Story in numbers: India's groundwater: Contaminated and dying

According to a Central Groundwater Board report as many as 650 cities and towns lie along polluted rivers, which contaminate groundwater

About half of India's groundwater is contaminated, according to a Central Groundwater Board report. As many as 276 districts have high levels of fluoride, 387 districts report nitrates above safe levels and 86 districts have high levels of arsenic, said the report.

On an average, contaminated water caused 10 million cases of diarrhoea, 740,000 cases of typhoid and 150,000 viral-hepatitis cases between 2007 and 2011, the groundwater board said.

As many as 650 cities and towns lie along polluted rivers, which contaminate groundwater, the report said.

"Poor environmental management systems" in industries lead to toxic and organic waste discharges of water, the report said. This has resulted in "pollution of surface and groundwater sources from which water is drawn for irrigation and domestic use".

Even this source of water - contaminated as it is - is dying.

In nine states - in south, west and central India- groundwater levels are now described as "critical", according to a 2016 Parliament committee report on water resources. "Critical" implies a stage where 90 per cent of groundwater has been extracted, with significant decline in recharge capability.

As of December 2015, of 6,607 units (blocks, mandals, talukas) assessed, 1,071 in 16 states and two in Union Territories were categorised as "over-exploited", which means 100% of groundwater has been drawn, with little chance of recharge.

Source: IndiaSpend