Lake Oswego Water Treatment Plant

he City of Lake Oswego required upgrades to its existing WTP to increase capacity from 16 MGD to 38 MGD. The Slayden team constructed the upgrades in three phases, demolishing existing structures after construction. There were zero unplanned shutdowns over the course of the construction.

This work included a 54-inch influent pipeline, raw water metering, chemical injection/rapid mixing facilities, ballasted flocculation (replacing existing sedimentation basins), intermediate ozone contact basin and ozone generation facilities, deep-bed granular activated carbon filtration facilities (replacing existing filters), 2.0 MG chlorine contact basin, and completed water storage clear well. Also included in the scope was a 48-inch finished water pipeline (replacing the existing clear well and finished water pump station pipeline), new residuals handling facilities, including wash water equalization basin and recycle pump station, solids thickening and mechanical dewatering facilities (replacing two of four existing solids lagoons), new chemical storage and feed facilities (replacing the existing chemical storage and feed facilities), new electrical building, and new administration building.

The project also included extensive site work including yard piping, new roadways, parking lots, stormwater detention and treatment facilities, primary and secondary electrical service, site lighting, fencing, and landscape features.

  • Total Project Value: $67 million
  • Delivery Methods: Design Bid Build
  • Owner: City of Lake Oswego