Harbor Pacific Contractors, Inc, Construction Services in the Pacific Northwest
Henderson / MLK Combined Sewage Overflow (CSO) Tunnel and Pipeline
Harbor Pacific Contractors, Inc.
Harbor Pacific Contractors, Inc.
Harbor Pacific Contractors, Inc.
Harbor Pacific Contractors, Inc.
Harbor Pacific Contractors, Inc.
Outlet Regulator Station - South Elevation

This is a combined sewage overflow "CSO" facility that includes two multi-story cast-in-place concrete structures (the Inlet Regulator Structure "IRS" and the Outlet Regulator Structure "ORS") with a 3,100 lineal foot tunnel below south Beacon Hill connecting them. During storm conditions the tunnel is designed to hold up to 3.5 million gallons of combined storm water and sewage. This prevents the untreated wastewater from discharging directly into Lake Washington. Once storm conditions have subsided the wastewater is discharged into King County's sewage conveyance system for final treatment.


Harbor Pacific Contractors, Inc.
19628 144th Avenue NE, Suite A, Woodinville, Washington 98072
phone 425.488.7131 - fax 425.489.3991
www.harborpacific.com -