How does testing water help us?

Testing water different ways can detect bacteria or other harmful objects in water. Many substances such as salt can dissolve in water and be unseen. Testing can prevent us from drinking salty water on a daily basis! Testing water can also help us find helpful objects in water. For example some nutrients that may be added in to other things to help the taste or purity. Testing water over all is one of the most helpful tests a scientist can do.