Septic Tanks & Wastewater

Septic Tank and Plumbing approvals, inspections and complaints

All sanitary plumbing work in South Australia must be carried out be a licensed plumber.

Where septic tanks are to be installed or plumbing is to be installed or extended, a Council permit is required.

Council staff assess the application under the SA Health Commissions' Standard for Installation of Septic Tanks. Copies are available from the Public & Environmental Health Service of the Department of Human Services.

Install a Septic Tank System Application(200 kb)

Wastewater Control

Building a new house or upgrading your existing wastewater control system? Then you will need to lodge an application to install or alter your wastewater control system. You will also require approval if you are adding on extra bathrooms or laundries and if there is any alteration to the existing plumbing work. This is required under the South Australian Public Health (Wastewater) Regulations 2013 and On-site Wastewater Systems Code.

There are many different types of on-site Wastewater systems including the septic tank and soakage system, aerobic systems, Communal Wastewater Management Systems or CWMS (formerly called STED systems) and alternative systems such as the reed bed system, and composting toilets.

Septic Tank and Soakage System

The minimum size septic tank for a 6 person dwelling is 3000 litres and 45 metres by 1.2 metre soakage trench however this is dependent on the soil report that is provided by the Geotechnical Engineer. A percolation test or geotechnical report will need to be submitted to indicate that the soil is suitable for soakage and what size area is required. Some soils such as clay aren't suitable for soakage as the water doesn't drain adequately.

A site plan showing the location of the septic tank and soakage trench in relation to the house, boundaries, driveways, any other structures and land features such as watercourses must be provided along with a plumbing layout.

Aerobic systems (including sand filter systems)

Aerobic systems treat the water with chlorine so that it can be used on your garden area. The system needs to be checked quarterly by a suitably qualified person to refill the chlorine and to ensure the pumps and aerators are working.

When lodging the application you will need to provide a site plan showing the location of the aerobic tank and layout of the irrigation area in relation to the house, boundaries, driveways and any other structures, a plumbing layout, and an Engineer's report outlining the size of the irrigation area required.

Due to changes in the legislation a qualified Engineer with experience in wastewater must now determine the size of the irrigation area required. This is dependant on the soil type on your property and the poorer the quality of the soil, the larger the irrigation area.

Note: Aerobic water can not be used on any lawn areas or vegetable gardens.

Compulsory Inspection Stages

Council must be notified at least 24 hours prior to the following stages have been reached to enable an inspection to be undertaken.

  • Underfloor plumbing
  • Installation of septic tank and drain
  • Installation of the irrigation area or soakage
  • Connection to the CWMS