Slayden, in partnership with MWH Constructors, served as the GCCM/CMGC for major upgrades to the City of Spokane’s Riverside Park Water Reclamation Facility. The project was completed to improve the quality of effluent discharged to the Spokane River by adding advanced tertiary membrane filtration and increasing phosphorus removal to more than 99 percent.

During preconstruction, the team worked with the City and design team to phase the work through 8 GMP packages, allowing early construction, long-lead procurement, and design development to move forward in parallel. Planning focused on maintaining full plant operations, sequencing work within a constrained operating facility, and coordinating major treatment upgrades tied to regulatory compliance and river water quality goals.

 Construction was delivered in two major phases. Phase 1 included upgrades to the existing facility, including a new primary clarifier, chemical storage improvements, SCADA upgrades, modifications to four aeration basins, digester gas improvements, and related process, yard piping, and electrical work.

Phase 2 included construction of a new 75 MGD peak-flow tertiary treatment complex centered around a Pall membrane filtration system. The two-story tertiary facility included rapid mix and flocculation basins for pretreatment, membrane feed and process pumps, membrane filtration equipment, clean-in-place systems, chemical systems, and supporting process piping, electrical, controls, and instrumentation. Additional Phase 2 structures included a diversion structure, drum screen structure, flocculation basins, membrane pump wet well, and the membrane filtration facility.