City points to pipe material as likely reason for water main breakPosted: Updated:
TEMPE, Ariz. -- The City of Tempe's water utilities department says the pipe material is likely to blame for the massive water main break that caused a Valley Metro bus to get stuck in a sinkhole and sent water rushing into nearby businesses.
"The pipe material was cast iron. It was a 12-inch line," said Marilyn DeRosa, deputy director of water utilities.
The failure happened right near the intersection of Apache Boulevard and McClintock Drive on Wednesday.
DeRosa told 3TV it was caused by a crack in the line, which they suspect had been there for years but yesterday just finally reached its limit and gave out.
The line, she said, has been in the ground since 1985. Relatively speaking, that's not that long.
"Contrary to what you might think, the oldest pipe isn't always the pipe that fails first," DeRosa said.
In this case, the city thinks the cast iron was to blame.
Tempe keeps track of all its water line breaks on a map using a dot to mark each break location. Each dot is a different color; yellow signifies a cast-iron pipe.
"A lot of our asset management program right now is focused on replacing cast-iron line," DeRosa said.
The material, the age of the pipe and the amount of water line breaks in an area are all taken into consideration when planning any rehabilitation or replacement projects.
Tempe re-evaluates its program at the start of each year to find out where the highest priorities are.
The City of Phoenix works in a similar fashion, trying to stay ahead of the water line breaks as much as possible.
"I think it's about $40 million a year we are spending on rehabilitation and replacement of aging water lines that we have in our system," said Troy Hayes with the City of Phoenix Water Services Department.
To replace all the lines that need it would cost billions, so Phoenix has to prioritize projects while at the same time reacting and responding to those unforeseen breaks, like Tempe had to do on Wednesday.
"At this point, this area is not a priority for replacement, but if this keeps happening then it will climb on the list," DeRosa said.
Work to repair the road is expected to take until the middle of next week, barring any weather which could cause delays.
Southbound lanes of McClintock Drive reopened early Thursday. Later in the afternoon, one northbound lane was opened as well.