Fairfax County Executive J. Hamilton Lambert, responding to complaints that the county is sluggish in its review of site plans for commercial and residential projects, said last week that about two-thirds of the proposals are faulty when they are first submitted.

In a Sept. 15 memo to the county Board of Supervisors, Lambert said that statistics compiled for fiscal 1987, which ended June 30, should dispel the notion that the county has deliberately slowed the review process in an effort to limit development.

The memo comes as the frenetic pace of development in Fairfax is swamping county inspectors and dominating nearly every local political race, especially the one for county board chairman, which pits Republican incumbent John F. Herrity against Supervisor Audrey Moore (D-Annandale).

For years, developers have complained of costly, monthslong delays and backlogs in the processing of site plans in Fairfax. The county's response last week is the latest development in the tense debate over how long processing of site plans should take.

Lambert said that, according to the county's statistics for fiscal 1987, two-thirds of the plans submitted were flawed and had to be sent back to the project engineers.

The plans that have been rejected have had "serious code deficiences," Lambert said.

"It's not the process, it's the caliber of the plans being submitted -- or the lack thereof," he said.

But developers say they have heard that argument many times before. They maintain that Fairfax's response time is too long and could be shortened if, among other things, the county let them know sooner if their projects have problems and did not put resubmitted site plans on the bottom of the pile.

In addition, a number of engineers and developers have said privately that there is political pressure on the county staff to slow the pace of development in this election year. But county officials deny that charge and note that their statistics show that the number of major site plans reviewed, and, "more importantly . . . approved," has remained consistent in recent months.

Samuel Finz, a developer and former chief executive officer of the Northern Virginia Builders Industry Association, said that the county, in saying that a large number of the site plans it reviews are flawed and must be returned to engineers, is not taking its share of blame once again.

"Rather than acknowledge the fact that it takes too long . . . , they always say that engineers' plans are not acceptable," he said.

"I would feel much better {if} the government came out and told us they were handling the problem, rather than continually telling us they can't handle the problem."

One group that knows firsthand how long a site plan review in the county can take is the congregation of Beth Emeth synagogue. While congregation members concede that some of the delay resulted from their inexperience in such matters, they say they became so frustrated with the county's system that they hired a former supervisor to guide them through the process. They finally got their approval in July -- more than three years after they first applied.