Do I have to replace my cesspool?
Yes, eventually. Hawaiʻi Act 125 (2017) requires every cesspool in the state to be upgraded, converted to an approved wastewater system, or connected to sewer by January 1, 2050.
How many cesspools are on Oʻahu?
The Hawaiʻi Department of Health estimates about 88,000 cesspools statewide, with over 11,000 on Oʻahu.
How much does a cesspool conversion cost?
Most estimates put a single-home conversion at roughly $25,000 to $50,000. Your price depends on soil, lot size, access, the type of system, and whether sewer is available nearby.
Is there financing?
A 2026 state law (HB 1618) set up a Cesspool Conversion Revolving Loan Fund run by the Hawaiʻi Green Infrastructure Authority (HGIA) for low-interest or forgivable loans. HGIA said it planned to launch by the end of 2026, so check HGIA for the current status.
What are my options?
The common options are a septic tank with a leach field or bed, an aerobic treatment unit, or connecting to city sewer where a line is available. The Department of Health must approve any individual wastewater system.
Can I sell a home with a cesspool?
Yes, but buyers, lenders and inspectors increasingly ask about it, and conversion costs often come up in negotiation. Getting a quote early tells you where you stand.
Who does the work?
Licensed contractors design and install the system, and an engineer usually designs the system and handles the DOH paperwork. We connect you with licensed local contractors. We do not do the work ourselves.
Sources: Hawaiʻi DOH; HB 1618; HPR