Progress at the Spokane Riverside Park Water Reclamation Facility Project

Slayden and MWH are working with the City of Spokane on major upgrades to their Riverside Park Water Reclamation Facility. This upgrade will include Next Level of Treatment (NLT) which is a new filtration system that will greatly improve the quality of effluent that is released into the Spokane River.

The NLT upgrade is a major initiative to improve the health of the Spokane River. It will increase phosphorus removal from the effluent from 90% to 99% which in return will help the oxygen levels in Lake Spokane, creating a more suitable environment for aquatic life. The new filtration system will also remove greater amounts of heavy metals such as PCBs and other pollutants. The new filtration technology will provide pollution reduction benefits and treat an average wastewater flow of 50 mgds.

This project will be the largest upgrade at the plant since 1970. Once the upgrade is completed, the system will treat the wastewater to a “Class A” standard, which would allow the water to be reused for irrigation, dust control, industrial processes, enhancing wetlands, and recharging groundwater supplies.

Currently, the Spokane Riverside Park Water Reclamation Facility project is entering Phase 1 of construction. This phase includes modifications to the existing plant in the process building, demolition of digester #1, primary clarifier #5, stormwater clarifier, chemical storage building, digester thickening, headworks, aeration basins and tunnel mechanical work.

Phase 2 of the project is focused on the NLT membrane system. Construction for Phase 2 includes drum screens, flash mix basins, chemical treatment, and a membrane facility. Project completion is forecasted for 2020.