?Pledging to transform Hawaii's largest wastewater treatment plant
February 10, 2026
?Using innovations like an aerobic granular sludge process to protect the environment, support a community, and solve challenges
?In this series,?we¡¯ll?explore the power of collaboration and co-creation with our clients. These partnerships?showcase?how we rise to the world¡¯s greatest challenges together.
?Most people?think of?Hawaii as a tropical paradise. The eight main islands?offer natural wonders with beaches,?Pacific Ocean waves, abundant sea life, and mountains that reach to the sky.
?But?it¡¯s?not easy to?maintain?paradise.?And?that¡¯s?where a unique pledge comes in.?
?More on that?pledge later.
?First, the reason for?it.?The?Sand Island Wastewater Treatment Plant?(SIWWTP) is Hawaii¡¯s largest treatment facility.?It serves?the major population areas of?Downtown?Honolulu and Waikiki.?It¡¯s?nearly 50?years old and?needs an upgrade.
?By 2035, the?U.S.?Environmental Protection Agency requires?the?City and County of?Honolulu?to?improve the quality of the water it discharges?into the ocean.?It needs to?go from?primary to secondary treatment of wastewater.
?But which?system?is right??After much research, our?team¡ªwhich includes joint venture partner RM?Towill¡ªand?the City and County of Honolulu settled on?the?aerobic granular sludge?process?for the Phase 2 upgrades. This supplements?the?membrane bioreactor process?being constructed as part of Phase?1.
?And that leads to the pledge:?vowing to do what it takes, not?what¡¯s?easy.
?We¡¯re on the right path, and we¡¯re going to get to the end, together.
?Preparing for complexity¡ªas a team
?The project is complex. There are?energy realities, strict climate action targets, and a limited site footprint¡ªall adding layers of difficulty?when?implementing the right solution.?
?And the new facility carries a?US$2.5?billion?price tag.?It¡¯s?also a solution?that¡¯s?not widely used elsewhere in the world, making it truly groundbreaking.?When complete, it will be the largest?aerobic granular sludge?facility in the world.?
?In addition, the?ongoing?Phase 2 work includes?a?strategic Organic Waste Sustainability?Plan. It will?provide for innovative energy creation through the management of?waste?streams like food waste and fats, oils, and grease.?Other creative solutions at the new facility?include?thermal hydrolysis and?combined heat and power.?¡°We knew the team at ²İİ®´«Ã½ was up to the challenge,¡± says Roger Babcock, director of the Department of Environmental Services at City and County of Honolulu. ¡°We can¡¯t accomplish a project of this scope and scale on our own, and with ²İİ®´«Ã½,?we¡¯re getting the A team.¡±?
?When?innovation is the standard, the payoff is large.
?¡°This project brings a level of innovation that¡¯s going to bring the City and County of Honolulu to the forefront as a leader in using this kind of technology,¡± says Bob Armstrong, vice president and?project?development?leader at ²İİ®´«Ã½. ¡°It¡¯s a very special project for me and for the people of Hawaii.¡±
?Dr. Roger Babcock and Bob Armstrong
?An?ocean of?opportunity
?The SIWWTP site is on the edge of Honolulu?Harbor, in view of the world-famous Waikiki?Beach and?Diamond Head¡ªmarking?Oahu¡¯s primary?center of?tourism.?And,?like many coastal cities, rising sea?levels are a reality?for the community,?along with?the?need to protect?the environment.
?Project supporters include?the Sierra Club and?other?environmental organizations.
?¡°Protecting our near-shore waters for years to come is imperative to this project,¡±?Armstrong says.
?Trust and?relationships
?Committing to innovation¡ªespecially in the face of obstacles¡ªreally comes down to trust and relationships.
?¡°²İİ®´«Ã½ brings a lot of things to the project, but the relationships and the people are what?matters,¡±?Babcock says. ¡°And I like the people at ²İİ®´«Ã½. This project has been successful to date because of those relationships,?and it will continue to be successful because of that.¡±
?Phase 2 of the SIWWTP upgrade is well underway with a targeted completion date of 2035 to meet the EPA¡¯s?Consent Decree.?
?As for the pledge??It¡¯s?still in full effect.
?¡°We made a commitment?to the selected treatment?technology?through signing a pledge with our partners at the City and County of Honolulu?and its consultants,?and we¡¯re here to see this through?to meet the?Consent Decree requirements,¡±?Armstrong says. ¡°We¡¯re on the right path, and we¡¯re going to get to the end, together.¡±
?With every community, we redefine?what¡¯s?possible. Through collaboration with our clients, together we will unlock outcomes neither could achieve alone.
