We might not be able to use Martian water after all
 

Back in 2011, NASA's Mars Reconnaissance Orbiter spotted dark streaks running down canyons and hillsides on the red planet, which indicate the presence of water. That was a cause for celebration, as having water on Mars means astronauts won't have to...

https://www.engadget.com/2016/07/10/...not-drinkable/