Is My Hawaii Home on Sewer, Septic or a Cesspool? How to Find Out
Short answer: look at your bill first. If you pay a sewer bill, or your water bill has a sewer charge, the Hawaii Department of Health says your home is on a sewer system. On Oahu, that charge shows up on your Board of Water Supply bill. No sewer charge means your home most likely has its own system on the lot, which could be a cesspool, a septic tank or an aerobic treatment unit. Confirm it with county sewer records, the Department of Health's records for your Tax Map Key (TMK), and if needed a camera inspection. Want us to locate it for you? Call (808) 772-0705.
Last updated October 27, 2026. Hawaii Plumbing Line provides this as general information. We are not a government agency. Phone numbers and rules come from the Department of Health and county pages listed at the bottom.
Step 1: Check your bill
- Oahu: your Board of Water Supply bill also carries the city's sewer charges. A sewer line item means you are connected. (Why that charge jumped in 2026 is covered in our high water bill guide.)
- Maui and Hawaii Island: sewer service is billed by the county wastewater office. Hawaii County's wastewater billing office is at (808) 961-8338. If you get a county sewer bill, you are connected.
- Condos and townhomes: the association usually pays for sewer, so you may never see a charge. Ask your managing agent. Some buildings and subdivisions use their own small treatment plant, which the Department of Health counts as a private system.
- Renting or buying: ask the owner or seller for a recent utility bill and any pumping or service invoices. A listing that says "sewer" is a claim, not a record.
Step 2: Ask the county, or check its sewer map
Each county publishes a sewer map, which the Department of Health links from its guide. Maps are a good clue, but a sewer main in your street does not prove your house is hooked up to it. For a definite answer:
| Island | Who can confirm a sewer connection |
|---|---|
| Oahu | Department of Planning and Permitting, Wastewater Branch, (808) 768-8210. It keeps the city sewer maps and records and can verify your connection, the location of your lateral and any sewer easement. |
| Maui | Wastewater Reclamation Division, (808) 270-7417. It helps the public locate sewer lines and connection laterals. Sewer spills: (808) 270-7465. |
| Hawaii Island | Department of Environmental Management, Wastewater Division, (808) 961-8615 (billing (808) 961-8338). |
| Kauai | County of Kauai Wastewater Management Division (Department of Public Works). Kauai also has the Department of Health office in Lihue at (808) 241-3321. |
Step 3: Ask the Department of Health what it has on file
If you are not on sewer, the Department of Health (DOH) Wastewater Branch may have a "cesspool card" or septic system record for your property. You will need your Tax Map Key (TMK), the parcel number used for property taxes. On Oahu you can look it up by address in the city's real property search; it is also on your property tax bill.
- By phone: Oahu main office (808) 586-4294, Maui (808) 984-8232, Hilo (808) 933-0401, Kona (808) 322-1963, Kauai (808) 241-3321.
- In writing: DOH asks for the state's Request to Access a Government Record form, emailed to the contact for your island, with "IWS Records Request" and your TMK in the subject line. The form and island contacts are on the DOH records request page. The form explains any fees.
- No record? That does not mean you have no cesspool. Many older cesspools were never inspected or recorded. If one is found, DOH requires a licensed engineer to fill out an existing cesspool information card.
Step 4: Check the permit history
On Oahu, the Department of Planning and Permitting's property search lists past permits by address or TMK; a sewer connection permit or a wastewater system permit settles the question. That older system holds data through July 28, 2025, and newer applications are in the city's HNL Build system. On the neighbor islands, ask the county building or permitting office for the permit history.
Step 5: Walk the yard
- Cesspool: DOH says a cesspool will typically have only one visible cover, located somewhere between the building and the property line. Over the years it may be buried under dirt, grass or plants.
- Septic tank: usually one or two access lids, often concrete or heavy plastic, plus a drain field: a stretch of lawn that greens up after rain and that nobody built or planted on.
- Aerobic treatment unit: a tank with a blower or control panel and, by DOH rules, a certified operator and service contract. If you have a service contract, you have one.
- Cleanout near the foundation: sewered homes have these too, so a cleanout alone does not answer the question.
Step 6: Have a plumber locate it
When the paperwork is missing, which is common with older homes, a plumber can run a camera with a locating beacon from a cleanout and follow the main line to where it ends: a sewer lateral at the street, a tank, or a pit. That answers the question directly and shows the pipe's condition along the way. To judge the condition of a cesspool or septic tank itself, it usually has to be pumped out first so the inside can be seen. On Oahu, private pumping companies are usually fastest; the city's Department of Environmental Services also pumps cesspools by appointment at (808) 768-7232, at $132.90 per truckload.
What your findings most likely mean
| What you found | What it most likely means | Next step |
|---|---|---|
| Sewer charge on your bill | Connected to a county or private sewer | Nothing to convert. Sewer line problems are on your side of the lateral. |
| No sewer charge, DOH has a cesspool card | Cesspool | Plan for the 2050 deadline (see our cesspool conversion guide). |
| No sewer charge, DOH has a septic or aerobic unit record | Approved onsite system | Keep up pumping or the service contract. |
| No sewer charge, no DOH record, one buried cover | Possibly an unrecorded cesspool | Camera locate and inspection. |
| Sewer main in the street but no sewer charge | Sewer may be available but not connected | Ask the county whether your lot has a lateral and whether you must connect. |
Why it matters
- Cesspools have a deadline. Every cesspool in Hawaii must be upgraded or connected to a sewer by January 1, 2050, and DOH rules can require it sooner, for example after adding bedrooms or when a cesspool is pumped more than twice in 12 months. DOH also says a buyer inherits a property's compliance status.
- Hawaii County requires connection when sewer is available. Under County Code Section 21-5(a), owners of buildings accessible to a public sewer must connect within 180 days after official notice, and a lot counts as accessible if a lateral has been provided. The connection must be made by a licensed contractor with a plumbing permit and a Wastewater Division permit, the county must be notified 48 hours ahead for inspection, and the old cesspool or septic tank must be backfilled and inspected.
- The cesspool prioritization map is context, not proof. UH and Hawaii Sea Grant's Cesspool Hazard Assessment and Prioritization Tool shows estimated cesspool locations and which areas are highest priority for conversion. It does not confirm what is on your lot.
Warning signs on a home that is not on sewer
Slow drains throughout the house rather than at one fixture, gurgling when the washer drains, a soggy or unusually green patch over the tank, pit or drain field, or a sewage smell outside all mean the system needs attention soon. Don't wait for the next pump-out. See our sewer, cesspool and septic service page.
Want us to find out for you?
Call (808) 772-0705 or use the form below. Tell us your island and town, whether you see a sewer charge, and whether you know of any lids in the yard. We will locate the line, tell you what you have and what condition it is in, and put it in writing. Always check a plumber's license before work starts.
Frequently asked questions
How do I know if my house is on sewer in Hawaii?
The Department of Health says that if you pay a sewer bill, or your water bill includes a sewer charge, your home is served by a county or private sewer system. On Oahu the city sewer charge appears on your Board of Water Supply bill. If you are still not sure, call your county wastewater office; on Oahu, the Department of Planning and Permitting Wastewater Branch at (808) 768-8210 verifies sewer connections.
If I have no sewer charge, does that mean I have a cesspool?
It means your home most likely has its own system on the property, but that could be a cesspool, a septic tank, an aerobic treatment unit, or a small treatment plant that serves a whole condo or subdivision. Check with the Department of Health Wastewater Branch using your TMK, and if there is no record, have a licensed plumber, wastewater engineer or certified operator locate the system.
How do I get the Department of Health cesspool card for my property?
Call the Wastewater Branch office for your island with your Tax Map Key (TMK) ready, or send the state's Request to Access a Government Record form by email with "IWS Records Request" and your TMK in the subject line, as described on the DOH records request page. Many older cesspools have no card because the original inspection was never requested.
What does a cesspool look like from the yard?
The Department of Health says a cesspool will typically have only one visible cover, somewhere between the building and the property line, though dirt or plants may have buried it. A septic tank usually has one or two access lids and a drain field, an area of lawn that often stays greener and that nobody built on.
Can a plumber tell me what system I have?
Yes. A plumber can run a camera with a locator down the main waste line from a cleanout and follow it to where it ends: a sewer lateral at the street, a tank, or a pit. To judge the condition of a cesspool or septic tank, it usually has to be pumped out first so the inside can be seen.
Does the Hawaii cesspool map show whether my house has one?
No. The Hawaii Cesspool Hazard Assessment and Prioritization Tool from UH and Hawaii Sea Grant shows estimated cesspool locations and priority areas for conversion. It is useful context, but it does not confirm what is on your lot. Use your bill, county records and DOH records for that.
I am buying a home. Why does this matter?
Under state law every cesspool must be upgraded or connected to a sewer by January 1, 2050, and some events, such as adding bedrooms, can require it sooner. The Department of Health says a buyer inherits the property's compliance status, and recent estimates for a conversion run tens of thousands of dollars. Confirm the system and its condition before you close.
Sources
- Hawaii DOH Wastewater Branch: What sort of wastewater system do I have? (sewer bill or sewer charge = sewered; county sewer maps; cesspools typically have one visible cover between the building and property line; call with your TMK to check for a cesspool card)
- Hawaii DOH Wastewater Branch: General info and FAQ (best to hire a licensed wastewater engineer, certified operator or licensed plumber; engineer must fill out a cesspool card if a cesspool is found)
- Hawaii DOH Wastewater Branch: Records request (UIPA form, "IWS Records Request" subject line, TMK more reliable than address, island-specific contacts)
- Hawaii DOH Wastewater Branch: office addresses and phone numbers
- Honolulu Department of Environmental Services: FAQ (DPP Wastewater Branch (808) 768-8210 verifies sewer connections, lateral location and easements; city cesspool pumping (808) 768-7232 at $132.90 per truckload)
- City and County of Honolulu real property search (qPublic) (find your TMK)
- Honolulu DPP Internet Permit System: Property search (historical permits; data through July 28, 2025, newer records in HNL Build)
- Hawaii Sea Grant / UH Water Resources Research Center: Hawaii Cesspool Hazard Assessment and Prioritization Tool
- Hawaii County Department of Environmental Management: Wastewater FAQ (County Code 21-5(a) connect within 180 days of official notice; licensed contractor, plumbing permit plus Wastewater Division permit, 48-hour notice, backfill inspection; billing (808) 961-8338; general (808) 961-8615)
- Maui County Wastewater Reclamation Division (questions and sewer lateral locations (808) 270-7417; sewer spills (808) 270-7465)
- Alpha Omega Plumbing: Septic or sewer? How to tell on Oahu (what septic lids and drain fields usually look like)
- Golden Penny: Septic and cesspool inspection on Oahu (system pumped out before the camera inspection)