Compliance testing of on-site domestic wastewater Secondary Treatment Systems

As a South Australian agricultural, environmental and water treatment consultancy organisation, Arris works for a range of clients from small business and research organisations, to government departments, peak industry bodies and large corporations.

Hahndorf STS Testing facility overview

One of the passive treatment systems being tested at Hahndorf.

Arris has constructed and is operating a state-of-the-art compliance testing facility at SA Water’s 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 1,200 and 5,000 L/d. 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 STSs under normal ‘steady-state’ design operations and also challenge ‘stress testing’ conditions.

Arris’ compliance testing facility has been fully operational since March 2019. The STS testing facility is located in Hahndorf, South Australia and has continuous 24/7 access to the raw sewage flow for uninterrupted compliance testing activities. The Hahndorf facility is located in climate zone 6, offering STS providers the capacity for full cold climate winter testing to verify low temperature performance as per AS 1546.3:2017. The facility has a 40 m long concrete bunker with nominal depth of 2.1 m which allows STS systems to be installed and backfilled with sand to simulate fully in-ground in situ operating conditions during testing. The facility has capacity to accommodate up to 10 domestic treatment units concurrently and the first round of STS compliance testing commenced June 2019.

View from atop the STS bunker under recent stress testing conditions.

STS units are supplied with macerated raw sewage from a 5,000 L balance tank which receives unscreened sewage from the Hahndorf sewer main at the head of the wastewater treatment plant. Sewage dosing and influent plus effluent sampling are fully automated and SCADA controlled. Automated refrigerated autosamplers are housed in the control sheds adjacent to the STS bunker, allowing for programmable and automated grab and composite sampling from influent and effluent lines as per the requirements of AS 1546.3:2017. All samples are analysed by our local NATA-accredited laboratory service provider (Envirolab Services). 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 facility is also covered 24 hours by full-span CCTV cameras, with data recorded and stored in the onsite facility control centre.

View this video for an in-depth presentation of small, on-site domestic wastewater treatment systems.

This event began with an introduction to decentralised wastewater treatment, followed by a survey of the landscape of standards/regulations governing on-site wastewater systems performance certification internationally, with a focus on the relevant Australian context.


Customer Testimonials

The below testimonials are from STS providers with units currently under test at the Hahndorf facility.

“All of us at Ri-Industries are extremely pleased with the progress of the compliance testing at the Hahndorf wastewater treatment plant. Testing commenced in June, and we are updated on a weekly basis on the performance of both our 1,500 L/d and 5,000 L/d units. The testing facility was built from the ground up, and all credit goes to the teams from Arris and Hydroscape for achieving a fantastic outcome. Any manufacturer considering having their units tested, I would highly recommend using the Hahndorf testing facility.”

Craig Ainslie – Sales Manager, Ri-Industries


“OzziKleen chose the Arris Hahndorf test site for testing one of our residential waste water treatment plants. As the National Residential Service Manager, I naturally have spent time dealing with Arris staff and have always been impressed at how professional their conduct has been. Being based in QLD the distance has always been a challenge, but, Arris and especially Michael Short, have been extremely helpful during the initial set-up and testing period, and provided all the assistance we required.”

Scott Humberstone – National Domestic Service Manager, OzziKleen