With climate change threatening freshwater sources, water demand across the globe is likely to increase by 20 - 30% between now and 2050. In this episode, we’re looking at two promising solutions to create clean drinking water from surprising places: our sewers and our oceans. We speak with General Manager of the Orange County Water District, Mike Markus, about debunking the “toilet to tap” fear and how turning our wastewater into clean drinking water can be a closed-loop solution to mounting water scarcity. We also hear from Dr. William Tarpeh about new research at Stanford University that could make desalination a more viable solution; one that’s less costly and better for the environment. Biographical Notes: Michael (Mike) R. Markus is the general manager of the Orange County Water District (OCWD; the District), which manages the Orange County Groundwater Basin that supplies water to more than 2.5 million people in north and central Orange County, Calif. During his 33-year career at the District, Mike has been responsible for managing the implementation of the $480 million Groundwater Replenishment System (GWRS) program. This project is the largest potable reuse project in the world and has won many awards including the 2008 Stockholm Industry Water Award, 2009 ASCE Outstanding Civil Engineering Achievement Award, 2014 U.S. Water Prize and the 2014 Lee Kuan Yew Prize.  Dr. William Tarpeh Dr. William Tarpeh is an assistant professor of chemical engineering at Stanford University. The Tarpeh Lab develops and evaluates novel approaches to resource recovery from “waste” waters at several synergistic scales. Will completed his B.S. in chemical engineering at Stanford and his M.S. and Ph.D. in environmental engineering at UC Berkeley, supported by an NSF Graduate Research Fellowship, Ford Foundation Predoctoral Fellowship, and a UC Berkeley Chancellor's Fellowship. Will conducted postdoctoral training at University of Michigan in environmental engineering. Will is a member of the Bouchet Honor Society, NBCBLK's "28 Under 28" African-American Innovators, and Forbes' "30 Under 30" 2019 Science List. His CV is available here.