Water is essential for sustaining life and our ecosystem as a whole and India is by far the largest and fastest growing consumer of ground water in the world. In our country, ground water is a common pool resource (CPR), used by millions of farmers, and about 84 percent of the total addition to the net irrigated area comes from ground water. It also remains the only drinking water resource in most of our rural households. Besides, many industries depend on ground water. Moreover, food, energy and water are interlinked. Despite the importance of water in our sustainability, it is distressing to note that ground water is being exploited beyond sustainable levels, and ground water pollution and depletion remain serious issues.
India possesses an estimated 1,123 billion cubic metres (bcm) of utilisable water out of an annual estimated available water of about 1,869 bcm. Over 80 percent of the rural and about 50 percent of urban and industrial water requirements of India are being met from ground water resources and about 45 percent of created irrigation potential in the country is through development of ground water resources. Despite such dependence on water, according to several studies the condition is alarming. It is glaring to note that,
- … As of May 2015, states have reported 63,282 water quality-affected rural habitations (arsenic: 1,482, fluoride: 11,309, salinity: 16,289, iron: 32,020, nitrate: 2,182). Heavy/toxic metals have been found in nearly 8,862 rural habitations. Punjab, Assam and West Bengal are the most affected states in terms of emerging water contaminants in drinking water resources.
- … 10 states have excess concentration of arsenic, 20 states have higher concentration of fluorides, 21 states have higher concentration of nitrate and 15 states have higher concentration of heavy metals such as lead, chromium beyond norms prescribed by the Bureau of Indian Standards (BIS-2012).
- … Fluoride contamination in ground water is mainly geo-genic, wherein, during weathering and circulation of water in rocks and soils, fluoride is leached out and dissolved in ground water and thermal gases.
- … There are 1,79,999 habitations in the country having water problem associated with fluoride, arsenic, iron, salinity and nitrate. This is over and above the hazard posed by anthropogenic/man-made contaminants such as manganese, lead, chromium, cadmium etc. in ground water in some parts of the country, resulting from mining activities or seepage from untreated industrial wastes. Growing construction of septic tanks has become for want of sewer lines in the countryside has become another source of sub-soil contamination. …