Project illustrations and photos

Along 42nd Avenue South—Storage/treatment tunnel, inlet & outlet regulators

With tunneling completed in October 2003, current work is focusing on building the underground infrastructures at the Inlet and Outlet Regulator stations. At the 85-foot deep Inlet Regulator shaft, work consists of fabricating interior walls and vaults, building the chemical room, running electrical conduits and piping. At the Outlet Regulator, walls are being for formed and poured. In the coming months vaults will be fabricated and interior mechanisms set in place for wastewater screening and treatment. (June 2004) more photos.

The tunnel boring machine was removed from the receiving shaft (north portal) in segments. The removal process took an entire day. (October 27, 2003) more photos.

On October 20, 2003, the project reached an important milestone when mining for 4-million-gallon wastewater storage and treatment tunnel was completed. The 150-ton, 200-inch tunnel boring machine (TBM) broke through a steel-reinforced concrete wall into an open receiving shaft, 80-feet deep and 43 feet in diameter at South Henderson Street and 42nd Avenue South. more photos.

Workers monitor ground settlement along the route of the tunnel. (October 2003) more photos

Aerial photo of the south portal. (October 2003)

Each day the tunnel boring machine (TBM) advances further north on its 3,100-foot trek from South Norfolk Street to South Fairbanks Street. (August 2003) more photos

The tunnel operator advances the TBM from the head of the tunnel. (August 2003) more photos

Concrete segments are fitted together to form tunnel’s 14-foor circular shell. (August 2003) more photos

As soils are mined, they are transported by conveyor belt to rail cars (often called ‘muck cars’). When the ‘muck cars’ reach the tunnel’s south portal, soils are transferred to a storage area and then hauled away from the site by truck. (August 2003). more photos

The project's five smaller diameter tunnels are complete. Three of these connect inside the two deep shafts. In mid-August, the last of these five smaller diameter tunnels ‘holed out’ in the 85-foot deep MLK junction manhole, which is contained in one of the two northern shafts. (August 2003) more photos

Tunneling on the large storage facility is now underway.   As the 14-foot diameter tunnel is mined, soils are carried out on a conveyor belt and transfered to "muck" cars, then lifted by crane and stored for hauling. (June 2003) more photos

Tunnel boring machine (TBM) at the south portal (May 2003). The 150-ton, tunnel-boring machine (TBM) arrived May 12, 2003 and was set in the pit at S. Norfolk and 42nd Ave. S. by huge cranes. Tunneling is scheduled to begin here at the south portal in early June. more photos

Deep shafts at northern end of storage/treatment tunnel. Two deep shafts are under construction at the northern point of the storage tunnel where the tunnel boring machine (TBM) will break through later this year. (April 2003) more photos

Micro-tunneling under I-5 and the railroad tracks. Micro-tunneling is underway to cross beneath BNSF railroad tracks and I-5 at S. Norfolk St. and Airport Way S. May 12, 2003. more photos

Pipe Installation on S. Norfolk St. from Airport Way S. to East Marginal Way S. A 72-inch pipeline is being installed in an open trench from the west micro-tunnel portal at Airport Way S. and S. Norfolk St to the new King County manhole at East Marginal Way South and Norfolk. (May 2003) more photos

Along South Henderson Street—Pump Station

Work at the Henderson Pump Station was completed this spring. Expansion, which occurred primarily underground, doubled the capacity of the original structure that was built in 1974. The brick etched artwork on the east wall facing Seward Park Ave. S. titled Quest for Clean Water was completed in 1974 by well-known, artist Richard S. Beyer. (June 2004) more photos.

August 16th, the Seattle Fire Department, King County and its tunnel contractor, NW Boring/Kenny JV, took part in a cooperative tunnel rescue drill in order to provide firefighters and tunnel workers rescue training inside a real tunnel. (August 16, 2003)

See also This Week in DNRP, Sept. 8, 2003 -- Firefighters rescue two injured workers in simulated sewer tunnel fire