Surface Water

Surface waters are constantly moving through the water cycle as they move downstream rivers or evaporate, condense, and precipitate. This means that a once polluted body of surface water can often be restored, reducing the amount of future treatment it needs. The same is not true of groundwater. Groundwater is water that fills the small spaces between loose soil and rock particles or in cracks in the bedrock and can be hundreds of thousands or even millions of years old. If this water gets contaminated, it is impossible to clean it at the source, which means that it will always have to be treated before it is used, or it may become unusable forever.