State Requirements
Hawaii Septic Tank Requirements
Complete guide to septic system requirements in Hawaii (HI). Use our calculator for personalized recommendations.
Regulatory Agency
Hawaii Department of Health
Permit Required
YesProfessional Install
RequiredMinimum Tank Size
1,000 gal
Tank Size Requirements
| Bedrooms | Min Tank Size | With Garbage Disposal |
|---|---|---|
| 3 | 1,200 gal | 1,800 gal |
| 4 | 1,500 gal | 2,250 gal |
| 1-2 | 1,000 gal | 1,500 gal |
| 5-6 | 2,000 gal | 3,000 gal |
Drainfield Sizing by Soil Type
Minimum square feet of absorption area based on soil percolation rate:
Gravel/Sandy
100
sq ft minimum
Sandy
150
sq ft minimum
Loam
200
sq ft minimum
Clay
300
sq ft minimum
Hawaii Specific Notes
- Volcanic soil conditions vary greatly
- Cesspool conversion requirements
- Near-ocean installations have strict rules
Regulatory Contact
Hawaii Department of Health
Important Disclaimer
This information is provided for reference only. Local county or city requirements may be stricter than state minimums. Always verify requirements with your local health department before installation.
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