Toward Safe Water for All
Dr. Sam Ying is an associate professor of biogeochemistry at the University of California, Riverside, with a passion for equitable water access. She is a friend and colleague of the department's Dr. Josh Lemonte, who introduced her as an "exceptional scientist and presenter" and described her work as the "intersection between geochemistry, biology, and environmental justice." She came to BYU on November 11th to present about her work and tell a story of how geology has helped real people live better lives.
Dr. Ying runs what is called the "Dirty Lab" at UC Riverside, which was created to test the water safety in impoverished communities and ensure that they have access to clean drinking water. California has one of the fastest decreasing supply of groundwater—a significant problem in an area where groundwater comprises up to ninety percent of available clean water. To maintain this natural resource, a process called groundwater recharge is needed. This procedure involves diverting rainwater into large recharge basins, where it can seep into the ground rather than running into the ocean. However, these basins are located on agricultural land, which often contains deadly amounts of nitrate from fertilizers, far more than what a person should consume. To fix the issue, they layered the basins with woodchips that were exceptionally effective in absorbing nitrate. Problem solved, right? Wrong.
In the late 1960s, Bangladesh had the highest infant mortality rate in the world due to unclean drinking water. After a worldwide fundraising effort, hundreds of thousands of wells were installed. The infant mortality rate decreased, but the level of arsenic poisoning skyrocketed. You see, in Bangladesh, floodwaters kill the vegetation during the wet season, putting vast amounts of carbon into the soil. The carbon breaks down metals in the soil, releasing arsenic and manganese into the groundwater. Halfway across the world, testing revealed that California was accidentally artificially adding these contaminants through the woodchips in their efforts to keep out nitrate.
Dr. Ying discovered that most of the manganese came from a lack of oxygen and a greater increase in carbon in the woodchips during the wet season. Oxygenating the basins through aeration, combined with faster filtration in the soil, would be able to mitigate the high concentrations of metals. This solution is notably exactly opposite of what is currently recommended for nitrate management. To avoid the situation altogether, Dr. Ying suggests relocating all recharge basins from off of agricultural land to avoid nitrate contamination in the first place, removing the need to add woodchips at all.
On a national level, arsenic concentrations in water are highly regulated, but manganese is classified as a secondary contaminant, meaning there is no official restriction on its permitted amount. Additionally, arsenic collects deep in the ground at the level that large public wells typically draw their water from. Yet, shallower private wells that supply smaller communities draw water at the level where manganese is more common. Arsenic levels are always monitored, but manganese is almost completely neglected. These issues are especially problematic for the ninety percent of domestic well users who live in disadvantaged communities and who have much less sampling data.
One such at-risk community that Dr. Ying's team works with is the Polanco's, a series of trailer parks in Southern California home to thousands of immigrant farmers. Though only a mere five miles from the affluent Palm Springs, Polanco families suffer far more from climate change and water availability. In the past, obtaining clean water has involved continued water testing for each individual home—an expensive and arduous process. Together with engineers and local community members eager to improve their situation, Dr. Ying and the team have developed a far more efficient method for testing, called the Ottersampler. The device is simple and easy for community members to use themselves, allowing for better, more immediate results. Local artists help raise awareness for the entire community by illustrating comics that instruct people on how to use the Ottersamplers.
Through her research and the success of the Ottersampler, Dr. Ying hopes to close the climate gap for the 2.2 billion people worldwide who still lack access to clean drinking water. Ying encourages people everywhere to educate themselves about water inequality in their area and bring it to the attention of local policy makers.