PROVIDENCE — City residents who still lack the automated devices that allow technicians from Providence Water to read their meters from outside will have to arrange to get one installed or face a cutoff of service.

Ricky Caruolo, Providence Water’s director of commercial services, says that while the utility has been installing the new meters since 1999 — and has equipped all but 3 percent of its customers in Cranston and all but 1 percent of its customers in North Providence and Johnston — there are 3,900 Providence customers (11 percent of the city’s total) who haven’t made the change.

Warnings are being sent through February that Providence customers will have their water shut off if they don’t call within 20 days of the warning to arrange an installation. The charge for having the water shut off and turned on again is $107.

Some 700 non-compliant residents of North Providence, Johnston and Cranston will also be receiving notices.

Known as AMRs, the meters have radio transmitters that allow a utility worker to “read” the meter simply by driving slowly down the street.

“Our position is that this is a win-win for everyone, because it virtually eliminates our having to go into someone’s house and allows us to bill customers for their actual water consumption,” Caruolo said.

“By billing people for actual consumption instead of an estimate, we eliminate the need for high catch-up bills and for high credits.”

Caruolo said it’s no surprise that there are still some customers who haven’t made the switch, because so many families have no one at home during the day. Many people may not have arranged an appointment because they don’t have the time to take from work, and, in some buildings, “the people living there are tenants who don’t have a key to the basement.”

Still, he said, the chances are good that someone in the house will make the time this time.

“The homeowner will be responsible for making the meters accessible. If it’s buried in the basement, the owner will have to dig it up. If there is a refrigerator in the way, it will have to be moved.”

To be sure, the switch to an automated system should produce some savings in the long run for the company, though radio transmitters cost almost $60, and, depending on the size, $38.50 to $196.16 for the meter. Dennis Salema, who manages the automated meter system and large meter project, said the new system is certainly more efficient; previously, a reader had to knock on every door and wait for someone to let them in. Typically, a reader could hit 80 homes a day. But with the automated readings, one of the utility’s 21 readers, technicians and installers can hit 6,500 homes in a day, though it might take another day or two to go back to get data from homes whose signals were missed.

Today, the company can cover its base of 72,500 homes in Providence, North Providence, Johnston and Cranston in about 25 days, using 12 routes instead of 300.

Residents should make sure the worker is wearing a Providence Water uniform, has an ID and is driving a utility company vehicle.