At 0630 hours, 0630 very dark, very cold, very sleep-inducing hours, the engines start coughing and spitting, and columns of exhaust smoke begin climbing toward the heavens.

The scene has the smell of a war movie - a World War II movie. We are on a mist-enshrouded Allied airfield preparing to launch a predawn bombing mission over Berlin. Men in uniform receive their assignments. assemble their gear, and give their machines the final once-over.

Where we really are, to be technical about it. is Service Area Two, Region Two, of the Solid Waste Management Administration of the Department of Environmental Services of the District of Columbia. ANd there is nothing special about the day, other than a wind-chill factor down around zero.

To most Washingtonians, the trash man is a CLUNK that invades our deep sleep a few hours before we are addressed by alarm clocks and family. Last night, if the head was sufficiently clear, we filled a plastic bag or two with ugly, unpleasant things, and left the package somewhere out back. And tonight - POOF! - VOILA! SHAZAM! - it will be gone.

To find out just how this disappearing act is accomplished, we spent a day with crew chief (and mobile equipment operator) Macon Moon, and environmental technicians John Hughes and Henry Philson. Every morning at this hour. Moon, a 27-year veteran who was handling solid waste long before anybody thought to call it that, firesup his Leach Packmaster - whose dashboard boasts as many gauges, dials. levers and pedals as the typical Allied bomber - and strikes out from the lot at Brentwood Road and W Street NE, accompanied by Hughes, a four-year man, and Philson, a self-described "rookie" with just six months on the job.

Today's route takes them first to the 1800 block of Upshur Street NE, where Hughes and Philson trade the warmth of the truck cab for the brisk alley air. They will not be back inside the cab until they have removed about 20,000 pounds of trash from the rears (or fronts, in a few cases) of about 600 addresses.

"We don't take no breaks." Moon explains, "cause we work task." When their day's work is done, in other words, it's done, whether it has taken them eight hours or four. (The average crew on the average day, according to Department of Environmental Services records, works 6.26 hours. The "tasks" were designed to take seven and a quarter hours, and that, plus two theoretical coffee breaks and one theoretical luch break, adds up to a theoretical full day.)

There has probably never been a job title that conveyed less of the flavor of the job than "environmental technician." Think of them instead as acrobats - or dancers. The whole operation, in fact, resembles a dance for three principal figures - two men and a truck - moving forward in alternating leaps and lurches, the men sometimes riding the truck, boots planted on the rear bumper, but more often trafling behind, hurling bags and cans and loose items of household flotsam and jetsam into the hopper, or charging ahead, readying the next cluster of refuse for the quickest possible handling.

At first glance, it is hard to figure why the crew chief is paid $6,36-$7.43 an hour and the technicians only $5,05-$5.90. But there is more to Moon's job than meets the eye. Washington is a city of alleys - wide alleys, narrow alleys, dead-end alleys, straight alleys, winding alleys - and Moon must know not only where one alley lets out, or meets another, but also which impossible-looking corner can be turned, and which can't. With two meager rear-view mirrors, he must continuously monitor the proximity of fences, curbs, lamposts and other such fixtures to the unseen extremities of a huge, unwieldy vehicle.

The intricate route he follows was once committed to official paper, but today exists only in Moon's and a few equally experienced heads. He has made some changes over the years - "They say you're supposed to go this way or that way," says Moon, "but they're not making the turns."

Nor can Moon afford to get too warm and comfortable inside the cab. The windows have to be left open so he can communicate with his crew, and his eyes have to stay trained on the rear-view mirrors so he can anticipate his crew's needs. Occasionally - when there is more than the usual loud at any one stop - Moon will step outside and lend a hand. "My job," he says, "is to set up here and drive and make it easy for them."

The law has a good deal to say about how District residents ought to store their solid waste, where it is to be left and when, which kinds of containers are acceptable and which aren't. Plastic bags, for instance, are supposed to be two to three mils thick. (Amil is equal to a thousandth of an inch.)

Environmental technicians are instructed to "report all instances where solid waste is not placed at the appropriately designated collection point, in one of the types of containers or combinations thereof indicated ..." But it is usually simpler to pick up after transgressors than to report them.

"Some people," says Moon, "will put glass in a plastic bag without a note to tell you it's there, and sometimes Varsol without a cover." Or dog litter - "When you pick up the bag you know what happens. COmes out of the bag on your clothes. Then you know what you're smelling like the rest of the day."

At a stop in the rear of Bunker Hill Road NE, someone has left a large, loose pile of odd-sized pieces of plywood and two-by-fours. "It's supposed to be in four-foot lengths and tied up so one person can handle it," says Hughes as he throws the lot, piece by piece, into the hopper.

At the next stop, "See how these people put their papers without tying it up?" says Hughes. "Little wind and they blow right away."

Another headache is the lightweight plastic trashcan available in super-markets and dime stores. When it gets a little cold, "they just break up in your hands," says Hughes. "They're just throwing their money away."

One such specimen is now down to the base plus a few jagged inches of wall, but rather than let it be gobbled up along with its contents, Philson returns it to its original station. He doesn't want to be accused of theft, after all.

The hopper is full and then-some. "Wind 'em up! Wind 'em up!" says Hughes, and Moon starts the hopper to churning. But even as the huge blade climbs from the bowels of the truck and seems to devour everything in sight, Hughes and Philson continue to stuff and stuff, apparently confident that the packer will manage to distinguish between solid waste and human flesh. And sure enough, their hands are returned miraculously intact.

Legend has it that the dog and the postman are natural enemies. But postmen don't deal with the same sort of dogs, or on the same terms with dogs, as 'environmental technicians.' For one thing, dogs have no God-given interest in reading people's mail.For another, alley dogs are a breed apart from street dogs.

Everywhere along the route, the dogs are on display - loose dogs, tied dogs, growling dogs, smiling dogs, imprisoned dogs making themselves heard from their sheds and garages; and dogs that must be half-wolf.

The arrival of the trashmen is, of course, THE major event in a dog's day. And where there are no living, breathing dogs on the premises, there is evidence of past canine activity - upturned cans, bags torn to tatters, refuse carefully scrutinized and spewed as far as the eye can see.

Crows are a lesser irriatant. "See them crows?" says Moon, and up ahead is a small militia of birds carefully maintaining a distance of 25 yards between themselves and the truck, driving their beaks through plastic bags considerably less than the required two mils thick.

And trees are still another hazard - the trees overhang narrow alleys and can knock a man right off the side of the truck if he isn't watching. Branches that are too small to strike such a blow can still leave a wicked impression if your face runs into them at 20 miles an hour.

"Watch them limbs out there!" Hughes warns. "Them limbs make you cry. Yes indeed!"

The front wall of the refuse tank is now in its forward-most position smack up against the truck cab, which means it's time to unload. So Moon leaves his crew behind to prepare the upcoming alleys, and drives the shortest route from 19th and Webster Street NE to the Fort Totten solid waste transfer station.

Moon is disappointed that they haven't crossed Michigan Avenue yet; most Mondays, they across Michigan Avenue before the first trip to the dump. But it's the holiday season, he explains, and volume is starting to build - "It's going to be awful from now right up through the 15th of January," says Moon.

At the transfer station, Moon backs his truck into an unloading bay, the hopper mechanism lifts clean up out of the body of the truck, and the contents are forced into a gaping trench, to be compressed and later whisked away by truck to a landfill site near Blue Plains.

Ten minutes later, Moon has rejoined Hughes and Philson, and they pick up where they left off. A discarded tricycle goes into the hopper ... a vacuum cleaner ... a stack of old textbooks .. a baby carriage ... a few thousand newspapers ... a few million leaves ...

A C&P phone company van pulls into the alley coming the opposite way, but suddenly shifts into reverse and is lost from view. There is no room for doubt about who is king of this alley.

We pull onto the grounds of the St. Gertrude's School of Arts and Crafts, which has been having its trash collected by the District for as long as anyone can remember, although private schools aren't normally so served. As we leave St. Gertrude's, a nun comes bounding out to hard Moon three blank white envelopes, while mumbling something or other about the onslaught of Christmas.

It is time for another trip to Fort Totten. "If we worked like the average crew," says Moon, "we would just be coming off the dump the first time. You know, taking the breaks and stuff like that." It is 10 a.m. now. Moon, Hughes and Philson will make a third and last journey to the dump at 11:30, then turn in the truck an sign off after five and three quarters hours of work - continuous work, that is.

As we ride back to the Brentwood Road lot, Macon Moon aplogizes for being close-mouthed. "We don't talk a whole lot, as you can see," says Moon.

But Henry Philson, who talks least of the three, has an explanation. "Short day like this have all your bones aching," he says.