This lesson was developed by Heidi Mehl
Bacteria are found everywhere. Even though bacteria have a bad reputation, most are completely harmless, or even helpful! They help us digest our food and fight off some illnesses. Bacteria are used in recycling and clean-up of environmental disasters like oil spills. Our world would not be able to survive without bacteria.
When we think about bacteria polluting our rivers and lakes, it is usually fecal coliform bacteria. Fecal coliform is a group of bacteria found in the intestines of warm-blooded animals (like us as well as cows). When large amounts of fecal coliform bacteria are present in water, it means that the water is being contaminated by some source of manure or other animal waste. It also indicates the possibility that disease-causing organisms could be present.
The fecal coliform group contains many types of bacteria that are not harmful to humans. When you do a test for total coliform bacteria, it doesn't necessarily mean that the bacteria will be bad for you.
But the fecal coliform group also includes a type of bacteria called Escherichia coli (E. coli). Whenever you hear about people getting sick from bacteria in drinking water, or from eating an undercooked hamburger, it is usually E. coli that is causing the illness. A water sample that tests positive for fecal coliform may also be positive for E. coli, and so the water should be treated or boiled before it is used as drinking water, otherwise you could get sick.In Kansas, the biggest contributors of fecal coliform bacteria to rivers and lakes are livestock, especially those that have a large number of animals in a small, confined area. Anyone who has been on a farm knows that cattle and other livestock produce large amounts of manure. Rain water washes this manure into our rivers, streams and lakes, carrying with it fecal coliform bacteria from the manure. Manure also contains the nutrients nitrogen and phosphorus, so manure is doubly bad for our rivers and lakes (bacteria + nutrients). Other sources of fecal coliform bacteria include wildlife populations (like deer), and leaky septic systems from people's homes that haven’t been well-maintained. Pet waste can also be a problem in cities, which is one reason you are asked to collect it when you walk your dogs on city streets.
Our drinking water is treated to remove bacteria before it comes through our taps in our homes. The problem is, everything that is removed from water costs money, and that money is paid by you and your family through taxes. So the more polluted the river or lake is, the more it costs to purify it before you drink it. The more we can reduce the pollution in our water, the cheaper it will be to make it suitable for us to drink.
One way to help keep our water clean is to plant "buffers" of native trees and grasses between livestock fields and streams to help filter out the manure before it reaches the river or lake. Some farmers build retention ponds to catch and isolate the runoff before it reaches drinking water sources like the Kansas River or Clinton Reservoir. It is also important to maintain rural septic systems, which can become cracked and leak over time. We must all work together as a community to reduce the amount of bacteria in our rivers, lakes, and streams.