Continuing the theme of talking about the Engineering Grand Challenges, today I'd like to talk about water.
Another of the Engineering Grand Challenges is to provide access to clean water. It helps to begin with discussing the water cycle. Here's a little song about it:
In the Sci-Quest Sprouting Scientists program, my preschooler made water cycle bracelets. The activity sheet in the link suggests using this book:
In most of the USA, we are blessed with running water. In developing countries, young girls often begin their day fetching water to bring back home. Water.org states that on average girls and women travel 3.7 miles a day to fetch water for their families. The chore takes so much time that girls drop out of school.
Here is a Ted.org video suggesting a partial solution, a way to decontaminate existing water.