posted 02-22-2006 06:41 PM            

Frequently, wells provide a healthier standard of water than the rivers and streams from which most early communities derive their water supply. The biggest cause of contamination of water supplies was and still is from impurities finding their way into surface water, which easily runs into streams. Well water, on the other hand usually has the benefit of being filtered through the ground - even two meters is a significant filter.

The depth of the well is not so important as the level of the water table. Many wells are in effect an underground reservoir collecting water from the surrounding rocks (make a hole, and it fills with water) - they are not usually much affected by surface water contamination. Obviously, an underwater stream would be nice - these often manifest themselves in springs rather than wells. Many of the springs in Europe have their source in watersheads many miles away and can take up to six months before reaching the spring (nice exploited nowadays by bottle water suppliers!).