Ballard Siphon Replacement Project

May 20, 2013 Project Update –

North site: Work is nearing completion on the structure that will connect the existing sewer pipes to the new siphon. Crews are also preparing the north shaft for receiving the tunnel boring machine.
El lado norte: El trabajo en la estructura que conecta las tuberías existentes de drenaje a la nueva tubería está casi terminado. El equipo de trabajo también está preparando el pasadizo norte para recibir la máquina excavadora del túnel. 

South site: Shoring will be removed near West Commodore Way beginning May 21; near neighbors may experience vibration. Tunneling continues 24 hours a day, Monday through Saturday. Crews may work some Sundays.
El lado sur: La protección de excavación va hacer removida al West Commodore Way comenzando el 21 de mayo; vecinos cerca pueden sentir vibraciónes. Los trabajos del túnel continúan las 24 horas del día de lunes a sábado y algunos domingos.

View project update (May 20, 2013). 


Take a video tour of the tunnel! (WTD YouTube channel) 

View construction photos.

Typical work hours: 7:00 a.m. – 6:00 p.m. weekdays
Horas normales de trabajo: De lunes a viernes de las 7:00 a.m. a las 6:00 p.m.
24-hour project hotline/Para más información*: 206-296-3848 
Para más información sobre el proyecto las 24 horas, llame  al 206-296-3848
Seleccione su idioma para solicitar hablar con un intérprete, este servicio es gratuito.

Project description

Project map. Click map to enlarge view. Also available as PDF


View construction photos at the South site and North site.

 
North Site - Pedestrian detour map (PDF), August 2011

To protect public health and the environment, King County is building a new 85-inch siphon pipe under Salmon Bay between the Ballard and Interbay areas of Seattle. The new siphon will be installed more than 120 feet underground and connect the Ballard Regulator Station at 5110 Shilshole Avenue Northwest in Ballard to the North Interceptor at West Commodore Way and 24th Avenue West intersection in Interbay (see project map).

After excavating vertical shafts at the Shilshole Avenue and Commodore Way sites, King County’s contractor will install a tunnel boring machine to bore a pipe corridor for the new siphon roughly 60 feet beneath Salmon Bay. The existing siphon will be cleaned out and relined as part of this project. Additional equipment supporting the new pipe will also be installed at the Ballard Regulator.

Project need

The new pipe is needed to accommodate growth in north Seattle. The new pipe replaces two 36-inch wooden stave pipes which have served the Ballard community since the 1930’s. The new pipe will meet north Seattle’s wastewater conveyance needs through the end of the century.

Wastewater from homes and businesses in Ballard now flows through the 36-inch siphons and across the bay, moving from the higher elevated pipes on the north side of the canal to the lower elevation on the south side, for treatment at the West Point Treatment Plant in Magnolia.

Project schedule

What to Expect

• Noise and other activity typical of a construction site at the intersection of Shilshole Avenue Northwest and Northwest 20th Avenue in Ballard and at the intersection of West Commodore Way and 24th Avenue West in Interbay.
• Crews, trucks and heavy equipment at the Ballard and Interbay sites
• Traffic detours near the construction sites on Shilshole Avenue Northwest and West Commodore Way.
• Increased truck traffic on Shilshole Avenue Northwest, 15th Avenue Northwest, Northwest Leary Street, West Nickerson Street and Aurora Avenue.