Definition

Ground water occurs when runoff and precipitation seep through the soil and are collected in underground reservoirs called aquifers. Aquifers can be a few hectares to thousands of square kilometres in area, and a few metres or hundreds of metres deep. Ground water is the technical name for well water.

Ground water comes in two general forms: deep and shallow.

Deep ground water is less susceptible to contamination from natural and human sources and generally does not need treatment for biological hazards.