The Orange County Water District (OCWD) has received $400,000 from The United States Bureau of Reclamation (USBR) Desalination and Water Purification (DWPR) program for a two-part water reuse study. OCWD, a world leader in water reuse, is a California special district that manages the groundwater basin for 2.4 million community residents of north and central Orange County; delivering 75 percent of the water supply.
OCWD’s director of research and development (R&D), Dr. Megan Plumlee, is the project leader. A study of N-nitrosodimethylamine (NDMA) in water quality is part of the project and will be conducted in collaboration with three universities. San Diego State University, with Dr. Eunha Hoh and Dr. Nathan G. Dodder, is among the university collaborators for the NDMA water quality study. NDMA is a disinfection byproduct that can be formed during or after water treatment from reactions of NDMA precursors. Understanding their sources and fate is critical to preventing NDMA formation. The project team will use advanced new methods known as “non-targeted” analysis via mass spectrometry to identify new NDMA precursors, and will determine strategies for reducing the amount of NDMA formed post-treatment, among other tasks.
The OCWD operated wastewater reclamation project for indirect potable reuse (IPR) aims “to increase local water supplies and protect the groundwater basin it manages from seawater intrusion.” OCWD manages the largest water reuse project of its type, the Groundwater Replenishment System (GWRS), serving local and international communities in exploring comparable projects to generate long-term water security. GWRS “puts highly treated wastewater through a three-step purification process consisting of microfiltration, reverse osmosis (RO) and ultraviolet advanced oxidation process (UV-AOP) to produce near-distilled quality water that meets or exceeds state and federal drinking water standards.”