Orange County shows how water recycling moves from idea to impact—linking history, science, and workforce to make reuse mainstream.

At Irvine Ranch Water District, Paul Cook explains how a simple visual breakthrough—the now-iconic purple pipe—was created in the 1980s to clearly mark recycled water and build public trust, a standard that spread across California and the world.

At Orange County Water District’s Groundwater Replenishment System, Mehul Patel traces the lineage from Water Factory 21 to today’s 130-MGD advanced purification that protects a coastal aquifer, pushes back seawater intrusion, and supplies enough water for about a million people. Research and innovation lead the way: Megan Plumley spotlights OCWD’s lab and pilots tackling energy use in RO, improving membranes and spacers, and continuously monitoring for PFAS, microplastics, and other emerging contaminants—evidence that potable reuse is built on decades of science, not slogans.

The future depends on people as much as plants. At Moulton Niguel Water District, Joone Kim-Lopez lays out the skills needed for direct potable reuse—high-level certification, data literacy, and creativity—while sharing how partnerships with colleges are creating new training pathways.

This episode is part of The Golden State of Reuse, a series exploring the past, present, and future of water recycling across California, showcasing the people and projects redefining how water is used again and again. 

The series is a collaboration with WateReuse California and sponsored by CDM Smith.

The series is also supported by the Sacramento Area Sewer District, Black & Veatch, and Monterey One Water.

waterloop is a nonprofit news outlet exploring solutions for water sustainability.