Performance solutions for OSSFs

When the standard design doesn’t fit – there’s another way!

If you’re installing an on-site sewage facility in the Fraser Coast region, your design usually needs to follow the Queensland Plumbing and Wastewater Code and Australian Standard 1547:2012.

But what if your project doesn’t quite fit the “standard box”? That’s where a performance solution comes in.

What the code normally requires?

Your sewage facility design should meet:

• Queensland Plumbing and Wastewater Code - Section C3
• Australian Standard 1547:2012 - Section 5 (Design of onsite systems and land application methods), including Appendices L to N
• Setback distances as listed in the Code’s Appendix 1, Part 2

If your project can’t meet these exactly, you’ll need to propose an alternative approach – one that still meets the intent of the rules. That’s your performance solution.

What is a performance solution? Key legislative referencesWhat to include in your ApplicationWho can prepare a performance solution?Summary checklist

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What is a performance solution?

A performance solution is a custom design that demonstrates compliance with required safety, health, and environmental outcomes under Queensland law, even if it differs from the standard approach.

It must show compliance with:

• Plumbing Code of Australia (PCA) – Section A2G2
• Supporting documents listed in Section 6 of the Plumbing and Drainage Regulation 2019
• Either:
  • Section A2G3 (Deemed-to-Satisfy equivalence), or
  • Section A2G4 (a combination of compliant approaches)

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Key legislative references

• Plumbing Code of Australia: Sections A2G2, A2G3, A2G4
• Plumbing and Drainage Regulation 2019: Section 6 and Part 5

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What to include in your Application

Applications for performance solutions are assessed under Part 5 of the Plumbing and Drainage Regulation 2019. Your submission must include:

• Applicable performance requirements
• Explanation of how your solution differs from standard DTS provisions
• Methodology used to prove compliance
• Supporting evidence and expert judgment
• Details of the competent person preparing the report
• Relevant codes, standards, technical data, or assessments
• Site and soil evaluations, design flow details, risk assessments, installation plans
• Test results, drawings, and certification documents

Additionally, technical documents such as engineering designs, installation manuals, and owner’s manuals must accompany the application.

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Who can prepare a performance solution?

The report must be prepared by one of the following suitably qualified persons:

• Holder of a QBCC hydraulic design licence
• Holder of a QBCC site classifier licence
• Registered Professional Engineer of Queensland (RPEQ)
• Holder of another relevant licence under the QBCC Act 1991
• Another person deemed competent by Council to develop the solution

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Summary checklist

Requirement	Details
Definition	Custom design meeting PCA outcomes
Legislation	PCA A2G2, A2G3, A2G4; PD Reg 2019 Sec 6, Part 5
Application Includes	Performance criteria, deviation, compliance method, evidence, site data, manuals, drawings
Qualified Person	QBCC or RPEQ with ODWM endorsement
Competent Person	Another person Council considers competent to develop the solution

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Need help?

Ensure your submission is complete and meets all legislative requirements. For guidance, refer to:

• Plumbing Code of Australia
• Plumbing and Drainage Regulation 2019