Feeding the ducks and geese along Little Hunting Creek in Fairfax County will be punishable by a $50 fine, the Board of Supervisors ruled yesterday -- but enforcement will depend on animal control officers who manage to witness the misdeed.

At the urging of residents who claim the quality of life in their neighborhood has been threatened by an onslaught of geese expecting to be fed, the board unanimously approved an ordinance that prohibits the feeding of Canada geese and mallard ducks on 174 properties around the creek near Mount Vernon. The land encompasses Stratford Landing, a waterfront neighborhood where dozens of geese have fouled lawns and docks with smelly droppings. The situation constitutes a health threat, residents have said.

The problem began when some residents began feeding the waterfowl, encouraging them to come ashore, where they not only defecate but aggressively go after anyone they think might offer them something to eat.

"The health issue is even more important than the nuisance issue," H. Jay Spiegel, an attorney who lives along the creek, said before the vote, referring to the threat of avian flu. He said some of his neighbors have "set up a professional waterfowl feeding station in our midst." Spiegel said he has spent two years appealing to state and county officials to deter geese feeders with penalties.

Supervisor Gerald W. Hyland (D-Mount Vernon) said he once raised Canada geese on Virginia's Eastern Shore. "I don't think there's anyone who loves Canada geese more than I do," he said. "On the other hand, there's a place to feed them and not to feed them."

The new law, with its $50 fine, will take effect in two weeks as a two-year pilot program that could be extended to other areas of Fairfax. But the county staff acknowledged in background materials provided to the supervisors that catching violators in the act will not be easy.

"Is it something that's enforceable?" asked Michael Lucas, the county's chief animal control officer. "We're going to see how this works."

An animal control officer has to see someone feeding a bird to issue a ticket, Lucas said, and an officer responding to a neighbor's complaint might not arrive in time to issue a citation. First-time violators would receive a warning.

Another option would be for an officer to go to a magistrate on behalf of a complaining neighbor to obtain a summons, which would be served on the alleged violator. Penalties would be up to a judge.

"We don't expect a lot of calls coming in on this," Lucas said. "I doubt a lot of people are going to want to go to court and testify against their neighbor."

One animal control office is assigned to the county's southern end, and the department does not plan to add patrols.

Also yesterday, county officials broke ground for a public safety operations center. The facility, to be built on 130 acres on West Ox Road between Route 29 and Interstate 66, will transform a former state prison into a high-tech complex.

It will include the county's 911 call center, emergency management headquarters, state police dispatchers and a traffic center for the Virginia Department of Transportation. A police forensics office will also be set up there.

The estimated cost of the complex is $122.5 million, with construction expected to be completed by the end of 2007.

The supervisors also agreed to let a temporary, $1-a-trip surcharge on taxi rides remain in effect until April 30. After Hurricane Katrina disrupted petroleum pipelines, sending pump prices soaring, the supervisors approved the temporary surcharge.

They recommended yesterday that the surcharge -- which came after an 11.3 percent fare increase in the summer -- not be raised because gas prices have stabilized.