The reaction among federal workers in the Washington area to President Reagan's proposed 3 1/2 percent pay raise appeared yesterday to be less than wildly enthusiastic and often angry.

The White House termed the proposal "a modest increase," but at various local federal offices, most workers interviewed said the raise was paltry and would hurt already low morale.

Some were satisfied, but others said it would add to the pressure federal employes feel to leave government and to seek higher pay in the private sector.

"I think it is totally unfair," said Rhonda Belinc, an administrative intern who earns $17,500 at the Internal Revenue Service. "Wait till next year, an election year. Then we'll get a more substantial raise. But it won't help Reagan because we don't have such short memories."

"It's just not enough," said Priscilla Lee, a procurement agent for eight years at the Veterans Administration, "Every time we get an increase, everything goes up--rent, food, insurance. You're left with nothing. I suppose we could protest, but I don't think it does much good."

Peter Dunn, an IRS training specialist who makes about $35,000 after 15 years in government, said a bigger issue than the raise itself is "the way Reagan plays down the professionalism and competence of bureaucrats and plays down what we do. He has to ask himself how long professional people are going to stay in government if they keep taking it in the teeth."

At the Small Business Administration office at 1411 L St. NW, an SBA computer specialist laughed about the raise and called it "dog food. . . . It's about enough to feed my dog, not my family."

The SBA worker, like some others interviewed, asked not to be identified for fear of reprisals from his superiors.

But some employes were pleased to be getting any raise at all.

"I guess I am glad to be getting something instead of nothing," said Gerald Hegeman, a wage specialist at the VA who earns about $36,000 and calls it "very tough" to make ends meet for his family of five. "I expected we'd get a wage freeze, and I think this is a good middle-of-the-road solution," he said.

Deborah Johnson, 22, gasped and said, "Thank God," when she heard the news shortly after leaving her Air Force office in the Pentagon. She said she had been waiting for word of Reagan's decision. "We do enough work to get paid like our counterparts in private industry," she said, "This raise will help."

Johnson said she types Air Force responses to congressional inquiries on a word processor, a task that usually earns $8 to $9 hourly in the private sector compared to roughly $4 to $6 for her federal colleagues.

Thomas Lindmeier, 34, a lawyer who earns $38,455 after seven years at the U.S. Customs Service, called the raise "niggardly."

He said "it's another indication that this administration is penny-wise and pound-foolish. Because of this you have recruiting problems, retention problems and people who do stay simply don't have the morale any more. They aren't up to doing their job and fulfilling their responsibilities to the public."