When Arlington officials recently announced that the county is likely to end the fiscal year with a surplus instead of the deficit projected last September, the response from County Board member Dorothy T. Grotos, a Republican, was quick and partisan.

The prediction of a shortfall, she said, was "political propaganda" designed to hurt the Republican Party this fall when control of the board will be in the hands of Arlington voters.

Walter L. Frankland Jr., the other GOP-endorsed board member, was equally vehement when the County Board's Democratic majority appointed a task force to study how families could be encouraged to move to Arlington.

Frankland said the plan smacked of "social engineering" and argued, with Grotos, that county staff shouldn't spend time to help fulfill what was a campaign pledge of Democrat board member Mary Margaret Whipple.

Such attacks have been increasingly frequent at the County Board's semi-monthly Saturday meetings since January, when Democrats took charge of the county government for the first time in four years.

The scrappiness the Republicans have demonstrated lately has led some politicians to conclude that the two conservative board members are laying the groundwork for a run this fall at third terms on the board. Grotos also has been widely mentioned as a possible candidate for the full-time job of county treasurer if the incumbent, Republican Bennie L. Fletcher, does not run again.

"I'm being encouraged to run for everything," Grotos said this week. "But most of the encouragement has been County Board-oriented."

Grotos has jokingly rebuffed questions about the fall campaign, saying campaigns should be "no more than four weeks"--a hint that she'd prefer to delay her decision as long as possible. Frankland all but announced a few weeks ago that he intends to run again.

The two board members have to make their decision before the Arlington Republican Committee's May 17 canvass, a selection process that is a cross between a party primary and a convention.

"I believe they both intend to run again," said board Chairman Ellen M. Bozman, a Democrat-backed independent. "They both appear to be running . . . . There is more sharpness and criticism recently than they've been accustomed to making in the past."

Grotos agreed that the two are "speaking up more" but attributes it to uncertainties inherent in Arlington's political arithmetic: For at least the next two years, the Democrats will have one more board member than the Republicans.

Maintaining a two-party presence on the board is expected to be the key issue in the coming compaign, Democrats and Republicans agree. So the question in GOP circles today is whether Grotos and Frankland, who are proven vote-getters, will seek reelection.

Should one or both decide against another board bid, many Republicans hope former County Board chairman Stephen H. Detwiler will run again. Detwiler, a GOP-backed independent when he was on the board, lost to Whipple last fall in the race that placed the Democrats in charge of the board.

Detwiler, a savings and loan executive who is considered a moderate, has not ruled himself out of the race. He is not expected to make his decision until Grotos, long active in conservation groups in the area, and Frankland, a Washington lobbyist for a silver users organization, announce their plans.

Meanwhile, the pair's barbs at board Democrats have led to often amusing exchanges that enliven otherwise routine meetings. And the remarks at times have caused some teeth-gritting by the Democrats.

Grotos' accusation about the deficit had Bozman counterattacking: "I'm very sorry to see her making charges I don't believe she can substantiate."

Virtually without exception in her 12 years on the board, Bozman said, the annual forecasts of deficits turn into surpluses as budget deliberations near and information becomes more accurate. Grotos made the same point last fall when she urged against taking the annual "gloom and doom" budget predictions seriously.

A similar deficit prediction last spring for this fiscal year prompted Detwiler to join with the board's two Democrats to raise the real estate tax rate by two cents--a move that Grotos said hurt him at the polls.

If there is a surplus, Grotos and Frankland are arguing, that increase should be returned to taxpayers. But falling property assessments and higher projected Metro costs are making it likely taxes will go up next year, the board's Democrats have said.

The county can save money by not implementing a staff reorganization proposed by County Manager Larry Brown, the Republicans have said. The county should be hiring more trash collectors than administrators, Grotos maintained.

Will such issues become part of a campaign platform this fall?.

"I'm not that politically oriented that I sit down and map out a campaign," Frankland said. "If they turn out to be campaign issues, so be it."