The Fairfax County Board of Supervisors showed perfect unity in Tuesday’s vote to give county employees a 2-percent bump in pay, and county workers expressed their gratitude too.

But there is unhappiness in at least one quarter — because, a tax watchdog says, that’s nearly how much county salaries consume of every dollar homeowners shell out in property taxes.

Arthur G. Purves, president of the Fairfax County Taxpayers Alliance, said Wednesday that number crunchers in his organization estimate that county employees’ salaries account for 25 cents of the $1.07 tax rate per $100 of assessed value on residential real estate. That’s too much, said Purves, who believes county homeowners are overtaxed to support county employees who are overpaid.

“When you consider pensions, they are much better compensated than the private sector,” Purves said in an interview on Wednesday.

Purves also disputed the assertion by public employees unions and some members of the Board of Supervisors that the three-year pay freeze has led to increased turnover and recruitment difficulties. Purves said county and schools continue to turn away large numbers of job applicants for every position that becomes available.

Purves also suggested that, this being an election year, the board’s unanimous vote was driven less by economics than by politics.

The Board of Supervisors, during Tuesday’s carryover review at its regular meeting, voted unanimously to give county workers a 2-percent raise. County officials said the total ending balance for fiscal 2011 was $104.4 million, of which about $59.3 million was unspoken for. Better-than-expected sales tax receipts, deeper-than-anticipated savings by agencies and other unexpected sources, such as the settlement of a lawsuit against the county that could have cost $8 million, freed up more money.

In deciding what to do with the unspent funds, the board agreed to spend nearly $23 million on a variety of “administrative adjustments,” such as $3 million to bring county facilities into compliance with the federal Americans with Disabilities Act, upgrading computer systems for $900,000 and spending $1 million on new leases for certain agencies. The Board also agreed to bank nearly $29 million in the face of an expected budget gap next year and approximately $10 million in damages caused by flooding earlier this month.

The pay hike, which was based on a formula that takes into account the rate of inflation and comparative salaries in the federal government and other jurisdictions, was the first in three years. Its total cost was put at $15 million in fiscal 2012, which began July 1.

Randy Creller, chairman of the Fairfax County Employees Advisory Council, told the board that a raise was overdue and should at least be 3.5 percent to help employees cope with rising costs for health care, food and energy.

“Your employees are currently being squeezed from all sides,” Creller said.

But Purves said Fairfax County homeowners are still smarting from tax bills that doubled under former Board of Supervisors chairman Gerald Connolly, who is now in Congress. Between 2000 and 2006, residential real estate taxes rose three times faster than inflation, the organization found.

“And most of that has gone to county pay and benefits,” Purves said.

Meanwhile, Matt Daly, an Arlington County firefighter and union representative, challenged the notion that Fairfax employees have slipped relative to their peers in neighboring jurisdictions.

Speaking only of firefighters, Daly, who is vice president of political affairs for Arlington Professional Firefighters and Paramedics Association Local 2800, said Arlington’s bravest have lagged Fairfax and Alexandria firefighters in pay for a long time.

“Like Fairfax, Arlington employees have not had pay raises in years. But, the raises for Fairfax employees (while overdue and admittedly deserved) only mean that Arlington will fall that much more behind,” Daly said in an e-mail. “For example, a typical mid-career firefighter in Fairfax working a 56 hour workweek, with 10 years of experience, earns $75,660.62. With the addition of the 2-percent increase, this amounts to $77,173.83. In Arlington, a firefighter doing the exact same job, also working 56 hours per week earns $62,441.60.”