PureWaterSF: PureWaterSF: Direct Potable Reuse Demonstration in San Francisco

The San Francisco Public Utilities Commission (SFPUC) is a leader in the innovative and sustainable use of water in an urban setting. Currently, SFPUC uses a constructed wetland system to treat the wastewater generated in its headquarters building for non-potable reuse. PureWaterSF will add to the existing system a direct potable reuse (DPR) building-scale demonstration system that includes ultrafiltration, reverse osmosis, and an ultraviolet advanced oxidation process (UF/RO/UVAOP) to purify the tertiary recycled water effluent from the wetland system. The treatment train was designed and selected to have a small footprint and produce high-quality water that meet every regulated drinking water standard and standards detailed in state and national DPR guidance documents, providing treatment for CECs and “unknown unknowns”. During the study, the treated water will be redirected to the non-potable reuse system.PureWaterSF focuses on the latest concerns and research challenges for direct potable reuse in California. The State Water Resources Control Board expert panel recommended the use of non-target analysis (NTA) and bioassays to better understand the significance of the “unknown unknowns.” During 9 months of extensive testing, PureWaterSF will continually monitor the process using precise, on-line real time monitoring tools. This project will leverage the ability to document on-line real time precise and accurate data and the use of advanced analytics to understand the impact of the “unknown unknowns” and well as look at surrogates for assessing treatment performance.The results from the PureWaterSF project will build on a body of knowledge and will provide valuable information about the reliability of advanced water treatment systems for potable water reuse, in particular for Direct Potable Reuse. Finally, the viability of DPR at a building scale will be demonstrated while educating the public on the importance and safety of potable water reuse.