The Risk Management Approach Used for On-site Wastewater System Accreditation in Australia (WWETT Show 2023)

The Australian Regulators have developed a Country-wide standard (AS 1546.3:2017) used by all States & Territories for the approval of domestic on-site wastewater treatment systems. This is similar to the NSF process used in the USA.

Once a treatment system is approved it can be used anywhere in Australia.  Arris has constructed and is operating a state-of-the-art compliance testing facility at the Hahndorf wastewater treatment plant in South Australia for undertaking AS 1546.3:2017 compliance testing according of on-site domestic wastewater treatment Secondary Treatment Systems (STSs) with design hydraulic treatment capacities of between 300 and 1320 gallon/day.

Compliance testing according to AS 1546.3:2017 comprises a 42 week long combined commissioning and testing period (minimum testing period 34 weeks) conducted under specified conditions in order to demonstrate the performance and reliability of under normal ‘steady-state’ design operations and also challenge ‘stress testing’ conditions. Units are supplied with macerated raw sewage from a 1320 gallon balance tank which receives unscreened sewage from the Hahndorf sewer main at the head of the wastewater treatment plant. A suite of parameter data are monitored and logged by control shed instrumentation, including STS sewage dosing volumes and flow rates; feed pipeline pressure; water and ambient air temperature; electricity consumption; system alarms etc.

The standard AS 1546.3:2017 has been developed using risk management techniques. As it is a new Standard the Regulators have undertaken a feedback process about the new approval process involving all industry stakeholders. This presentation will outline the feedback received from the 1st rounds of testing and how it has impacted on the new Standard. The aim of this presentation is to see how a risk management approach can be used to develop approvals and regulations for the domestic on-site industry.

Learning Objectives:

1. Identify the risks used to formulate on-site wastewater regulations (both national & international

2. Explain the differences between the Australian accreditation system and the North American NSF process

3. Discuss how the accreditation systems address risks and how the testing processes ensure performance of on-site wastewater treatment systems

4. Be aware of the feedback from the practical application of the accreditation process and how changes to the regulations are negotiated

Speakers:  Ben Kele, Water Treatment Consultant at Arris Water; Tim Woods, Associate at Arris Water; Michael Short, Water and Environmental Consultant at Consultant