This year’s Monterey County Science and Engineering Fair fell on a partly cloudy weekend in early March sandwiched between two El Nino storms. But that did not stop nearly 500 middle and high school students from gathering in the University Ballroom at California State University, Monterey Bay. Nor did it stop a team of judges from searching for this year’s winner of the “Water For Our Future” award.
This special water award is co-sponsored by Stanford’s Hopkins Marine Station and CSUMB’s Watershed Institute. It recognizes projects that find ways to solve a water shortage at home, at work (school), or on the farm. Of 330 posters presented at the fair, 29 were identified as “water-related.” Of these, 11 were short-listed for our award. Among these projects were topics ranging from seawater desalination to aquaponics; from the benefits of worms to improve soil porosity to assist groundwater recharge to the use of drones to measure crop cover, which can reduce the need for irrigation. After reading through hundreds of titles and dozens of posters, one project emerged as the unanimous winner.
This year’s Water For Our Future award goes to 8th graders Katherine Dean and Dilan Patel from Carmel Middle School. The title of their project: GOT DESAL?
Katherine and Dilan were motivated to study seawater desalination out of concern for water shortages impacting not only California, but throughout much of the world. Because 97% of earth’s water is contained in salty seas, why not make use of seawater to meet future water demands? However, removing salt with modern methods such as reverse osmosis is costly. These students wondered if there were other alternatives.
During their literature research, Katherine and Dilan discovered how ancient civilizations desalinated seawater with virtually no cost at all. For example, ancient Greek sailors would place buckets of seawater beneath sails. As the sun heated the buckets, fresh water would evaporate and condense as droplets on the cooler sails. In time, the sails would drip with fresh water, which was collected for sailors to drink. By harnessing the power of the sun, ancient seafarers obtained low-cost fresh water from the ocean.
Our students searched online for information to build a solar desalination device (check out ScienceBuddies.org). They began with a light-colored plastic container as their seawater bucket (or reservoir). Because they knew heat energy from the sun was best absorbed by darker colors, they wondered if the solar device could be made to produce more water if they darkened the color of the reservoir. They decided to test this idea by placing white, black, blue, and brown papers beneath the plastic reservoir.
Katherine and Dilan repeated their experiment three times for each color. I have taken the liberty to reproduce their results, with error bars, on the graph below. The error bars outline the variability across all three trials. Each bar represents two standard deviations of the variance, also known as the 95% confidence interval, which scientists use to support or reject hypotheses. Because the black paper consistently produced the same amount of fresh water for all three trials, there is no variability in that data for the error bars to show.
The graph clearly shows that the black paper consistently produced the most water. The brown reservoir appears to be second best. However, look closely at the error bars. You will notice that the brown error bars overlap with those of both white and blue. This overlap tells us that there is too much variation in the data to conclusively say brown is better at producing water than either blue or white. In fact, this experiment would need many more trials showing the same trend before we could statistically support that statement in a scientific study. Meanwhile, none of the error bars overlapped with the black bars. Therefore, we can say that the results support the hypothesis that the black paper beneath the reservoir produces significantly more water than the other colors. This is what Katherine and Dilan concluded.
Congratulations to Dilan and Katherine, their parents and teachers, and the many other students who undertook water projects at the science fair this year!
A Special Thanks To Our Judges:
The science of water is a huge, multidisciplinary field encompasses fields of study for land, sea, and atmosphere. This year, I was happy to welcome four graduate students from CSUMB’s Watershed Institute and Stanford’s Hopkins Marine Station to help judge a wide variety of projects for this award. These Master’s and Ph.D. candidates volunteered their time and expertise in hydrology and ocean science. They sorted through hundreds of titles, contemplated a broad range of hypotheses, interviewed dozens of students, and thoughtfully discussed the merits of each project before deciding on a winner.
This year for the first time, I was able to mentor these graduate student while they took on the role of mentoring our youngest scientists. On that weekend, for the first time in a long time, the high Sierras were covered in snow. The hills of Monterey County had turned a lush shade of green. Even the Carmel River was flowing with a rush down the watershed to the sea, all thanks to an ocean-driven El Nino event causing atmospheric rivers of rain to rumble ashore and rejuvenate the land. And for the first time that I can recall, three generations of scientists assembled together under one roof to discuss the future of water in California while sharing their perspectives of both land and sea.