City officials today announced the completion of the $375 million Kaneohe-Kailua gravity sewer tunnel project that is designed to increase storage capacity for Windward Oahu’s wastewater system and reduce the possibility of overflow.
The project, required by a court-mandated consent decree, began in 2013. It features a three-mile tunnel bored beneath Oneawa Hills that took roughly 13 months to complete using a tunnel-boring machine to drill the 13-foot-diameter tunnel to house a 10-foot sewage pipe.
The pipe will deliver sewage to the Kailua Regional Wastewater Treatment Plant from the Kaneohe Wastewater Pre-Treatment Facility by way of gravity.
The tunnel runs from a depth of 35 feet below ground level on the Kaneohe side down to a depth of 62 feet on the Kailua side, city officials said.
The project also includes a new pump station, generator building, and odor-control facilities.
For more on the project, go to https://www.kktunnel.org/project-overview/.