A Hazardous Convergence Lies Underfoot in Escondido : Toxics: Leaking oil and gasoline from four former service stations are poisoning the ground water. It’s happening throughout the county, in numbers officials call astonishing.

Below the bustle of East Valley Parkway and Ash Street, oozing oil and gasoline from four dead service stations have formed a kind of toxic crossroads, poisoning the ground water and threatening Escondido Creek.

Three of the leaks--like nearly 1,000 others throughout the county--were unleashed when neglected underground petroleum tanks eroded and loosed their contents into the shallow ground water.

The fourth spill was caused by Texaco mechanics, county officials say, who flushed waste oil down pipes that led directly into the soil.

The mechanics thought the pipes were attached to storage tanks, but they were wrong, the county says.

Together, the spills rest unseen below the surface of a gritty, noisy urban drag jammed with fast-food restaurants and dilapidated shopping centers and scented with exhaust fumes.

Although the county is dotted with similar spills, four separate messes so close together is atypical, county officials say, and a particularly egregious example of a statewide environmental issue.

“It’s a very major problem. There’s just oodles and oodles of these leaks all over,” said Michael Perry of the nonprofit San Diego Environmental Health Coalition. “Once you’re aware of what a cleanup looks like--a really large pile of dirt at a gas station covered with a tarpaulin--you’ll start to see them all over the place. Every tank that has been buried probably has leaked or will leak, given the time.”

Although the extent of the Escondido spills is uncertain, county officials say a leak from the now-defunct Express Gas service station is under and around the Ralphs supermarket on East Valley Parkway and is creeping toward the creek. More than 6,000 gallons of petroleum have been pumped from the site.

Ralphs, meanwhile, is moving across the street, but supermarket officials say the spill isn’t the reason.

“As far as we know, the contamination is not affecting Ralphs,” said Dan Avera, a county Environmental Health Services official. “If we thought there was a public health threat to Ralphs, it wouldn’t be operating.”

Across the street, another leak has sullied an unknown amount of soil below a busy Circle K convenience store, and 417,000 gallons of contaminated ground water have been pumped from below the nearby Parkway Carwash.

County officials say the Express Gas leak is probably the worst of the four; a foot of petroleum-soaked soil is floating on the ground water about 15 feet below the surface. The leak is also threatening to mingle with other leaks, which could blur responsibility for portions of the cleanup.

“It’s quite astonishing the number of tanks that are actually leaking,” said Bob Morris, a senior engineer with the state Regional Water Quality Control Board, which, with the county Department of Health Services, is responsible for forcing cleanup of the leaks. “It’s a difficult cleanup operation when you’re talking about chemicals dissolved in the ground water. It’s like trying to wash the soil.”

“The danger is being minimized each day,” Avera said, “but it’s still going to take some time to clean it. It’s a significant spill in that the ground water has been affected.”

Although Escondido Creek runs past the spill in a concrete culvert, county officials and environmentalists are worried that the petroleum could enter the already-polluted water through vents and cracks.

“We’re definitely concerned. The water is definitely disgusting already,” said Martha Blane, president of the Escondido Creek Conservancy, a grass-roots group dedicated to preserving the creek’s watershed.

Blane said fish and plants are already suffering from the heavy concentrations of motor oil, pet feces, household chemicals and other contaminants that residents discard in the storm drains.

The creek carries the contaminants along the stream’s winding course and into the San Elijo Lagoon nature preserve in Encinitas, Blane said, which is becoming clogged with dirty silt from the creek and elsewhere.

But federal soil experts studying the creek say road runoff and toxics intentionally thrown into the water pose a greater threat to the creek than the slow-moving spill.

“That one source I don’t think is that bad. All these sources as a whole could be bad. Clear as mud, right?” said Jason Jackson, a district conservationist with the federal Soil Conservation Service.

Morris said the spill would be far more serious in towns such as Julian and Santa Ysabel, where residents drink the ground water.

The county health department, meanwhile, worries about the petroleum reaching an enclosed space, where it could become volatile. The department is also monitoring the creek to keep tabs on the spill.

“If gas gets into a pipe or storm drain, it will become a potential explosive,” Avera said. “It will go boom.”

By the time cleanup laws and strict construction standards for underground tanks were enacted in the mid-1980s, decades of unregulated service stations had already left their mark on the environment.

Inspections in 1986 revealed that nearly half of San Diego County’s underground gas tanks were leaking and that many had contaminated ground water, said Ken Calvert, a county hazardous materials specialist.

Since then, about 7,500 old tanks have been hauled out of the ground, and 850 spills have been cleaned at an average cost of $100,000 each. Nearly 1,000 more cleanups are under way, including an estimated 100 in Escondido and many in El Cajon and San Diego.

Before the tighter laws, tanks were single-walled and no rules existed for monitoring them.

“It was really just a matter of time before the tanks would fail,” Calvert said. “In the old days, people would fix the leaks only when they were losing so much product that it was expensive for them.”

New leaks and new tanks are discovered often, he said, even though all tanks are supposed to be registered by the county so they can be inspected.

The new laws led to complex rules for installing and keeping watch over petroleum tanks. They call for double-walled steel tanks with a space in between that is monitored for leaks. It also sets up standards for reporting a tank’s condition and for cleaning up old spills.

State standards insist that, unless the ground water is naturally undrinkable, as it is in salty coastal areas, then the spiller must clean the water to drinking standards.

But officials acknowledge that often that’s impossible.

“It’s very expensive to treat the water after it’s been contaminated. And it can be so bad that it’s not treatable,” Calvert said.

Private cleanup crews have worked on the toxic Escondido intersection since 1986, when the Texaco and Parkway Carwash spills were discovered. A year later, the Circle K spill was found, and the Express Gas spill was found last year.

Workers have bored wells, pumped out petroleum and oil, cleaned the water and sucked vapors from the ground with huge fans called “blowers.” They’ve removed nine underground tanks and excavated soil, but the time-consuming task isn’t finished.

Officials with Eneco Tech, a San Diego company engineering the Express Gas cleanup, say they can’t estimate how much longer it will take to finish the job, but one county official guessed “years and years.”

Even after a diligent effort, some experts say, it’s impossible to guarantee that the land is cleansed. Testing methods are imprecise, they say, and chemicals migrate in unpredictable ways.

“Basically, the underground plumes are very hard to clean because the petroleum likes to stick to sediment,” said Laura Hunter of the San Diego Environmental Health Coalition. “And if it gets into water, it can emerge far from where the spill happened.”

But Calvert was more blunt.

“Once there’s a leak on a site, there’s always going to be a residual there,” he said. “It’s damaged forever.”