Soil is the key to pure water.
Soil works as a physical strainer, a biochemical renovator, and a biological recycler of all wastewater passing through it. Besides a mix of sand, silt, clay, and organic matter (humus), each teaspoon of rich soil contains a million to a billion bacteria, hundreds of thousands of protozoa, up to a hundred thousand or more algae, and up to millions of fungal strands.
The soil community eliminates pathogens, turbidity, and most color and taste problems in water in five ways:
- Soil harbors creatures that out-compete the pathogens for food, as well as protozoa that prey on pathogens.
- The soil, bacteria, and fungi produce antibiotics that poison pathogens (penicillin is produced by a soil mold).
- The soil's clay adsorbs viruses and other potential pollutants, and the water-repelling surfaces adsorb uncharged particles that could degrade drinking water supplies.
- Soil's texture and structure act as a physical strainer.
- The soil's moisture, temperature, acidity, and nutrient conditions are so different from those of the host that excreted the pathogens that they simply die.