Challenges Associated with the Implementation of the Carlsbad Desalination Conveyance System

Abstract

The San Diego County Water Authority (Water Authority), in conjunction with a private development team, is nearing completion with the construction of the Carlsbad Desalination Conveyance System (Conveyance System). A series of projects will deliver water from the new 54-mgd Carlsbad Desalination Plant to the Water Authority's Aqueduct System. The Conveyance System consists of four separate projects, three of which are being implemented through separate design-build (DB) contracts. The fourth is being implemented through a design-bid-build (DBB) contract. The fifth project, which is the desalination plant itself, is included herein for clarity, but is not considered as part of the conveyance facilities. The projects include the following: (1) Carlsbad Desalination Plant—50 mgd seawater desalination plant (2) Carlsbad Desalination Product Water Conveyance Pipeline: (DB) Ten (10) miles of 54-inch steel pipeline with operating pressures up to 550 psi. (3) Pipeline 3 Relining (DBB): Five (5) miles of existing 75-inch and 72-inch pipe are being relined with 69-inch and 67.75-inch steel liners. (4) TOVWTP Improvement Project (DB): Approximately 1,500 feet of 54-inch steel pipeline, clearwell improvements, a flow control facility, and chemical injection facilities. (5) San Marcos Vent Desal Modifications (DB): Includes connections between Pipelines 3 and 4 of the Water Authority's Second Aqueduct. This paper addresses multiple challenges associated with the implementation of the Conveyance System. Specifically, it will address the challenge of coordinating design and construction of interrelated projects, handling simultaneous reviews of numerous pipeline headings, and establishing design criteria and resolving conflicting recommendations.