The Indo-Gangetic basin accounts for roughly a quarter of the global extraction of groundwater, and is the key source of freshwater for over 700 million people in India, Pakistan, Bangladesh and Nepal. According to a new study based on water quality data collected between 2000 and 2012, 60 percent of groundwater in the region now has excessive amounts of arsenic and salinity, making it unfit for consumption or irrigation. 
 
 “We present, for the first time, an analysis of the status of groundwater across the IGB [Indo-Gangetic basin] alluvial aquifer based entirely on in situ measurements. We use statistical analyses of multi-year groundwater-level records from 3,429 water wells and a compilation and interpretation of existing high-resolution spatial data sets and studies within Pakistan, India, Nepal and Bangladesh to assess: groundwater-level variations; groundwater quality; and groundwater storage within the top 200 m of the aquifer,” the authors of the study, published in the journal Nature Geoscience, wrote. 
 
 The researchers’ analysis of the quality of groundwater up to a depth of 200 meters (650 feet) found that about 23 percent of the water is too salty, while nearly 37 percent contains arsenic at concentrations toxic to humans. 
 
 Photo: Nature Geoscience 
 
 “Elevated arsenic is primarily a concern for drinking water, while salinity affects irrigation and also the acceptability of groundwater for drinking,” the researchers wrote in the study. 
 
 Although a certain level of salinity in groundwater is natural, the concentration is pushed beyond acceptable levels through inefficient farmland irrigation and poor drainage. Similarly, groundwater arsenic concentration is also raised beyond its natural levels by the indiscriminate use of phosphate fertilizers and mining. 
 
 Photo: NASA 
 
 Arsenic poisoning through consumption of contaminated groundwater has long been a serious public health issue in South Asia. In Bangladesh, for instance, a third of the wells still draw up water that contains arsenic in concentrations higher than 50 parts per billion — the country’s official safe level. 
 
 According to the World Health Organization (WHO), long-term exposure to arsenic can not only cause cancer and skin lesions, it can also severely impair cognitive development in children. 
 
 “The symptoms and signs caused by long-term elevated exposure to inorganic arsenic differ between individuals, population groups and geographical areas. Thus, there is no universal definition of the disease caused by arsenic. This complicates the assessment of the burden on health of arsenic,” the WHO says in its fact sheet on arsenic. 
 
 The findings of the new study indicate that contamination is a much bigger threat to groundwater in South Asia than depletion, as the water table across the Indo-Gangetic Basin remained largely stable — and even rose — in 70 percent of the aquifer between 2000 and 2012. ||||| A water crisis has hit southern Asia, but breaks with current global trends and is not caused by depletion of the resource. 
 
 A large river basin is the main source of groundwater for more than 750 million people in Pakistan, India, Nepal and Bangladesh. Salinity and arsenic contamination have rendered 60 perfect of the river basin unusable for drinking or irrigation, according to a paper published in Nature Geoscience on Monday. 
 
 The basin is close to the Indus and Ganges rivers, thus is named the Indo-Gangetic Basin. Nearly one quarter of groundwater extracted world wide comes from this basin. 
 
 Groundwater comes from rivers or rainfall, and is stored underground. Fifteen to twenty million wells use groundwater from the Indo-Gangetic Basin. 
 
 Previous concerns about over reliance on groundwater in the basin were related to depletion of water within the basin. The new study shows that water levels are stable for the majority of the basin, but raises the pressing concern of widespread arsenic and saline contamination. 
 
 Unsafe levels of salinity in the groundwater could be because of natural or manmade causes. If they're manmade, it's likely related to improper agricultural practices. 
 
 Hypernatremia, or salt poisoning, symptoms include thirst, swollen tongue, nausea, vomiting, diarrhea, abdominal cramps, weakness, headache, convulsions and coma. 
 
 Arsenic toxicity found in the basin is almost certainly manmade. Though natural levels of Arsenic occur, the amounts being reported by the researchers are indicative of fertilizer and mining activity. 
 
 Arsenic poisoning has been labeled a crisis in the region. Symptoms include abdominal pain, diarrhea, vomiting, dark urine, dehydration, vertigo, delirium, shock, and death. 
 
 The good news is that understanding the toxicity levels and their causes allows for solutions to be decided upon and enacted. Deep tube wells could go below the contaminated water, which was found at depths of up to 200 meters.
– A river basin in southern Asia is so enormous that 750 million people rely on it for their groundwater. Now, a new study in Nature Geoscience presents an equally staggering stat: 60% of that water is unfit for drinking or farming because it's contaminated by salt or arsenic, reports the Guardian. About 23% of the groundwater in the Indo-Gangetic Basin to a depth of 650 feet is too salty—an issue perhaps caused by poor farmland irrigation or drainage—and another 37% is tainted by toxic levels of arsenic, researchers say. Like salt, arsenic is present naturally, but levels can spike with mining and the use of fertilizers. The basin, so named because it's near the Indus and Ganges rivers, serves people in Pakistan, India, Nepal, and Bangladesh, and it accounts for one-quarter of the world's groundwater. "Elevated arsenic is primarily a concern for drinking water, while salinity affects irrigation and also the acceptability of groundwater for drinking," the researchers say, per International Business Times. However, researchers say that "deep tube wells" could penetrate deeper into the basin to pull out non-contaminated water, per Nature World News. Perhaps the only good news from the report is that the amount of water in the basin remained relatively stable, in contrast to other groundwater sources around the world. (Testing has found issues with 2,000 US water systems.)