Last year, Fairfax County police responded to 343 burglar alarms -- nearly one a day -- at Tysons Corner Center alone. All were false.

County public safety officials, hoping to silence malfunctioning alarm systems, are now proposing to bill businesses and homeowners for excessive false alarms. The county spent nearly $1.1 million responding to such calls last year, according to figures put out by the police.

"What we are looking at are alarms that are going off and there's obviously no criminal activity," said Lt. Dana Libby, an aide to the deputy chief for police operations. "It's not a difficult thing to have an alarm system that works, and we spend an awful lot to go to those that don't."

The proposed changes, which the county Board of Supervisors will consider June 25, are similar to those enacted in other local jurisdictions, including Prince George's and Montgomery counties and the cities of Falls Church and Fairfax.

Under the Fairfax County plan, businesses or residents with more than five false alarms a year, three in four consecutive months or three in one month would be required to have the devices inspected. Fines of $20 to $150 would be levied for alarms that continue to go off without reason, beginning with the third false alarm in a year.

Last year, 98 percent of all burglar alarms in the county were false, according to Richard A. King, deputy county executive for public safety. Of 37,383 alarms, police were needed in 439 cases, but police personnel spent more than 15,000 hours working the calls. Seven addresses had more than 100 calls each.

There are 150,000 burglar alarms in Fairfax County, according to industry estimates. False alarms are generally triggered by inadequate hardware, electronic glitches or careless users. While businesses generally have higher quality alarms, problems arise when new employees are not properly trained how to operate them, Libby said.

In addition to saving money, county officials hope the proposed ordinance will reduce complacency among police and security officers who may grow lax after responding to repeated false alarms.

In 1981, a Montgomery County police officer and an alarm company security employee responding to at least two alarms were fatally shot by burglars at a W. Bell & Co. store.

"What we are trying to do is create a situation that when the alarm sounds we have reason to believe it is a valid alarm," King said. "When you respond to alarm after alarm and it's not, there's a tendency to look at it as the 'cry wolf syndrome.' "

Fairfax City's alarm ordinance, enacted in 1987, allows two free false alarms a year but charges $25 for the third, $50 for the fourth, $75 for the fifth and $100 for every one after that, City Treasurer Steve Maloney said. Last year, the city treasury collected about $40,000 in fines from the ordinance, the "vast majority" of which came from businesses, Maloney said.

Several people, including members of the burglar alarm industry and the business community, are likely to testify at the June 25 public hearing, although there has been no major opposition to the plan.

Brad Shipp, president of the Virginia Burglar and Fire Alarm Association Inc. and vice president of a Chantilly alarm company, said he has yet to review the ordinance but that a major concern will be how it defines a false alarm, since many devices are designed to scare off would-be intruders.

"There's no doubt that there are cases where equipment has fallen into disrepair or is not used properly," Shipp said. "But there are other cases where police arrive and find no one there in a burglar outfit and assume that it is a false alarm."