North Stonington — The almost 230 homes and businesses that lost water service after the "catastrophic failure" of a pressure tank early Tuesday morning could start getting a trickle sometime Tuesday night, officials said.

Since the failure of the 5,000-gallon tank — the force of which blew the welded head of the tank off and caused the pump station's roof to collapse — crews have been working to get a temporary water system in place.

Reports of the "explosion" and of a lack of running water first came in around 3 a.m. Tuesday.

Around 6:15 p.m., Southeastern CT Water Authority General Manager Josh Cansler said workers were putting in a valve to shut off the affected end of the system.

At the time, Cansler said they were still a few hours from beginning to fill the water system with tanker trucks, a process he said would take several more hours.

"People should start getting a trickle in next few hours, and through night that will improve," he said, adding that the town is using Connecticut Water tanker trucks and water from Groton.

In the meantime, residents in need of water can bring their own containers and fill up at the volunteer fire company station, located at 267 Norwich-Westerly Road. The station has its own well.

Cansler noted that even after the water begins running again, residents will remain under a "boil water" advisory for at least "a couple days."

First Selectman Nick Mullane said that's because after the water runs through the system for a while, it will have to be treated, then flushed, then tested.

Thirteen of the 229 affected buildings, which are primarily in the village and on parts of Route 2, are businesses. The rest of the 55-square-mile town's 5,000 residents have wells and are unaffected by the issue.

The failed hydropneumatic tank, responsible for pushing water throughout the water system, is one of two the system used. Each had a 5,000-gallon capacity but typically was filled with 2,500 gallons of water.

Mullane said he "wouldn't be surprised" if inspectors decide the town should replace both tanks rather than eventually resuming use of the second tank.

Mullane said the pump station that partially covered the tank is "totally damaged" and also will need to be replaced. Already, the town has hired Lenard Engineering Inc. to start laying out the new design with specifications that are "correct in regard to public health."

Neither Mullane nor Cansler could estimate when the new pump station will be finished, but Cansler said the new tank or tanks could be in place in a few days.

"A final solution with the pump house rebuilt will take quite a long time," Cansler said. "But in the next few days, customers should be back to at least feeling normal water pressure."

Both Mullane, who's been first selectman for 28 years, and Cansler, who works with 15 water systems in southeastern Connecticut, said the tank's failure is unprecedented.

"This is very unusual that this happened," Cansler said. "I've been talking to people who've been dealing with the water system for a long time and they've never heard of this happening."

Southeastern CT Water Authority workers last checked the about 30-year-old tank Monday.

At the time, Cansler said, there were no issues. He added that the system is "a fairly new system as water systems go" and that those investigating are considering every possible reason the tank may have failed.

In addition to insurer and state environmental and health agency representatives, police and a fire marshal were brought to the site to check for any possible wrongdoing — something Mullane said is standard procedure "when something like that happens."

As of Tuesday evening, a possible cause of the failure had not been determined.

Mullane said the failure will lead to a "big bill" for the town — one he's not yet sure whether insurance will cover.

"That's not our interest right now," Mullane said regarding the cost of the repairs. "Right now we're interested in getting the temporary service back on, and then to get a permanent one that's dependable."

l.boyle@theday.com

Twitter: @LindsayABoyle