Potable Reuse
Potable reuse purifies treated wastewater to drinking-water quality, either by returning it to an environmental buffer (indirect potable reuse) or introducing it directly into the supply (direct potable reuse). California adopted DPR regulations in 2023.
Approach
Potable reuse relies on multiple independent treatment barriers plus extensive monitoring and operator certification. Full advanced treatment — ultrafiltration, reverse osmosis and UV advanced oxidation — is the widely validated core, sometimes augmented with ozone and biologically active carbon.
Singapore's NEWater program is the best-known large-scale reuse system; California's 2023 DPR framework and comparable efforts in Texas, Arizona, Australia and the Gulf mark the move from indirect to direct reuse as water scarcity intensifies.
- [1]Potable Reuse: Guidance for Producing Safe Drinking-Water. World Health Organization, 2017.
- [2]Direct Potable Reuse Regulations. California State Water Resources Control Board, 2023.