Water quality encompasses a wide range of water characteristics, including biological, chemical, and physical descriptions of water clarity or contamination. Water quality assessment is typically based on the examination of certain attributes, conditions or properties of a lake, river, bay, aquifer, or other water body. The most important of these attributes are pollutants that demand oxygen or cause disease, nutrients that stimulate excessive plant growth, synthetic organic and inorganic chemicals, mineral substances, sediments, radioactive substances, and temperature. Since the 1950s, routine tests for water quality have evaluated temperature, turbidity, color, odor, total solids after evaporation, hardness (pH), and concentrations of carbon dioxide, iron, nitrogen, chloride, active chlorine, microorganisms, coliform bacteria, and amorphous matter. In recent years increasing contamination and growing public concern over water quality have led to the addition of a number of additional parameters, including algal growth, chemical oxygen demand, and the presence of...