Have you ever wondered how we make sure our water is safe to use? One important measurement is turbidity. Turbidity is related to the cloudiness of a water sample.
In this lesson, we’ll learn about water quality and why turbidity is important. We’ll explore how light can help us measure this property of water, and ultimately, monitor water cleanliness. You’ll even design and build your own working turbidity meter!

Global Goals & Indigenous Perspectives
This lesson supports the United Nations Sustainable Development Goals (SDGs), 17 goals designed to make the world a better place. Specifically, we’ll focus on:
- Goal 6: Clean Water and Sanitation (ensuring access to clean and safe water for communities)
- Goal 14: Life Below Water (protect aquatic ecosystems and the life within them)


To fully achieve these goals, it’s crucial to integrate diverse knowledge systems. The American Indian Science and Engineering Society (AISES) emphasizes that for many Indigenous cultures, the relationship with water and the environment is deeply significant. When we discuss clean water, we consider not only scientific measurements, but also the profound impacts on ancestral lands, cultures, and ways of life.
