Every guide to buying or selling in Hilo mentions the same date: January 1, 2050, when state law says every cesspool on the island has to be gone. It's a real deadline, and it's worth knowing. But if you're actually under contract on a Hilo property this fall, that date is not what slows down your closing, spooks your lender, or shows up in your counteroffer. Something much smaller does: a single checkbox on the state disclosure form, and a brand new loan program that sounds like relief but currently has almost nothing in it.
The One Checkbox That Changes Everything
Hawaii's Seller's Real Property Disclosure Statement asks a plain question about every property sold in the state: is the wastewater system a cesspool, a septic system, or an individual sewage treatment plant. It also asks for the location, the last pumping date, how often it's been pumped, and whether the cesspool serves more than one dwelling, including an ohana unit. Sellers have to hand this form to buyers within ten calendar days of an accepted contract under HRS chapter 508D, and buyers get fifteen calendar days after receiving it to review and, if they choose, walk away.
That sounds procedural until you notice what the form actually captures and what it doesn't. A "last pumped" date proves someone hired a truck. It says nothing about whether the system is legal, correctly sized, or anywhere near compliant. Sellers frequently describe a cesspool as a "septic system" without knowing the difference, and a home inspection can only see what's visible: covers, plumbing routes, and inconsistencies between what's described and what's actually on the ground. If you want the real answer, the path is a Wastewater Branch records request tied to the property's Tax Map Key, and for East Hawaii properties that request goes through the Hilo Wastewater Branch office. Most buyers never make that request. Most sellers never offer to.
Why Hilo Carries More of This Than Anywhere Else on the Island
Hilo isn't just another Big Island town with some old cesspools. It has been described as the nation's largest unsewered city, with up to 70% of its houses still running on cesspools rather than sewer or septic, according to a Wastewater Alternatives presentation given at a December 2024 town hall. That number alone would make Hilo unusual. What makes it more urgent is what's happening on the other end of the pipe.
Hilo's municipal wastewater treatment plant has been the subject of federal concern for decades. Hilo Bay has been considered impaired by federal regulators since 1998, and the plant serving it has a documented history of large accidental discharges of raw or partially treated sewage. The situation got serious enough that in February 2025, Mayor Kimo Alameda signed an emergency proclamation authorizing emergency action if the corroded plant collapses or discharges a significant amount of sewage. Alameda, whose county holds well over half the state's cesspools, has also said publicly that meeting the 2050 statewide deadline isn't realistic given current funding, even as he's pushed the county to produce an integrated wastewater management plan and convened a task force to look for a path forward.
That context matters for a buyer or seller in Hilo specifically. The deadline you're reading about online is a statewide average. The actual pressure on Hilo's system, both the private cesspools under individual lots and the public plant handling everything downstream, is higher than that average suggests.
What "Priority Level" Actually Means (And Doesn't)
The state's Cesspool Prioritization Tool assigns every cesspool in Hawaii a color based on how close it sits to sensitive water resources. It's a useful map, but it gets misread constantly, including by people already deep into a transaction.
| Priority Level | What It Signals | Does It Change the 2050 Deadline? |
|---|---|---|
| Level 1 (red) | Directly adjacent to sensitive assets like coral reefs or drinking water aquifers | No, but a lender or future buyer may treat the risk as more immediate |
| Level 2 (orange) | Close to streams or drinking water aquifers, meaningful but lower urgency than Level 1 | No |
| Level 3 (yellow) | Some impact on water resources, generally further from sensitive assets | No |
A Priority 1 designation is not a legal replacement date of 2030 or 2035. It's a risk signal, not a court order. What can actually move the timeline sooner than 2050 is far more concrete: if a renovation adds a bedroom, bathroom, or kitchen and changes how much wastewater the system handles, or if the cesspool starts causing odors, illness, or other nuisance conditions, the Department of Health can require action well before the statewide deadline arrives. That's the trigger buyers should be asking about, not the map color.
The New Loan Fund Is Real. So Is the Math Problem With It.
In July 2026, Governor Josh Green signed HB 1618 into law as Act 204, creating a Cesspool Conversion Revolving Loan Fund through the Hawaii Green Infrastructure Authority. It's a genuine policy shift, offering low-interest or potentially forgivable loans to homeowners who need to convert. Representative Nicole Lowen, who introduced the bill and represents a Kona district, helped move it through. At the signing, Green called the broader conversion effort "a big challenge for our state," and he wasn't overstating it.
The fund started with $2 million. Estimates for converting all of Hawaii's roughly 88,000 cesspools statewide, if the work were done today, run to a conservative $2.4 billion. Individual conversion costs vary widely depending on site conditions, from roughly $8,000 for a straightforward septic swap up to $50,000 or more when a property needs an advanced treatment system because of proximity to reefs or groundwater. House Speaker Nadine Nakamura put the affordability gap plainly during the signing: a large share of Hawaii families simply cannot absorb a $30,000 to $50,000 bill on their own, which is exactly why the loan fund exists. But $2 million in seed money against tens of thousands of Hawaii Island properties needing that kind of money is a start, not a solution. As of September 2026, Hawaii County still needs to convert roughly 2,000 cesspools a year to stay on pace for 2050, according to reporting from Hawaii Public Radio, and the county's own environmental management division has called the price tag for getting there astronomical.
For a Hilo transaction happening right now, that means the loan program is worth mentioning to a seller or buyer, but it is not yet the kind of resource that changes a purchase decision this year. It's a name to know for 2027 and beyond, not a line item to count on for October.
What This Changes About How You Write an Offer
None of this means a cesspool should end a deal. Thousands of solid Hilo properties run on them, and state law doesn't require a seller to convert simply because the home is changing hands. What it does mean is that the negotiation should happen around real information instead of a checkbox. A pumping receipt is not proof of compliance. A seller's disclosure that says "septic" deserves a records check before anyone takes it at face value. And a Priority 1 designation, while it doesn't move the legal deadline, is exactly the kind of detail an appraiser or lender may weigh when comparing your subject property to a neighboring home that has already converted.
A few things worth doing before you make an offer or list a Hilo property with a cesspool:
- Request the property's wastewater records from the Hilo Wastewater Branch office using the Tax Map Key, rather than relying on the MLS description
- Confirm whether any past renovation added a bedroom, bathroom, or kitchen, since that can trigger an earlier compliance requirement regardless of the 2050 date
- Check the property's status on the state's Cesspool Prioritization Tool, understanding that the color tells you about risk, not a court-ordered timeline
- Ask directly whether the cesspool serves more than one dwelling, including an ohana unit, since that answer affects both disclosure and future conversion cost
A Few Questions Worth Asking Directly
Does a cesspool mean a Hilo home can't get financed? Not automatically. Lenders are increasingly asking about wastewater systems during underwriting, but a disclosed cesspool with clear records is a very different conversation than an undisclosed or misdescribed one.
Is the seller required to convert before selling? No. State law doesn't currently require conversion at point of sale. The seller does have to disclose the system accurately and note any known problems.
Can I get a loan through the new state fund right now? The Cesspool Conversion Revolving Loan Fund exists, but as of this year it's still being built out by the Hawaii Green Infrastructure Authority with limited initial funding. It's worth watching for 2027 rather than counting on for a purchase happening this quarter.
If you're weighing a Hilo purchase or sale and want to talk through what a specific property's wastewater history actually says, or what it might mean for your offer, Noelani Spencer has spent years untangling exactly this kind of local detail. Let's connect and request your free home valuation.
