The Reagan administration's personnel policies are undermining activities essential to the nation's economic recovery and could cost the Washington area $2.5 billion a year in consumer and related spending, a congressional group has charged.

In a special "white paper" released by members of Congress with large federal worker constituencies, the Federal Government Service Task Force said that past and proposed measures to cut federal pay and benefits are distracting government employes from jobs that contribute to improvements in the economy.

"We see a poisoned work environment in agency after agency, not just the Environmental Protection Agency," said Rep. Michael D. Barnes (D-Md.), chairman of the task force. "Fear and distress divert employe attentions from public service to self-preservation."

Barnes said that reductions in force, increases in health insurance costs and current and proposed changes in federal pay and retirement benefits have left the government work force in disarray. And this, in turn, hurts private sector firms that depend directly or indirectly on federal programs, statistical data and expertise, Barnes said.

Objecting to the report, Mark Tapscott, assistant director for public affairs at the Office of Personnel Management, accused the task force of partisanship and said "any evaluation of federal employe morale has to be considered in that context." He noted also that there had been a morale problem in the federal work force before Reagan's election.

The task force report, released Tuesday, listed several areas in which it contends pay and benefit cuts and employe preoccupation with these problems can affect the quality of federal service on behalf of economic recovery. Federal employes, it said, implement recovery programs, help eliminate waste and inefficiency, identify market trends and sustain citizens most in need. They also contribute to the economy as consumers and taxpayers, so that declines in their income affect the jurisdictions where they live.

The impact of current and proposed federal personnel actions, according to the task force, could cost the Washington region $2.5 billion in consumer spending, loss of state and local revenues and related declines in economic activity. Nationally, the loss could total more than $15 billion.

Tapscott, while not challenging the figures, said he wondered if Barnes or Rep. Steny H. Hoyer (D-Md.), another task force member, had considered the per capita cost to their nonfederal constituents of the civil service retirement system's "half a trillion" unfunded liability. He said it amounted to more than $440 million for all nonfederally employed families in Prince George's County and more than $500 million in Montgomery.

Focusing on the Reagan budget, the task force said proposals to freeze federal pay and raise the employe contribution rate for civil service retirement would amount to a 2 percent pay cut for workers.

Hoyer criticized the administration for making further changes in the civil service system despite the recommendations of its own pay panel that federal wages should first be made comparable to the private sector. And he said federal retirement benefits are not as generous as perceived when compared with stock options and other benefits offered by large private sector employers.

Task force co-vice chairman Rep. Barbara Boxer (D-Calif.) has introduced a resolution co-sponsored by 13 other House members calling on the House to reaffirm the government's commitment to maintaining the full value of retirement benefits for current and future retirees.