FAQs
Septic tanks are constructed of reinforced concrete, polypropylene or fibre glass and is divided into a two thirds / one third arrangement which provides primary treatment of wastewater.
The tank retains waste and reduces solids by physical and biological means. Effluent is retained within the first chamber of the tank where most of the solid material settles to the bottom, and then microbial activity causes a reduction in solids.
Septic tanks require periodic emptying in order to ensure they function correctly. To arrange this, we recommend engaging a suitably licensed contractor.
If you are in a CWMS area, Council’s contractor will send you a letter every five years. Remember to uncover your septic tank lid and make contact with the contractor to arrange the pump out.
The CWMS works by receiving effluent from individual septic tanks which flows to Councils wastewater treatment plant. After treatment, this effluent is reused in various ways by Council.
Most properties within Mount Barker, Littlehampton, Nairne, Meadows, Echunga and Macclesfield are connected to the CWMS.
The township of Hahndorf is connected to an SA Water system. Any enquiries regarding sewer systems in Hahndorf should be directed to SA Water.
The developments of Aston Hills and Emerald Way are connected to a private sewer.
An annual levy is charged for each allotment connected to the CWMS. This levy contributes to upgrades and maintenance of the system, including the treatment plant, and provides for the pumping out of septic tanks connected to the CWMS every five years.
Where a property is not serviced by Council or a sewer system, an onsite effluent treatment and disposal is required. The most common of these systems are:
- Subsurface effluent soakage system
- Aerobic wastewater treatment system (AWTS)
Depending on the soil type, fall of the land, disposal area and distance from watercourses, bores, wells and dams.
Subsurface effluent soakage system is usually the cheapest option. The system takes effluent from the septic tank and disposes it underground via a subsurface soakage trench.
Instead of disposing effluent underground, AWTS’ allow the reuse of treated effluent on trees and shrubs within designated irrigation areas. Operation and maintenance costs must be taken into consideration as servicing by a suitably qualified person is required on a quarterly basis, and electricity is required to run these systems.
For more information that is helpful refer to Council’s fact sheets:
Septic Tanks
Onsite Waste Control Systems
Acknowledgements and References
“Standard for the Construction, Installation and Operation of Septic Tank Systems
in South Australia” South Australian Health Commission, March 1995.