ASCE Recognizes Hawaii Wastewater Reclamation Facility for Innovative Planning and Environmental Preservation

The American Society of Civil Engineers (ASCE) Hawaii Section awarded the Kennedy Jenks (KJ) team in Hawaii the 2023 Outstanding Civil Engineering Achievement (OCEA) for Best Water/Wastewater/Environmental project for the Wailuku-Kahului Wastewater Reclamation Facility (W-K WWRF) Facility Plan Project. This is the fifth ASCE OCEA award for KJ. 

The W-K WWRF plays a crucial role in serving the economic heart of Maui by treating wastewater and discharging treated effluent, protecting recreational waters for residents and visitors. The County of Maui Wastewater Reclamation Division and KJ developed the W-K WWRF Facility Plan, to establish the level of service goals and requirements for the facility through the planning horizon of 2050. The Plan evaluated the W-K WWRF’s condition, capacity, and reliability.

The evaluation included holistic solutions for the design challenges by considering “outside–the–fence–line” solutions. This approach addressed the vulnerable location of W-K WWRF near the shore, exposed to potential tsunamis and sea level rise. KJ collaborated with the County to identify recommendations and create a timeline with milestones as a roadmap for improvements. The Plan provided the information needed to make informed decisions and secure timely funding.  

Critical findings included the facility’s unsustainable location due to environmental risks, capacity limitations of the injection wells, insufficient treatment capacity, and operational challenges. To address these issues, the Plan proposed recommended actions and evaluated multiple solutions. A Pretreatment and Primary Microscreens solution was recommended.  

For immediate implementation that could provide quick benefits at a relatively low cost to the County, the Plan recommended pretreatment at key local commercial establishments. Primary Microscreens were recommended if pretreatment did not reduce the organic load level to the existing plant capacity. The Primary Microscreens offer the added benefit of an opportunity to centralize solids handling operations, reduce energy use, and provide firm renewable energy production. 

By implementing Pretreatment at high-concentration dischargers, capacity and infrastructure upgrades at the W-K WWRF can be reduced and potentially avoided completely. Additionally, the cost of treating high-concentration wastewater would be financed by the dischargers rather than impacting community wastewater rates. Implementing the recommended cost-effective pretreatment alternative will reduce both construction costs and construction needs at W-K WWRF. By choosing this approach, the County’s taxpayers will save a significant amount of money.  

The Primary Microscreen process helps protect the environment and supports cost-effective decisions, avoiding unnecessary construction and increasing the project’s long-term success even in changing conditions. Implementing this solution helps to avoid constructing a fourth concrete aeration basin and reduces infrastructure investment, prioritizing environmental preservation and long-term viability.

Incorporating a Primary Microscreen for diverting carbon allows the County to increase capacity and reduce energy consumption. Primary solids-liquid separation is a novel and successful treatment method used at facilities in other parts of the country and around the world. Introducing this technology to the region would mark a significant milestone in using advanced materials and methods for managing wastewater.

KJ’s work on the Wailuku-Kahului Wastewater Reclamation Facility plan received recognition based on its contribution to the well-being of people and communities, resourcefulness in planning and solving design challenges, pioneering use of materials and methods, innovation in construction, and reduction of impact on the physical environment. To do this, the project team acted as facilitators, bringing together representatives from different sections within the organization to discuss their viewpoints and reach a consensus on critical technical decisions. The result is a project that reduced infrastructure investment, prioritized environmental preservation, and delivered long-term viability.