Most people who learn they have a cesspool ask two questions. The first is whether it is hurting anything. The second comes a little later, usually at the kitchen table, and it is harder to say out loud: how are we supposed to pay for this?
It is a fair question, and the numbers explain why. Hawaiʻi County’s 2025 Cesspool Conversion Task Force put the median price of a septic conversion at about $40,000, with an upper range of about $70,000. The same report put the median household income on this island at about $74,600. For a lot of families, that is more than half a year’s pay for something buried in the yard that nobody will ever see.
- Median price of a septic conversion on Hawaiʻi Island (County Task Force, 2025)
- $40,000
- Median price of a septic conversion on Hawaiʻi Island (County Task Force, 2025)
- Median household income on the island (County Task Force, 2025)
- $74,600
- Median household income on the island (County Task Force, 2025)
- Conversions HGIA expects its first $2 million to cover (Hawaiʻi Public Radio, 2026)
- < 100
- Conversions HGIA expects its first $2 million to cover (Hawaiʻi Public Radio, 2026)
Why it costs what it costs
A cesspool is about the simplest thing there is: a hole in the ground, lined or unlined, that takes whatever leaves the house and lets it soak away. Replacing it means building a small treatment system in its place. Someone has to study the ground. A licensed engineer has to design a system that fits the lot and the soil. The Department of Health has to approve the plans. Then a licensed contractor digs, sets a tank, lays pipe and builds a field where treated water can spread out slowly instead of dropping straight into the lava rock below.
Every one of those steps is real work by licensed professionals. That is why the price is high. It is not a scam, and it is not going away on its own.
What changed in 2026
For years, the honest answer to “how do I pay for this?” was “mostly on your own.” In 2026 that started to change. Act 204 created a Cesspool Conversion Revolving Loan Fund, run by the Hawaiʻi Green Infrastructure Authority (HGIA), the same state agency that helps households finance solar. The law lets HGIA offer low-interest loans and other financial help, including forgivable loans, for cesspool conversions in every county, with a preference for low- and moderate-income households.
The word that matters is revolving. The money is meant to move in a circle, so the same dollars can help family after family.
- State, county and private money goes into the fund
- HGIA lends to a household
- The household converts its cesspool
- Repayments flow back into the fund
- The fund lends to the next family
The law lets the fund draw from the Department of Health’s water pollution control revolving fund, and from federal, county and private sources. Lawmakers also budgeted about $2 million in Green Fee funds for it. Counties can help too. Honolulu committed $625,000 of its own money to buy down interest rates, which could mean zero-percent loans for Oʻahu homeowners who apply before 2030. HGIA’s director told Hawaiʻi Public Radio she wants similar partnerships with other counties and with philanthropic partners.
So can I apply?
Not yet. That does not mean nothing is happening. The fund is still being set up. The Department of Health lists it as under development, and HGIA’s director said she aims to launch it by the end of 2026. Nobody can tell you today what the rates, terms or eligibility rules will be, and nobody should promise you a loan before the program exists.
It is also worth being clear-eyed about scale. HGIA’s director said the first $2 million will likely cover fewer than one hundred conversions, because each one costs so much. There are about 48,600 cesspools on Hawaiʻi Island alone. The fund is a real start, and it is designed to grow, but early on there will be far more families who want help than money to go around.
If you want to hear from the source, you can contact HGIA at dbedt.greenbank@hawaii.gov or (808) 587-3868.
What about grants and tax credits?
This is where people often get bad information, so here it is plainly. There are no State or Hawaiʻi County cesspool grants available right now. The State’s cesspool tax credit, worth up to $10,000, expired at the end of 2020, and bills to bring it back in 2026 did not pass. The Department of Health’s pilot grant, which offered up to $20,000 to low- and moderate-income owners in Priority 1 and 2 areas, ended in June 2024. Hawaiʻi County does not run its own cesspool grant program.
The County is at least talking about it. Its 2025 Task Force named creative financing as a need and called helping low-income homeowners a top priority. It also looked closely at communities such as Puakō, Keaukaha, Miloliʻi and Kahaluʻu as possible sites for community pilot projects. None of that is money in hand, but it is worth watching.
One federal program is worth knowing about. USDA Rural Development’s Section 504 home repair program offers loans to very-low-income owners who live in their homes in eligible rural areas, which can include much of Hawaiʻi Island. Its grants are limited to homeowners 62 and older. Limits and rules change, so confirm the current details with USDA before counting on it.
What you can do while you wait
The calm, practical move is to get ready rather than wait for someone to announce good news. The law gives every cesspool in Hawaiʻi until 2050 to be upgraded, converted or connected to sewer. That is a long runway, but the families who move first when money opens up tend to be the ones who already know what they need.
Knowing what you need means turning a scary guess into a real number. Find out where your cesspool is and whether your lot is in a priority area. Gather your property records. When you are ready, have a licensed engineer look at your site, because a design approved by the Department of Health tells you what your system will actually involve instead of what a neighbor paid ten years ago. If a loan program opens with a short line and limited funds, a homeowner holding a real plan is in a much better position than one starting from scratch.
None of this makes $40,000 small. But a cost you understand, spread over years, with help arriving slowly, is a different thing from a cost you have only imagined. A real number is easier to plan around than a fear.
If it would help to see where your property stands, you can Check My Property and mention you are interested in financing. ʻĀina Force keeps track of these programs and will let you know as they open. We coordinate; licensed independent engineers and contractors do the design and installation, and funding and eligibility are never guaranteed.
