Kennedy Jenks (KJ) is proud to announce that its Hawaii team was awarded the 2025 Outstanding Civil Engineering Achievement (OCEA) Award by the American Society of Civil Engineers (ASCE) Hawai‘i Section for its work on the Sand Island Wastewater Treatment Plant (WWTP) Disinfection System Upgrade. This marks the team’s sixth consecutive OCEA award, reinforcing KJ’s legacy of engineering excellence and environmental stewardship across the islands.
The Sand Island WWTP, originally constructed in 1978, is the largest treatment facility in the State of Hawaii, serving the majority of urban Honolulu with a rated capacity of 82 million gallons per day (MGD). In 2024, KJ completed an upgrade to the plant’s disinfection system, replacing medium pressure ultraviolet (UV) lamps with low pressure UV technology. The project was delivered through a Design-Build method, fostering collaboration and creative problem-solving.
Project Benefits and Innovations
The upgrade increased disinfection capacity by 30 MGD, improved system reliability, and reduced energy consumption by 42%, resulting in an estimated $1.95 million in annual operational savings. These improvements support Hawaii’s sustainability goals and help stabilize wastewater rates for the community. Other benefits and innovations included:
- Ensuring continued compliance with environmental discharge permits.
- Protecting marine ecosystems near the outfall.
- Reducing operating costs and energy use.
- Maintaining uninterrupted plant operations during phased installation.
To overcome technical challenges, engineers installed modulating actuators on downstream butterfly valves to balance flow between old and new UV systems. A removable deck was also designed to allow maintenance access to the low-pressure modules installed below the UV channel deck.
A First in the Nation
Sand Island WWTP is currently the only facility in the United States to employ UV disinfection on primary effluent. The City’s decision to transition to low pressure UV lamps reflects a commitment to innovative, cost-effective technology that reduces the plant’s carbon footprint.
About Kennedy Jenks
Kennedy Jenks is a leading water and environmental engineering and environmental sciences firm that serves public agencies and private-sector clients with over 500 employees nationwide. The employee-owned firm delivers innovative design, construction, and technology solutions for water and environmental projects across the United States.
Media Contact
For more information about Kennedy Jenks, please contact media@kennedyjenks.com.
The information on this page was accurate at the time of publication.
