BWS Initiatives > Seawater Desalination

Kalaeloa Seawater Desalination Facility

Now Available: Kalaeloa Desalco Project Website

Friday, November 24, 2023 – The website for the desalination project being built in Campbell Industrial Park is now available. For more information, please visit

Project Update for the Kalaeloa Seawater Desalination Facility

Thursday, September 14, 2023 – The Honolulu Board of Water Supply and Kalaeloa Desalco LLC is planning to build an innovative desalination water facility in Campbell Industrial Park that will produce 1.7 million gallons of fresh water daily. Known as the Kalaeloa Seawater Desalination Facility, the plant will be a new source of fresh water to support the needs of Campbell Industrial Park.

Informational Materials: 

For more details, please see the following or download informational posters or frequently asked questions.

Location (PDF)

Kalaeloa Seawater Desalination Plant Location

Renderings (PDF)

Kalaeloa Seawater Desalination Plant Renderings

Process (PDF)

Kalaeloa Seawater Desalination Plant Process

Project Overview (PDF)

Kalaeloa Seawater Desalination Plant Project Overivew

Project Partners (PDF)

Kalaeloa Seawater Desalination Plant Project Partners

Project FAQ (PDF)

Kalaeloa Seawater Desalination Plant FAQ

BWS to Issue Request for Proposals for Desalination Facility

Friday, May 4, 2021 -- The Honolulu Board of Water Supply is preparing to issue a Request for Proposals (“RFP”) for design-build-operate-maintain services (“DBOM”) for the Kalaeloa Seawater Desalination Facility Project, a seawater reverse osmosis desalination water treatment plant with a capacity of 1.7 MGD, expandable to 5 mgd. The purpose of the Project is to design, pilot test, permit, construct, start-up, test, and subsequently operate and maintain the Project for a term of twenty years.

kalaeloa seawater desalination facility map location

The objective of this Project is to develop a sustainable seawater desalination facility that is cost effective on a life-cycle basis and supports the Ewa Development Plans directed growth policies with a drought-proof, high quality local water supply that is environmentally sustainable, enhance water resilience to climate change and reduce water transfers from Central Oahu. BWS also seeks to ensure that the introduction of a new source water into the distribution system will cause no detrimental impact to the existing distribution system assets or to local customer’s water systems and their uses.

kalaeloa seawater desalination facility site plan

The 20 acres project site is located in Campbell Industrial Park on a BWS-owned property at 91-447 Olai Street, TMK: 9-1-31: 28. The structures will include an administration building, laboratory, office, visitor accommodations and process building for process equipment tanks, grading, drainage, roads, parking lots, utilities, fencing, landscaping, mechanical, and security systems.

The Project was authorized by Congress on September 21, 2005 in P.L. 109-70, Section 1638. A US Bureau of Reclamation Grant Application has been accepted for an up to 25% Federal match.  A Final EIS was filed in 2008 with OEQC.  As part of the grant application, an updated engineering feasibility study and financial capability determination has been completed and a NEPA EA FONSI meeting Section 106 Archaeological Inventory Survey is being developed.

ewa district capacity

Fresh water demand is approaching BWS Ewa system capacity. BWS is already working to reduce its reliance on groundwater supplies and diversify its supply by encouraging conservation, using recycled water to meet nonpotable water demands, leveraging brackish and saline aquifer supplies where possible. The Ewa District is anticipating a population increase of about 30 percent, or 50,000 people, between 2020 and 2040. Although projected per capita demand is expected to fall from about 168 gallons per capita day (gpcd) in 2020 to about 160 gpcd in 2040, potable demand is anticipated to increase from about 24 mgd in 2019 to nearly 27 mgd in 2030 and additional potable supply will be needed.

one water supply options

environmental mitigation

Environmental Mitigation:
Saltwater source is from deep wells.  Brine injection into the overlying caprock. JCIP is an underground injection control area regulated by DOH.

desalination simulation

Brine will sink because of higher density and flow along the caprock/basal contact along a 4% slope to the ocean and be diluted.  Brine will not impact the benthic nearshore environment.

The desalination process will include an energy recovery system to reduce power consumption and Photovoltaics are planned in a later phase.

Proposed Kalaeloa Seawater Desalination Facility Site