Tips & Advice

What Is Subsurface Irrigation?

When your house or property is not connected to a council/municipal sewer, on-site wastewater systems like Septic Tanks or Aerated Wastewater Treatment Systems are often installed to treat the sewage and blackwater generated.

The latter and most popular of the two options (Aerated Wastewater Treatment Systems or AWTS) receives all wastewater from the premises, including the kitchen, toilet, shower and laundry, and quietly and efficiently recycles all your household wastewater into clean, clear and odourless water suitable for irrigation on your garden and lawns via sub-surface irrigation. 

Subsurface irrigation is the best method of disposal of the cleaned and disinfected wastewater for most local governing authorities. The considerable benefit of subsurface irrigation is that there is no contact with the treated effluent for humans, pets or livestock.

It works by the AWTS being connected to the sub-surface irrigation, allowing the secondary/aerated treated effluent to be dispersed via multiple polyethylene drip lines, covering a targeted area (often called a leach field). Subsurface irrigation evenly disperses the treated effluent underground (after disinfection by an Advanced Secondary Treatment System) straight to the biologically active layer of the soil. The soil consumes residual bacteria or organic matter, and vegetation such as grass will absorb the nutrients. 

Sub-Surface Irrigation Being Installed:

 

The sub-surface poly drip lines are buried in a grid between 100mm – 150mm below the ground, where inserted emitters disperse the wastewater evenly through the irrigation network.

 

The constant dispersal of the water means there is no run-off or pooling on the top of the leach field, reducing human contact and contamination of waterways.

When considering sub-surface irrigation as part of your wastewater solution, you will need to consider your soil type, site conditions, size of the leach field and the intended application of the area. The grass of the leach field should be maintained short to allow good airflow and for the sunlight to dry excess dampness. 

Planting on septic drain fields and around your septic system and leach field is not only permissible but advisable. Plants will prevent erosion and suck up some of the excess moisture from the drain field. At the very least, grow a Tall Fescue grass or Kentucky Bluegrass. Tall Fescue and Kentucky Bluegrass are often mixed and can handle high water levels.

 

Read our full article: What Plants Can You Plant Around A Septic System?

 

Large areas (over 250 to 300 linear metres of drip line) are usually split into equal-sized zones. The zones are controlled automatically through your AWTS system using a water indexing valve that spreads the treated wastewater to a different zone every time the pump operates.

 

The Dangers Of Poor Irrigation

A good irrigation system is necessary on any property.

Whether you’re building a new home or figuring out ways to save water and alleviate water damage, it’s important to know just how significant the impact of poor irrigation can be on your home. All homeowners should consider installing an excellent quality irrigation system.

Below are some of the ramifications of having poor irrigation:

Damage to the Surrounding Concrete and Footpaths

Uncontrolled water from poor irrigation can eventually gather underneath or on top of concrete, causing it to become both aesthetically and structurally damaged. Paths in your garden, driveways, and even footpaths surrounding your home are at risk if subjected to continuous water build-up.

Higher Risk of Erosion

Excess water in your garden can cause topsoil runoff into surrounding drains. Not only does this significantly impact the environment, but it also means the root system of your lawn and plants is more likely to sustain damage due to losing the nutrients and protection that topsoil gives them.

Wood Rot and Termites

Poor irrigation may result in rotting wood around your property or home. Termites absolutely love rotting, moist wood so if you’ve got irrigation leaks around wood, you need to think fast and resolve the problem before it causes major structural damage.

Increase in Pests

It’s not just termites that might invade your property if you have poor irrigation. There’s also the chance that you’ll have an increase in spiders and rodents on your property due to the increased moisture.

Dryness

Contrary to all of the above, if you have an irrigation system that isn’t leaking but is not releasing enough or any water, then you are basically running with no irrigation at all. This can leave your property dry, kill plants and trees in your garden, and damage your lawn.

 

Garden Master provides environmentally friendly Septic Solutions and Subsurface Irrigation services for domestic and commercial properties across NSW, ACT and Victoria.

Garden Master offers only the highest quality residential septic tanks, secondary treatment systems (STS), and commercial-grade wastewater treatment systems. We have septic treatment systems with subsurface irrigation suitable for domestic homes, cabins, and commercial industries. We pride ourselves on customer service, meaning you won’t just get a one-size-fits-all approach with us but rather a tailored solution to suit your exact wastewater needs. With over 30 years of experience, you can rely on Garden Master to provide the best wastewater treatment products and services.

If you’re unsure what septic system would suit your property, check out our article, Septic Tank Buying Guide or get in touch for some friendly advice.

 

Tips & Advice

Unsewered Areas, What Is The Septic Tank Alternative?

Septic Tank Alternatives: Modern Wastewater Solutions for Unsewered Properties

If you’ve recently purchased a home or vacant land in an unsewered area, you’re likely exploring septic tank alternatives to manage your household wastewater. While traditional septic tanks have long been the standard, they’re no longer the only option—and in many cases, they’re not the most efficient or environmentally friendly.

Whether you’re installing a new system or reviewing the performance of an old one, it’s worth considering more advanced wastewater treatment solutions. Outdated systems can be inefficient, prone to failure, and potentially harmful to the environment. In contrast, modern systems like Aerated Wastewater Treatment Systems (AWTS) and Advanced Secondary Treatment Systems (STS) offer cleaner, safer, and more sustainable outcomes.

In this article, we’ll explore the different types of wastewater treatment systems available today, the benefits of upgrading, and why making the switch from a septic tank could be a smarter long-term decision for your property and the planet.

First, let’s consider the following.

 

What’s Wrong with Outdated Septic Systems in Unsewered Areas?

Older septic systems, like septic tanks, can be costly and pose a real threat to both water quality and the health of others. Outdated septic tanks may:

  • Be poorly built and designed

  • Have expensive pump-out services

  • Leak frequently

  • Be non-compliant with local and state Government Health regulations

 

Types of Wastewater Treatment Systems: Septic Tanks vs Alternatives

When it comes to managing household wastewater on properties without access to municipal sewerage, you have a few key options. The right system for your property depends on your location, site conditions, household size, and local council regulations.

While traditional septic tanks are still used, many homeowners are now considering septic tank alternatives like Home Sewage Treatment Plants (HSTPs) and Aerated Wastewater Treatment Systems (AWTS). These modern systems are more efficient, environmentally friendly, and often produce higher-quality treated water.

💧 What Are the Main On-Property Wastewater Treatment Options?

If your property isn’t connected to a council-managed sewerage system, your wastewater must be treated and disposed of on-site. There are two main categories of systems that can handle this:

1. Septic Systems
  • Sometimes referred to as septic tanks

  • A watertight underground container, usually made from concrete, fibreglass, or plastic

  • Collects all household wastewater, allowing solids to settle and scum to float

  • Effluent is dispersed into a drainage field or an absorption trench

  • Inexpensive and low-tech, but limited in treatment quality (only partial treatment of wastewater)

2. Home Sewage Treatment Plants (HSTPs)
  • Treat both blackwater (toilets) and greywater (sinks, showers, laundry)

  • Function like small-scale versions of municipal sewage treatment plants

  • Use multiple treatment stages to significantly reduce pollutants in wastewater

  • Treated water (effluent) can often be reused for subsurface irrigation

  • Require ongoing maintenance and electricity, but offer better environmental performance

 

🔁 Septic Tank Alternatives: Other Common Terms You Might Hear

Many systems that perform similar wastewater treatment functions go by different names. While they may vary slightly in design or performance, they all share the goal of treating and reusing water on-site.

Here are some common terms and their meanings:

  • Wastewater Treatment System
    A broad term that includes all types of on-site wastewater treatment solutions.

  • On-site Sewage Facility (OSSF or OSF)
    Any system that stores, treats, and disposes of wastewater on a property not connected to town sewer.

  • Wastewater Treatment Plant (WWTP)
    More commonly used for larger or commercial systems, but also refers to residential units that treat wastewater to a high standard.

  • Sewage Treatment Unit (STU or STP)
    A multi-stage system used to treat sewage and greywater, typically involving biological and mechanical processes.

  • Aerated Wastewater Treatment System (AWTS)
    A residential system that uses air to support aerobic bacteria, providing thorough treatment suitable for garden irrigation.

  • Aerobic Treatment Unit (ATU)
    Similar to AWTS, but often modular or designed for smaller scale use. Uses oxygen to break down waste.

  • Aerobic Septic System (ATS)
    A step up from conventional septic tanks, using aerobic processes to treat wastewater more effectively.

  • Domestic Wastewater Treatment System
    Any system designed specifically for use on a residential property to treat and manage household wastewater.

 

While the names vary, all of these systems are considered alternatives to traditional septic tanks. They provide greater flexibility, improved treatment outcomes, and better environmental protection—especially important in sensitive or high-rainfall areas.

🤔 Is a Septic Tank or HSTP Better?

Generally speaking, Home Sewage Treatment Plants (HSTPs) are considered a more advanced and environmentally friendly solution than conventional septic tanks. They treat wastewater in multiple stages—typically three—resulting in much cleaner effluent that can be safely reused for subsurface irrigation.

However, the best system for your property depends on:

  • Soil type and drainage capacity

  • Available land area

  • Proximity to waterways or neighbours

  • Local council regulations

  • Your household’s size and water usage

  • Budget and maintenance expectations

 

Talk to a Wastewater Professional

Choosing the right system isn’t just about comparing septic tank alternatives. It’s about understanding your site’s specific conditions and legal requirements. A licensed wastewater system designer or environmental engineer can assess your property and recommend the most suitable solution.

At Garden Master, we design, install, and maintain a wide range of wastewater treatment systems across NSW, Victoria, and the ACT. Whether you’re upgrading an outdated septic tank or building on a new unsewered block, we can help you choose the right solution for your property.

Recommended Reading:

 

Choose the Garden Master Solution. Garden Master provides environmentally friendly solutions for both commercial and domestic properties across Australia. We believe wastewater treatment and recycling are far more efficient than relying on rainfall and play an essential role in relieving the stress put on water usage in Australia and around the world.

With more than 30 years of experience, we can provide you with the best wastewater treatment products and services. We’re available seven days a week—contact us today to find out more!

 

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