The national debate over the Affordable Care Act seemed an unlikely topic of discussion at Tuesday’s meeting of the Fairfax County Board of Supervisors — especially since the item on the agenda was whether to reappoint a longtime member of the local water authority.

Yet the law was what the supervisors focused on, specifically a letter to members of Congress written last fall by water board veteran Burton J. Rubin, warning that the insurance requirements of the Affordable Care Act would cause the water authority to stop insuring its employees.

“[I]t is irrefutable that the ACA is fatally flawed,” Rubin wrote last September to the Virginia congressional delegation, urging them to push for changes in the so-called “Cadillac tax” provision in the law that punishes companies with expensive health-care plans.

“If it is intended to make health care coverage available to those who do not have it, it does so only by jeopardizing the coverage earned by those who have it.”

Some county supervisors called the letter an “embarrassment” and argued against Rubin’s reappointment. They said the letter crossed the line of propriety, especially for a quasi-government agency whose primary function is to make sure something drinkable comes out of its 2 million customers’ faucets.

“That letter is an over-the-top partisan letter,” said Supervisor John Foust (Dranesville), the Democratic nominee in the House race in Virginia’s 10th congressional district.

Fellow Democratic Supervisor Jeff McKay (Lee) called the letter a ploy for publicity. “It was a couple of individuals who decided to insert themselves [in] what we know is a very toxic, heated conversation,” he said. “Our water authority invited themselves into the conversation, and that is wrong.”

Rubin, who was recently released from the hospital after a stroke, told The Washington Post that he was drafted to write the letter to the congressional delegation and that several members of the water authority signed off on it, including those appointed by supervisors who fought his reappointment Tuesday .

“I just am a bit bewildered as to the controversy and why I am the subject of controversy with respect to that,” said Rubin, who chairs the authority’s government relations committee. “It’s sort of amusing given the circumstances.”

The three Republican supervisors said Rubin’s letter voiced very real concerns over the health-care law — concerns the county itself expressed in January after voting to explore ways to push for changes to the Cadillac tax.

“To lay this at the feet at a 30-year appointee to the water authority is not right,” said Supervisor Pat Herrity (Springfield.)

Supervisor John Cook (Braddock) said the discussion over whether to reappoint Rubin based on the letter sets a dangerous tone for a county board that has a reputation for reaching across political lines more than crossing swords.

“This seems a little partisan to me, and I would hate to see that kind of thing open up because it goes both ways,” Cook said.

After the discussion, Rubin was approved for another four-year term. The vote was 7-3.