BOSTON — State police divers scoured the bottom of the Charles River with metal detectors Tuesday, but failed to find a key piece of evidence to the catastrophic water main breach that left up to 2 million Boston area residents without safe drinking water.
Police were searching for a giant metal coupling weighing up to a ton that investigators believe gave way on Saturday, forcing residents to boil tap water or rely on bottled water for drinking, cooking and brushing their teeth.
The boil-water order was lifted early Tuesday after tests confirmed that clean water was again flowing through pipes to 30 cities and towns, including Boston.
The coupling could be key to answering a series of questions, including what caused the breach, who if anyone is responsible for the total cost of the blowout, including repairs, and whether the system has any other potentially problematic couplings.
Gov. Deval Patrick said he’s determined to get to the bottom of the incident. He said a close inspection of the coupling is critical to the investigation.
“We have to figure out how that happened and that is no small task,” Patrick said at an early morning press conference. “I want to do the forensics on it because if there is some party that needs to be held accountable you better believe they will be held accountable.”
A spokesman for the Massachusetts Water Resources Authority, the agency in charge of the delivering safe drinking water from the Quabbin Reservoir in central Massachusetts to much of the eastern part of the state, said the search for the coupling will resume on Wednesday.
David Gilmartin said Barletta Heavy Division Inc., the Canton, Mass.-based company that built the 10-foot pipe, will begin excavating two large sand bars that were formed when the pipe blew, spewing water and an estimated 400 cubic yards of soil and sand into the river.
“We really think that it’s under one of those two sand bars,” he said.
He said he didn’t know how many other similar couplings were used in the project.
Gilmartin said the MWRA is also trying to add up the overall cost of the breach. He said those costs were likely be held down in part because the pipe was repaired and clean water restored within days instead of weeks, as originally feared.
“It wasn’t something that was outrageously expensive,” he said.
Political leaders at the Massachusetts Statehouse are also pledging to get to the bottom of what happened, and who should pay for it.
Democratic House Speaker Robert DeLeo said he will schedule public hearings in the next several weeks to hear testimony on the breach. DeLeo’s hometown of Winthrop was one of those forced to boil water.
DeLeo said he wants to protect customers for bearing the brunt of the cost of the repairs. Ratepayers had seen their bills increase during the years when the project was under construction.
The seven-year-old pipe where the blowout happened was built to avoid exactly the kind of disruption that occurred during the past several days.
Completed in November, 2003, the pipe replaced an 1940′s-era surface aqueduct. At the time, water system officials worried that a failure of the aqueduct “could have caused nearly complete interruption of Boston’s water supply,” according to the agency’s website.
A retrofit of the aqueduct, meant to be used as a backup to the new tunnel, is under way but not completed.
Patrick said the fact that the pipe was just completed seven years ago made the breach even more infuriating.
“We have so much neglected infrastructure that something relatively new failing this way is obviously very, very troubling,” he said.
The federal government is pitching in to help cover some of the costs.
On Monday, President Obama signed an emergency disaster declaration offering federal help. The declaration authorizes the Department of Homeland Security and Federal Emergency Management Agency to coordinate disaster relief efforts with local authorities.