In Singapore, one brewery has used treated wastewater to make craft beer since 2018. This is a prime example of how innovative water management can reshape perceptions and demonstrate the feasibility of recycled water.

There are currently two approaches to recycle wastewater into drinking (or potable) water.

Indirect potable recycling (IPR) adds highly treated wastewater to ground water supplies, rivers or reservoirs. This offers longer-term environmental buffering and mixing of the water. In San Diego, the Pure Water recyling programme aims to provide half of the city’s water by 2035. In Austin, the GoPurple on-site water recycling initiative will save 22 million litres of drinking water a day by 2040.

Direct potable recycling (DPR) adds highly treated wastewater directly to the distribution system. In Windhoek, Namibia, the Gammams wastewater treatment plant has been producing scientifically validated, high-quality drinking water since the early 1960s. But there are fewer examples of this “toilet-to-tap” approach globally.