What does a cesspool conversion cost on Maui?
We don’t set prices. The figures below are ranges published by Maui contractors and a state agency on their own websites (as checked in October 2026). Your actual price depends on your site, soil, rock, access, and system design.
| Source | Published range | Notes |
|---|---|---|
| Tom’s Backhoe & Excavation (tomsbackhoe.com) | $11K–$18K; $18K–$22K | Septic install with 200–600 sq ft or 600+ sq ft absorption bed and 1,000–1,250 gal tank. Aerobic/complex systems vary. |
| Po Brothers Excavation (pobroexcavation.com) | $30K–$60K typical new system; +$5K–$10K for cesspool conversion | Extra covers pumping, demolishing and backfilling the old cesspool. Rock clause $250/hr while breaker runs. |
| Hawai‘i Green Infrastructure Authority (gems.hawaii.gov) | $25K–$50K | Statewide figure cited in a June 2026 post about its loan program. |
What moves the price
- Rock: Po Brothers reports rock is common in Kula and is hit on most digs in Kihei/Wailea, and rarely in Kahului.
- System type (septic vs. aerobic treatment unit), lot size, access, house size.
- Engineering and permitting fees.
These are other companies’ published ranges, not quotes or endorsements. Get an itemized estimate after a site visit.
Referral service disclosure: Maui Cesspool Help is an independent referral service run by a Maui resident. We are not a contractor, do not perform any work, and may be paid by the licensed contractors we refer you to.