There are many different factors that affect water quality. Often these factors are related to each other. When we want to figure out if a body of water is “good” or “bad” quality, the best place to start is by making observations. In this lesson, we will learn what to observe and how to understand what we are seeing.
We can learn a lot about a stream, lake, or river simply by what we see. For our field work, we will begin by making observations and recording general data at the site. For more specific tests, we will collect samples of water to be taken back to the laboratory, but we will discuss that later.
When arriving at the site, take a moment to simply look around and write down a few notes about the environment around you. It is good to take note of the weather, and you can never be too detailed. Is it cloudy, overcast, or sunny? Is it hot or cold? Has it rained or snowed recently, or is your area in a drought? You don’t have to know everything, but the more you can observe, the better.
Next, look at the land around you. Is the water you are studying in an urban area surrounded by buildings and pavement, in a field, or surrounded by forest? Are there crops or herds of cows in the area? In later lessons, we’ll discuss why the land use surrounding the water makes a huge difference to water quality (refer to lessons on nutrients and bacteria).
Now, we are finally ready to examine the water! It is important to remember that no
body of water is an isolated system – virtually everything in the environment
can affect water quality. So the study of any body of water has to begin with a
study of the land surrounding it. This land is part of the lake or stream’s
watershed. A watershed is the area of
land where all of the water that is under it or drains off of it goes into the
Our first "test" of water quality is to use our senses to detect any odor in the water, look at it and see what color it is, and determine if there is any foam on the surface. Go to the Odor, Color and Foam field observations