Brightwater Treatment Plant Marine Outfall Pipeline

Vanir provided the owner extensive pre-construction services, as well as full construction phase CM and Inspection services. The QA/QC coverage included the construction site on land and underwater, as well as several offsite locations where components and pipes were fabricated and coated.

A 13-Mile Journey

The program aimed to provide northern King County and southern Snohomish County with a new state-of-the-art 36 million gallon per day tertiary treatment plant. Effluent from the plant is treated inland and then conveyed via 12 miles of tunnels to the shore of Puget Sound where it enters the outfall and then discharges a mile offshore. The journey is a total length of 13 miles.

Early Completion and Under Budget

The $29.8 million design/build was completed 22.5 months before the contracted completion date and $8 million under budget.

A Nationally Recognized Award Winning Project

  • ENR – Best of the Best Heavy Civil Projects 2009
  • APWA – Northwest Chapter Project of the Year
  • ASCE – Seattle Section Structural Engineering Honor
  • CEBC – 2009 Award for Engineering Excellence
  • CMAA – 2009 Project Achievement Award
  • NWCCC – Distinguished Project Award (Honorable Mention)
  • Northwest Construction magazine – Best Civil Project of 2009
  • ACEC Washington Engineering Excellence Gold Award – Water and Wastewater


Puget Sound, WA


King County Department of Natural Resources and Parks

Design Team

(Design-Build) Engineer: Dayton & Knight, Inc. Contractor: Triton Marine Construction

Construction Cost

$29.8 million


December 2008