Charting a trusted future for reuse through consistent validation

As Australia continues to grapple with the twin pressures of climate variability and growing urban demand, water reuse is becoming an increasingly critical part of the potable supply conversation. But with complex source waters and heightened public scrutiny, one thing remains essential: trust in the treatment processes that make reuse safe.

WaterVal is a nationally recognised framework designed to give water professionals, regulators and communities confidence that water treatment processes are performing as they should.

Developed through the Australian Water Recycling Centre of Excellence in the wake of the Millennium Drought, WaterVal has helped streamline the validation of treatment systems for recycled water. But its influence hasn’t stopped at our borders.

AWA Recycled Water Specialist Network member and Water Research Australia Senior Research Manager Marty Hancock said the framework has quietly shaped the direction of water reuse regulation in one of the most drought-stressed and innovation-driven regions of the world: California.

“In a recent workshop with the Californian Department of Drinking Water, their senior reuse regulator explained that when they developed their potable reuse regulations, they needed a standardised validation approach, so they borrowed from Australia,” he said.

“In 2016, Australia was in front. We were recognised us as world leaders in reuse and validation, but since then California has moved ahead rapidly while we haven’t implemented the framework or continued with its development.”

Hancock said WaterVal’s origins lie in a time of challenge and opportunity. The Millennium Drought catalysed investment in more resilient, rainfall-independent water supplies, and with it, the need for rigorous validation of treatment processes. While the framework was originally developed with recycled water in mind, its relevance has since expanded.

“There’s no doubt that the risk from source water for reuse is higher, and with greater risk comes a greater requirement for confidence that you meet requirements. Reuse has driven the validation process from the beginning,” he said.

“WaterVal is now broader. It’s still reuse-focused, but it applies to any treatment process for any water supply, giving regulators and the industry confidence that treatment processes are providing the water quality we expect.”

Learning with California

Australia’s leadership in the reuse validation space attracted early attention from California, a region facing parallel water security challenges and undergoing its own regulatory evolution, Hancock said.

“California’s story is basically the same as ours, different names, same challenges. High demand for water, drying climate, population growth, and the need to diversify water sources. We realised quickly that there was a real opportunity to work together,” he said.

That collaboration has since evolved into a formal partnership, bringing Australian and US researchers, utilities and regulators into shared projects and dialogue.

“Back when we were doing a lot of research, Californian researchers, consultants and regulators came to Australia and collaborated. Some of them returned recently, which shows how longstanding the relationship has been,” Hancock said.

“CalVal is a specific project with many lead organisations, including regulators, developing guidance for implementing indirect and direct potable reuse in California. Through a memorandum of understanding, Water Research Australia and the National Water Research Institute agreed to collaborate wherever resources or research could benefit both.”

Validation alone isn't enough

While technical frameworks like WaterVal and CalVal help ensure safe, consistent outcomes, Hancock said the Californian experience reinforced the critical importance of community trust in unlocking reuse progress.

“One of the biggest themes discussed was how California managed to win social legitimacy with the community. If you don’t get past that point, all the technical solutions in the world won’t matter because politicians won’t support anything without strong social acceptance,” he said.

“There is no magic pill for this. It’s a long, difficult journey. Californians emphasise that you need to start early, accept that it’s going to be long, and understand that the journey never finishes. Even with well-established programs, you are always communicating, reassuring and building confidence.”

Australia, too, is grappling with how best to engage the public on the benefits and safety of water reuse.

“We learned a lot from their diversity of communication techniques, everything from big education centres to small mobile treatment plants on trailers. We learned what works where and how, and we’re trying to apply that so we can be more effective in Australia.”

“One of the key lessons is that it’s a journey and you need to continue with it. Don’t think you build your community engagement structure, spend a year telling the story, and then say, thank you, we’ll just get on with it now.”

“At the heart of social legitimacy is trust. You’ve got to build trust with your community. And that’s ongoing.”

Australia’s next steps in reuse and validation

With population growth, drought pressures and infrastructure investment accelerating across the country, Australia’s interest in reuse is strong and so is the appetite for robust validation.

“There is strong momentum in Australia for reuse. As we try to diversify and get more drought-resistant, rainfall-independent supplies, reuse has to be an option. It has significant cost savings compared with desalination, and it suits urban areas,” he said.

“We’ve identified the highest priorities for the Australian water industry, and the Californians have identified theirs. They don’t align exactly, but they’re close. We’ve mapped that together and we’re now detailing how their research will help guide our validation processes.”

Thinking globally, validating locally

With globally standardised products and increasing international collaboration, Hancock said WaterVal’s evolution must include a global outlook, not just for the benefit of others, but to strengthen Australia’s own systems and credibility.

“Ultrafiltration membranes are manufactured globally, and everyone uses the same products. So validation needs to be global facing. WaterVal recognises this and is developing best-science validation resources that can be used anywhere in the world,” he said.

“It sounds altruistic for Australia to be developing global protocols, but it actually benefits us. International recognition adds credibility and value to the validation framework. When manufacturers and overseas researchers build on our framework, we gain back many times over.”

Interested in learning more about the AWA Recycled Water Specialist Network? Take a look here.