The Vista Village Trunk Sewer Project addressed one of the City of Vista’s highest priority capacity deficiencies within its largest trunk sewer. The existing 30 to 36 inch pipeline transected the most visible entry to the city, an environmentally sensitive habitat within Buena Vista Creek and the SR-78 freeway. 

For this Project, the City of Vista retained and organized a three phase Progressive Design-Build (PDB) solution. This approach effectively partnered the owner, operator, designer, contractor, and advisory construction manager to significantly improve outcomes. TC Construction was shortlisted and eventually selected by the City of Vista. Applying the innovative, concurrent PDB project delivery process, TC Construction, and our design partner, Michael Baker, Intl., identified a new trunk sewer alignment. This alignment would avoid environmental impacts, the need for new easements, and minimize impacts to existing buildings, roads, and the surrounding community. 

The selected alignment was challenging as it was known that a significant portion of the new pipeline would need to be installed in hard granite rock. By utilizing advanced perforation drilling, combined with hydraulic hammering, and expansive chemical breaking, TC Construction installed 3,200 linear feet of 24 inch PVC via open trench construction ranging in depths from 25 to 33 feet. With parallel construction and sequencing, live-flow cut-ins for connections were able to be performed, which avoided the need for sewer bypassing. The project included day and night work, dewatering, extensive engineered shoring, micro tunneling under the CA Fwy 78, environmental mitigation, and asphalt paving.

The PDB team, led by TC Construction, had completed many traditional design-build projects in the past. PDB brought unprecedented levels of collaboration to the entire team and delivered a high-priority, complex project in a way that greatly exceeded the expectations of the City of Vista. Notably, the projected GMP was nearly $10,000,000 below the original $24,800,000 planning estimates and delivered within schedule.