Water, commonly referred to as “the universal solvent,” is our planet’s single most precious natural resource. Comprising over 70 % of the Earth’s surface, this compound of hydrogen and oxygen is essential to the growth and prosperity of all living things. Without it, life on Earth would not be possible. Although we as humans are aware of this fact, the continuing pollution of our rivers, lakes, and oceans illustrates a continuing disregard for it. This pollution threatens the well-being of various types of living organisms and in turn weakens fragile ecosystems. It also reduces the availability of suitable drinking water, often causing inordinately high incidence of disease, and inhibits our ability to use water for recreational purposes.Right now our freshwater resources are threatened by pollutants from factories and runoff from farm fields and city streets, from dams and diversions, from overfishing and exotic species, and from over-manipulation of rivers and streams so that they no longer connect with their natural floodplain. Many of the world’s rivers no longer run free and wild. Our coasts and their precious marine ecosystems are increasingly threatened by oil spills caused by offshore drilling activities and the shipping industry.