UPDATE: See Boil order lifted.
A ruptured 6-inch water main at Missouri American Water left most of its 11,000 customers without water Tuesday morning, causing schools to let out early and many employers to send their workers home. The resulting boil order remains in effect.
Gilbert Cole, Missouri American's operations superintendent, said the rupture occurred about 7:55 a.m. He said no water damage was caused to the company's operations.
Although water pressure came back around noon, the city reamins under a boil order until Missouri American completes the required water testing.
That means the boil order could last until Thursday, Cole said.
"Basically, we are sorry it happened," Cole said. "But it's an old system, and we've got it under control. It was a pipe on the manifold of the pumps at the treatment plant that broke. It's a more than 90-year-old relief valve system."
This occurred in area that was not part of recent upgrades done at the plant, said Ann Dettmer, Missouri American spokeswoman.
Dettmer thanked Cole County Public Water Districts 1 and 2 for sending some of their water supplies to help build pressure back in the Missouri American lines. Missouri American provides water to about 75 percent of the city, with the two water districts supplying the remaining 25 percent.
Dettmer said they have crews from St. Louis County flushing out the system to make sure it is clean. When test samples are found to be safe, the boil order will be lifted.
"We advise folks to run their faucets to clean them out," she said. "Throw out ice and start fresh. The water is fine for washing clothes and taking a shower, just don't drink or cook with it until you boil it first."
Earlier coverage, posted Tuesday: