Fight Bac ! Put a Stop to Harmful Bacteria
Pollution comes in many forms . Metals , dirt , litter and chemicals are a few of the items that make their way into our waterways . But there is another kind of living pollution : bacteria .
It turns out “ The Contaminator ” thrives on it . Bacteria are single cell organisms that exist everywhere . As many as a million bacteria may live in a milliliter of freshwater .
The good news is that not all bacteria are bad for you . Beneficial bacteria are used to make cheese and yogurt among other things . Water treatment plants use bacterial processes to help clean water .
The bad news is that some forms of bacteria can be deadly , while others can make you sick .
The U . S . Environmental Protection agency looked at a typical suburban area . The area streams and lakes were deemed unfit to drink or swim in due to bacterial contamination .
About 40 % of the watershed was covered with surfaces — roads , homes , walks , parking lots — that don ’ t absorb water .
The area didn ’ t have any manufacturing facilities or farming operations to blame for the pollution , but there were high levels of Escherichia coli , also known as E . coli , in the water .
This strain of bacteria lives in the intestines of humans and other warm-blooded animals , and many birds . Because each warmblooded species has a unique DNA fingerprint , scientists can examine DNA from the E . coli and link it to the animal that produced it . Then they will know which animals are responsible for the bacteria in the waterways .
The first suspects were dogs . In a suburban setting of 20 square miles , the scientists estimated that dogs contributed about 5,000 pounds of droppings every day .
The pie chart shows the levels at which each species was contributing to the contamination . Using your knowledge of runoff pollution , develop a plan that would help reduce pollution by these animals .
Be creative ! You can make this suburban area similar to where you live or make up an entirely new city .
6 % 6 %
19 %
14 %
E . coli Sources
20 %
33 %
Waterfowl Raccoon Human Canine Deer Other
For each part of your anti-bacteria plan , list the possible objections and problems your plan might encounter during a city council meeting .
Ground Water on the Move
You can ’ t see it , but hundreds of thousands of people in Colorado depend on water below the ground for drinking water and growing food .
The water is contained in aquifers , which are underground layers of waterbearing rock , gravel , sand , silt , or clay from which ground water can be usefully extracted using a water well .
This water is part of the water cycle . Some aquifers are recharged by melting snow and runoff . The water moves through the layers of the soil . Sometimes the soil provides a filtering effect , absorbing chemicals and excess nutrients that could harm clean water supplies .
Ground water can also become contaminated . Using our E . coli example , mismanaged septic systems can put excessive amounts of bacteria in the ground water , which in turn can make its way to local waterways . This is particularly true when you have a concentration of homes in an area with high ground water . For example , summer cabins around a lake .
Old mine shafts can also cause problems . Water moving through the ground can encounter minerals and metals that otherwise would be held in the rock .
Mining for oil and natural gas has the potential to harm ground water , but modern mining is regulated to protect ground water supplies .
14 Watershed Defenders produced by Colorado Agriculture in the Classroom