By early October, Montgomery County librarians, bus drivers and other managers will have the power to banish people they deem "disruptive" from county facilities for up to 90 days, under a bill approved yesterday by the County Council.

The American Civil Liberties Union and other watchdog groups had objected to the measure, and the council made changes to respond to some -- but not all -- of their concerns. The bill passed the council unanimously, although council member Michael L. Subin (D-At Large) was absent for the vote.

"It's great," said Harriet Henderson, the county's director of public libraries and one of the measure's leading proponents. She said county officials had wanted a "flexible tool that could be tailored to different situations," and the council gave them one.

"Too many of our county employees are being verbally abused or threatened, and in some cases patrons of libraries are threatened," said council member Phil Andrews (D-Gaithersburg), chairman of the council's public safety committee. "We have had some really serious physical assaults of Ride On bus drivers during the past few years."

Giving facility managers the power to ban disruptive people, he and other council members argued, would give them a way to keep order short of calling the police, which is the existing practice. Police can issue an order banning people from a county facility for one year, and Andrews noted that the council's measure is less severe.

Under the law, people using a county facility must not act in a way that "a reasonable person would find disrupts the normal functions being carried on at that public facility." A person who engages in such activity must "accurately identify himself or herself" when asked by the facility manager. If the person continues acting in a disruptive manner, the manager can write an order banning the person for up to 90 days; in the case of transit vehicles, the order can ban the person from the entire transit system for that period.

The order can also "impose any other reasonable condition" to ensure that a facility's normal functions are not disrupted.

In most cases, county officials said, library branch managers and Ride On road supervisors will be responsible for enforcing the bill's provisions.

One objection raised by the ACLU -- in an April letter to the council from Stephen M. Block, legislative counsel of the organization's National Capital Area office -- was that the bill did not offer much of a due process review. The council strengthened that provision yesterday so that a person banned from a library or the transit system would have an automatic hearing the next business day by the county's chief administrative officer or an assistant chief administrative officer. An earlier version also allowed department heads to perform the review function.

But the council did not address the ACLU's objection that the bill was preempted by existing state law. Rather, the council relied on its own attorneys' advice that the ACLU's concern was not valid.

Council members and county officials stressed that the measure was focused on people's behavior and was not "content-based," intending to calm fears that public employees could deem certain types of speech disruptive.

Some lawmakers seemed to sense they were treading on constitutionally shaky ground.

"I do think there is room for interpretation here," said council member Tom Perez (D-Silver Spring). "Disruptive may be in the eye of the beholder."

Marilyn Praisner (D-Eastern County) said she stumbled over language in the bill that allows public employees to ban people from facilities "used by" the county, such as a park that hosts a county program. "I can see challenges to this right and left," she said.

But Andrews said that "the bill is carefully crafted, narrowly tailored, and clearly conduct-based, and it will withstand constitutional scrutiny."

The bill was drafted at the behest of County Executive Douglas M. Duncan (D), who has until the end of the month to sign it into law. The measure would take effect 91 days later.