Rep. Pete Stark was rummaging through a dumpster behind a Giant supermarket on 14th and Newton streets NW at around 8:30 a.m. yesterday. He was knee-deep in rain-ripened garbage and loving every minute of it.

"Ah, here's some cottage cheese!" he said, lifting out a container. "And here's some tomatoes, perfectly good tomatoes." Not worrying a whit for his tan poplin suit, Stark (D-Calif.) started lining up Giant rejects--white bread, cucumbers, apples, strawberries--on top of the dumpster.

It was raining. Stark was covered with garbage. But he was not alone. He was surrounded and well-observed.

This was the first of several supermarket stops on a media caravan organized yesterday by the Community for Creative Non-Violence (CCNV) in a campaign intended to dramatize food waste.

"Hey, Congressman!" yelled a cameraman. "Could you lift that stuff up a little higher so we can see it?"

Cameras whirred, flash guns lit up the dismal, gray scene, reporters zipped around as quickly as lab mice.

"That's just fine, Congressman."

And as Stark climbed out of the dumpster and headed for the van, another cameraman took him aside.

"Congressman, would you do us a favor? When we get to the next dumpster could you wait for the TV guys to get there before you climb in?"

"No problem," said Stark solemnly.

Giant assistant manager Ed Thomas walked to the loading dock, took one look and was not amused.

For a minute he was silent and confused. It's not every day you see a guy in a suit standing in your dumpster, looking happier than a pig in a poke. But after he saw all the cameras and the notebooks, it all clicked.

"Oh, man," said Thomas. "Hell, this ain't no good for me."

He turned toward the store's inner office.

"Hey, Jim. I think you better get here quick."

But by the time store manager Jim Embrey came out, people were heading for the vans.

According to CCNV member Carol Fennelley, the group has been able to feed 300 to 500 people seven days a week for the past 10 years at various D.C. "drop-in centers" on food scavenged from supermarket and wholesale-market dumpsters in the metropolitan area.

Reps. Stark and Tony Hall (D-Ohio) came along to call for congressional legislation that would discourage waste and encourage distribution to the needy of food that might otherwise be thrown out. CCNV members quoted a 1977 General Accounting Office report that found that 137 tons of food, 20 percent of total U.S. food production, is "lost or wasted" in all phases of production and consumption every year.

"The other day we found 50 frozen pizzas, still cold, in the garbage at a Grand Union on Old Georgetown Road in Bethesda," said CCNV member Justin Brown en route to the Safeway across from Van Ness Plaza for more high-profile scavenging. "What we just picked up today at Giant was below average. It's late; the garbage trucks have already been there. But sometimes we find things you wouldn't believe--produce, meat, canned stuff that's just a little dented, everything. We depend more on luck, though, than plan. I'd say it's best out near the Beltway in the suburbs, principally because it's probably easier for an inner city store to sell stuff that's a little beat-up."

But Barry Scher, director of public affairs for Giant, said most of the garbage in the dumpsters is "inedible."

"Giant does a lot for the poor," said Scher. "We give 20,000 pounds of food a year to Food Bank programs, and this is wholesome food, right off the shelf. If CCNV would declare itself tax-exempt, they'd be eligible for that food, but they refuse to fill out the form."

"We aren't tax-exempt because we don't believe another bureaucracy is a cure to people's needs. But that has nothing to do with the story," said Brown. "Food Bank and Giant's generosity is a good thing, but that program doesn't take in fresh produce and fresh dairy products. We still think that to discard edible food in these times when people are going hungry is wrong."

On Wednesday, in the Gold Room of the Rayburn Building, CCNV and congressional chefs will prepare a luncheon made solely from food scavenged from supermarket and wholesale-market dumpsters.

CCNV and Reps. Stark and Hall are hoping their supermarket dumpster caravan will help draw attention to their cause.

In the van, Hall, who stayed out of the dumpsters, turned to Stark, who didn't. Stark had just surfaced from a Safeway dumpster with boxes of glazed doughnuts and containers of French onion dip and Hungry Jack biscuits, gnawing on some white bread for the cameras and notebooks.

"I think you're beginning to stink a little," said Hall.

Stark smiled. "I sure haven't had trouble getting a seat."

Can he picture other politicians taking nose dives into the trash?

"Reagan might if he had prime-time coverage," said Stark. "And he'd probably come up with a pearl, saying, 'See what a little private enterprise will do?' "