To identify the substances present in a stream or lake, scientists collect samples of the water, living organisms, and suspended and bottom sediments. Then, technicians analyze these samples in a laboratory with specialized instruments and procedures. State-of-the-art analytical instruments can detect down to one part per trillion of some substances. This is comparable to tracing one thousandth of a teaspoon of salt dissolved in an Olympic-size swimming pool!

More information about water quality can be found in these Fact Sheets:

• Monitoring Water Quality


• Water Quality Summary for Grand Traverse Bay


• Monitoring Programs