2050 sounds comfortably far away. It's the kind of date you file next to "someday I'll clean out the garage." But if your home has a cesspool, that deadline matters more than you might think, and there are a couple of earlier dates floating around that cause a lot of confusion. Let's sort out what's law, what's a recommendation and what it means for you.
The law: Act 125 (2017)
In 2017 the Hawaii Legislature passed Act 125. It requires every cesspool in the state to be upgraded to a septic system or aerobic treatment unit, or connected to a sewer, by January 1, 2050 (Hawaii DOH, UH Sea Grant). New cesspools were already banned before that.
That's the firm, on-the-books deadline. Every cesspool in Hawaii, about 83,000 of them statewide and about 7,500 on Oahu (CCWG final report), has to be dealt with by then.
The other dates: 2030 and 2035
You may have seen "Priority 1 by 2030." Here's where that comes from.
In 2019, Act 170 created the Cesspool Conversion Working Group (CCWG) to figure out how the state could actually hit the 2050 goal. Its final report in 2022 recommended a phased schedule (CCWG report):
- Priority 1 cesspools converted by 2030
- Priority 2 by 2035
- Priority 3 by 2050
The important word is recommended. The working group made recommendations; it didn't pass a law. So the only legally binding statewide deadline today is 2050. But the recommendation tells you where policy is heading, and it's a strong hint that the highest-risk cesspools will get the most attention first.
What are the priority levels?
Researchers at the University of Hawaii built the Hawaii Cesspool Hazard Assessment and Prioritization Tool. It scores each cesspool on things like how close it is to drinking water wells, streams and the shoreline, and how close groundwater is to the surface. Each one lands in Priority 1, 2 or 3.
Oahu has the fewest cesspools of the four main counties, but the highest share of urgent ones. About 64% of Oahu cesspools are Priority 1, 22% are Priority 2 and 14% are Priority 3 (CCWG briefing). High-priority areas include the Windward coast from Kahaluu to Kahuku and the North Shore from Sunset Beach to Haleiwa.
You can check your area on the interactive prioritization map.
Why not just wait until 2049?
Technically you could. Practically, it's a bit like waiting until December 24 to buy holiday gifts, except everyone in the state is shopping for the same gift and there are only so many stores.
Some math: the state recorded 435 cesspool upgrades in 2024 and 408 conversions in 2025, according to DOH figures cited in legislative testimony (2026 HB1730 testimony). With roughly 82,000 still to go, that pace doesn't come close to finishing by 2050. Either the pace speeds up a lot, which means more demand for designers, permits and installers, or rules tighten. Neither scenario rewards procrastination.
A few other practical reasons people act sooner:
- Selling your home. The working group also recommended requiring cesspool disclosure when a home is sold (CCWG briefing). Buyers and lenders already ask about it.
- Failing cesspools. An old cesspool that backs up doesn't care what year the deadline is.
- Funding windows. Grant and loan programs open and close. Being ready with a plan helps you move when one opens. See our funding guide.
What should you do now?
Step one is simply knowing what you have and what your lot can support. A site evaluation answers both. From there, a Hawaii-licensed engineer designs the system, the Department of Health approves it, a licensed contractor installs it and DOH signs off. Our Cesspool 101 page walks through each step.
2050 will be here sooner than it sounds. Your future self, and the reef, will thank you for getting ahead of it.