The Fairfax City Board of Zoning Appeals voted unanimously to deny a controversial application by Amoco Oil Corp. to build two 5 million-gallon gasoline storage tanks in an industrial park on Pickett Road.

Homeowners from neighborhoods adjoining the facility and representatives of civic associations throughout the city who spoke for more than 1,000 households opposed the proposed construction at a public hearing last week.

Betsy Beckman, president of the Comstock residents association, which represents the neighborhood bordering the tank farm, argued that the safety of nearby homes and businesses could not be guaranteed despite approval of the plans by the Fairfax City Fire Department and a pledge by Amoco to meet or exceed all fire safety and building codes.

Citgo, Chevron, Eastern, Texaco and Amoco have terminals at the tank farm, where tankers from area gas stations come to fill up at the rate of approximately one every two minutes. Amoco has six tanks at the site, with a combined capacity of 14.3 million gallons. The proposed 5 million-gallon tanks would have boosted Amoco's total capacity by more than 70 percent.

The concerns of city officials and residents over the environmental impact of the proposed tanks have been heightened by at least two incidents. One was the discovery in September of contaminated soil and ground water under the Texaco facility at the plant. Star Enterprise, Texaco's Virginia distributor, is investigating the contamination.

The second incident was the failure in November of an Amoco vapor recovery system designed to prevent toxic fumes from escaping into the air while tanker trucks are filling up. Low levels of a gasoline additive were detected in the air.

Explaining why he proposed the motion to deny Amoco the required special use permit, board member Allen Griffith said, "I think the records show, our newspapers show, that even the best-designed facilities can fail. These facilities are inherently dangerous . . . . And when they do fail we have cataclysmic results."

The motion was seconded by Rufus Caldwell and passed 5 to 0.

The vote affirmed a staff report that recommended against the plan because it said the new tanks would pose "many potential hazards to the health, safety and welfare of the residents and workers of the city."

Amoco lawyer Benjamin Trichilo argued that the city report was unfairly denying Amoco the rightful use of a property zoned for heavy industry in 1962, a decision that was reaffirmed in 1978 when Amoco was granted a permit to build one additional tank that referred to "future tank additions."

Fairfax City zoning administrator Dawn Heric told the board that changes in the city since the tank farm was built "have created an environment incompatible with such an intensive industrial use."

"The staff report makes points as if this property was not zoned industrial," Trichilo said. "I respectfully submit that there is a moral commitment by the city not only when it zoned this property but when it planned that expansion."

Trichilo also argued that a drop-off in demand for gasoline; plans to use the new tanks to store jet fuel, which is piped out of the facility; and expected new fuel efficiency standards would counterbalance any increases in tanker truck traffic that might result from the addition of the new tanks.

The board dismissed those arguments.

"I am not calling the applicant a liar," Griffith said, "but how the applicant proposed to say, 'We're adding 10 million gallons' inventory capacity for gasoline in that facility and trust us, not one additional truck will move on our highway,' beggars the imagination . . . . No reasonable explanation was given by the applicant of what they're going to do with 10 million gallons of gasoline if not move it."

Trichilo produced three experts on storage tank safety to support Amoco's case.

"These two tanks will be as safe as any storage tanks in the whole country," said Donald Johnson, chairman of the National Fire Protection Association, which sets safety standards for oil storage tanks. "There is no higher standard than this."

But the testimony was to no avail. "It appeared to me that the decision had already been made" before the hearing, Trichilo said after the vote. No residents testified in support of the tanks.

Fairfax City Mayor John Mason said in an interview later that the board "made the right decision. The potential for any kind of major conflagration near residential areas is simply not acceptable."

"I do not think that the decision will be appealed to the courts," City Council member Arnold L. Larsen said in an interview later. "After all, this is a very small tank farm."