Each week, Atlas Obscura is providing a new short excerpt from our upcoming book, Wild Life: An Explorer’s Guide to the World’s Living Wonders (September 17, 2024). Gruba Kaśka is one of Warsaw’s largest water filtration plants. Every day, it pumps tens of millions of gallons out of the Vistula River and through taps across Poland’s capital. Each drop is guaranteed by the plant’s unusual quality-control team: freshwater mussels hooked up to a computer. The concept is simple. All kinds of pollutants can sneak into drinking water: Heavy metals seep…
