With a boil order extended through Wednesday, Northbrook officials were trying to figure out what caused an 18-foot-long tear in a 41-year-old iron water pipe, which shut down water service in the North Shore community.
The water flowed Monday after workers repaired the ruptured water main that broke about midnight Saturday. But school drinking fountains and ice machines remained off limits as officials extended a boil order an extra day after state officials required additional water samples.
As they waited for the results of initial water tests, officials collected a second round of samples Monday to check for bacteria, as required by the Illinois Environmental Protection Agency, said Jim Reynolds, director of Northbrook’s Public Works Department.
The IEPA, which requires that at least 40 water samples come back clean, requested an additional 40 samples, which will be collected Tuesday, he said.
The agency told Northbrook officials that one of the samples appeared to be inadvertently contaminated, though it did not test positive for bacteria. It wasn’t clear if the problem came from the water or the fixture from which it was taken, Reynolds said.
Because it takes 24 hours to process the water samples, the boil order was extended, officials said.
Homes and businesses were ordered to boil water for 3 to 5 minutes if used for consumption.
The community went dry for nearly 15 hours Sunday after the 24-inch-diameter main burst at Dundee and Lee Roads. The rupture was unusual in that the crack split the pipe lengthwise; more common are breaks where the pipe snaps in half, Reynolds said.
As a result, more than 1 1/2 million gallons of water erupted from underground, he said.
“It raised up the road and flooded the intersection,” Reynolds said Monday, a day after water service was restored. “It was a mess.”
Officials closed the village’s water plant about 3 a.m. Sunday so workers could fix the main.
Reynolds said the pipe, built in 1963, was laid on concrete, which is unusual.
“The main must have shifted,” he said.
Others suggested a manufacturing flaw might have been to blame.
The department plans to send the pipe for examination to a national institute that researches cast iron, Reynolds said.
The last time the community lost water service was 34 years ago, when the same pipe ruptured about three-quarters of a mile west of the latest break, according to Reynolds, who said the pipe does not rest on concrete at that location.
Students were encouraged to bring bottled water to school. On Monday, Glenbrook North High School students found fewer choices on the lunch menu because workers were unable to wash vegetables properly for the salad bar, said spokeswoman Diane Freeman.
“The water fountains throughout the school were covered with trash bags and signs saying [students] were prohibited from drinking from the fountains,” she said.
Physical education students drank water that was supplied by the district’s sister school, Glenbrook South High School in Glenview, which was unaffected by the break.
By coincidence, Northbrook officials attended a training session Monday at Village Hall that covered emergency procedures mandated by the federal government.
The training was aimed at preparing for incidents ranging from acts of terrorism to water main breaks, Reynolds said.
After struggling to return water service to Northbrook, some felt as if they had already been through the training.
“We had a terrific team working on [the water main break] non-stop for more than 40 hours,” Reynolds said. “It took a lot of people to finally get this thing resolved.”
