water, safe or sick?
By Paige Banks
Elementary Category (Grades 4-6)
Experiment | Biology, Environment
BCVSF Note: The required ethics forms have been submitted for this project.
I became interested in water safety when I was at school. No one drinks from the water fountain upstairs because it tastes metallic, and there is a green stain around the drain. I did some research on water safety and then emailed the CRD water station, who invited me for a tour. I learned about water safety guidelines, and they connected me to the lab that they use, who offered to test the water at my school. When the results came back we found that the water from that fountain had high copper levels; this explained the weird stain and the taste. The levels were high enough to cause a bad taste but not high enough to be dangerous. I wondered how good people are at being able to predict if water is safe before consuming it, and can we use water filters to make it safe? My hypothesis was that we can’t trust our senses or our filters to detect safe water. My project tested this idea by preparing various samples of both safe and contaminated water, and having participants check to see if they could correctly guess which water was safe, using only their senses of sight and smell. I also wanted to see if most common filters removed these contaminants enough to make them safe. I used ‘JNW Direct’ Drinking water strips to test each sample to confirm that the samples actually had contamination. I wrote the contaminant name and amount on the jar, then covered it up with tape so that my test subjects didn’t know what was in each jar and neither did I.
Once I finished, I ran the samples through a commercial under-counter filter and a Brita filter; the Brita filter did not work as well as the under counter filter, but neither really worked to fully purify the water. I noticed that when water obviously looked cloudy or colored, or had a strong smell, people assumed it was unsafe. My results show that 70% of people guessed correctly on the unsafe samples. And 50% of people guessed the safe samples correctly. This shows that water can taste, smell and/or look bad but not actually be bad. I also learned that water might not smell, taste and/or look bad but actually be very harmful.
People get their water from different sources,including large reservoirs, wells, and even streams. Whatever the water supply, it should be reliably tested and treated. As we noticed with the upstairs water fountain, we cannot trust our senses to protect us from contaminated water.