Eighteen members of Congress yesterday said they would help out with the digging if Rep. Gladys N. Spellman (D-Md.) decides to bury President Carter's controversial federal pay "reform" plan.

What the group -- Democrats, Republicans, liberals and conservatives -- has in common is a back-home-federal workforce worried about the future growth of its paychecks. They range from sophisticated federal stock market regulators to radar technicians at Pearl Harbor and even the gang down at the country agent's office in Beckley, W.Va.

Legislators from Alaska, Texas and Guam joined their Virginia and Maryland metro area colleagues (who represent 14 percent of the U.S. federal workforce) to say that the president's plan is bad, ill thought out, a possible political power grab or worse. They don't like it.

Spellman was the person to tell because her House subcommittee is the first hurdle the Carter pay bill must negotiate if it wants to become the law of the land.

Carter's proposal, in brief would:

Give the president broad authority to set federal white collar and blue collar pay raises based on comparisons of pay and fringe levels among government, industry and local governments.

Link federal wages to hometown salaries in geographic areas set by the president or his agents.

Carter aides say the plan could save the government about $3 billion in a few years in reduced pay raises while guaranteeing civil servants in high-cost areas bigger boost than their colleagues in less expensive areas. Opponents say that is political double-talk.

Rep. Joseph L. Fisher (D-Va.) said the president's plan raises more potential problems than it solves, and appears even worse than the present federal pay-fixing system which, he said, has allowed private pay to go up 16 percent higher than federal pay since 1970.

Rep. Daniel K. Akaka (D-Hawaii) said the Administration had used "deceptive and misleading" data about federal pay to sell reform. He said the Carter bill is an "attempt to transfer public dissatisfaction over the problems of the nation onto the backs of federal employes where it does not belong."

Rep. Abraham Kazen (D-Tex.) said the large Hispanic workforce in his hometown of San Antonio would be hurt by the president's geographic wage scheme. "I hope you kill this bill," he told Spellman. Of all members testifying or submitting statements on the pay reform bill, only Rep. Edward J. Derwinski (R-Ill.) supported it.

Spellman said she is concerned about the extraordinary power any president would have in setting federal pay, and about the potential -- in "reform" -- to geerymander or readjust, federal wage-setting areas to raise, or lower, salaries. Normally Washington and its suburbs would be considered a high-cost area. That would make it likely that local civil servants would get relatively high future raises based on job matchups with local industry.

"But suppose," Spellman said, a president were to say "'okay Spellman, you, and Harris, and Fisher haven't been backing my major bills!" To punish them in the eyes of the voters, Spellman said, the president were to say "Okay Spellington wage area to include all of Appalachia."

As the day's hearings concluded, Spellman said something that could be very significant for pay reform. She said if future hearings continue to generate as much opposition to pay reform, it may have to be studied for a long, long time.