Septic vs AWTS: Choosing the Right Wastewater System for Your Property
Understanding your wastewater options
When building or upgrading a home in Tasmania, one crucial consideration is how to manage wastewater. If your property isn’t connected to the mains sewer system, you’ll need a solution that will be managed onsite, often based on soil conditions and number of occupants. The two primary options are Septic Systems and Aerated Wastewater Treatment Systems (AWTS). Understanding the differences, advantages, and potential challenges of each system can help you make the best decision for your site. These systems are required to be designed by appropriately qualified persons to ensure the longevity and correct type of system installed.
What is a Septic System?
A septic system is a traditional and passive method of treating household wastewater. It consists of a large underground tank where solids settle, and naturally occurring bacteria break down the waste. Once solids are separated, the partially treated liquid flows into a designated trench or soakage area underground. The surrounding soil then completes the treatment process by filtering and absorbing the wastewater. This method relies on anaerobic bacteria and gravity, meaning it has no moving parts and does not need electricity.
Septic systems are typically less expensive to install and require minimal maintenance, usually needing a pump-out every three to five years. However, their effectiveness is heavily reliant on soil quality and site conditions. Properties with high groundwater levels, clay soils, or limited space may struggle to disperse wastewater effectively, increasing the risk of system failure or groundwater contamination, and the need to move to an AWTS instead.
What is an AWTS?
In contrast, an Aerated Wastewater Treatment System (AWTS) is a more advanced, active solution that treats household waste to a higher standard. This system includes multiple chambers where the waste undergoes various stages of treatment, including aeration. Air is introduced into the wastewater to encourage the growth of aerobic bacteria, which are more effective at breaking down organic waste. The water is then clarified in a settling chamber, and, in some systems, disinfected using chlorine or UV light.
The treated water is clean enough for sub-surface irrigation, making AWTS a more environmentally friendly option, particularly in sensitive locations or smaller sites. AWTS systems can handle poor soil conditions and work well on blocks with limited space. However, they are more expensive to install and require regular servicing, typically every three months, as well as electricity to operate. This means they come with ongoing costs and may not be ideal for off-grid properties unless supported by a reliable power source.
Key Factors to Consider When Choosing a System
When choosing between a septic system and an AWTS, there are several important factors to consider. The size and location of your property play a critical role—rural sites with ample space and good drainage are often suitable for septic systems, while AWTS are better suited to smaller lots or areas with poor soil quality. Soil type is essential because it determines how well wastewater can be absorbed and treated by the ground, often times this being the deciding factor on the system installed.
Council regulations will also influence your decision, as local authorities often require specific wastewater systems to be nominated and approved before construction begins.
Cost is another significant consideration, while septic systems generally have a lower initial cost, they may not be viable for all sites. AWTS have higher upfront and ongoing maintenance costs, but their ability to treat wastewater more effectively may be worth the investment, particularly in environmentally sensitive areas.
The environmental impact should not be overlooked—AWTS discharge treated water that is cleaner and safer, reducing the risk of polluting groundwater. Additionally, if your home relies on tank water, ensuring proper wastewater treatment is vital for protecting your water supply and maintaining a safe, healthy environment.
Planning for Success
Selecting the right wastewater treatment system is a vital step in the design and approval process for any new build or renovation. At Prime Design Tasmania, we collaborate with wastewater engineers and consultants to make sure your system not only suits your land but also meets all council requirements and your own preferences if they can be met. Early planning can help avoid costly delays and ensure your system functions efficiently for years to come.
Need Help Deciding?
If you’re unsure which system is right for your property, contact Prime Design Tasmania today. We can help arrange an experienced wastewater expert with a full report detailing the best option for your property. We’re here to help guide you through the process and connect you with the right professionals for the job.