Cesspool Conversion in Honolulu & Oahu

Frequently Asked Questions

• Do I have to convert my cesspool right now?

  No. As of mid-2026 the only deadline in law is January 1, 2050, and there is no requirement to convert when you sell — though sellers must disclose a cesspool, and buyers increasingly negotiate the conversion cost into the price. The reason not to wait is practical rather than legal: Hawaiʻi converts only about 400 cesspools a year, lawmakers keep proposing earlier deadlines of 2035 to 2040 for high-priority areas, and as 2050 nears tens of thousands of owners will be competing for the same contractors and permits.

• Does the 2050 law apply to my property, or only near the shoreline?

  It applies to every cesspool in the state. Act 125 requires all of them — roughly 88,000 statewide and about 11,300 on Oʻahu — to be upgraded, converted or connected to a sewer by January 1, 2050, regardless of how far you are from the water. If you have read otherwise, call (808) 630-9966 and we will tell you straight what applies to your property.

• How much does cesspool conversion cost on Oahu?

  A typical conversion runs $25,000 to $50,000. Roughly, that breaks into $3,500 to $5,500 for system evaluation and engineering, $500 to $1,500 for permits and Department of Health fees, and $15,000 to $45,000 or more for the system, excavation, leach field and closing the old cesspool. An aerobic treatment unit, needed where the water table is high or soils are poor, adds about $5,000 to $10,000. Site access, soil type and ground difficulty move every one of those figures.

• Is the inspection really free?

  Yes, and there is no obligation attached to it. We come out, look at what you actually have, and tell you what conversion options your property can support and what the work would realistically involve — before you spend anything on engineering. Nobody should commit to a five-figure conversion off a web page. Call (808) 630-9966 to set one up.

• What are my conversion options?

  Three. Connecting to the county sewer is the cleanest long-term answer where a main runs nearby. Installing a septic system is the most common and usually the most cost-effective conversion. An aerobic treatment unit suits small lots, poor soils, or shoreline properties. Which ones your property can actually support comes out of the site and soil assessment.

• Do you handle the Department of Health permits?

  Yes. The design has to be approved before any digging starts, and we file and track that permit ourselves rather than leaving it to you. An unpermitted system becomes the property owner’s liability and tends to surface during a sale, a refinance, or an inspection.

• How do I find out whether I even have a cesspool?

  Your closing paperwork or a past inspection usually names the system, the Department of Health keeps records of registered cesspools, and the University of Hawaiʻi Sea Grant cesspool map shows locations and priority levels. Or ask us — if we pump your system we can tell you exactly what you have, at no charge.

• What should I do until I convert?

  Keep the cesspool you have maintained. That means pumping every one to three years depending on size and use, and paying attention to slow drains, gurgling plumbing, odors, or soggy ground nearby. We handle cesspool pumping and service now and septic system installation and replacement when you are ready to convert.