Septic Tanks Sydney

If your property isn’t connected to municipal sewer services, you’ll need a reliable and council-approved septic tank system. Garden Master has over 30 years of experience designing, installing and maintaining septic tanks in Sydney, providing high-quality systems tailored to your land, usage, and local council requirements.

This guide will walk you through everything you need to know about choosing and installing the right septic tank in Sydney, including key regulations, site conditions, system types, and ongoing maintenance.

Table of Contents

1. Why You Need a Septic Tank in Sydney
2. Key Considerations for Septic Tank Installation in Sydney
3. Soil Conditions in Sydney
4. The Garden Master Elite STS System
5. Subsurface Irrigation Systems in Sydney
6. Get Expert Advice & Local Support
7. Recommended Reading

Why You Need a Septic Tank in Sydney

Septic tanks are commonly required in Sydney’s semi-rural and fringe suburbs where mains sewer is unavailable. Choosing the right system isn’t just about function — it’s about ensuring environmental protection, council compliance, and long-term efficiency.

Key Considerations for Septic Tank Installation in Sydney

1. Soil Conditions

The soil type and quality on your property affect how well effluent can be absorbed and treated. A percolation test is often required to assess soil permeability and to help design the appropriate size and layout for your absorption trench or irrigation system.

2. Tank Size

The right tank size depends on the number of bedrooms, residents, and expected water use. For most Sydney households, a single 3,000L to 7,000L tank will suffice. Our Garden Master Elite system features a 7,100L single concrete tank suitable for families of up to 10 people. We also have a dual tank option! Not sure what tank size is right for you? Check out our article What Size Septic Tank Do I Need?

3. Maintenance Requirements

All septic tanks must be pumped out every 3–5 years, and Advanced Secondary Treatment Systems require quarterly servicing by a licensed technician. Regular maintenance prevents costly damage and ensures system performance remains compliant with your local council.

4. Local Council Regulations

Sydney councils require specific approvals and permits before installation. You’ll often need:

• Site and soil assessments
• Detailed site plans
• NSW Health-accredited system specifications
• Minimum setback distances from boundaries, buildings, and water sources

Quick links to Sydney councils:

• City of Parramatta Council
• Penrith City Council
• The Hills Shire Council
• Liverpool City Council
• Northern Beaches Council
• Hornsby Shire Council
• Sutherland Shire Council
• Blue Mountains City Council

For more, visit the NSW Health Septic Systems page.

5. Choosing the Right System

There are several types of systems used in Sydney:

• Traditional Septic Tank & Absorption Trenches
• Aerated Wastewater Treatment Systems (AWTS)
• Advanced Secondary Treatment Systems (STS) like the Garden Master Elite
• Membrane Bio-Reactors for high-performance treatment

We recommend reading our Septic Tank Buying Guide if you’re unsure which system is right for your site and usage. Check out our Guide to Wastewater Terms article if you don’t know your HSTPS or AWTS.

Common Soil Types in Sydney

1. Sandy Soils (Eastern Suburbs & Coastal Areas)

• Location: Northern Beaches, Eastern Suburbs, parts of Sutherland Shire

• Characteristics: Fast-draining, low nutrient content, low clay

• Impact on Septic Systems: High permeability can cause effluent to move too quickly, requiring deeper absorption trenches or soil amendments to improve treatment time.

2. Clay Soils (Western Sydney & Hills District)

• Location: Penrith, Blacktown, Parramatta, The Hills Shire

• Characteristics: Poor drainage, slow percolation, high water retention

• Impact on Septic Systems: Can lead to waterlogging and trench failure. May require raised absorption beds, engineered drainage, or alternative systems like Advanced Secondary Treatment with subsurface irrigation.

3. Loamy Soils (Parts of the Upper North Shore & Blue Mountains Foothills)

• Location: Hornsby, Berowra, parts of Hawkesbury and Camden

• Characteristics: Balanced drainage and nutrient content, ideal for plant growth

• Impact on Septic Systems: Generally well-suited to traditional absorption trenches or subsurface irrigation if setback requirements and slopes are compliant.

4. Shale and Rocky Soils (Western Edge & Some Elevated Areas)

• Location: Blue Mountains, parts of Camden and Wollondilly

• Characteristics: Shallow depth, limited infiltration capacity, potential for rock layers

• Impact on Septic Systems: May require excavation or engineered solutions. In some cases, alternative systems or effluent disposal methods may be necessary.

Importance of Site-Specific Soil Testing

Before installing any septic tank in Sydney, Councils require a site and soil assessment, often including a percolation test or site classification. This helps determine:

• Whether the soil can absorb treated effluent safely

• What size and type of trench or irrigation system is needed

• How to prevent surface pooling or groundwater contamination

The Garden Master Elite STS System

Our flagship solution for Sydney homes, the Garden Master Elite Advanced Secondary Treatment System (STS), is a robust concrete tank system designed for maximum performance, long-term durability, and compliance with NSW Health and council regulations.

The Elite STS is engineered for properties with varying needs and is available in two high-performance configurations:

• 7,100L Single Tank System – ideal for compact sites with limited access and suitable for households with up to 10 people
• Dual Concrete Tank System – a powerful two-tank solution with a 5,000L per day treatment capacity, perfect for larger premises with up to 20 people

Both systems feature:

• Advanced aeration and clarification chambers
• Reliable treatment of household wastewater to high environmental standards
• Optional subsurface irrigation system for safe, efficient effluent dispersal and improved garden hydration

We recommend pairing the dual tank system with subsurface irrigation to maximise performance, safety, and sustainability.

Our team can help assess which configuration best suits your household size, site slope, and access conditions.

Subsurface Irrigation Systems in Sydney

Looking to reuse treated effluent safely and sustainably? Our Subsurface Irrigation Systems are ideal for Sydney properties. They distribute disinfected water below ground level, protecting health and improving garden hydration year-round.

Get Expert Advice & Local Support

Whether you’re in Penrith, the Northern Beaches, the Hills District, or the Blue Mountains, Garden Master can help you choose, install and maintain the ideal septic solution.

We provide:

• Site assessments
• Council application support
• Full system installation
• Ongoing maintenance services