Water Service Restored in Aftermath of University Bridge Main Break

City of Seattle FOR IMMEDIATE RELEASE: 5/2/2007

Water Service Restored in Aftermath of University Bridge Main Break

Bridge Remains Closed Until Further Notice; Update Expected Later This Evening

SEATTLE -- Water was restored to areas of Seattle’s Eastlake and Capitol Hill neighborhoods at 5 p.m. today, following a morning break in a 24-inch water main which shut down the University Bridge and disrupted water service to some local business and residences.

The bridge remains closed until further notice, and commuters are advised to find alternate routes. An update on the bridge’s status is expected later this evening.

The cause of the water main break, first reported at 7:36 a.m. on Portage Bay Place which runs under the south end of the bridge, is still under investigation. The bridge was closed at 7:45 this morning as a precaution.

At around 11 a.m., Seattle Public Utilities (SPU) crews had completed the complex job of shutting off the water main, which involved closing a number of valves. Water pressure in the pipe had been slowly reduced to avoid damage to the system. Crews were finishing up the process of restoring limited local service.

Two unoccupied, parked cars, which fell into a large sinkhole caused by the break, have been removed.

Seattle Department of Transportation engineers were on the scene to determine whether there has been any structural damage to the bridge.

Some Metro buses are being rerouted. For more information call 206-553-3000, or go to http://transit.metrokc.gov.

Seattle Public Utilities (SPU) received several hundred customer phone calls who have lost water service or pressure due to the broken water main. Water pressure has been restored to neighborhoods outside the affected project area.

The City’s water is safe. If you have discolored water, as a general precaution we recommend that you wait until the water clears before drinking it.

  • There is no reason to believe that contamination entered the water system.

  • Discolored water results from internal pipe rust getting stirred up with changes in flow and pressure.

  • If the water does not clear, let the water sit for an hour. Then run the water for a few minutes and flush the toilet a couple of times. If the water remains discolored, please contact SPU Customer Service at (206) 684-3000.

Only one leak in the cast iron water main has been reported in the last 15 years.

The section of pipe that broke is 90 years old. There are 147 miles of cast iron pipes in Seattle’s system. This pipe is a feeder line which is part of the backbone of the distribution grid for the City.

The last similar break was on Western Avenue in 1998, near Pike Place Market. A major contributing factor in that break was a footing for a pedestrian walkway that was directly over the pipe. Small but repeated loading caused a crack that ultimately leak to the break.

The cause of the current break remains under investigation. The existing pipe had a 12-foot longitudinal split.

The durability of cast iron pipe is influenced by how well it was installed, the surrounding soil, the presence of vibration and other loads over the top of the pipe. Based on these factors and the current leak rates, SPU assessed that the life expectancy of pipes in its system is 150 to 200 years.

In Seattle, pipes are monitored based on their leak history. Pipes that have frequent leaks are typically replaced.

SPU has benchmarked its system nationally and internationally. The results show that Seattle has one of the most robust water systems in the world. Our leak rate is one-third of the national average, and one-tenth of Australia’s.

In addition to providing a reliable water supply to more than 1.3 million customers in the Seattle metropolitan area, SPU provides essential sewer, drainage, solid waste and engineering services that safeguard public health, maintain the city’s infrastructure and protect, conserve and enhance the region's environmental resources.

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