Drinking water has been found to contain small amounts of a large number of synthetic organic compounds such as phenols, pesticides, herbicides, aliphatic and aromatic hydrocarbons, and their halogen derivatives, dyes, surfactants, organic sulfur compounds, ethers, amines, and nitro compounds. More than 1500 different organic compounds are suspected to be present in drinking waters. These organic compounds are derived from industrial and municipal waste water, rural and urban runoff, natural decomposition of animal and vegetable matter, and from agricultural practices. In addition, several halogenated compounds such as trihalomethanes and chlorophenols are produced during chlorination practices for disinfection of drinking water. The leaching of solid industrial wastes is also a source of several organic chemical compounds in water.