Arsenic contamination of groundwater

Arsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tube wells for water supply in the Ganges Delta, causing serious arsenic poisoning to large numbers of people. A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water. The problem became a serious health concern after mass poisoning of water in Bangladesh. Arsenic contamination of ground water is found in many countries throughout the world, including the US.

The World Health Organization recommends limiting arsenic concentrations in water to 10 μg/L, although this is often an unattainable goal for many problem areas due to the difficult nature of removing arsenic from water sources.

Approximately 20 major incidents of groundwater arsenic contamination have been reported. Of these, four major incidents occurred in Asia—in Bangladesh; West Bengal, India; Inner Mongolia, China; and Taiwan. Locations of potentially hazardous wells have been mapped in China.