By Martina Kamaka, MD
Saturday, June 8, 2024, was a beautiful day at Kualoa Beach Park. Dozens of single- and double-hulled canoes gathered to celebrate the legacy of voyaging as part of the 13th Festival of Pacific Arts and Culture (FestPAC). Locals and visitors swam in the waters and clambered onto waʻa (canoes) for rides in Kāneʻohe Bay.
Just a few days later, on June 13, those festivities would have been impossible. On that day, the Department of Health (DOH) issued yet another brown water advisory for Kāneʻohe Bay.
“Brown water” fouls the coastline when heavy rain or floodwaters flush pollutants from the land, contaminating the ocean with toxic chemicals, flood debris, and sewage from overflowing cesspools.
Brown water advisories are becoming more frequent. That’s because severe weather events are increasing as our climate heats up. In addition, the seas are rising, contributing to long term and chronic contamination of our waters and ocean. We already know heavy rains overwhelm sewage treatment facilities, but many Hawaiʻi residents arenʻt aware of the huge role played by our islands’ 83,000+ cesspools.
Most of these cesspools service homes that are located in rural and in low-lying areas which are particularly susceptible to flooding.
On Oʻahu, about 4,800 cesspools at highest risk for contaminating our waters (and designated priority 1 for conversion), are located along the northeast, north and west coasts stretching from Waikāne to Nānākuli with a few pockets in Waimānalo, Kailua, Waikīkī and ʻEwa.
These are communities where large numbers of Native Hawaiians live (for example, in the 2010 census, Native Hawaiians made up about 55%-80% of the population on the west side, 20-50% along the north shore and 80% in Waimānalo homestead).
Cesspools do not treat wastewater; they do not remove human pathogens from feces, or neutralize toxins or contaminants that are being flushed down the drain. Cesspools are simply collection receptacles buried 1-3 feet underground where wastewater from homes is collected. This waste slowly percolates out of the walls into the surrounding earth.
Cesspools are especially vulnerable to sea level rise. Rising seawater not only inundates areas around cesspools, but also pushes the groundwater closer to the cesspool discharge. The result is human waste flowing directly into our groundwater, streams and ocean. In 2023, it was estimated that cesspools accounted for 52 million gallons of untreated sewage entering our groundwater daily.
The cost – to human health and to the environment – is enormous.
On Hawaiʻi Island, researchers found that sewage contamination from cesspools was a major cause of degraded coral reefs off of Puakō, near major resorts on the Kona Coast. Both local families and visitors swim in those waters, not realizing that these contaminants can cause ailments ranging from skin and respiratory infections to gastrointestinal illnesses to kidney failure. Young children and those who are immunocompromised from chronic illnesses or cancer are especially at risk.
Hawaiʻi, the state with the highest per capita number of cesspools in the U.S., was also the last to ban them.
A 2017 state law requires that homes convert current cesspools to septic systems or sewers by 2050. However, septic systems are also problematic: they are expensive, require regular maintenance and are not immune to failure from water inundation, whether from sea level rise or flooding.
This problem is not unique to Hawaiʻi. A recent article in the Washington Post highlights impacts of septic system failures from sea level rise in Florida and other low-lying Southeastern states.
Fixing this problem is expensive. It can cost homeowners $10,000 to $38,000 to convert cesspools to septic systems. The preferred option (if available) is to connect to a centralized wastewater treatment system. But management of centralized sewer systems must take coastal erosion and sea level rise into consideration.
For rural communities, decentralized wastewater treatment that allows for creative alternatives while also protecting our waters may provide options.
Currently homeowners being asked to convert their systems are those least able to afford the cost. A $5 million Hawaiʻi DOH cesspool pilot grant program offering $20,000 in reimbursements to income-qualifying homeowners is closed to new applicants and many are waitlisted. Others have used tax breaks or loans, but these can be complicated to process and qualify for.
Converting all cesspools in Hawaiʻi by 2050 will cost almost $2 billion – possibly more when considering that the best option is a centralized, climate-resilient wastewater treatment system. We also can’t forget that we need to “harden” our stormwater collection systems for the more frequent severe weather events that lie in our future.
Hawaiʻi has been working on this problem for years while confronting other expensive climate-related emergencies such as the increase in severe heat and weather events as well as wildfires.
Nevertheless, we must urge our legislatures and government officials to prioritize the protection of human health and our precious oceans and reefs. The ocean nourishes and sustains us physically, culturally and spiritually, while also attracting visitors who support our economy.
Conversions are occurring too slowly, tax breaks and grants have proven inadequate, and new potential funding streams appear insufficient to fully address the problem on the large scale that is needed. Hawaiʻi’s state government needs to not only pick up more of the costs, but also facilitate these conversions urgently, before itʻs too late.
For the sake of our health, our ʻāina, our community – and most importantly our children and grandchildren – we need to fix this problem now.
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