Septic system approval in Western Australia
Written by Septic Help editors Checked against the WA Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974 Last reviewed
The rules in WA at a glance
- Approval name
- Application to construct or install an apparatus for the treatment of sewage (Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974)
- Who signs off
- Your local government's environmental health team; Department of Health for larger or unusual systems
- What you need
- Application form, plans and specifications of the apparatus, three copies of a site plan, soil evaluation where required
- Typical timeframe
- 2–6 weeks from a complete application
- Typical fees
- $118 application + $118 permit to use (statutory); soil and design reports on top
- The WA twist
- Two-stage sign-off — an approval to install first, then a separate permit to use after inspection
Western Australia still runs its septic approvals under health legislation from 1974 — the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations, made under what is now the Health (Miscellaneous Provisions) Act 1911. In practice it's one of the simpler systems in the country: you (or your plumber) lodge an application to construct or install an apparatus for the treatment of sewage with your local government, the environmental health officer assesses it, and after installation and inspection you're issued a permit to use.
The Department of Health's role is mostly upstream. It approves the system types that may be installed — conventional septic tanks meeting the standards plus the list of approved secondary treatment systems such as aerobic treatment units (ATUs) — and it assesses applications the local government can't, including commercial-scale systems and installations in sewage-sensitive areas like public drinking water source catchments. For a normal house on a normal block, your shire is the only body you'll deal with.
The process, step by step
Confirm you can't connect to sewer
WA has a long-standing policy preference for sewer connection where it's available. If reticulated sewer runs past the block, expect the local government to require connection rather than approve a new on-site system.
Site and soil check
The application form asks for a site and soil evaluation "where required" per AS/NZS 1547 — sandy Perth soils often sail through, while clay, high water tables and small coastal lots trigger a proper report. See what a site assessment costs.
Choose an approved apparatus
A code-compliant septic tank and leach drains, or a Department of Health–approved secondary system if you need irrigation reuse or have a constrained site. Compare the system types first.
Lodge with your local government
The application form (many shires use the model form, code WK0085) plus plans and specifications of the apparatus, three copies of the site plan, and the fee. Applications affecting sensitive areas are referred to the Department of Health.
Install, inspection, permit to use
A licensed plumber installs the system; the environmental health officer inspects before backfill. Once the work matches the approval, the local government issues the permit to use — don't run the system before you have it.
| Item | Typical fee | Notes |
|---|---|---|
| Application to construct or install an apparatus | $118 | Statutory fee set by the regulations — the same across WA (shires like Augusta–Margaret River and Nannup list it on their forms) |
| Permit to use apparatus | $118 | Issued after a satisfactory final inspection |
| Site & soil evaluation (where required) | $500 – $1,800 | Private consultant; commonly triggered by clay soils, high water tables or small lots |
| ATU annual servicing (if you choose one) | $300 – $600 /yr | Approved aerobic units carry mandatory servicing conditions — see servicing costs |
Check your local government
Setbacks to bores, lot-size minimums and sensitive-area referrals differ between shires — and some add their own administration fees on top of the statutory ones. Shire-by-shire guides are coming soon.
WA local governments where septic approvals are common
- Mundaring
- Kalamunda
- Serpentine–Jarrahdale
- Chittering
- Gingin
- Toodyay
- Busselton
- Augusta–Margaret River
- Denmark
- Albany
- Northam
- Esperance
Common questions
Can I install a septic if sewer is available in my street?
Usually not — WA policy strongly favours connecting to reticulated sewer where it exists, and local governments generally refuse on-site applications for sewered lots. On unsewered lots the on-site pathway is routine.
Who approves an aerobic treatment unit (ATU) in WA?
The system type is approved by the Department of Health and published on its approved list; your local government then approves the installation on your block the same way it would a septic. ATUs carry mandatory servicing conditions.
When does the Department of Health get involved directly?
For commercial-scale systems, systems in sensitive areas such as drinking water catchments, and apparatus types outside the approved lists. The department publishes specific guidance for commercial on-site wastewater applications.
Is $118 really all the government charges?
The two statutory fees are $118 each, which makes WA the cheapest state for the approval itself. The real costs sit elsewhere — the soil report, the system and the installation. See our full septic cost guide.
Ready to talk to someone?
Browse accredited WA installers and service agents — or get quotes and let them come to you.