If Sally Michael had any doubts about how strongly some Arlington residents dislike the county's proposed center for jail inmates, drug and alcohol abusers and the homeless, her doubts were erased during a recent trip to a grocery store.

Michael, one of 13 county staff members who have been meeting with community groups during the past five weeks to explain the proposal, recognized a man in the store as a resident who had spoken out against the plan at a recent meeting Michael had conducted.

Michael began to move toward the man to say hello, but when he saw her coming, he whipped his shopping cart around and quickly moved to another aisle.

"I guess I'm not the most popular person around these days," Michael said.

For Michael, the episode was another glimpse of the anger among residents created by County Manager Anton S. Gardner's proposal for a $4.7 million, 130-bed facility next to Barcroft Park in South Arlington.

Although most groups have been fairly cordial before grilling county representatives about the proposal, a few meetings have turned nasty, with catcalls and boos at a recent meeting in the Claremont neighborhood.

"Thank goodness they haven't all been like that," said John Mausert-Mooney, director of the treatment center project.

Arlington officials knew the proposal announced last month would be controversial, and they formed a team of staff members to explain the plan to neighborhood groups. On most recent weeknights, Michael and her colleagues have stood before such groups and let residents take their best shots.

"Part of our function is to give people a chance to ventilate, to get it off their chest," Michael said.

At a meeting in the Barcroft neighborhood this week, the questions were typical: Why is Arlington moving so fast with this proposal? Can the county guarantee that criminals and transients won't mix with the children and other people who use the park? Why put this facility next to a park?

One by one, county staff members ticked off the answers: Arlington's crowded jail requires quick action; there will be tight security at the center but no one can guarantee that people from the center won't ever enter the park; and other sites considered for the facility cost too much.

Like residents at other meetings, the Barcroft neighbors seemed unimpressed. After the county staff members left, the neighbors voted to join two dozen other civic groups in opposing the center.

"It's difficult knowing that before you get there, people have made up their minds," said Chief Deputy Sheriff Tom Faust, who has gone to several meetings to explain the inclusion of jail inmates in the proposed center. "Some people are emotional and angry, and that's hard to respond to."