EPA Announces $109 Million Loan for Oahu's First Seawater Desalination Plant

The U.S. Environmental Protection Agency has announced a $109 million loan to the Honolulu Board of Water Supply to help design and build a large-scale reverse osmosis seawater desalination plant on Oahu, according to an EPA news release dated October 16, 2026. EPA says the plant will provide 1.7 million gallons of water a day to island residents while decreasing pressure on groundwater aquifers.

The loan comes from EPA’s Water Infrastructure Finance and Innovation Act (WIFIA) program and will go toward the Board’s Kalaeloa Seawater Desalination Facility Project, the release says.

What the loan pays for

• A new kind of source for Oahu. The project will help “convert abundant saltwater into clean and safe drinking water, establishing an alternative drinking water source for the island,” according to EPA. Ernest Lau, manager and chief engineer of the Honolulu Board of Water Supply, said the financing “will assist in constructing the first seawater desalination facility for our island community.”
• More than the plant. EPA says the project includes byproduct disposal facilities, a recycled water pipeline and transmission lines, and is meant to increase supply reliability and reduce reliance on groundwater aquifers in the more arid district the Board serves, west of Honolulu and Pearl Harbor.
• Easier on ratepayers during construction. The Board is making the WIFIA loan a subordinate lien and will use the option to defer principal payments during construction to reduce the impact on ratepayers, according to the release.
• EPA’s view. “We are thrilled that Honolulu is using this $109 million WIFIA loan to create a reliable and renewable source of drinking water to benefit the community,” said Jess Kramer, EPA assistant administrator for water.

Why Oahu is turning to the ocean

The Honolulu Board of Water Supply says fresh water demand is approaching the capacity of its ‘Ewa system. On its Kalaeloa project page, the Board says the ‘Ewa District expects its population to grow by about 30 percent, or 50,000 people, between 2020 and 2040, and that potable demand is expected to rise from about 24 million gallons a day in 2019 to nearly 27 million in 2030.

The plant will sit on a 20-acre Board-owned site in Campbell Industrial Park and will produce 1.7 to 2.55 million gallons of fresh water a day, according to the Board. Its saltwater source is deep wells, with brine injected into the overlying caprock. The Board says the process will include an energy recovery system to reduce power consumption, with solar photovoltaics planned in a later phase. A pilot phase completed in May 2025 showed the proposed reverse osmosis membrane and post-treatment systems can meet the project’s regulatory and enhanced water quality standards, the Board says, and its November 2025 project update said a construction notice to proceed was anticipated in fall 2026.

Why WaterVO™ follows this

Oahu’s plan is a reminder that where drinking water comes from is a choice. Wells, rivers and the ocean all carry what they pick up along the way. Atmospheric water generation, which we call vapor optimizing (VO), starts from a different source: it filters incoming air and condenses drinking water from humidity. Like seawater desalination, it takes electricity, and energy is the honest trade-off. We think that trade is worth weighing for the water you drink.

Sources

• U.S. EPA, “EPA Announces $109 Million WIFIA Loan to Increase Water Supply Reliability in Honolulu, Hawaii,” October 16, 2026: epa.gov
• Honolulu Board of Water Supply, “Seawater Desalination” (Kalaeloa Seawater Desalination Facility page, updated Sept. 15, 2026, including a November 2025 project update; read Oct. 19, 2026): boardofwatersupply.com

Photo: Ewa Beach, Oahu, Hawaii, by Thomas Woodtli via Wikimedia Commons (CC BY-SA 2.0); cropped, headline added in the featured image. Illustrative; not the plant site.

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