WHEN A COUNTY official is making development decisions involving millions of dollars at a time -- and contemplating future employment with one of the developers -- is there a conflict of interest, an unsavory atmosphere for policy-making -- or nothing to worry about? And what about after that official does quit the county -- should he or she be able to work on the same project on behalf of the private interests? Though questions similar to these continue to be explored on the federal level, the local impact on the lives of people can be far more dramatic and permanent. That is why the Fairfax County Board of Supervisors' unanimous decision last Monday to adopt some form of an ethics measure is as important as it is difficult to achieve.

Supervisor Audrey Moore, who has been pushing for passage of an ethics law since the early 1970s, wanted immediate action by her colleagues at the board meeting. She accused some members of trying to buy time in an attempt to sidestep the issue for the fourth time since 1980. While her concern is understandable, so is the reluctance of the other supervisors to approve a measure without weighing its possible defects. Board Chairman John Herrity, who has expressed his support for a sharp limit on the contact that a former supervisor or county employee has with the Fairfax government, says he merely wants County Executive J. Hamilton Lambert to review proposals before the board. That makes sense, because writing a precise set of restrictions is no simple task.

For example, how strict should limitations be on post-government service? A lifetime prohibition from reestablishing contact with the government? That's one proposal, and it strikes us as grotesquely restrictive. How about a policy discouraging former Fairfax employees from contacting the government on certain matters and directing current county employees to refrain from discussing those subjects with their former colleagues? That would appear to be closer to the mark -- but it depends on how it's drafted.

Full disclosure of contacts and associations can accomplish a lot. Yet who's to know what a county policy-maker might be thinking about future employment while still making up-or-down decisions on, say, sewer connections for developments? Mrs. Moore is right to keep her colleagues on the subject, and the supervisors should forward a proposal to the General Assembly for consideration as soon as possible. But first, please, a better discussion of specifics.