Water Bottle Safety Science Fair Projects

Bacteria and Water Bottles

Reusable drink containers are much better for the environment than disposable ones are. However, they do pose a few health risks that you can examine in a science fair project. For example, why not see how many bacteria develop on your water bottle if you do not wash it after you use it.

PURPOSE

My purpose is to show that the bacteria content does increase in a water bottle when it is not properly washed between uses. In the summer during swim team, I see my teammates fill the same water bottle every day for the whole season. They do not wash the water bottles as evidenced by the lip-gloss colors that don’t go away. The water bottles are stored in their swim bags with moldy dirty towels or they rattle under the seats of their parents’ cars. Also I am doing this experiment in the winter when the temperatures are cooler and bacterial growth tends to be slower than during the hot summer months. If the bacteria do grow in my experiment, the bacteria growth could be greater during the summer months.

My sister’s first grade class uses water bottles in the classroom. I know that my sister does not always take a new water bottle as she is instructed. In addition she just tosses the water bottle in her backpack with her snow boots and everything else, regardless of what we tell her. I know her classmates are probably no different than her.

I would like to prove my hypothesis so I can teach others that their water bottle can make them sick if they don’t take precautions to protect themselves.

HYPOTHESIS

I hypothesize that the bacteria content will increase in just a few days when you drink from a water bottle without washing it prior to filling the water bottle.

EXPERIMENT DESIGN

The constant in this study were:

• The brand and the amount of water in each of the water bottles.
• The type of agar and agar plates.
• The incubator.
• That you use a new bottle each time you refill the test subject’s water bottles
• How the bacteria colonies were counted.
• The amount of days each subject drank from their individual water bottle

The responding variable was the amount of growth of the individual samples.
To measure the responding variable I counted the number of colonies in the petri dishes after they had been incubated.

MATERIALS

16 Kirkland brand water bottles, 16.9 fl.oz. (0.5 L)
1 Sharpie marker pen
6 Gallon size Ziploc bags
1 Comet cleanser
1 Liquid dish detergent
1 Roll paper towels
1 Lab coat
12 Vials BHI agar slants, 10 ml. each
1 Metal container to melt BHI agar in
1 Bunsen burner
6 Nalgene filtration units. (115 ml capacity)
1 Pair of hot pad gloves
1 Trivet
1 Vacuum to filter the water
6 Petri dishes
1 Sterile scalpel
1 Pair of forceps
6 Disposable inoculating loops
1 Container with Stat III disinfectant
1 Incubator to incubate the bacteria
1 Stat lll liquid disinfectant
1 Hibiclens cleanser
1 Autoclave

Water bottle safety science fair projects continues at sanitary water bottles scifair projects.