Slayden served as the CM/GC for the Joint Water Commission Water Treatment Plant Expansion in Forest Grove, Oregon. The project increased plant capacity from 75 MGD to 85 MGD while improving seismic resiliency, treatment reliability, and long-term capacity for communities across Washington County.

During preconstruction, Slayden worked with the JWC and design team to support constructability reviews, cost estimating, bid-package planning, scheduling, and phased construction planning. The team focused on maintaining plant operations throughout construction while sequencing workaround major process upgrades, filter improvements, and pretreatment modifications.

A key part of the expansion was construction of two new filters to increase overall plant capacity and provide added operational flexibility. The new filters were integrated into the existing treatment process and included new concrete filter structures, underdrain systems, filter media, backwash piping, process valves, access improvements, electrical, controls, and instrumentation. Slayden also replaced filter media in the 12existing filters, helping improve performance across the full filtration system.

 The project also included plate settler pretreatment improvements to support more consistent settling ahead of filtration. This work included process piping, valves, equipment installation, controls, and tie-ins to the existing treatment process. Additional scope included rapid mix and chemical system improvements, new solids drying beds, a new backwash surge basin and recycle pump station, sedimentation basin modifications, large-diameter yard piping, and raw water pump station upgrades.