The Prince William County Board of Supervisors recently declined to accept $4.3 million in federal money for an expanded mental health center in what is apparently the first time that such funds have been sought and then rejected by a local community before a new program was even started.

The supervisors' vote, reversing their decision of a year ago to seek the U.S. grant, also illustrates the growing reluctance on the part of local governments to accept federal grants that diminish annually once the new programs are established, leaving the financial burden for them on local governments.

Robert L. Dirks, executive director of the county's Mental Health and Mental Retardation Board, said the supervisors' decision "was not slanted against mental health . . . but rather against federal (and state) funds which dangle the carrot (by providing money for start-ups) and then leave the whole burden back on the county when the federal government funds end."

The supervisors recently refused to approve an applications for a similar type of grant from the Virginia state government to combat drug abuse, he said.

Prince William's 9-year-old mental health center currently has 23 full-time employees and operates on a budget of nearly $430,000, of which Dirks said the county contributes $173,000. The difference is supplied by patient fees, the state government and the cities of Manassas and Manassas Park, he said.

Under the expanded program that the federal funds would have financed, the budget would have risen to slightly more than $1 million in the year starting July 1, with the county contributing $230,000 of that and the federal government $640,000.

Over the next eight years, the federal share would have shrunk annually until the ninth year it would have been nothing. Meanwhile, the county would have had to finance an increasing portion of the program and most of the $1.2-million operating budget in the ninth year. That was the "scarcy figure," Dirks said.

The expanded program call for the addition of about 40 staff members who would administer 12 federally mandated services, including specialized programs for the elderly, an inpatient clinic, half-way homes for mentally ill patients and increased emergency services, according to its director, Dr. William L. Claiborn.

The Prince William mental health center was one of four programs approved out of 19 that requested federal funds in the mid-Atlantic region. The area is composed of the five states of Pennsylvania, Maryland, Virginia, West Virginia, Delaware and the District of Columbia.

Claiborn said he was "dumbfounded" by the supervisors' reversal. "I think we got caught in the world's worst timing," he said, explaining that the federal grant came up in county budget discussions this year at the same time that the supervisors had to advertise a "horrendous" tax rate increase of 90 cents for each $100 of assessed vaulation.

Alice Humphries, chairman of the Board of Supervisors, favored accepting the grant because she said she thinks the county needs more mental health services. She said the Board's reversal of its 1976 decision to seek the grant was due to the fact that "we have (had) a year to consider its impact."

She said the Board has adopted what she concedes is a relatively new attitude of "looking past the first year of 100 per cent funding and totaling out what it would cost the local tax-payers if they had to pay without any federal funds."

Clay T. Wood, the Brentsville district supervisor, said he voted against accepting the grant because, "I was just protecting the pocketbooks of my constituents."

The Mount Vernon Mental Health Center in Fairfax County was also one of the four successful applicants for federal funds.

Howard M. Collum, an aide to Fairfax's county executive, said the Fairfax supervisors unanimously accepted the federal grant for the Mount Vernon Center three weeks ago because "the county has had a substantial commitment to three mental health centers for 10 years."

He said the present Board is "more concerned (than past boards) about future fianancial liabilities and implications" of the so-called "seed" grants. The Board rejected one such grant to set up a county human rights office in February, 1976, Collum said.

Dirks said the mental health board's "pitch" to the Prince William supervisors was that "reality must set into them sooner or later" and that as a fast-growing county, the needs in the mental health area would not diminish.

Their reply was that they would rather work on a "pay as you go" scheme as mental health needs are identified to them each year, Dirks said.

Dirks said he himself "was not sure that Prince William County has defined needs for such a sizable grant right now."

Marty Noyes Stein, the mental health project officer for Virginia in the Department of Health, Education and Welfare's Philadelphia office, said her agency was "upset" about Prince William's decision. But she added that "We don't want them to reconsider if it's wrong financially. We want to see the center continue even after the funding ends."

David Frankel, spokesman for HEW's Philadelphia office, said that Prince William's rejection was the first time he recalls already approved funds being declined before they are used. Other grants have been partially returned either because the local people "could not deliver (the services) or because (the agencies) went out of business," Frankel said.