orchard keeper Nancy Garrison frightened and angry.
“I don’t know how bad the contamination is here, to tell you the truth,” Garrison said. “There’s not much information that’s gotten out about it that I have picked up on, and I would like to be more informed.”
So would Tom Berkins, groundwater protection program coordinator at the Alameda County Water District. Berkins said district officials requested an exemption for agencies like theirs, which rely heavily on local aquifers for drinking water supplies. The state board declined, Berkins said, promising to confer with Alameda County on individual closure cases.
“We submitted a 14-page letter spelling out all the reasons why a case shouldn’t be closed. And the response (came) back, ‘It’s not necessary,’ without responding to the actual detailed comments that we’d submitted,” Berkins said.
“Focusing on the details of one side of a plume being unstable or not, when that is really no likelihood of impacting a well ever, that’s not a good use of our resources and our time,” he said.
A Southern California case shows how policy has changed
Twenty-five ago, California legislators established programs to clean up leaking underground storage tanks at gas stations and storage locations throughout the state. Some 43,000 leaks have been identified, and all but 6,000 have been resolved. The other contaminated sites have been stabilized and ruled no longer a threat to drinking water.
Many of the problems at the remaining sites are persistent and expensive to fix, like the former Sammons & Sons site in Lynwood. There, amid the rusting steel buildings of the defunct warehouse company south of Los Angeles, huge compressors force air deep into the ground. Bubbling back up through the groundwater, the air carries the residues of a decades-old gasoline leak to an air filtration system.
Until recently, remediation work like this was supposed to get the groundwater close to drinking water standards. That’s 1 part per billion for benzene, a known carcinogen, and 13 parts per billion for MTBE, which makes water taste like turpentine at only 5 parts per billion.
Recognizing that this standard of cleanliness is not always attainable, a long-standing Water Resources Control Board policy directs that pollution sites be cleaned up either to “background” standards -- the water quality in the surrounding area -- or the best water quality that is reasonable if background water quality cannot be restored.
The low-threat policy makes an exception for some petroleum leak sites.
Remediation efforts began at the Sammons & Sons site in 2006, and so far the site has cost the state cleanup fund slightly more than $1.1 million. Today, benzene levels in the groundwater are approaching 3,000 ppb and MTBE is close to 1,000, said Dwayne Ziegler, general manager for the site’s current remediation company, the Reynolds Group.
“That’s generally what you’re shooting for, to where you can stop cleaning up and close the site down,” Ziegler said.
The policy sets five classes for sites where it might be appropriate to end cleanup and monitoring.
They range from Class 1, where the contaminant plume must be under 100 feet long, to Class 5, which is determined by a regulator’s judgment that it doesn’t pose a threat to public health or the environment and will clean itself up in “a reasonable time.”
The policy makes no mention of tertiary butyl alcohol, or TBA, a byproduct of MTBE decomposition that has caused cancer in animals.
All these assessment tools rely on the fact that common microorganisms in the dirt consume such pollution in a process called biodegradation.
“At every underground storage tank site, biodegradation is demonstrating that it is working,” Graves said.
“The reason that we don’t see large petroleum plumes, (while) we do see widespread nitrate problems; we see widespread solvent problems, is because biodegradation is pervasive.”
Graves said that once a plume of petroleum pollution stops spreading, the microbes take over and it’s doomed. It might take decades. It might even take centuries. But eventually nature will clean itself up. Low-Threat seeks to define the point at which it’s safe to let nature take over.
The policy aims to ease the strain on a state account, funded by fees on fuel tank owners, that reimburses those owners for cleanup costs.
In 2012, a state performance audit found that remediation efforts sometimes took up to 17 years. In the preceding four years, the fund’s average total cost to complete a cleanup project nearly doubled, hitting $250,000, and costs for active projects had risen to about $400,000 per site, the auditors reported.
Today, John Russell, deputy director in the state water board’s Division of Financial Assistance, predicts that the fund will be about $2 billion short when it expires in January 2016.
“We need to get those sites that have been sitting around with nothing really going on, except for continuous monitoring out of the program, so that frees up money for sites where new discoveries have occurred, or sites that have been waiting to get into the reimbursement program,” McKeeman said.
Russell said the fund may expire without compensating most big companies, which are last in line for reimbursement, for their cleanup work.
In the face of such financial pressures, Russell said it’s only reasonable to make the biggest commitment to the state’s most polluted sites.
Reasonable calculation or gamble?
Where state officials portray a reasoned response based on proven science and fiscal responsibility, critics see a gamble that puts access to safe drinking water and the public health at risk.
Jim Munch, a former senior engineer with the Sacramento Regional Water Quality Control Board, said he can understand the need for stronger guiding policy. Over the years, authority over cleanup efforts had been divided among scores of local regulatory agencies throughout the state. In some cases, local officials with little training in groundwater remediation insisted on extravagant and impracticable cleanup programs, Munch said.
However, what the state board developed in response was a one-size-fits-all approach that doesn’t give proper consideration to local soil conditions or water use, Munch said.
For example, he said, in some mountainous areas with fractured rock in the ground, predicting the flow of water – and possible spread of contaminants – can be very difficult. In determining whether it’s safe to end cleanup efforts in such cases, it’s essential to rely on experts intimately familiar with the site, Munch said. But he said he sometimes saw state regulators far from the site invoke partial information in their own files to overrule local authorities who wanted to keep sites open.
Herndon, of the Orange County Water District, said a mistaken call on even one site could have broad implications. He is especially concerned by assertions that contamination like that around the Costa Mesa Mobil station won’t penetrate a clay layer between the aquifer where it’s spreading and the deeper aquifer set aside for drinking water.
“I’ve seen way too many examples where that’s not the case. Clay layers are laid down by nature, and they’re not always continuous, and they have holes in them,” Herndon said.
Barbara Bekins, a research hydrologist with the U.S. Geological Survey, said some deeper aquifers are anaerobic, or lacking in oxygen. In such cases, it may be harder to rely on biodegradation, she said.
But attorney Howard Mehler said that whatever the pressure to move cases through the system, Low-Threat undermines long-standing state policies that seek to preserve water quality. He said the policy could set a dangerous precedent for other cleanup programs.
“There’s always been an emphasis on maintaining the original quality of the water," he said. It's never been board practice that "every time you have a contaminant that’s difficult to remove, you adjust your baseline higher because it’s too expensive to remove that contaminant."
Mehler’s clients are landowners who once rented a corner lot in Northridge to a gas station, The station is long since closed.
At the site, he unlocked a gate and walked over to a monitoring well covered by a metal plate in the asphalt, next to a concrete block wall. On the other side of the wall, there’s a house. Mehler said MTBE has tested at 400 parts per billion here.
He said his clients would love it if the state declared cleanup work completed. They don’t want to be left holding the bag for a partially finished job. “If closure’s granted, they want peace of mind that it will be full and final,” he said.
Chevron spokesman Ron Spackman said the spill occurred long before Chevron acquired the station, and his company has been diligent in cleaning up a problem it inherited. The landowner didn’t respond to an interview request.
Other attorneys have written to the state board voicing similar property rights and liability concerns.
Communication and the final say
Unlike Mehler’s clients, water agencies that draw on local aquifers for drinking supplies say they have to start planning now for the possibility that climate change may compel them to draw even more heavily on their aquifers.
Russell, the reimbursement fund administrator, acknowledged that there are still divisions within his agency over Low-Threat.
“Everyone’s not on the same page,” he said. “There are still a few people who think the low-threat policy was a bad idea.”
Barry Marcus, who helped write Low-Threat while serving as the supervising environmental specialist at the Sacramento County Environmental Management Department, suspects some of those questioning the policy from within may have ulterior motives.
“If all of these sites get closed, or the vast majority of them, get closed, they’re going to be out of a job,” he said.
Still, Graves said he and his staff try to keep open minds.
“We’re not above being told that we’re wrong. And when it’s pointed out, we say, ‘Wow, you know, we didn’t think of that,’ or ‘You’re right,’ ” he said.
So far, the board has upheld local regulators and refused to close a case five times. Six other cases have been "noticed for closure," meaning that the board is leaning toward ending cleanup work there but is awaiting further public comment, records show.