What is direct potable reuse of water?

Direct potable reuse provides a reliable water source to supplement traditional ones. By diversifying their water suppliers, communities can strengthen their resilience and become less vulnerable to droughts, the impacts of climate change, and other factors affecting water availability.

Water conservation is also improved by direct potable reuse. Instead of relying solely on limited freshwater supplies, communities can use treated wastewater that would otherwise be discharged into rivers or oceans (and thus also avoid polluting them.) This approach reduces strain on existing water supplies and promotes a circular and more efficient water system.

Since direct potable reuse uses wastewater, it needs advanced treatment technologies such as filtration, reverse osmosis, and disinfection. These methods effectively remove impurities and produce high-quality water, often removing even more pollutants than conventional drinking water treatments.

However, while there is an initial investment in implementing direct potable reuse systems, they offer long-term cost benefits. By recycling wastewater, communities can reduce the need for expensive infrastructure projects, such as constructing new reservoirs or importing water from distant sources.

DPR is widely popular in areas with water scarcity, where water resilience is essential for the community. Although it may seem like a novelty approach, direct potable reuse has been in practice for many years, like the case of Windhoek, Namibia’s capital city, which has applying direct potable reuse since the 1960s. The city employs a multi-barrier approach that combines modern treatment technology with natural processes like soil aquifer remediation.

Direct potable reuse has reduced Windhoek’s dependence on distant water sources and helped establish a sustainable water supply. Another example is Big Spring, Texas, which has endured severe drought conditions and has relied on DPR for the last decade. In 2013 they constructed an advanced treatment facility that purifies wastewater to meet drinking water standards, thereby increasing the city’s overall water supply and enhancing its resilience.

In response to persistent water scarcity, the city of Perth in Australia implemented the groundwater replenishment scheme in 2017. This plan uses advanced water-treatment processes such as reverse osmosis and UV disinfection to filter wastewater. The treated water is stored in aquifers before being extracted for drinking. The project successfully reduced reliance on rain-fed sources and established a reliable water supply.

As we strive to enhance global water resilience, it is crucial to consider all options and include diverse perspectives. At GHD, we recognise that direct potable reuse will become increasingly common, particularly where there are insufficient environmental buffers or cost constraints.

Furthermore, as we strive to create viable solutions for sustainable and thriving communities, we need to consider the direct potable reuse of water as one of the key factors for long-term water sustainability and resiliency.

We assist our clients with a range of water services, including the following:

• Aquatic science
• Water treatment and desalination
• Water collection and distribution
• Wastewater treatment and recycling
• Maritime and coastal engineering
• Hydrology and hydrodynamics
• Hydrogeology
• Future of water services
• Dams

To learn more about how we can help you consider and manage direct potable reuse of water and other water services, please visit our water expertise and services page on the GHD website. Together, let’s deliver safer water-supply solutions to every community.

Articles referenced

^{Environmental Protection Agency 2023, ‘Potable water reuse and drinking water’, retrieved June 27, 2023, from https://www.epa.gov/ground-water-and-drinking-water/potable-water-reuse-and-drinking-water}

^{Lahnsteiner, J., van Rensburg, P., and Esterhuizen, J. 2018, ‘Direct potable reuse — a feasible water management option’, In Journal of Water Reuse and Desalination, retrieved June 27, 2023, from https://iwaponline.com/jwrd/article/8/1/14/38008/Direct-potable-reuse-a-feasible-water-management}