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Sand Island Wastewater Treatment Plant Upgrade - Planning and Design

Advancing wastewater treatment technology in paradise

  • Honolulu, Hawaii

    Honolulu, Hawaii

Creating opportunities for reducing greenhouse gas emissions and producing green power

Sand Island Wastewater Treatment Plant is the largest treatment facility in Hawaii and serves Honolulu and Waikiki, from East Oahu to Pearl Harbor. The City and County of Honolulu is currently responding to a consent decree to upgrade the facility to secondary treatment standards.

The plant treats an average flow of 65 million gallons per day (MGD)—246 megalitres per day (MLD)—a maximum monthly flow of 90 MGD (341 MLD), and a wet weather peak flow of 240 MGD (909 MLD), through chemically-enhanced primary treatment and UV disinfection prior to ocean discharge. The plant is undergoing construction of a 20 MGD (76 MLD) membrane bioreactor (MBR) process as Phase 1 of the secondary expansion. Along with our joint venture partner, RM Towill Corporation, we’re completing the planning phase and entering the design phase of the Phase 2 expansion to achieve complete secondary treatment, employing aerobic granular sludge (AGS) in a dual system with the MBR process.

Phase 2 will include peak flow equalization, upgrades to preliminary and primary treatment, and expanded solids treatment to manage the additional waste-activated solids generated by the new dual secondary process train. Additionally, Phase 2 includes an organic waste sustainability plan (OWSP) that focuses on sustainable approaches to use feedstocks, such as fats, oils, grease, and commercially-available food waste to supplement anaerobic digestion—creating opportunities for reducing greenhouse gas emissions and producing green power through cogeneration.

At a Glance

Offices
Client
  • City and County of Honolulu
Partners
  • Joint Venture (JV) Partner
  • RM Towill Corporation (RMTC)
Meet Our Team

Bob Armstrong, Project Development Leader

I enjoy working with our clients’ staff—from operations to engineering—to learn about their issues and deliver purposeful solutions.

Heather Stephens, Senior Principal, Wastewater Leader

I’m passionate about working as a team to foster creativity and arrive at better solutions together than we could come up with individually.
Heather Stephens Senior Principal, Wastewater Leader Read More

Sarang Agarwal, Civil Engineer

I’m passionate about working in the wastewater and the water treatment field—I feel like I’m part of the community I serve.

Pooja Sinha, Engineer in Training

Finding universal solutions for climate change crisis is a global priority—resources recovery in water and wastewater should be our focus.

Dru Whitlock, Vice President, Global Practice Leader, Biosolids & Energy Recovery

Organics is evolving—we’re closing the loop on wastes, creating renewable energy, and radically reducing greenhouse gases.
Dru Whitlock Vice President, Global Practice Leader, Biosolids & Energy Recovery Read More

Katerina (Kat) Messologitis, Process Engineer

The heart of my work centers around people—I’m driven to give back to communities to make clean water access more equitable.
Katerina (Kat) Messologitis Process Engineer Read More

Bob Armstrong

Project Development Leader

Heather Stephens

Senior Principal, Wastewater Leader

Sarang Agarwal

Civil Engineer

Pooja Sinha

Engineer in Training

Dru Whitlock

Vice President, Global Practice Leader, Biosolids & Energy Recovery

Katerina (Kat) Messologitis

Process Engineer

We're better together

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