Hawaii Water Service to evaluate decentralized recycled water plant for Kapalua

Hawaii Water Service is moving ahead with a feasibility study to evaluate the potential development of a decentralized wastewater treatment plant in Kapalua. The proposed facility would supply recycled water for irrigation, helping to strengthen local water security and reduce vulnerability to future drought conditions.

To support the evaluation, the utility has engaged Carollo Engineering Inc. to carry out the study. Currently, wastewater generated in Kapalua is conveyed through Hawaii Water Service’s system and treated at the County of Maui’s Lahaina Wastewater Reclamation Facility. The feasibility assessment will determine whether treating wastewater locally could provide long-term operational and sustainability benefits.

Expected to conclude in fall 2026, the study will identify and assess potential sites for the new treatment plant and examine advanced treatment technologies that could enhance system performance. In addition, it will review regulatory considerations, land area needs, and projected operations and maintenance costs associated with the facility.

“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.”

On the island of Maui, Hawaii Water Service already operates a wastewater treatment plant in Pukalani that produces recycled water using flat plate membrane bioreactor technology. The facility treats about 200,000 gallons of wastewater per day and was selected for its compact footprint, lower maintenance requirements, and ability to generate recycled water suitable for unrestricted reuse.

“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.”