Costco Building 4

This project expands Costco’s headquarters and consists of building a 620,000 SF building on a 3.5 acres bordered by Issaquah Creek and consisting of protected wetlands within the site.
Encore is overseeing the environmental management and compliance during construction, performing weekly CESCL inspections, water quality monitoring for groundwater dewatering as well as water treatment operation of a Chitosan Enhanced Sand Filtration system.