With the development of mining, smelting and other industrial activities, heavy metals are increasingly being found in freshwater sources which can pose severe threats to human and environmental health. Pollution by heavy metals (such as Cd, Pb, etc.) not only affects the productivity of crops, but also the quality of the atmosphere as well as water bodies and threatens the health and life of animals and human beings by way of the food chain. The environmental pollution caused by these heavy metals is a long-term and irreversible process. Such metals are not required for routine functioning of the human body and can be toxic even at low concentration. Drinking water from a tap, such as a private well or public water system, is a source of potential exposure to environmental contaminants. Natural contamination of heavy metals usually originates from weathering of minerals, rocks and aquatic environments which result in the entry of heavy metals into water bodies. Disposal of industrial effluents, wastes (domestic and industrial), such as sewage sludge and mining effluents, are other causes of contamination. Many of the metals are retained relatively strongly in the surface water and soil and do not readily leach out – causing accumulation that may ultimately pose a threat to humans, animals, plants and microbes. Regulatory bodies (e.g. U.S. EPA) have set maximum contaminant levels (MCL) for various metal ions in drinking water (Table 1 – Page 2). This requires that public water supplies be monitored for these metals regularly. Private drinking water systems are not monitored and it is the responsibility of the owner or consumer to test and treat their water.