"If there were a sink in here, I would take a glass from the tap and drink it myself. I'm very confident," Gov. Deval Patrick said at a news conference.
An estimated 2 million people lost clean drinking water for about 72 hours after a 10-foot-diameter pipe ruptured Saturday in the system bringing water from central Massachusetts reservoirs east to Boston.
Deval said a repair that could have taken weeks was accomplished within three days. The goal now, he said, was to determine how the break occurred and to prevent a recurrence.
"If there is fault to be found, we will find it and we will hold those responsible accountable," Patrick said.
President Obama Monday approved federal reimbursement for as much as 75 percent of the cost of responding to the crisis, the amount of which has yet to be tallied.