It was almost midnight Monday when the Fairfax County Board of Supervisors started talking about where to dump the county's trash.

The major items of the day -- a proposed bond referendum, the search for a new county executive -- had been discussed for almost 15 hours.

Suddenly, the nine-member board was wracked with a convulsive attack of the giggles that escalated into wild, raucous laughter.

"I can't remember what we were talking about -- it's all mush," said Supervisor Martha V. Pennino the next day. "One person just said something silly and we all started laughing. We couldn't stop."

Monday's length meeting -- in which major economic issues shared the agenda with minor sewer problems -- was in many way no different from the superisors' hundreds of other Monday meetings.

Every year, it seems, one board member of another vows to streamline the meetings. And every year, observers swear, the meetings get longer and longer.

What in the world, my bosses keep asking, do you do out there all day long? Well, folks, it's like this:

8:30 a.m. Arrive at the Post's Fairfax office to read the mail, with plenty of time to get to the supervisors' meeting. Having read the foot-high stack of documents from the county explaining the board's activities, I'm feeling fairly cocky.

I've done my homework on a $59.57 million bond proposal, a county employment discrimination case, an I-66 study, a Metro funding squabble. I know my editors probably won't want stories on most of the items, but I have to be prepared.

9:30 a.m. It's strangely quiet in the Massey Building, the hub of county government. The supervisors are huddled in executive session, ostensibly discussing "legal and personnel matters," all perfectly legal under Virginia law. While waiting for them to finish, I chat with a few county aides hanging around outside the door.

One has noticed The Post didn't carry a story about the supervisors' slap at Metro last week. "Good thing you didn't," he says, muttering an obscenity. "It was all just a lot posturing."

He cautions me not to tell anyone he's spoken to me -- a caution I'm getting often these days. Fairfax employes know better than to talk against the board. As a result, they've got more secerts -- or think they do -- than anyone I've ever seen.

10:30 a.m. The board convenes after an hour in closed session, most of it probably devoted to the search for a permanent county executive. Many in the cramped press room think the supervisors may offer the job to Acting Executive J. Hamilton Lambert, a puckish man who turned them down at least twice. Lambert won't confirm it. "My position is the same as it has always been," he says as he races by.

10:35 a.m. A discussion on a "transfer station" -- to treat the county's sewage -- precedes some political gyrations by the board's blustery chairman, Republican John F. Herrity, who is determined to get the board to reverse an appointment it made to the Civil Service Commission.

Twenty minutes of furious maneuvering by Herrity ends in something less than triumph. The board repeats its initial vote, and Herrity's candidate loses again, 5 to 4.

A few minutes later, Supervisor Sandra Duckwork (D-Mount Vernon) grumbles when discussion of another matter is cut short. By notion, the board reopens discussion. Duckworth has nothing to say.

11 a.m. The board moves swiftly through consideration of produce stands. A letter being sent to county commissions warning against entaglements with cable television companies looks as though it might produce a short story, but items on road-clearing and an application for federal refugee aid funds don't look promising. There are mostly reporters here now, with only a spinkling of non-media observers.

12:15 p.m. The board adjourns for lunch, with another executive session scheduled immediately afterward.

Supervisor Audrey Moore (D-Annandale) takes me aside in the county building's cafeteria to criticize a county study favoring intensive development along I-66. The development sites are in the middle of the Occoquan watershed, she says, and construction there would cause massive pollution of the county's main water supply.

12:30 p.m. In conversations with high-level aides, it becomes clear the board won't be giving me a story I had hoped for: a decision on what to do about a recent court order citing Fairfax for employment discrimination. The options are complicated, one aide says, and it isn't likely the board can sift through the options today.

Besides, aides say, the suprvisors are feeing more than a little insulted by the criticism of what they considered a strong affirmative action plan.

3 p.m. After a two-hour executive session, the board resumes its public meeting with a long list of zoning matters. The board postpones a decision on development of the Chiles tract, at Rte. 50 and the Beltway. There goes another story.

A supervisor's aide wanders into the press room. How did I get into the news business? he asks. My explanation must be wobbly because he leaves wondering why anyone would want to sit with the board all day.

5 p.m. The board hears the report promoting I-66 development, and several supervisors claim they were the first to support this now-popular idea. After listening to several collegues proclaim theselves as the first "lone voice" for I-66 development, Herrity says he's heard enough about the Lone Ranger: "Now, I'll call on Tonto."

6 p.m. Herrity calls the third executive session of the day, to discuss "legal and personnel matters and anything else we want to talk about."

8 p.m. More than 100 citizens arrive for a public hearing on the proposed bond package, but the board is still in executive session. Reporters are still trying to find out if there has been a decision on a county executive.

8:30 p.m. The executive session breaks up. At usual, the supervisors won't say what they discussed. "Well, we had some nice sandwiches and they had mustard on them," Duckworth says with a shy grin. "Don't worry, the county's in safe hands," says Supervisor Joseph Alexander (D-Leee. No news on the executive search.

8:35 p.m. More than two dozen citizens address the board on the intricacies of a bond referendum. Many comments focus on overcrowding in the county jail, but the supervisors also get an earful about sewer gas leaks and storefront libraries that don't have enough books.

11:30 p.m. Several supervisors show signs of wear. A motion to postpone action on the bond package takes longer than necessary because Alexander, probably testy from fatigue, wont't stop complaining about a procedural call by the chairman long enough to vote.

Midnight Most citizens and reporters leave, but the board continues until 1:15 a.m. As I stumble into the misty morning, I wonder about that aide's question. Why I am in the news business? At this hour, the explanation is still wobbly.