About 2,000 gasoline dispensers at California service stations are gradually being repaired after a discovery that they have been leaking large volumes of smog-causing fumes into the air, probably for several years.
The state Air Resources Board has detected faulty vapor recovery systems manufactured by the Wayne Division of Dresser Industries Inc., known as Dresser Wayne, and installed at many gasoline stations. Nearly half of the dispensers made by the Maryland-based company are leaking, but similar equipment made by other companies is not faulty, according to air board officials.
When working properly, anti-smog nozzles and hoses are supposed to be highly effective, eliminating 95% of the fumes that seep into the air while motorists fill their tanks.
The amount of hydrocarbons, a key ingredient in smog, flowing from the faulty nozzles is extremely large--about 13 times the emissions that normally come while fueling a car, said air board spokesman Allan Hirsch.
The 2,000 faulty systems constitute about 4% of gasoline dispensers statewide. But the extra pollution they emit amounts to seven tons a day statewide, equivalent to the emissions of several massive oil refineries combined.
In addition to forming smog, gasoline fumes contain cancer-causing compounds, so motorists face an unexpected health risk as they fill their tanks with the company's nozzles.
"It's a very significant problem," Hirsch said. "Because these systems are not working properly, there are a lot of emissions going into the air that should be captured. It was clear to us that something had to be done."
Many of the stations with Dresser Wayne dispensers are Mobil and Shell stations, but there is no way for motorists to tell whether the nozzle they are using is faulty.
Some of the leaks, however, are so severe that people can smell fumes. With functioning vapor controls, there should be little, if any, gasoline odor.
Dresser Wayne representatives did not return phone calls on Thursday.
The faulty fuel systems apparently escaped notice for years. They were first installed in some new stations in 1994 and phased in at existing stations over the past four years. It is not known when the leaks began.
The defects were detected last fall during inspections the state agency conducted in the Bay Area as part of an audit of the area's air pollution programs. Further testing uncovered widespread problems statewide.
One reason the pollution escaped detection for so long is that the South Coast Air Quality Management District had discontinued its inspections of gasoline stations in the Los Angeles Basin. The AQMD, as a cost-saving move, was instead using an honor system that let the stations report their own problems. The agency resumed inspections last year.
Vapor control systems have been required in California gasoline stations since the 1970s and are considered one of the most cost-effective anti-smog technologies in history. Before their use, automobile refueling was a leading source of air pollution.
The current problem was discovered in so-called "bootless" nozzles, which have metal spouts instead of the unwieldy, rubbery ones that motorists often have complained about.
A vapor recovery line is supposed to pull fumes back into the dispenser. But in the defective systems, the aluminum spouts wore out, causing leaks. Because the configuration of the tubing was improper, those leaks of gasoline plugged up the line, causing vapors to vent into the air.
"If the system was designed properly, it wouldn't have happened," Hirsch said.
The Air Resources Board issued a violation notice to Dresser Wayne and last month ordered the company to retrofit all its dispensers with new piping. Also, the maker of the spouts is replacing aluminum with more durable stainless steel.
The company reported to the state agency that it has fixed dispensers at 13 stations so far and shipped 100 repair kits to California last week. Each station has an average of five dispensers.
Repairs are starting in the Los Angeles Basin, which has the most severe smog, then will move on to the Bay Area, followed by the rest of the state.
"We've been working with Dresser Wayne to try to get a solution to this problem as expeditiously as possible," Hirsch said. "We want the whole state to be finished within a matter of months, hopefully by the end of the year."
Service station owners were not blamed for the malfunctions because they bought equipment that had been certified to meet state standards.
"After the fact, unfortunately, the equipment was found to be faulty," said Jeff Wilson of Western States Petroleum Assn., an oil industry trade group. "There was never any intent to violate requirements."
Ron Wilkniss, the oil group's air-quality expert, said the "conversion, of course, isn't going to happen overnight," but the "bottom line is we collectively are on the road to solving the problem."
Wilkniss said the leaks are caused by "a basic design shortcoming," so the excess pollution has probably occurred ever since the dispensers were installed.
To avoid future problems, the Air Resources Board is considering forcing gasoline stations to install warning devices that alert owners to leaks.