In unsewered areas, all properties require onsite effluent disposal. The most common type of onsite effluent disposal system consists of two septic tanks (or one large tank with a baffle) and two leach drains (alternating) and is commonly referred to as a conventional onsite effluent disposal system.
The septic tanks treat the effluent to a primary level which then drains into the ground through leach drains. These alternating systems have a diverter box to change the flow of effluent between each of the leach drains on an annual basis. This allows one leach drain to dry out, rejuvenating the soil's ability to receive effluent.
There are a number of factors that influence whether a septic tank/leach drain system can be used on a property. These include the amount of space available, depth of ground water, proximity to water bodies, soil types and contours of the land.
Each site is assessed individually by the Shire's Health Service to determine the most appropriate effluent disposal system.
To install a conventional onsite effluent disposal system an Application to Construct or Install an Apparatus for the Treatment of Sewage must be submitted to the Shire. For commercial properties, application for a second system on a property or systems expecting more than 540L of sewage per day the Department of Health's application form must be submitted to the Shire.
More information –
Wastewater systems – Department of Health