Laguna Treatment Plant Disinfection Improvements Project
Laguna Treatment Plant Disinfection Improvements Project
To replace aging infrastructure and expand disinfection capacity, the City of Santa Rosa selected Shimmick to deliver critical upgrades to its Laguna Treatment Plant. Initially commissioned in 1998, the plant’s ultraviolet (UV) system had reached the end of its service life and could no longer support peak wet weather flows. This project includes constructing a new UV facility with storm and diversion pump stations, a new hypochlorite chemical feed facility, an electrical building, and new training offices. It also features the installation of a 42-inch HDPE diversion pipeline, deep shoring, and dewatering systems, and reinforced concrete structures totaling over 6,700 cubic yards. With a design built to meet evolving regulatory standards and improve operational flexibility, the improvements ensure the city can maintain reliable wastewater treatment and reuse.
Project Details
Location
Santa Rosa, CA
Amount
$68M
Delivery Method
Bid-Build
Client Name
City of Santa Rosa
Duration
2022 – 2025
Project Highlights & Unique Aspects
- Complex Excavation Solutions: Sheet pile shoring and deep well point dewatering to support the below-ground construction beneath the water table.
- UV Disinfection System Upgrade: Installation of De Nora channel-type UV reactors as a pre-negotiated basis-of-design package.
- Micro-pile Foundation System: Utilization of micro-piles to support the new UV diversion structure.
Shimmick's Role & Expertise Bridge Construction
Shimmick is instrumental in the successful execution of this large-scale infrastructure project, providing:
- Electrical and Control Systems Integration: SCADA, switchgear, process instrumentation, and low/medium voltage power distribution across all new facilities.
- Civil and Structural Concrete: Self-performing over 6,700 cubic yards of concrete placement, including mass concrete and water-bearing structures.
- Mechanical Systems: Upgrades to chemical feed, HVAC, pumping, and UV disinfection systems.
Coordination & Community Impact
- Improve the plant’s capacity to manage peak wet weather flows.
- Increase flexibility for operational and regulatory compliance through retreatment capabilities.
- Enhance system reliability with new electrical, control, and chemical infrastructure.
Shimmick plays a key role in replacing critical infrastructure in Santa Rosa to enhance wastewater treatment reliability and resiliency. We are proud to support the city’s long-term water quality and system efficiency goals.