City crews shore up risky sewer pipe

Nov. 16, 2000
An exposed sewer pipe that was in danger of rupturing and sending solid waste into the Spokane River near the T.J. Meenach Bridge was successfully buttressed Monday afternoon.

By ROB MCDONALD

Nov. 15, 2000 (The Spokesman Review)—An exposed sewer pipe that was in danger of rupturing and sending solid waste into the Spokane River near the T.J. Meenach Bridge was successfully buttressed Monday afternoon.

City of Spokane crews removed temporary supports under the 36- inch pipe and poured a concrete-like substance underneath to form a permanent bed.

"It's like setting it into a concrete block," said Spokane water superintendent Frank Triplett.

Today, crews will begin replacing much of the soil that was washed away, approximately 50 dump truck loads, Triplett said.

The 20-foot-wide gully was carved Saturday afternoon after a 12- inch water main broke on Northwest Boulevard, causing a river that flowed down several streets before pouring over the lowest bank on Riverview Drive.

As the ground begins to freeze, water mains begin bursting, Triplett said. Frost in the ground causes more downward force on the water main, he said.

"We usually get a rash this time of year," Triplett said.

But Spokane has fewer breaks than similar-sized cities, he said.

In general, the city has had few problems with its water mains, less than industry averages, said Brad Blegen, director of the water department.

The rupture this weekend was caused by cast iron pipes, which tend to be more brittle than the more flexible ductile iron pipes the city now installs.

Cast iron was used in the 1940s and '50s, and presently makes up about a third of the city's 890 miles of water pipes, Blegen said.

"Cast iron is a good pipe, but it is brittle, and when it gets cold, these things can happen," he said.

If the 18-foot-long pipes are laid improperly, for instance on a large rock that can act like a fulcrum, problems can occur, Triplett said.

"It's perfectly safe if it's installed properly," Triplett said. This week, crews will replace the soil, lay down a ground strengthening cover and top it with rocks for drainage. In the spring, crews will return to re-seed the hill, Triplett said.

The cost of repairing the pipe and shoring up the damage from the spill will be $40,000 to $50,000, with the cost to be covered by the water department, said Assistant City Manager Roger Flint.

While the efforts of the city's crews were praised by Flint and City Manager Hank Miggins, City Councilman Steve Eugster took them to task for not doing more at the time.

He said the washout could have been prevented if the crews that responded had dammed the runoff and diverted it down another street.

"I think the severity of this problem could have been avoided by more thoughtful application of resources at the scene," Eugster said at Monday's City Council meeting. "I don't know if that was due to lack of imagination. I don't know if it was due to union contracts (that may prevent employees from taking certain actions)."

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