Project Summary:

Project: Mt. Vernon Waste Water Treatment Plant Project
Project Location: Britt Rd. & Dike Rd., Mt. Vernon, WA
General Contractor: McClure & Sons
Type of Pile: Augercast
Number of Piles: 631
Pile Depth: 90’
Pile Capacity: 120 Tons
Pile Diameter: 24”

Project Overview:

The Mt. Vernon Waste Water Treatment plant represents the largest single project for McDowell NW with 631 24” diameter auger cast piles ranging in depths from 84’ to 90’. The 120 ton capacity pile included an extra heavy duty rebar cage with center bar and 4,000 psi high strength grout mix. The piles supported the pretreatment and secondary pump buildings, a primary clarifier tank foundation and 2 clarifier tank foundations. Some of the foundations were located next to the Skagit River dike and below the river elevation. Installation was made possible by a large dewatering well system which lowered the water table. As an additional quality assurance measure in these conditions, McDowell NW provided pile integrity testing of the completed piles.