There are a number of different types of septic tank (wastewater management) systems. They are designed for and used in different site conditions. The type and location of your land may decide which system you need to install.
The main types of systems are:
These systems rely mostly on gravity and consist of a septic tank, normally 3200 litres, connected to a distribution pit followed by effluent (absorption) trenches which are generally slotted pipe laid underground in aggregate (usually scoria) filled trenches. Length and width of these trenches is determined by the size of the development.
Solids settle in the bottom of the tank and liquid known as the effluent passes through the distribution pit to the trenches where it is absorbed by the soil.
These systems normally have two tanks and consist of a primary settling chamber with an aeration system which treats effluent with chlorination or ultra violet to an approved standard, 20/30, for use as onsite fixed underground irrigation.
These systems require power to operate and need to have an alarm fitted to warn you if it is not working properly. Regular servicing is needed by a qualified service agent, generally every 3 months.
It is important that you follow the manufacturer’s guidelines to make sure the system works properly at all times.
Primary treatment is composting, for example Worm Farms. These systems require care to ensure the composting system is operating properly. Some systems require grey water to be treated separately.
These systems are similar to conventional system being made up of a tank connected in an underground sand filter structure where the effluent is filtered before going into the effluent (absorption) trenches.
Reed bed systems have a septic tank with the effluent passing through a lined bed of reeds to filter the effluent before it goes into underground effluent trenches.
Reeds need to be kept alive for this system to work.
Treats grey water only. Grey water is the generally wastewater from your shower, bath and washing machine only.