Cesspool Conversion Permit Process for Hawaiʻi Island
This is the practical sequence most Hawaiʻi Island homeowners can expect when replacing a cesspool with an approved individual wastewater system. The engineer remains the primary technical contact and determines which steps apply to the property.
1. Confirm the property and system
Collect the TMK, site address, ownership information, known wastewater records, and any cesspool card. Confirm whether the property is sewer-connected or served by an onsite system.
2. Hire a Hawaii-licensed civil engineer
Verify the engineer's license status through DCCA. The engineer evaluates the site, develops the design, and communicates with DOH for IWS approval.
3. Complete site evaluation and design
The engineer documents property conditions, wastewater demand, proposed system type, setbacks, and the disposal area. Additional testing or specialist input may be needed.
4. Submit the IWS application
The engineer assembles the applicable DOH forms, certifications, plans, and supporting documents and submits the application through the state process.
5. Resolve review comments
DOH may approve the plans or return comments. The engineer answers questions and revises the package when necessary. Do not start construction before the required approval.
6. Obtain construction permits and hire contractors
Confirm county building or plumbing permit needs. Verify contractor licenses and use the approved plans when obtaining proposals.
7. Build and document the system
The contractor installs the system. The engineer inspects required work, documents deviations, and prepares the final construction information.
8. Close the old cesspool correctly
Closure and filling must follow the approved design and applicable rules. Keep contractor certification, photos, receipts, and inspection records.
9. Obtain final approval to use
The engineer submits the construction inspection report and required certifications. Keep the final DOH approval and maintenance information with the property records.
Documents commonly involved
- TMK, owner name, site address, and property map
- Existing cesspool or wastewater records
- Site Evaluation Form and supporting field information
- IWS application, owner certification, plans, and design calculations
- DOH review comments and approval to construct
- County permits when applicable
- Contract, invoices, product information, and construction photos
- IWS Construction Inspection Report
- Contractor Certification Form
- Final approval-to-use letter and maintenance records
Official starting points
This resource is general information, not engineering, legal, tax, real-estate, or permitting advice. Requirements vary by property. Confirm decisions with the applicable agency and Hawaii-licensed professionals.