Especially since the population will only continue to grow, it’s important to fulfill this basic need. Luckily, the Sehgal Foundation has come up with an insanely easy and simple way to alleviate some of the problem. Their new recharge wells are simply taller, taking advantage of hydrostatic pressure to create a well.
When liquids are confined to narrow space that are long in length, like a tube, it increases the pressure. This is called capillary action. A good example of this seen in everyday life are paper towels. If you take a paper towel and just dip the corner in a puddle of water, the water will spread to more of the towel. Capillary action is a fundamental principle of physics, and it is especially wonderful when innovation can be gleaned from old concepts and shows the power of creativity in science.
The civil engineers at the Sehgal Foundation, an Indian non-profit that has been around for sixteen years, improved on the recharge wells already used in India. Recharge wells take rainwater and “push” it back underground where it can be safely stored. However, in rural India, most of the underground water is too salty for humans to drink and they have been struggling with contamination problems.
The recharge wells are tubes that stick out of the ground to redirect the water. The increased hydrostatic pressure from the longer tubes creates a pocket of fresh water at the bottom, preventing it from mixing with the salty water. A hand pump will deliver the liquid to the surface.
Simple, efficient, and innovative. If only all problems could be solved this easily.
Image (c) Seghal Foundation