Oceanit’s Resilient & Sustainable Engineering (RiSE) team conducted two Environmental Assessments (EA) to evaluate and facilitate critical upgrades to the effluent disposal system and the aging water supply system infrastructure of the Waikīkī Aquarium in Honolulu.
Situated along the shoreline near Kapahulu Avenue and adjacent to the War Memorial Natatorium, the Waikīkī Aquarium has been a prominent Honolulu landmark for over a century. Founded in 1904, it became part of the University of Hawaiʻi at Mānoa in 1919. As the second-oldest public aquarium in continuous operation in the United States, it welcomes over 250,000 visitors annually. Its mission is to enhance public awareness of the ecology and conservation of marine life and reef habitats through exhibitions, research, and education.
When it opened, the Waikīkī Aquarium featured 35 tanks and housed 400 marine organisms, making it a state-of-the-art facility for its time. Now, over a century later, the aquarium remains a vital institution but faces challenges as an aging facility. It has undergone several renovations and supports 60 public exhibits and holding tanks using three primary water sources: (1) natural seawater from two offshore intake pipes, (2) saltwater derived from a saltwater production well, and (3) freshwater supplied by the City and County of Honolulu water system.
Plans are underway for significant upgrades to the water intake and wastewater discharge systems. Oceanit’s RiSE team has initiated this process by conducting environmental assessments for both systems.
Effluent Discharge System
The Waikīkī Aquarium currently discharges wastewater from native marine life exhibits into the ocean through a permitted outfall located approximately 150 feet offshore. Wastewater from non-native exhibits is directed into the City and County of Honolulu (CCH) wastewater system. This approach has led to water quality issues that fail to meet existing—and are unlikely to meet future—regulatory standards for nearshore water quality.
Ocean wastewater discharge is regulated under the National Pollutant Discharge Elimination System (NPDES) permit limitations. However, the aquarium’s ocean disposal system has long been out of compliance with both its discharge permit conditions and the Federal Clean Water Act due to the facility’s aging infrastructure. Additionally, the disposal of saltwater into the CCH wastewater system creates significant challenges, including collection and treatment complications within the municipal infrastructure.
The planned wastewater system upgrade aims to ensure the aquarium surpasses the regulatory standards set by the Hawaii State Department of Health, the CCH Department of Environmental Services, and NPDES requirements. Oceanit is designing an improved water system infrastructure for the aquarium’s exhibits to achieve full compliance with federal, state, and municipal regulations.
The Final EA for the discharge system was filed February 32, 2024. Click here to access the Final Environmental Assessment for the Waikīkī Aquarium Discharge System Upgrade.
Supply Water Intake System
The aging water intake system infrastructure at the Waikīkī Aquarium is slated for a significant upgrade. Planned improvements include replacing the two existing ocean water intake pipes, which extend 160 feet offshore, constructing a new well water pump vault, installing a new aeration tank, reconstructing and extending the existing pump building, rehabilitating the saltwater production well, and adding new equipment and piping. These upgrades will support the expanded Edge of Reef (EOR) exhibit, which will replace older exhibits being removed as part of a new discharge system project.
To facilitate this extensive rehabilitation project, Oceanit first completed a comprehensive environmental assessment (EA) for the proposed upgrades. This assessment evaluated potential environmental impacts associated with the project, particularly given that much of the existing infrastructure dates back to the 1950s. Environmental assessments generally examine the potential effects of proposed actions on the environment, offering alternatives or mitigation measures to minimize or eliminate those effects. This process ensures that decision-makers consider environmental implications before approving or modifying a project’s scope.
The upgrade project is expected to yield long-term benefits for environmental and ocean water quality by replacing the current asbestos-containing intake pipes with modern high-density polyethylene (HDPE) pipes. The new system will provide the aquarium with a more reliable water supply infrastructure while reducing the need for future upgrades. The construction will also deliver higher-quality water to exhibits, along with enhanced redundancy and backup systems, allowing for equipment maintenance with minimal operational disruptions. These improvements will bolster the overall functionality and sustainability of the aquarium for years to come.
