Construction to Begin on 1 Million Gallon Tank to Reduce Combined Sewer Overflows to River

Project will reduce basement flooding in Lincoln Heights area

Marlene Feist, Utilities Communications Manager, 509.625.6505

Monday, September 16, 2013 at 1:50 p.m.

Construction on a 1 million gallon tank to reduce overflows from a combined sanitary and stormwater sewer on the west side of Ray Street at 21st Avenue is set to begin in late September.

The tank will capture and retain excess flows from combined sewers during a large storm from an area that includes Lincoln Heights and part of the East Central neighborhood. In addition to reducing overflows to the river, this project also will help with localized basement flooding in homes near the tank. Construction is expected to continue through November 2014.

To make room for the tank and for enhanced neighborhood safety, about 100 pine trees will be removed from the site, beginning Monday, Sept. 23. As part of the project, landscaping will be added that will return the location to a nature area. A rendering of what the site will look like once the landscaping has had an opportunity to grow in is shown.

The project at 21st & Ray is part of a major initiative to improve the health of the Spokane River by reducing the amount of stormwater and wastewater entering the Spokane River. The City is developing an Integrated Clean Water Plan that will prioritize projects based on their positive environmental impact to the river. The plan will include a number of projects to reduce untreated discharges to the river from both separated storm sewers and combined sanitary and stormwater sewers.

Overall, some 54 million gallons of combined wastewater and stormwater enters the river through 20 discharge points from our combined sewer system annually. Another 1 billion gallons of untreated stormwater enters the river through separated storm drains, primarily located on the North Side.

The 21st & Ray tank will be the largest one the City has constructed to date to address overflows from combined sewers. City engineers say the tank will be as long as a football field, end zone to end zone. Some comparisons to the tank size are included.

The Ray & 21st CSO tank will hold a million gallons of combined wastewater; here's how its size compares to the the downtown Bank of America building and the Clock Tower in Riverfront Park

The $5 million construction project at 21st & Ray is being funded by the City's Wastewater Management Department.

More information about the City's Integrated Clean Water Plan can be found on the Spokane Waste Water website. Updated construction information on this and all of the City's construction work can be found on the City of Spokane's construction page.

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