The Claude “Bud” Lewis Carlsbad Desalination Plant is the largest, most technologically advanced and energy-efficient seawater desalination plant in the US. Each day, the plant delivers nearly 190.000 m3 (56,000 acre-feet per year (AFY)) of fresh, desalinated water to San Diego County – enough to serve approximately 400,000 people and accounting for about one-third of all water generated in the County.
Claude “Bud” Lewis Carlsbad Desalination Plant
Located adjacent to the Encina Power Station in Carlsbad, California, the Carlsbad Desalination Plant was developed as a public-private partnership. The project originated in 1998 and was launched in 2015 with a purchase agreement between Poseidon Water and the San Diego County Water Authority. It uses a reverse osmosis filtering process that separates salt from seawater, and has garnered numerous awards for design, implementation and energy efficiency. Poseidon Water is the owner and operator of the desalination plant. IDE is the operator for the next 25 years.
Commemorative photo of the team (Indar – Poseidon Water, HDR, KIEWIT) taken after the witnessed test in Indar (Spain) facilities
Sustainable Water Production: The Challenge
In May 2019, the San Diego Regional Water Quality Control Board and the California Coastal Commission issued a permit for the installation of new, technologically advanced and environmentally sensitive seawater intake and discharge facilities at the Claude “Bud” Lewis Carlsbad Desalination Plant. The new intake-discharge system is needed for long-term operations of the desalination plant that now uses water withdrawn from Agua Hedionda Lagoon for once-through cooling at the Encina Power Station.
The Claude “Bud” Lewis Carlsbad Plant is the largest, most advanced and energy-efficient seawater desalination plant in the U.S.
The closure of the power station in December 2018 led to temporary intake-discharge operations that continued while new, stand-alone desal intake-discharge facilities were built.
H-1800-1697 +S-450-X/8 Motorpump set, Fishfriendly design. Impeller view
Sustainable Water Production: The New Intake
With the decommissioning of Encina Power Station, the Carlsbad Desalination Plant is modernizing the existing intake facilities to provide additional environmental enhancements to protect and preserve the marine environment complying with the regulations in the California State Water Board’s Ocean Plan Amendment.
The new screened-intake (1mm) is using, since May 2020, three (3) Indar high-tech customized fish-friendly submersible pumps that replace the existing circulating pumps: H-1800-1697 +S-450-X/8. The pumps are projected with variable speed to absorb all the potential possibilities of demand in the plant.
The new screened-intake (1mm) is using, since May 2020, three Indar high-tech customized fish-friendly submersible pumps
The submersible pumps with axial flow, single stage and single inlet have an opened multi-channel (3) impeller with big free ball passage. Being projected with shroud (H-type Pumps), the cables once outside the unit are protected, preventing these from coming into contact with the pumped water. Motorpump sets are installed suspended from the discharge piping.
This innovative solution of Dilution PS, for Carlsbad Desalination Plant, allows protection and preservation of the lagoon so that the community can enjoy its recreational and marine resources now and for generations to come.
H-1800-1697 +S-450-X/8 Motorpump set, Fishfriendly design, front view
The New Intake: Transition
The transition to the new intake and discharge facilities were implemented in three phases. First, during temporary operations, NRG Energy, which owns Encina Power Station, continued to operate the water circulation pumps while the interim intake system was constructed.
Next, interim operations started in May 2020; this phase uses new Indar fish-friendly pumps as a replacement for the existing circulation pumps. A new, permanent screened intake system also was designed and built in the lagoon during this phase of operation. The new intake relies on innovative technology.
Projected with shroud (H-type Pumps), the cables once outside the unit are protected, preventing contact with the pumped water
Finally, permanent operations: the new submerged, screened-intake system is expected to be connected in late 2023, achieving the best available technology to minimize impacts to marine life in full compliance with the 2015 California Ocean Plan Amendment.
Once permanent operations begin in 2023, the Carlsbad Desalination Plant will be the first to comply with the 2015 Ocean Plan Amendment, designed to advance ocean water as a reliable supplement to traditional water supplies while protecting marine life and water quality.