You can’t tell by looking whether a beach is clean. Clear water can carry bacteria. Murky water can be harmless. So who actually checks, and how often?
The Surfrider Foundation made a short film that starts with that question. It runs about three and a half minutes, and it’s worth watching before you read on.
The numbers in the film
Surfrider’s description of the video says that nearly 88,000 cesspools in Hawaiʻi discharge 53 million gallons of sewage into coastal waters every day, and that rising seas and heavier storms are making it worse.
You may see a slightly different cesspool count on this site. We use about 83,000, which comes from the Department of Health’s 2022 working group report. Counts shift by source and by year, and the film is Surfrider’s own accounting. What doesn’t shift is the direction: tens of thousands of cesspools, on porous volcanic ground, close to the sea.
The people with the test kits
Surfrider’s answer to “who’s checking?” is the Blue Water Task Force, which its Hawaiʻi page calls the nation’s largest volunteer-run beach water testing network. Volunteers take water samples, and labs measure fecal indicator bacteria, the germs that show up when human or animal waste is in the water. The results are compared with the standards set to protect public health.
The volunteers go where the gaps are. According to Surfrider, they sample beaches and surf breaks, but also stream mouths, creeks and storm drains that flow out onto the sand, places the Department of Health often leaves unmonitored.
- water samples collected by volunteers in 2025 (Surfrider Hawaiʻi report)
- 1,138
- water samples collected by volunteers in 2025 (Surfrider Hawaiʻi report)
- sites sampled across Kauaʻi, Maui and Oʻahu
- 90
- sites sampled across Kauaʻi, Maui and Oʻahu
Those two numbers are the whole point. Hawaiʻi’s sewage problem is mostly invisible, and it doesn’t get measured unless someone decides to measure it. Here, that someone is volunteers with sample bottles. Their results go public, and Surfrider says it uses them to find pollution sources and push for policy change.
You can’t fix what nobody is measuring.
What this means for Hawaiʻi Island
Surfrider’s 2025 Hawaiʻi report covers Kauaʻi, Maui and Oʻahu. Hawaiʻi Island isn’t in it, even though the island has the most cesspools of any island, about 48,600 of them by the Department of Health’s count. That’s not a criticism of the volunteers. It’s a reminder of how much of the picture here comes from university research and State advisories instead of a volunteer network.
That research is specific. At Puakō, UH Hilo scientists traced home wastewater to the shoreline in as little as six hours. The same kind of work has found sewage reaching the water at Kahaluʻu and Keaukaha. If you’d like the full story, we wrote it up in Is Hawaiʻi’s ocean full of sewage?
What you can do today
- Check the Department of Health’s Clean Water Branch beach advisories before you swim, and skip the water after heavy rain.
- Read Surfrider’s water quality results for the islands they cover, and sign up as a volunteer if you want to help collect them.
- If you own a home on a cesspool, know that the State requires every cesspool to be upgraded, converted or connected to sewer by 2050.
None of this means you should stay out of the ocean. It means the ocean is worth watching, and that the data only exists because people chose to collect it.
Wondering what your own property’s wastewater is doing? Start My Property Check shows how far your cesspool is from the ocean and the nearest drinking-water wells, free, in about a minute.
