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Why You Need a Wastewater Assessment

If your property isn’t connected to sewer, council will usually ask for an on-site wastewater assessment or land capability assessment as part of your DA. This report shows:

• the type of system you plan to use (AWTS, septic tank + trenches, membrane system, etc.)

• how wastewater will be treated

• how effluent will be safely disposed of on your land

• how the system meets WaterNSW requirements and your local DCP

This is to make sure your system won’t pollute nearby waterways, especially in high-risk catchment areas.

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Key things WaterNSW looks for

WaterNSW’s guideline focuses on making sure wastewater systems have a neutral or beneficial effect on water quality.

 

That means your design must show:

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1. Your land can safely handle the wastewater

Your wastewater report must assess soil type, slope, drainage, flooding, rock depth, and available space for the effluent management area (EMA).

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2. The system is sized correctly

The size of the tank or AWTS must match the expected daily flows, usually based on how many bedrooms the home has.

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3. Effluent can be disposed of safely

Disposal methods (trenches, beds, drip irrigation, mounds) must suit your soil and meet required buffers from:

• waterways

• dams

• drainage lines

• boundaries

• bores

• buildings.

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Buffers in WaterNSW’s guideline are often stricter than standard council rules because the catchment is so sensitive.

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4. The right technology is chosen

The guideline covers a range of Wastewater Treatment & Effluent Management Technologies, including:

• Septic tanks + absorption trenches

• AWTS with irrigation

• Sand filters and mounds

• Pump wells and dosing systems

• Upgrades to existing systems.

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Typical regions that must comply

The Sydney catchment is by no means just Sydney. Infact, many areas across the South Coast, Southern Highlands, Shoalhaven, Wingecarribee, and parts of the Southern Tablelands fall inside the Sydney catchment. If you’re in places like Robertson, Bundanoon, Kangaroo Valley, Berry, Exeter, Moss Vale, Fitzroy Falls, Penrose, Tallong, Bungonia, Braidwood and THOSE surrounding rural areas, you likely need to comply with WaterNSW’s rules.

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Why This Matters

Poorly designed systems can leak into groundwater or creeks, harming both public health and the environment. Following the guideline—and getting a thorough wastewater assessment—helps protect drinking water supplies and ensures your development meets council and WaterNSW requirements.

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Need help? Contact Southern Wastewater

If you’re lodging a DA, building a home, subdividing, or replacing an old septic tank or AWTS, you’ll need a clear, accurate and council-ready wastewater assessment report to get your project approved.

Southern Wastewater specialises entirely in on-site wastewater assessments, wastewater system design, and DCP-compliant reports across the South Coast, Southern Highlands, Southern Tablelands and surrounding regions.

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We know the WaterNSW requirements inside out, understand local council expectations, and can guide you through the whole process—from site inspection to a polished wastewater report that meets both WaterNSW and council standards.

 

Get in touch with Southern Wastewater via info@southernwastewater.com.au or 0435 575 403 today to make your wastewater approvals simple, stress-free and fully compliant.