Brightwater WWTP Project, US

Plant Type

Municipal WWTP

Initial Capacity (2011)

136,000m³/d (average), 495,000m³/d (peak flow)

Capacity By 2040

205,000m³/d (average), 645,000m³/d (peak flow)

Secondary Treatment Type

Membrane bioreactor

Effluent BOD


Effluent TSS


Effluent NH3-N


Effluent TN


Effluent TP


Effluent Turbidity

<0.5 NTU

Effluent Faecal Coliform

<10 CFU/100ml

Effluent SDI


Effluent Mixed Liquor Solids Concentration

8,000mg/l to 10,000mg/l


Class A reclaimed water

Total Site Area

114 acres

Treatment and Support Facilities Footprint

43 acres


King County, Washington, US


King County



Project Commenced

November 2005

Project Completed

September 2011

Conveyance System Project Completion


Regional Wastewater Services Plan Approved

November 1999

Identification and Evaluation of Sites, Marine Outfall Zones and Construction Methods

2000 - 2001

Siting Process Phase II Began

June 2001

Environmental Review Systems Identified

December 2001

Pipeline Corridors Evaluation

Spring 2002

Environmental Review Process Begins

May 2002

Public Meetings

June 2002

Draft EIS Issued

November 2002

Public Consultation on EIS

December 2002

Final EIS Issued

November 2003

Site and System Selected

December 2003

Supplemental EIS Issued

July 2005

Site Selection Formally Reaffirmed

July 2005

Demolition and Clearing Work Began

November 2005

Subcontractor Bidding and Selection

Early 2006

Site Excavation Begins; Work Begins on the Point Wells and Ballinger Way Tunnels; Treatment Plant Construction Begins


Main Pipe Installation / Construct Site Portal; Marine Outfall Construction Begins, Construction of the Bothell Influent Pumping Station Begins


Building Work Completed; M&E Installation; Conveyance Tunnel Construction Completed


Testing, Site Restoration and Start Up



King County Wastewater Treatment Division

General Contractor / Construction Manager

Hoffman Construction

Membrane Systems Supplier

GE Water & Process Technologies

Engineering and Architectural Services

CH2M Hill, Brown and Caldwell, Hargreaves Associates, HDR, Mithun

Design Subconsultants

Brown and Caldwell, Mithun Architects + Designers + Planners

Solids Stream and Odour Control Design-Build Contractor

Kiewit-Pacific Co

North Creek Facilities Contractor

James W Fowler

Hollywood PS Upgrade Contractor

McClure and Sons

Brightwater Tunnel (BT) Contractors

Vinci, Parsons and Frontier-Kemper (VPFK); Jay Dee Contractors and Frank Coluccio Construction (JDC) JV