Water Tests Underway After Piping Repairs

The region's drinking water supply could be back to normal in a day or two as state officials on Monday conducted water quality tests, leaving in place the order to boil water after a ruptured pipe disrupted the flow of clean water to about 2 million people.

The testing of hundreds of water samples accelerated after crews working through the night successfully repaired the 10-foot-wide pipe that broke in suburban Weston on Saturday, prompting Gov. Deval Patrick to declare a state of emergency.

"We're now going to shift our attention to water quality testing," said Fred Laskey, executive director of the Massachusetts Water Resources Authority, on Monday morning.

Laskey is confident the repair will hold. "That's as solid as solid can be," he said of the repaired pipe, which has been reinforced by concrete.

The exact reason the coupling gave way remains under investigation. Officials have spent all their time and effort fixing the problem, Laskey said. "Why it blew out is something we're going to work on," he said.

Government officials threw an "open-for-business" sign on Boston for residents returning to work Monday, with Boston Mayor Thomas M. Menino and the governor urging commuters to return to the capital city.

Menino also told consumers Sunday that restaurants were open "and serving delicious meals," while the city's school superintendent, Carol Johnson, spoke for her suburban colleagues when she told schoolchildren: "We expect to see you in class on time."

Health officials warned of the risk of a parasite infection if residents used unboiled tap water for brushing their teeth, washing raw vegetables or making ice. The water remained safe for showering and toilet flushing, with one official likening it to lake water.

Laskey didn't shy from stating the magnitude of the problem created when the pipe burst at a seam Saturday morning. Over the next eight hours, an estimated 65 million gallons spilled into the Charles River and forced officials to tap a reservoir filled with untreated water, potentially contaminating the supply to 750,000 households.

"For the people in the water industry, it is everyone's worst nightmare: to lose your main transmission line coming into a metropolitan area," Laskey said.

Customers lined up at stores to buy bottled water, and both Patrick and Attorney General Martha Coakley warned against price-gouging.

Hongbin Luo of Lexington came upon a Stop & Shop that had just restocked its shelves. He wheeled out a shopping cart with two cases of water, plus 18 one-gallon bottles.

"We want to have something to use and send off with the kids to school," Luo said.

Fellow Lexington resident Ira Goldman said he had boiled water but added that he was going to Europe on Monday so "it's not a big inconvenience."

Boston's water runs from the Quabbin Reservoir, in the central part of the state, to the Wachusett Reservoir before being treated at a plant in Marlborough. It travels through an 18-foot-wide pipe to suburban Weston, where it branches off into the 10-foot-wide pipe that broke.

When the breach occurred, the MWRA rerouted the clean water supply through an aqueduct that hadn't been used in decades. It also briefly tapped a reservoir to maintain pressure and meet expected demand across the system. While the water in the aqueduct was clean, the water from the reservoir — which is in open air next to Boston College — is not, prompting the warning to boil water for one minute.

"It's difficult to determine where that line (between clean and dirty water) is so, under the rules, you make the whole district a boil-only condition, even though we know and suspect that there are substantial portions that are getting purely treated water," said Laskey.

The repair was initially expected to perhaps take weeks, but officials diverted a spare coupling from a nearby project and welders modified the parts in a matter of hours.

Officials remained puzzled by the cause because the break was in a stretch of pipe just seven years old. They said they would be checking the blueprints for other similar connections, to assess the risk of another breach.

"It could have been a design flaw, it could have been a construction flaw, it could have been that the product was faulty, it could have been something in our system," said Laskey. "There's just so many different variables that come into play here when you're dealing with that much strength."

Concerned about such a vulnerability in the system, the MWRA has been repairing the original line that supplied Boston, which runs parallel to the new one. That $700 million project started nine months ago and is still three to four years from completion.

"We were working hard to have a solution in place for just this type of problem. Unfortunately, it came up before we were finished," said MWRA spokeswoman Ria Convery.