City to Test Membrane Technology at Wastewater Treatment Plant

Test is part of major upgrade to the facility

Marlene Feist, Utilities Communications Manager, (509) 625-6505

Wednesday, July 9, 2014 at 3:30 p.m.

The City of Spokane is planning to test membrane filtration technology as it prepares for an $80 million to $100 million upgrade to its Riverside Park Water Reclamation Facility.

The City will seek out suppliers of such technology later this month and select two firms to set up a six- to 12-month test of the membranes at the facility. After the test is complete, the City will select one of the suppliers to supply its membranes for the City’s upgrade.

The membranes are a key component of the upgrade that will add a new filtration system at the plant, commonly called the Next Level of Treatment. It will be designed to treat an average wastewater flow of 50 million gallons a day. The project will be the largest upgrade at the facility since the 1970s.

The upgrade will increase the removal of phosphorus from the effluent that’s released to the Spokane River to more than 99 percent, from 90 percent today. Phosphorus has been associated with low oxygen levels and algae blooms in Lake Spokane. The system also will remove greater amounts of heavy metals, PCBs, and other pollutants. 

The upgrade at the plant is part of major initiative to improve the health of the Spokane River. In May, the City Council adopted the City’s Integrated Clean Water Plan that details $310 million in work to:

  • Reduce overflows from combined sanitary and stormwater sewers.
  • Reduce the amount of stormwater reaching the river from separated storm sewers.
  • And upgrade the Water Reclamation Facility to remove more pollutants from the plant’s effluent.

The discharge permit for the plant requires the City to reduce the amount of phosphorus going into the river during a “critical” period from March through October. As part of the Integrated Plan, the City voluntarily plans to run the system year round because it makes sense for the health of the river.

The City plans to issue a request for qualifications from membrane system suppliers on July 23. Suppliers will be required to participate in a pre-submittal conference either by phone or in person prior to the submission deadline. A notice of intent is available at Information on the RFQ, once issued, also will be posted there.