The quality of water is central to all of the roles that water plays in our lives. From the beauty of natural waterways teem- ing with wildlife, to the vital livelihoods that clean rivers and streams support, to the essential role that safe water plays in drinking water and health – good water quality is fundamental to the network of life and livelihood that water supports. Water is the source of life on earth, and human civilizations blossomed where there was reliable and clean freshwater. Use of water by humans – for drinking, washing, and recreation – requires water free from.