RESIDENTS AND INDUSTRIES OF WASHINGTON STATE, USA, WILL HAVE MORE SECURE ACCESS TO ENERGY THANKS TO THE REPLACEMENT OF A PIPELINE CONSTRUCTED NEARLY 50 YEARS AGO.

The Williams Northwest pipeline carries natural gas south from the Canadian border and north from the southwestern USA, and distributes it to customers throughout the Pacific Northwest and other parts of the country. However, there were concerns regarding the integrity of the pipeline, constructed in 1956, because of two pipeline explosions in 2003. The pipeline was idled until its safety could be proven.

To address these concerns, Williams Northwest decided it could replace the capacity of 431 km (268 miles) of 26-inch diameter pipeline in western Washington with approximately 133 km (80 miles) of 36-inch pipeline. Using the recently acquired team from PIC Technologies, Golder helped obtain Federal Energy Regulatory Commission (FERC) approvals and other federal, state and local approvals, prepared habitat management and mitigation plans, performed local permitting and hydrological monitoring, and carried out the geotechnical work, including stream crossing design.

Other challenges came from the steep mountainous terrain along portions of the existing right-of-way and over 100 stream crossings, which in some cases called for directional drilling to avoid disrupting the stream beds.

The area also contains fragile wetlands and many threatened and endangered species. As well as helping gain the approvals for the new pipeline, Golder’s work included decommissioning parts of the older pipeline that have reached the end of their service life.

The result is a more efficient and secure pipeline system that can continue supplying energy to the region for decades to come.