Prince William County Executive Robert S. Noe Jr. painted a picture yesterday of a county walking so precariously on a fiscal tightrope that restoring balance will require two politically unpopular measures -- tax increases and financing through bond sales.

Noe, addressing the first meeting of the newly elected Board of County Supervisors, described a locality heaving under the pressures of meteoric population growth and demands for increased services from a government ill-equipped to pay for them.

"We can't provide the level of service that the people are accustomed to receiving and the board has been accustomed to providing" without raising the county's real estate tax above its current level of $1.30 of assessed valuation, Noe said at an earlier news conference.

Noe, who serves at the pleasure of the seven-member board, said a dramatic real estate tax cut -- 12 cents per $100 of assessed valuation -- passed in 1987, an election year, had left the county government with "no flexibility" to provide better police, fire and social services.

In addition, he said pressing needs for road improvements and expanded county facilities must be met through the issuance of bonds.

Asked at his news conference about the cuts in services that would occur if his recommendations were not followed, Noe said, "I differentiate between pain and pinch, because it's more severe than pinch."

Noe's statements represented broad strides into what could be a thorny political thicket. At least two of the four new supervisors called for lower taxes during their fall campaigns.

Bond financing, moreover, historically has been among the most unpalatable political notions in Prince William, where most proposed issuances have been rejected by the voters.

The supervisors' reaction to Noe's statements was muted, with board members saying they will wait for Noe's annual budget proposal and capital improvements plan before passing final judgment.

"At this time, I would vote no," said Hilda M. Barg (D-Woodbridge), perhaps the most outspoken of last year's candidates in her opposition to taxes. However, she added, "I'm willing to look and listen."

Fellow Democrat Edwin C. King of Dumfries District was more enthusiastic. He said the board would "have to look very closely" at Noe's recommendations and predicted a majority would come around to supporting both a bond proposal and a tax increase.

Among the provocative ideas Noe put forth yesterday was a promise to improve county fire service, now provided mostly by volunteers.

Noe said he wanted to preserve the volunteer emphasis while beefing up the quality of service, which varies widely around the county.

Noe's interest may raise hackles among the volunteers, a fiercely independent and politically influential group that often eyes local government suspiciously.

With about 200,000 residents, Prince William is the second largest Northern Virginia locality. County planners predict the population will rise to more than 240,000 by 1990, and almost 300,000 by the turn of the century.

As Noe presented the supervisors with his "Major Goals" document -- intended as a general primer to the challenges facing Prince William -- he acknowledged that the county government had suffered from a widespread perception that its workings are secretive and ignore community concerns.

"We're doing what needs to be done, but we're not convincing the people," said Noe, who is in his ninth year in the county's top administrative job.

The county executive proposed several measures to buff the county's image, including annual opinion surveys to "elicit feedback" from residents.

"The county government must aggressively market itself to residents," his goals document said.

At the same time, Noe said that Prince William's urgent need to improve its tax base through economic development, and the recurring problem of where to place unpopular county facilities such as landfills, ensure that controversy will be a constant for the seven supervisors, four of whom are new to the board.

"The interest of the neighborhood is not always the same as the interest of the county," Noe said at his news conference. "Obviously, the interest of the county must prevail if we are to meet our challenges."

A vivid example of Noe's perception of county interests clashing with those of neighborhood residents surfaced later at the board meeting.

A parade of residents urged the supervisors to reconsider a proposal to expand the county's sanitary landfill off Rte. 234 in midcounty.

On a 6-to-1 vote, with Coles independent Terrence W. Spellane dissenting, the supervisors agreed to reconsider at a later meeting the previous board's action last month to aquire land to enlarge the landfill.

Also at the meeting, the board named its senior member, four-term Supervisor Kathleen K. Seefeldt (D-Occoquan), as chairwoman, and John D. Jenkins (D-Neabsco) as vice chairman.Staff writer Peter Pae contibuted to this report.