How do you make wastewater drinkable? It starts at the sewage treatment plant. Ongoing droughts are straining the supply of clean drinking water. One solution might lie in an unexpected source: wastewater. Through a method of purification called reverse osmosis, Orange Country is making millions of gallons of dirty water drinkable again. Follow on social for more NOVA content! Twitter: https://twitter.com/novapbs Instagram: https://www.instagram.com/novapbs TikTok: https://www.tiktok.com/@novapbs This excerpt from a NOVA documentary is made possible by viewers like you. Support your local PBS station here: https://pbs.org/donate/