Lessons on the global shift toward water reuse

1. Valuing clean water appropriately and pricing water to reflect its true cost
2. Prioritising high-value applications by directing reclaimed water where it delivers the most benefit
3. Normalising the creation and use of 'new' water, shifting public perception to accept treated water as safe and reliable
4. Advancing programmatic, platform-based approaches by building integrated systems rather than one-off projects
5. Mobilising private innovation and finance by bringing in commercial investment and new technologies.

Reuse is an impressive technical achievement, but technology and investment alone won't succeed without community buy-in.

Building trust is a priority before building any infrastructure. Agencies leading reuse initiatives first need to be reputable and transparent with communities. The most successful programs are those where the community already sees the agency as responsive, engaged and, most of all, credible.

Education plays a central role when building trust. Allowing communities to see how these technologies work in demonstration facilities, as well as clear communication about treatment processes, are needed to secure buy-in. These facilities also serve purposes beyond public education, supporting technical training and broader stakeholder engagement. Meanwhile, engaging external specialists adds credibility and reinforces the science behind the systems.

Terminology matters too. In the US, “pure water” has become a trusted label, while “purified recycled water” (PRW) is gaining traction in Australia. These naming conventions are deliberate, focused choices to help shape perception and build acceptance.

Regulators, elected officials and industry partners all need to be aligned. Clear policy goals and consistent terminology help create a shared understanding of what reuse means and why it matters, while expert guidance reinforces that foundation.

Water reuse looks different depending on where you are. But the underlying challenge — securing water for the future — is shared.

In the US, indirect potable reuse (IPR) has been the dominant model. Projects like San Diego County’s surface water augmentation project and Orange County’s Groundwater Replenishment System are excellent examples of how we can scale water reuse reliably and efficiently.  More recently, direct potable reuse (DPR) is gaining ground, with states like Arizona and California adopting supportive legislation. During droughts over the past two decades, the US has leaned heavily towards potable reuse as its primary response.

By contrast, Australia has taken a different path. During the Millennium Drought, seawater desalination became a key strategy. But reuse has grown steadily, with landmark projects, like the Western Corridor Recycled Water Scheme in Queensland and Perth’s Groundwater Replenishment Scheme, are demonstrating the viability of alternative water supply solutions.   

Singapore offers another alternative. With limited land and no natural aquifers, the country had little choice but to innovate. The bold decision to invest heavily in NEWater, an IPR system that now supplies around 40 percent of national demand, was driven by necessity. It’s a case study in how constraints can sometimes drive ambitious planning and public engagement.

These examples show that there’s no single blueprint. What matters is matching technology to context and aligning infrastructure with community needs and regulatory frameworks.

Reuse involves a spectrum of technologies, each suited to different sources and regulatory requirements.

Current systems often combine:

• Wastewater treatment
• Ozonation and biofiltration
• Membrane bioreactors
• Ultrafiltration
• Reverse osmosis
• Advanced oxidation
  

These multi-barrier approaches are designed to meet stringent health standards, especially for potable applications. Log removal values are used to quantify pathogen and contaminant reduction, with some systems achieving >99 percent removal.

Our options are continuing to expand. Emerging technologies like algal turf scrubbers, nanobubbles, zero-liquid discharge systems, thermal hydrolysis and AI-driven optimisation are being trialled in regions like the Middle East. These innovations offer new ways to decentralise treatment and recover resources while cutting energy use. A growing trend involves upgrading existing wastewater treatment plants with membrane bioreactors before advanced treatment, rather than building standalone facilities.

Carbon-based advanced treatment trains are also gaining interest, especially in inland areas where brine disposal is challenging. By removing reverse osmosis from the process, these systems can reduce salinity without compromising safety.
Systems are becoming more flexible and efficient, with better integration into broader environmental goals.

Water reuse protects water security and is foundational to how we plan for the future.

The shift is happening now. Pilot projects are scaling into full programs, and what was once public hesitation is turning into community support. Fragmented efforts are giving way to coordinated strategies. The challenge is real, but so is the momentum.

For planners and policymakers, the next steps are clear:

• Treat reuse as a strategic asset, not a contingency
• Engage and educate the public sooner rather than later
• Match technology to context, not just cost
• Build regulatory clarity and cross-sector collaboration
• Share data and lessons learned globally — collaboration accelerates adoption.
  

Water reuse is a commitment to resilience and long-term thinking. The infrastructure we build today will determine how we’ll secure our future water resources.