50,000 LF
Length
2026-2029
Duration
$117 million
Contract Value
Oceanside Mesa Garrison Force Main, Oceanside Mesa Garrison Lift Station, Mission Ave Lift Station Force Main Replacement, and Land Outfall Replacement Progressive Design-Build Project
The City of Oceanside is advancing a Capital Improvement Program to decommission the La Salina Wastewater Treatment Plant and redirect wastewater flows to the San Luis Rey Water Reclamation Facility. This initiative will increase recycled water production, strengthen the City’s indirect potable reuse program, ability to increase flexibility within their repair and maintenance of existing force-mains, and convey treated effluent to the existing Ocean Outfall.
Orion/TC Joint Venture has been awarded the Progressive Design-Build contract for the Oceanside Mesa garrison (OMG) Force Main, OMG Lift Station (OMG LS), Mission Avenue Lift Station (MALS) Force Main Replacement, and Land Outfall Replacement, with GHD serving as the design engineer. The Project includes installation of multiple parallel HDPE force mains ranging from 24-inch to 42-inch diameters, constructed primarily via open-cut methods with targeted trenchless segments to reduce environmental and community impacts. Upon completion, flows from the new OMGLS, Buccaneer Lift Station, and Buena Vista Lift Station will converge into the OMG Force Main and be conveyed to the San Luis Rey Water Reclamation Facility.
The Joint Venture has successfully completed the design phase of the Project, incorporating extensive value engineering measures to optimize cost, constructability, and long-term performance for the City of Oceanside. As part of an Early Start Package, the team installed approximately 1,500 linear feet of all three force mains beneath a proposed residential development, coordinating closely to maintain the overall program schedule. This work was completed on time and under the anticipated budget during the winter of 2023–2024, despite record rainfall across California, and was delivered with zero safety incidents.
The Orion/TC Joint Venture successfully advanced the City of Oceanside’s Capital Improvement Program by completing the project design with comprehensive value engineering, prioritizing the City’s operational needs to ensure long-term reliability, maintainability, and system integration. The team also delivered a critical Early Start Package that installed 1,500 linear feet of parallel force mains beneath a proposed residential development during the record-setting 2023–2024 winter rainfall season, completing the work on schedule, under budget, and without a single safety incident.
Owner: City of Oceanside Water Utilities Department
Location: Mesa Drive and Garrison Street, Oceanside CA 92054
Designer: GHD Inc.
Contractor: Orion/TC a Joint Venture
Delivery Model: Progressive Design Build
Contract Value: $117M
Schedule: 04/22/26 – 04/24/29
Scope: Construct Oceanside Mesa Garrison (OMG) sewer lift station with 10,000SF subterranean pump room with 3.74 -6.66 MGD pumping capability inclusive of a wet well (19,808 gallons), and emergency storage basin (853,333 gallons). The pipeline portion of the project consists of parallel force main installation: 24” Mission Avenue Lift Station Force-main replacement, 30” Land Outfall Force-main replacement, and 36” OMG replacement that spans approximately 50,000LF of pipeline installation/replacement.
Challenges: The project involves the installation of three large-diameter force mains within an existing City of Oceanside easement ranging from approximately 12 to 40 feet in width. The corridor contains numerous existing, unrestrained utilities, requiring extensive coordination and carefully sequenced construction activities.
All three force mains will be installed via horizontal directional drilling beneath the environmentally sensitive San Luis Rey River, with pipe depths exceeding 60 feet. The alignments terminate at the existing San Luis Rey Waste Reclamation Facility (SLRWRF), a heavily congested and fully operational wastewater treatment plant with significant space and utility constraints.
A portion of the proposed OMG Force Main includes rehabilitation of an existing 42-inch fiberglass reinforced pipe (FRP). Select segments will be slip-lined with new 36-inch HDPE pipe, while other sections will be rehabilitated using a cured-in-place fiberglass liner. This work will be executed within an existing utility tunnel beneath the SDG&E substation at depths exceeding 100 feet below ground surface, requiring specialized access, safety, and construction controls.
In addition, construction of the new OMG Sewer Lift Station includes installation of a soil nail retaining wall and comprehensive shoring system to support excavation for the wet well and emergency storage basin. The excavation will extend more than 50 feet below existing grade, necessitating advanced geotechnical design, groundwater control measures, and structural support systems.
Results: The City of Oceanside is advancing a Capital Improvement Program to decommission the La Salina Wastewater Treatment Plant (LSWWTP). As part of this initiative, wastewater flows currently tributary to the LSWWTP will be diverted to the (SLRWRF). This diversion will enhance recycled water production and strengthen the City’s indirect potable reuse program. Additionally, treated effluent from the SLRWRF will be conveyed to the City’s existing Ocean Outfall.
