Fairfax County Board Chairman John F. Herrity lashed out at Supervisor Audrey Moore yesterday, charging that her opposition to construction of the massive Westfields office park near Dulles International Airport was irresponsible and contradicted a position she had taken in 1982.

"Ms. Moore has flip-flopped on this issue," Herrity said in an interview. He said that Moore, who is concerned about traffic problems in the area, reversed a position she took three years ago when she endorsed a zoning change that Herrity said foreshadowed Monday's 5-to-1 vote. "You can't vote for something in 1982 and vote against it with invective in 1985," said Herrity, a Republican.

"It's not a truthful approach."

Supervisor Elaine N. McConnell (R-Springfield) also attacked Moore, accusing her of "hypocrisy" in opposing the Westfields project.

Moore, an Annandale Democrat and a maverick member of the nine-member board, disputed those charges, contending that the rezoning she favored in 1982 did not envision the massive amount of office development proposed in the 1,048-acre Westfields project. On Monday the board approved a redesign of parts of the project along with the proposed road improvements to be financed by the developer.

One reason she opposed the project, Moore said, was to block the total development of the Westfields site at a time when roads surrounding it are ill equipped to handle the increased traffic. While she conceded that the property would eventually be developed, Moore said that gradual, piecemeal development would give officials time to find the funds for road improvements.

At dispute in the exchange was a unanimous vote by the Board of Supervisors in 1982 to rezone most of what is now the Westfields property to allow low-density industrial development. The property, just south of the airport, is along the Va. Rte. 28 corridor (Sully Road) at the western edge of Fairfax County.

The 1982 rezoning was part of a zoning change implemented by the county that downzoned 40,000 acres in the Occoquan Basin area.

The basis of the charges leveled by Herrity and McConnell was that Moore voted along with the rest of the board on the 1982 rezoning and that the Westfields project approved this week merely confirmed that decision.

"This is making a bad matter worse," Moore said, alluding to the board's Monday vote on Westfields, an estimated $2 billion project that is expected to rival the Tysons Corner area in office space. "By encouraging this development, we're going to create a tremendous transportation demand that we're not going to meet."

The two Republican supervisors said the 1982 decision authorized industrial and office construction and that development of that type would occur whether or not they approved the Westfields project.

Supervisor Thomas M. Davis III (R-Mason) agreed, saying, "It was already [zoned] industrial. The underlying density was already fixed, and Audrey voted for that." Davis said there would have been "very intense development" at the Westfields site even if the board rejected the project Monday.

Moore said that although the developer has agreed to build four- and six-lane roads throughout the office park, the estimated 30,000 people expected to be working there by 2000 will still be faced with two-lane roads outside the development.

"This is just too much at one time," Moore said. "It's just too big."