Cesspool Priority Tool Walkthrough for Big Island Homeowners

By Hawaiʻi Cesspool Help · Published

This walkthrough guides you through the priority tools and resources available for understanding and addressing cesspool compliance on Hawaiʻi Island. The steps follow the natural order a homeowner would encounter: discover your system, understand risk, learn requirements, hire help, execute conversion, secure funding, and maintain compliance.

Phase 1: Identify Your Wastewater System

Before anything else, you need to know what kind of system your property uses — sewer-connected or onsite, and if onsite, whether it is a cesspool, septic tank with absorption field (IWS), or something else.

Step 1.1 — Check sewer connection via utility bill

Determine whether your property connects to county sewer or uses an onsite system by reviewing your water and sewer bills.

Source: DOH Wastewater System Identification Guide (S-04)

Step 1.2 — Consult county interactive sewer maps

Verify sewer availability for your area using Hawaii County's official sewer map tool.

Source: DOH County Sewer Maps (S-04)

Step 1.3 — Understand system type definitions

Learn the difference between cesspools (substandard, no treatment), IWS (septic + absorption field or ATU), and WWTP (>1000 gpd commercial systems).

Source: DOH FAQ page (S-02), DOH Wastewater home (S-03)

Step 1.4 — Locate existing records or hire an engineer

If your system type is unclear from documents, locate property records or engage a licensed engineer for identification.

Source: DOH System Identification Guide (S-04)

Phase 2: Understand Your Priority and Risk Level

Once you know you have a cesspool, you need to understand where your property falls in the state's prioritization scheme — this determines urgency and eligibility for support.

Step 2.1 — Read about Act 125 and the 2050 deadline

Learn why cesspools must be converted (legislative mandate, environmental protection of groundwater).

Source: DOH Cesspools page (S-01), Act 125 Report (S-07)

Step 2.2 — Review statewide and Big Island statistics

Contextualize the scale (~88K statewide cesspools, ~50K on Big Island, 43K at-risk) to understand why prioritization exists.

Source: DOH Cesspools page (S-01), EPA cesspool data (S-12)

Step 2.3 — Study the 14 priority areas and P1–P4 categories

Understand how DOH ranks risk: Priority 1 (significant human/drinking water/sensitive water impact) through Priority 4 (not yet analyzed).

Source: DOH Cesspools page (S-01), Act 125 Report (S-07)

Step 2.4 — Look up your property on the UH Sea Grant prioritization map

Use the interactive map tool to find your specific cesspool's priority ranking based on proximity to groundwater wells, streams, and nearshore waters.

Source: UH Sea Grant Prioritization Map (S-14)

Understand what the current priority rating means before using the map result to make parcel-specific legal, condition, cost, or scheduling decisions.

Phase 3: Know What You Are Required to Do

You need to know the legal triggers that force conversion — is it mandatory now, or can you plan ahead?

Step 3.1 — Review HAR 11-62-06(m) escalation triggers

Learn the five conditions that mandate immediate action: building modification, illness/nuisance reports, pumping more than twice in 12 months, spills, or direct groundwater disposal.

Source: DOH FAQ (S-02), HAR 11-62 regulations (S-08)

Step 3.2 — Understand Act 224 (2025) dwelling-count changes

Know how the new amendment to HRS 342D affects properties with multiple dwellings sharing one IWS.

Source: DOH Wastewater home (S-03), Act 224 legislation (S-09)

Phase 4: Hire a Licensed Professional

DOH requires an engineer to be the point of contact for all IWS approvals. You need to know how to verify credentials before hiring.

Step 4.1 — Understand the engineer's role

Learn that the licensed engineer communicates with DOH on your behalf — homeowners should not call reviewers directly.

Source: DOH FAQ (S-02), IWS page (S-05)

Step 4.2 — Verify credentials via DCCA License Search Tool

Use the official DCCA tool to confirm an engineer or contractor holds valid Hawaii licenses before hiring.

Source: DOH FAQ (S-02), DCCA License Search (S-10)

Step 4.3 — Know required contractor license classes

Understand which license classes (A, C-9, C-37, C-37a, C-43) are valid for IWS installation work.

Source: DOH IWS page (S-05)

Phase 5: Execute the Conversion Process

The step-by-step process from initial site visit through final DOH approval of a new system.

Step 5.1 — Follow the six-step homeowner process

Walk through the full sequence: (1) hire engineer, (2) site visit, (3) design submission to DOH, (4) Approval to Construct, (5) contractor installation, (6) Approval to Use.

Source: DOH IWS page (S-05)

Step 5.2 — Understand approval milestones

Distinguish between "Approval to Construct" (permission to begin work) and "Approval to Use" (final sign-off after installation).

Source: DOH FAQ (S-02), IWS page (S-05)

Step 5.3 — Know the DOH review timeline

Set expectations: ~10 days for agency review, ~25 days for engineer response time, ~200 days total for construction and installation.

Source: DOH FAQ (S-02)

Step 5.4 — Use the eHawaii submittal portal

Learn that engineers submit IWS design packages electronically via wastewater.ehawaii.gov (streamlined process).

Source: DOH Wastewater home (S-03), eHawaii portal (S-11)

Step 5.5 — Obtain county building and plumbing permits

Understand that Hawaii County requires separate building/plumbing permits in addition to DOH approval.

Source: DOH FAQ (S-02)

Phase 6: Explore Financial Support

Cesspool conversion is costly — you need to know what funding programs are available before committing.

Step 6.1 — Review past and upcoming grant/loan programs

Browse the Financial Support Programs page for historical context on available grants and loans for cesspool conversion.

Source: DOH Wastewater home (S-03), Financial Support page (S-06)

Step 6.2 — Learn about the new 2026 loan program

Understand the newly announced loan program from the 2026 Legislative Session and how to apply.

Source: DOH Wastewater home (S-03), Financial Support page (S-06)

Phase 7: Maintain Ongoing Compliance

After conversion, you must maintain your new system to stay compliant with state regulations.

Step 7.1 — Follow maintenance requirements by system type

Learn pumping intervals, ATU operator certification requirements, and the 5-year IWS inspection cycle.

Source: DOH FAQ (S-02)

Step 7.2 — Understand Large Capacity Cesspool (LCC) rules if applicable

Know whether your property falls under LCC regulations (commercial/high-flow systems) and what additional requirements apply.

Source: DOH FAQ (S-02), EPA LCC guidance (S-13)

How to use this walkthrough

The steps above follow the natural homeowner journey:

  1. Discovery first — You cannot act until you know what system you have (Phase 1).
  2. Risk assessment second — Once you know it is a cesspool, understand urgency and priority level before deciding how urgently to act (Phase 2).
  3. Legal obligations third — Before hiring anyone, know whether conversion is mandatory now or can be planned for later (Phase 3).
  4. Hiring fourth — With requirements clear, hire a qualified professional with verified credentials (Phase 4).
  5. Execution fifth — The actual conversion process unfolds step by step under the engineer's guidance (Phase 5).
  6. Funding sixth — Financial support can be explored at any point, but is most actionable once scope and cost are estimated during execution planning (Phase 6).
  7. Maintenance last — Ongoing compliance only matters after conversion is complete (Phase 7).

This ordering avoids presenting the six-step process before you understand whether you even need to convert, and ensures legal triggers are known before financial commitments are made.

Official sources referenced in this walkthrough

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This walkthrough is for informational purposes only and does not constitute legal or engineering advice. Hawaiʻi Cesspool Help coordinates between homeowners and licensed professionals. It does not provide engineering services directly.