Shreya Ramachandran, 17, of Fremont, California, was first inspired to learn more about water recycling in 2014 when she was visiting Tulare County in her home state. During that time, Tulare, a predominantly agricultural community, was facing a serious water shortage due to drought and climate change, leaving many residents’ wells (and irrigation systems) completely dry. That visit motivated Ramachandran to find ways to reuse gray water (water from sinks, showers and laundry machines) in her own household. 

Shortly after her visit to Tulare County, Shreya received a visit from her grandmother, who lives in India. She brought with her some soap nuts for bathing and cleaning. Native to India, soap nuts are small yellow or brown fruits housed inside a hard, brown shell. They are typically used for bathing, but can also serve other cleaning purposes. While using them to wash her hair, Ramachandran got the idea to use the soap nuts as a natural laundry detergent, and to reuse the water left behind for other purposes. 

Soap nuts are an effective and efficient cleaning agent. Four or five nuts in a cloth bag can clean a full load of laundry, and can be reused up to 10 times. Ramachandran had an idea that the leftover laundry water could be used to water plants since the soap nuts are 100% natural. 

After an intense research and planning phase, Ramachandran contacted professors at several universities in California, including University of California, Berkeley, to look over her project plan. Céline Pallud, a professor and environmental scientist at UC-Berkeley who studies soil, was impressed by Ramanchandran’s experiments, especially given that Shreya was only 12 when she conducted the research.

Ramanchandran performed thorough testing of the used laundry water on tall fescue, a type of turfgrass, and a variety of vegetable plants. She compared the effect on plants of used laundry water containing both natural and conventional soaps/detergents. Needing a space that mimicked a greenhouse, she kicked her own parents out of their master bedroom so that the plants would have the ideal lighting and temperature conditions. 

By tracking the levels of various nutrients and bacteria in the soil, Ramachandran found that the gray water from the soap nuts and from several organic laundry detergents could be safely reused to nourish the plants. The gray water from conventional detergents, however, contained salts and boron that were not safe for plant irrigation. 

Ramachandran’s research shows that gray water free of harsh salts and chemicals can be safely used for other purposes in the average household. It is the basis of the nonprofit that she founded, The Grey Water Project, which aims to teach people how to recycle gray water in their own homes. Through workshops and a science curriculum, Shreya spreads her knowledge and research at libraries, schools, and even corporate events. 

Ramachandran, who is now a senior in high school, plans to continue her studies of biology and environmental science in college. She would also like to study public policy so that she can learn ways to implement the types of research she conducts. Ramanchandran was named a global finalist in the 2019 Google Science Fair, and is a part of the PBS climate change documentary, The Power of Us.