2019Waterqualitychemhero

Academics, Upper School

Exploring the Science of Water Quality

Poor water quality and contamination poses a health threat to many people around the world. Examining that issue, Northwest 11th graders engaged in a comprehensive unit studying the science behind metal ions in water and the ramifications of the health issues that can result from tainted water. This included the recent water crises in Flint, Michigan.

“By talking about the Flint water crisis and looking at the environmental racism that happened there, we can create empathy and understanding,” says chemistry teacher Olivia Heeter. "This allows students to realize just how important clean water is in life.”

To begin the unit, students collected water from all around Seattle, excluding tap water, and, using test strips, looked at a variety of the ionic compounds that are in the water. Students read the annual Seattle Water Quality Report and examined if their water samples had any measurable substances above what the Environmental Protection Agency considers safe levels. Then, students created a mock news report to detail their findings.

Olivia and fellow chemistry teacher Clare Prowse invited alumnus Rad Cunningham ‘97, a senior epidemiologist with the state of Washington Department of Health, and Dr. Shirlee Tan, a toxicologist at King County Public Health, to showcase how public policy and government agencies fit in with the science students learned. Rad discussed the history of “acceptable” lead levels and how they have dropped throughout the past century, specifically noting the correlation between higher blood lead levels in low-income communities as a product of systematic racism in the United States.

After watching a film about the Flint water crisis and discussing it as a class, students moved onto the culminating lab—testing lead levels in water. Olivia and Clare gave the students a mandate: Determine what is the best corrosive inhibitor for removing lead ions from water. Students created their own tests with controls and constants to arrive at their conclusions.

Sophie R. ‘21 and her group decided to test four different anions: phosphate, sodium silicate, sodium sulfate, and activated carbon. Sophie had read about using activated carbon as a home remedy, and, surprisingly, their group found that the activated carbon was as effective as the sodium sulfate. For Sophie and other students, the application of the science helped them fully comprehend the effects of lead in water.

“Seeing the water samples physically on the test strip and the high amounts of lead is very tangible,” says Sophie. “We can read stories about people in the news, and we can try and empathize, but this lab helped hammer home the severity of the issue.