Cesspool Pollution and Conversion in Hawaii: A Wastewater Infrastructure Emergency

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By: Sion Calabretta

Hawaii is known as a tropical paradise of white sand beaches, crystal clear waters, and vibrant fish playing in the colorful coral, but it faces a dire issue of crumbling wastewater infrastructure. As Hawaii has become a popular destination for living and travel, the state has likewise experienced a need to handle large volumes of human waste. The islands’ terrain makes it expensive to build sewer connections throughout the state, so communities have for years relied on cesspools – essentially just holes in the ground - that collect and drain out sewage. Unlike its mainland counterparts, Hawaii has been very slow in replacing these cesspools with more advanced treatment techniques. 

The high cost of living in Hawaii makes the conversion of cesspools unaffordable for many residents. Likewise, the diverse soil and rain conditions across the islands make septic systems more likely to fail as standard septics do not function in all soil types. As a result, roughly 88,000 households still rely on cesspools, discharging an estimated 53 million gallons of untreated sewage into the ground and groundwater resources everyday in Hawaii. Sewage pollution is a threat to public, environmental, and economic health in Hawaii. Cesspools pollute groundwater and reefs, killing corals, collapsing fisheries, causing algae overgrowth, and exposing people to harmful levels of bacteria in their drinking water. Wastewater Alternatives & Innovations, a Hawaiian non-profit, is working to protect water quality and reduce sewage pollution by providing innovative, affordable and eco-friendly solutions to waste and wastewater management. 

Abbreviated as WAI, the Hawaiian word for water, the organization is deeply involved in the work to upgrade all cesspools in Hawaii and develop accessible, affordable, and viable solutions for wastewater treatment and dispersal. It helped pass the state’s Act 125, a mandate to upgrade all cesspools in Hawaii by 2050. Generally, conventional septic systems do not work in Hawaii because of shallow groundwater, tiny lot sizes, porous sand, or very heavy clays, so they are not a viable solution in such a challenging environment. The diverse climates and soils across Hawaii make for a unique combination of issues affecting decentralized wastewater infrastructure. Mountainous terrain on the islands create microclimates where some parts of the island have much more rain than others. The soil goes from porous and sandy to clayier and impenetrable moving from sea level up to the mountains. Cesspools and septic tanks are not always well-placed or have the proper design for heavy rain and clay soils. This results in cesspools and septic tanks failing across the islands, leeching millions of gallons of untreated sewage into water systems.

WAI’s current focus is on the five Hawaiian Islands that have cesspools: Oahu, Hawaii, Kauai, Molokai, and Maui. In higher populated islands like Honolulu on Oahu, extending sewer systems to connect most houses allows for the most efficient and environmentally conscious option for eliminating sewage pollution. In rural areas, however, it is not always feasible to connect to sewer systems due to the large distances between houses. Where centralized sewer is still not an option, WAI has advocated for enhanced septic systems such as a constructed wetland and leach field. Installation of a septic system in Hawaii costs $20,000-50,000, with enhanced systems costing $5,000-10,000 more. Installation costs are higher in Hawaii than on the mainland since materials and equipment are imported, and labor costs are higher. WAI is also looking at implementing Cinderella Toilets, developing alternative septic systems that can withstand the diverse terrain and climates of Hawaii, and building decentralized wastewater treatment plants that serve 20-200 homes. WAI is a member of Hawaii's Cesspool Conversion Working Group, a group researching and reporting on the best solutions to cesspools. They are also a part of DigDeep’s Decentralized Wastewater Innovation cohort and Ocean Sewage Alliance, helping develop innovative solutions to cesspools and failing septics. 

While there are a plethora of options for addressing untreated wastewater pollution in Hawaii, a major roadblock is funding. WAI is working to help build programs in Hawaii where residents and communities can access State Revolving Funds (SRFs), the biggest source of federal water infrastructure funding. Following the lead of programs like Craft3 in Washington and Ohio's SRF program, WAI is working to support the creation of similar financing programs. The Department of Health could be a huge asset in creating programs to finance and fund cesspool conversion, but like any government agency, it is limited by staffing and funding shortages.  

Another aspect WAI focuses on is building public support and understanding of the magnitude of the issue in Hawaii. On the Big Island (also named Hawaii Island), sewage reaches reefs in about six hours from flush, causing significant reef degradation; drinking water wells there have also reported high fecal bacteria levels. Through community engagement on the issue, WAI is helping the public build understanding and momentum towards addressing equitable wastewater infrastructure access. 

Looking forward, WAI is a stronghold in ensuring Hawaii moves away from cesspool pollution. They have already helped lead numerous initiatives including legislation requiring people to convert cesspools before doing major property updates and currently are advocating for legislation establishing cesspool conversion grants for low-income homeowners. Through community engagement, building financing programs with SRF dollars, and innovative research, Hawaii can turn the corner on ensuring all cesspools and failing septic systems are upgraded to new systems that are affordable, efficient, and better for the environment.

Thank you to Stuart Coleman, Christina Comfort, Joachim “Joko” Schneider and Jackie Orsa for taking the time to share your work with us.