Where is the water on Earth? Soil treats all groundwater. Water in the environment is filtered

Soil is critical to our food, fiber, and shelter. It also plays an important role in the cycling of another essential item: water. The amount of water on Earth is constant--there is no loss or gain of it. And only a small portion of that finite amount (approximately 1%) of water is usable for drinking. How does this water remain clean enough for us to drink? You might think it’s because we treat it before we drink it. While this is true in many urban or suburban areas, many people worldwide get their drinking water from groundwater. This groundwater is often not treated before people drink it. Instead, it is treated by the soil. As water infiltrates and percolates through soil, the soil’s chemical, biological, and physical properties clean the water by removing contaminants. This means that soil is perhaps the largest single water (and wastewater) treatment plant in the world. Soil helps keep water clean by filtering it.