Imagine snorkeling in crystal-clear Hawaiian waters, only to find out later you’ve been swimming in the most contaminated beach in the U.S. That’s the shocking reality at Kahaluu Beach Park.
Located on Oahu at Kanehoe Bay, Kahaluu Beach failed state water quality standards in 92 percent of recent samples. That staggering rate, published in the Surfrider Foundation’s 2024 Clean Water Report, puts this well-trafficked bay at the top of the national list of bacterial hot spots.
Why Kahaluu Beach is a hidden health hazard.
At first glance, Kahaluu seems like the perfect spot, and BOH will revisit it soon. Calm waters, sea turtles, and beginner-friendly snorkeling and surfing draw visitors monthly. But the scenic bay masks a problem beneath the surface.
Runoff from uphill neighborhoods, leaking cesspools, and stormwater surge all drain into the beach, especially after rain. Bacteria from human and animal waste flood the shoreline, making the water unsafe to enter most of the time.
Contaminated water doesn’t necessarily look dirty, but that’s part of what makes it dangerous. Tourists often swim or snorkel without knowing they’re wading into water with elevated levels of harmful microbes that can cause ear infections, stomach illness, rashes, and more.
A resident volunteer told us, “I’ve warned families in real time—pulling kids out of the tidepools. They had no clue the water was risky that day.”
More Hawaii beaches are on the list.
Kahaluu isn’t the only Hawaii beach raising alarms. The report’s second-worst site in the nation was Waikomo Stream at Koloa Landing in Poipu, Kauai, where 90 percent of water samples failed health standards. While Koloa Landing is best known among experienced shore divers, it remains a well-used coastal access point in a heavily visited resort area.
Another site not included in the 2024 national top 10—but arguably just as concerning—is Kalapaki Beach in Lihue, fronting the Royal Sonesta Kauai (formerly the Marriott). While Kalapaki itself didn’t appear in this year’s Clean Water Report, the Nawiliwili Stream that empties directly into it failed 100 percent of water quality tests last year, according to Surfrider data. Despite this, the beach remains busy with visitors, many unaware of the ongoing contamination. It’s a beautiful crescent bay in the heart of Lihue, but one that BOH editors no longer enter, even as others swim and surf just offshore.
Statewide, the Surfrider Foundation’s Blue Water Task Force found that 80 percent of Hawaii beaches tested exceeded health limits at least once. Some were far inland, and others were popular swimming spots with no signs posted.
If Hawaii’s clean beach image will survive, something has to change.
Why water testing may soon disappear.
Despite the serious risks, the federal government may soon eliminate all funding for coastal water testing. The EPA’s BEACH Act Grant Program—used by 35 states and territories to test and report beach water quality—is slated for complete defunding in the 2026 budget proposal.
If Congress allows the cuts, testing programs in Hawaii will rely entirely on local or volunteer efforts. Beaches like Kahaluu may go unmonitored, and visitors will have even fewer tools than they do now to make safe decisions.
Surfrider Foundation is calling on travelers and residents to speak up. They’ve launched a petition urging Congress to restore full funding for the BEACH Act. You can sign it here: Pass the BEACH Act of 2025. Without action, water testing across Hawaii and the rest of the U.S. could be at serious risk.
A deeper infrastructure crisis.
Kahaluu’s problems are a symptom of something bigger: Hawaii’s outdated and overburdened infrastructure. The state still has over 80,000 active cesspools, many of which leak directly into groundwater and coastal waters.
While Hawaii has committed to eliminating all cesspools by 2050, progress has been slow. In the meantime, tourism numbers remain high—and environmental safeguards haven’t kept up.
One Beat of Hawaii reader shared, “We booked this spot for the snorkeling. No one mentioned the contamination. I got sick for three days. Hawaii needs to tell people the truth.”
What travelers can do to stay safe in Hawaii’s waters.
Planning a beach day in Hawaii now means doing a little extra homework. Here’s how to stay safe:
- Check water quality data before you swim. Surfrider’s Blue Water Task Force publishes updated results online. Look for recent tests near your destination.
- Avoid the ocean after heavy rain, especially near stream mouths or tidepools. That’s when contamination levels spike.
- Don’t rely on posted signs. Many beaches don’t have them—even when bacteria is present.
- Support beach monitoring programs by donating or volunteering.
The truth about paradise isn’t always pretty.
Hawaii’s image as a pristine beach escape is still powerful. But the reality is also more complicated. Some of the same beaches promoted in travel guides and booking sites are now regularly failing health inspections, week after week.
No one should have to choose between enjoying Hawaii’s beauty and risking their health. But that’s what’s happening now, and ignoring it only worsens the situation.
Would you still snorkel at Kahaluu?
We’d love to hear from you. Share your story below and help others stay informed. Together, we can push for cleaner beaches and safer visits.
(Post has been updated to reflect that the beach in question is Kahaluu on Oahu, not Kahaluu on the Big Island).
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2050 that’s off the hook time is now to clean up, or how about we start a class A law suit against the stote Hawaii since people a losing. Limbs from staff infections and strepp
Wow, didn’t know that. It’s criminal what governments will do to keep their pockets lined
That’s really sad I grew up on Oahu but it was the aliwai we had to worry about I vote yes for cleaning up hawaii
Kahalu’u is actually where I grew up. Very few people know where it’s at, even on Oahu. I just tell folks I’m from Kaneohe. They Do know about the Hygienic Store there (It used to be the company store for the Hygienic Dairy which encompassed most of the Ahuimanu Valley at the time). No, I Wouldn’t swim at the beach there…
Best Regards
It is everyone’s responsibility. Federal, State, or County needs to pool resources to share the costs along with the publics help to sample, monitor, or identify areas of concern. The State should take the initiative if we the people are really concerned by utilizing the University to study and identify what is needed to achieve any results.🤔👍
Wake up Hawaii…this is what you get for letting one party rule for over 40+ years. Please check out the “Genki Ball Ala Wai Project.” Working trying to clean up the Ala Wai Canal with “bio-remediation.”
This isn’t the most contaminated beach in the US – that’s Imperial Beach on the Mexican border which gets untreated Tijuana sewage.
I would not snorkel at Kahaluu Beach, but most any other beach on Oahu unless it is right after a rainstorm. The world is certainly experiencing a rise in global temperatures but I doubt humans can make any real difference. I just know that Kane’ohe used to be cooler and now we need far more ceiling fans and maybe AC installed.
State and County officials do not prioritize this. Their number one goal is to create revenue to spend, with occasional outreach as if they care about the native people. Kauai is a testing ground for pesticides, and it kills the reefs. It is a testing site for the military, which drops its torpedoes into the water. Kauai’s infrastructure can grow 100’s of additional hotel rooms that use the same sewage plants and lift stations that overflow every rain. They never give beaches, trails, or rest time to recover. They have more money pouring in, more bureaucracy, and fewer people in boots working on the ground. And what they do have, there’s no accountability.
The deferential in resorts is the lack of local evening entertainment. When we first started visiting Hawaii most hotels had hula every evening. Now it’s harder to find.The hotels are charging more and providing less aloha.
Maybe Hawaii can stop waisting resources on climate change hoax and address its lack of proper sewage treatment? Have their been reported illnesses due to contaminated ocean water?
maybe Hawaii can stop wasting resources on climate change denialists as well.
it’s been well established that outsiders downplaying ever-worsening problems that Hawai’i residents have been experiencing for decades can make the locals feel really sick.
Monitoring is very important. Convincing the Hawaii Government to do something about it could be important too.
I would think Oahu would have the most bacteria in the beach area’s because of the greatest amount of tourists. I have come across stories of fish processing places on other islands and sewage drainage issues. Maybe if all the abandoned vehicles, appliances and such were cleaned up the rust, soap, motor oil and fluids wouldn’t leach into the ocean when it rains. Somehow Hawaii will point a finger to the tourist for this problem and access a special fee to gouge the tourist even more. What next bacterial cleanup fee?
No one surfs or goes snorkeling at kahaluu beach on oahu. The kahaluu beach that everyone surfs and goes snorkeling at is on the big island. I do feel bad 4 the canoe club that paddles at the kahaluu beach on oahu those kid deserve better and the community needs to do better for them. But the state and county diverted all the natural streams in to big storm drain and that’s the root of the problem
No I would not still snorkel at the K. beach. I have signed up for the water clean up report. Its a sad situation. And its only just beginning. The whole USA will experience this. ..if not the world from over population and the new congress acts! What a darn shame!
Surfrider Foundation complaining about beach monitoring? Perhaps as a private entity, they should takeover doing beach monitoring / sampling with their own funds. That would save Hawaii taxpayers some money.
I have surfed there 100’s of X’s. Never gotten sick of an ear infection.
There is some sort of sewage pumping station on the grounds of Kahalu’u Beach Park. It has had many problems and undergoes maintanence/repair fairly often. There has been auxiliary generators, or pumps installed there many times in the last few years. Sometimes the stench from their operations simply drives visitors away. Your quick to point out septic tanks as a problem, how about investigating leaks or problems with the county sewer system that are colocated with the beach park.
When I went to this location to snorkel last year, several volunteers descended on me to make sure that I was applying reef safe sunscreen. Apparently they should have also let me know that the water had potential health risks. I didn’t get that warning.
The surfrider.org site does not show a clear link for signing to support the Pass the Beach Act of 2025 as indicated. Please advise.
I also went on there, but did sign up for newsletter and will see how that goes from there. Maybe they will send me a link?!
The runoff part isn’t as much of a problem as is the old plumbing systems that were plague most of all Hawaii beach’s. Many of the metal pipes are corroded or broken so wastewater flows out into the ocean. Side note there is a Kahalu’u beach park in Oahu as well and same thing older homes and parks sit along the ocean.
If Hawaiians cared they could start cleaning the water today by tracing the bacterial sources. The fact is they don’t care.
Stop whining about cuts to the federal budget. The US is in debt $34,000,000,000,000. Time for Hawaii to use some of the outrageous tourist taxes and fees to fix the sewers now, not 25 years from now.
The beach where we swim in Maui – Kamaole Beach Park II – posts health warnings right on the beach when bacterial levels are high. They did it several times this winter.
Interesting. We primarily snorkel at Kahaluu for our two week visit. Never had an illness issue and never, ever, over the decades heard anything about problems. You’d think that a place (the whole state) that relies on the ocean for food, recreation, and economic support would be tad more concerned about what was going on. I live in Washington and with those levels of contamination the beach would be closed. I suspect, but could be wrong here, that if the popular beaches were all closed that something might get done. Or, are the warnings overblown?
The neighborhood is old .. and the levels of run off are incredibly high .. tourists don’t care, newcomers don’t take time to learn or ask… Guys fish and catch crabs in the toxic water… None of those people are locals… Dear tourists, if you don’t see locals in or playing in certain places, waterways, shorelines, etc, it’s probably not safe, for whatever reason.
Have snorkeled at Kahalu’u Beach Park almost yearly since 2008 – now I know to be careful and at least avoid it after heavy rains!
Its Hawaii’s beach, so let the State of Hawaii pay for water testing their own beach. Hawaii earns hundreds of Millions of Dollars of tourist money, so Hawaii should pay to test and clean their own beach.
What a selfish statement! Beaches, rivers, streams, and other bodies of water all over the United States are tested using federal funding. Just because a state has tourism, which all states do to some degree, doesn’t mean that they should be excluded from Federal funding for water testing. We all pay federal taxes and those federal taxes should be used to improve our environment including our air and water quality as well as our food safety, adequate traffic controllers, safe bridges and highways, and affordable medical insurance to name a few. After all, the US is supposedly the wealthiest and greatest nation in the world, right?
Sorry .. that’s not correct. As of 2025, the good ol’ USA is #9 on the “wealthiest” scale …
Singapore is #1 … followed (in order) by:
Luxembourg
Ireland
Qatar
Norway
Switzerland
Brunei Darussalam
Guyana
(source: World Atlas; ranked by GDP per capita in purchasing power parity (PPP)