地下水是位于可渗透岩石的地下的水。通常在地面以下100 - 300英尺处发现它。但是在某些情况下，根据地理区域的不同，它可能更深或更浅。

尽管这自然是“干净”水源，但这取决于几种自然和人类学因素。

地下水经常被降雨，雪和海水充电。它可能因其近乎海岸而造成的损害，从而被海洋中的盐水充电。土壤和岩石类型等地质因素以及一个区域的水文地质学会污染该水源。

水对于生活和任何人类社会的可持续发展至关重要。它的角色不能过分说明。提供便携式水是千年发展目标的第七项，用于消除全球贫困和疾病。

水也许是地球上最丰富的资源，覆盖了地球表面的三分之二。然而，可悲的是，估计世界上有十​​亿人，尤其是在非洲农村地区，许多发展中的地区缺乏足够的便携式水。

Water is a universal solvent. As it dissolves a wide range of substances, it is difficult to find “pure” water naturally. There are national and international guidelines stating values for safe drinking water. TheWorld Health Organization’s water quality standards，在全球范围内脱颖而出。这些指南值涵盖了与水相关的各种物理，化学和微生物参数。

Temperature, pH, conductivity, total dissolved solids (TDS), turbidity, are some of the physical water quality parameters often determined in any water/groundwater sample. Besides these, odour and colour give clear indication of pollution. However, their absence does not imply clean water.

Chemical contaminants (Ba²⁺，，，，Ca²⁺，na⁺，，，，Pb²⁺，fe²⁺，mg²⁺，，，，Al³⁺，，，，As³⁺，，，，CN^-，，，，Cd²⁺，，，，Cd⁶⁺、汞²⁺，N0^3-，po₄^3-，，，，SO₄^2-，，，，Cl^-， F^-，，，，organics, amongst others) some of which are carcinogenic, maybe found in groundwater from agricultural industry (including fertilizer and pesticides), industrial wastes from sundry industries and mining.

Government and health agencies are obligated to carry out periodic evaluation of groundwater to predict the possibility of bioaccumulation of toxic chemicals.

Arising from mineral dissolution and ion-exchange occasioned by pH differentials along flow paths through rock and soil types; and leachates from faulty septic tanks, landfills, underground storage tanks, oil spills, used motor oil, automobile and metal dumpsites.

Microbiological pathogenic organisms can contaminate groundwater from sewage leachates, especially in aquifers with a low lying water table. These can be hazardous on human and animal health.

根据更新谁和联合国儿童基金会，18亿人使用粪便污染的饮用水来源。每年18万人死亡归因于waterborne diarrheal diseases根据世界卫生组织的说法。

Up to 88% of this is attributable to unsafe water supply, sanitation and hygiene. Acute side effects of diarrhoea, headache, nausea and vomiting as well as chronic cases of cancer, anaemia, kidney and liver damage, nervous, circulatory, and reproductive problems are associated with consumption of contaminated groundwater. Governments in many of these countries struggle to provide water for the teeming population especially in remote areas.

地下水供应为根除迄今流行的疾病做出了巨大贡献河盲，，，，guinea worm，，，，cholera，，，，andtyphoid fever在世界各地的许多社区中。

许多人不再依靠溪流，停滞的湖泊和被污染的井来供水。从而挽救生命，医院账单和巨大的时间。现在使用的撒哈拉以南60％的人口和大洋洲的50％的人口使用improved sources of drinking-water。

在我们的研究中尼日利亚三角洲的Agbor和OWA社区的地下水质量，我们发现地下水在很大程度上是有益健康的，而且通常是安全的。此外，当您从乡镇转移到郊区/农村地区时，它还揭示了地下水质量的略有差异。后者的质量相对更好。

Presently, many households now have borehole water source within the precinct of their homes. However, government and health agencies are obligated to carry out periodic evaluation of groundwater to predict the possibility of bioaccumulation of toxic chemicals and diseases of possible epidemic proportion.