Puyallup crews replace century-old ‘phenomenal feat of engineering’

The Puyallup City Council approved the completion of the first phase of the Salmon Springs Main Replacement, which shines the light on a water source that first began supplying water to the city more than a century ago — and still does today.

Salmon Springs, located in Sumner, supplies anywhere between 50 and 60 percent of Puyallup’s water supply depending on the time of year, according to Rob Andreotti, the director of public works for the city.

When Puyallup was first incorporated in 1890, one of the first acts of the government was to set up an agreement with Puyallup Water and Light Company to construct a public water and power system. In 1906, the city purchased that system and constructed a water line that ran from Salmon Springs to Puyallup — an “ambitious project for its time,” according to the city.

“It was a phenomenal feat of engineering,” Andreotti said.

The water main remained in use for more than 100 years, until the city proposed the construction of a new transmission main due to age of the original.

“We have not replaced that pipe since 1906,” Andreotti said, adding that the main focus for the replacement pipe was at its joints, where technology has come a long way for this type of construction. “Where (older pipes) tend to start to fail is at the joints.”

The City Council awarded a design contract to Parametrix in 2013, then awarded a $699,756 construction contract to WHH Nisqually in June 2016. Construction concluded in January. The project included lying approximately 600 feet of new 20-inch pipe parallel to the original.

“We went from the Springs themselves down to the chlorine station,” Andreotti said. “The (original) pipe was left in the ground.”

While it’s no longer being used, the original pipe will remain in place in case of a landslide or a seismic event and to “minimize ground disturbance and vegetation removal.”

The city is initiating the second phase of the project, which will continue the replacement to West Valley Highway. For now, the main will be monitored for the next six years.

This story was originally published February 22, 2017 at 11:14 AM with the headline "Puyallup crews replace century-old ‘phenomenal feat of engineering’."