Situation
The Willamette Water Treatment Plant located in Sherwood, Oregon, approximately 15 miles south of Portland is a key component of the Willamette Water Supply Program. The program was developed to meet the long-term water needs of the growing community. Designed to produce up to 60 million gallons of water per day, with future ability to increase to 120 million gallons of water per day.
In addition to increased capacity, the project prioritized structural resilience in anticipation of a major seismic event and its ability to stay operational. The site’s favorable geological profile of stable rock conditions was an important factor in the plant’s location being selected.
Solution
GBI was responsible for 250,000 cubic yards of mass and structural excavation, including 350,000 bank cubic yards of drilling and blasting performed by our in-house blasting team, Blasting Tech. Drilling and blasting supported both site and structure excavation, and included blasting trenches for site utilities and process piping.
In addition, GBI produced 500,000 tons of crushed aggregate and placed 200,000 tons of structural backfill, including 5,000 cubic yards of CLSM. Our scope also included construction of 28,000 square feet of retaining walls, including cast-in-place, gabion, and soil nail wall systems, along with off-site street improvements to support access and surrounding infrastructure.
Notable
Following a significant seismic event, the facility is designed to provide drinking water to emergency responders and the community within 48 hours of a disaster.
