Hawaii Water Service launches feasibility study for new Kapalua Recycled Water Treatment Plant

Hawaii Water Service is moving forward with a feasibility study for a decentralized wastewater treatment plant in Kapalua that would produce recycled water and give the community a drought-resistant supply of irrigation water.

Hawaii Water has selected Carollo Engineering Inc. to conduct the feasibility study for the plant. Currently, wastewater in Kapalua travels through Hawaii Water’s system and is treated at the County of Maui’s Lahaina Wastewater Reclamation Facility.

The study, expected to be complete in fall 2026, will identify and evaluate potential sites for the new plant in Kapalua. It will also analyze advanced technologies that could improve the efficiency and effectiveness of Hawaii Water’s wastewater treatment, along with regulatory and land area requirements and operations and maintenance costs.

“We’re dedicated to enhancing the quality of life for our customers and communities. We do this by investing in and responsibly maintaining our system for water and wastewater services,” said Geoff Fulks, General Manager of Hawaii Water. “This study will help us determine if this new plant is the next investment that we need to make to increase supply reliability for our Kapalua customers.”

Already on Maui, Hawaii Water operates a wastewater treatment plant in Pukalani producing recycled water. It was the first such plant in the State of Hawaiʻi to use state-of-the-art flat plate membrane bio-reactor filtration technology, which treats 200,000 gallons of wastewater per day for reuse. Hawaii Water selected the flat plate membrane process because it has a very small footprint, is less costly to maintain, and produces water that can be reused without restriction, freeing up precious potable water supplies.

“Severe drought conditions have limited our customers’ use of water for irrigation, and we can expect droughts again in the future,” Fulks said. “This study is about finding ways that we can continue to provide excellent value to our customers, increase water supply reliability, and be a responsible steward of our limited, natural resource.”