Fort Collins Wastewater Treatment Plant
Fort Collins, Colorado

JFSA was retained by CH2MHill to provide structural design and construction support services for expansion of the Fort Collins water treatment facility. The firm's contribution to this project included the complete design of two major structures: the flow blending facility and the chemical feed building.

The 7,100-square-foot concrete flow blending facility includes an underground valve vault, an above-grade control room, and associated stairs, catwalks, and ladders. Most of the structure consists of rectangular water tanks and channels, some as deep as 55 feet. Careful design was necessary due to the considerable pressure generated by water at this depth. To ensure complete mixing, supports for redwood baffle walls were provided throughout the tanks. Unusual soil conditions meant that part of the facility, including tanks 35 feet deep, was founded on caissons. The valve vault and deeper tanks are on a mat foundation.

The chemical feed building is a complex 12,500-square-foot steel and masonry structure. It includes a number of secondary containment areas covered with fiber-reinforced plastic gratings that are penetrated by equipment pedestals and access ladders. Chemical silo foundations were incorporated, along with removable roof panels to enable replacement of silos. Material handling monorail cranes, supports, and switches are suspended from the roof structure. For architectural purposes, tall slender brick walls with masonry strengths up to 10,000 psi were constructed and reinforced to span horizontally between pilasters.

Client: City of Fort Collins, Colorado