Tuesday April 23, 2019
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Contamination Of Contaminating Groundwater In Assam Remains A Silent Issue

"Climatic changes, like erratic rainfall which results in sudden long, dry spells, leads to less runoff water seeping into the ground and rejuvenating the water table. This results in increase in concentration of minerals like fluoride, that is pumped up by borewells."

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"When dilution of aquifers is low (because of erratic rainfall), the concentration (of minerals like fluoride) goes up," he said. And although Assam gets a good amount of rainfall, "the water table has depleted in some places". Pixabay

It’s peak election season. But, even as political parties go all out to appease voters, the worsening quality of groundwater hardly finds any mention.

In northeast India, Assam is in the middle of a grave groundwater contamination crisis. According to government estimates, fluoride contamination affects 23 districts and arsenic contamination affects 24 districts (out of a total 33) in the state. Even as people grapple to survive this basic necessity of life – excess fluoride can lead to dental and skeletal fluorosis, and arsenic is known to cause cancer – experts warn of a worsening situation in the future.

Understanding the root of a crisis is essential to finding its pragmatic solution, and in this context, Dr Manish Kumar, faculty at Discipline of Earth Science in IIT Gandhinagar, compared the situation to a glass of water in which spoonfuls of sugar are added. Until the water is saturated, it will keep dissolving the sugar, and then, the granules would start settling without further dissolution.

Likewise, minerals containing fluoride and arsenic found naturally in rocks of underground aquifers will dissolve more and leach more fluoride and arsenic under unsaturated conditions. Aquifers essentially constitute rocks and water, surrounded by microbes and organic matter.

“Any kind of anthropogenic stress on aquifers, like pumping, irrigation and return flow, leads to change in the saturation condition of groundwater and thereby enhances the release of arsenic (and fluoride) into the water,” Dr Kumar told this correspondent. Through extensive research on spatial distribution of geogenic contaminants across the Brahmaputra river, Dr Kumar and his team found the co-existence of arsenic, fluoride and uranium at some places.

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Likewise, minerals containing fluoride and arsenic found naturally in rocks of underground aquifers will dissolve more and leach more fluoride and arsenic under unsaturated conditions. Aquifers essentially constitute rocks and water, surrounded by microbes and organic matter. Pixabay

“We also found several places in Assam where the water is not yet saturated with arsenic and fluoride bearing minerals and thus prone to higher arsenic and fluoride concentration in their aquifers,” he said. In Nagaon district, for example, about 60 per cent of the samples tested were found to have “unsaturated” water.

Climatic factors like erratic rainfall, recharge and runoff also play a role in governing the weathering of minerals – otherwise found naturally – in groundwater, Dr Kumar said. The draft report of the Assam State Action Plan on Climate Change (2015-2020) states that Assam has been facing “continued warming of atmosphere” and “erratic rainfall” as a result of which there have been erratic flood and drought conditions since 2003.

Dr Robin Kumar Dutta, professor in the Chemical Sciences department of the Tezpur University, concurred with the linkage between climatic change and groundwater contamination.

“When dilution of aquifers is low (because of erratic rainfall), the concentration (of minerals like fluoride) goes up,” he said. And although Assam gets a good amount of rainfall, “the water table has depleted in some places”.

The issue, Dr Dutta added, also needs to be examined through the lens of geomorphology. “Karbi Anglong and Hojai, for example, fall in the rain shadow area and are among the fluoride-affected places in Assam,” he said. Dr Dutta has designed a low-cost filter technology to remove fluoride and arsenic (and iron) from water, which he has patented.

Cancer
ven as people grapple to survive this basic necessity of life – excess fluoride can lead to dental and skeletal fluorosis, and arsenic is known to cause cancer – experts warn of a worsening situation in the future.
VOA

Geomorphology, added activist Dharani Saikia, is why, at times, adjoining villages can have completely different results when their water is tested for fluoride (or arsenic) contamination. Working on the issue of fluoride contamination for many years now, particularly in the Nagaon and Hojai districts – two of the worst-affected in Assam – he stated the example of the Tapatjuri village.

“Tapatjuri in the Hojai district is one of the worst affected by fluoride contamination of groundwater. Any child you see here has stained teeth – the sign of dental fluorosis – and some have bent legs (skeletal fluorosis). In contrast, its nearby villages have no problem of fluoride contamination,” he explained.

“Climatic changes, like erratic rainfall which results in sudden long, dry spells, leads to less runoff water seeping into the ground and rejuvenating the water table. This results in increase in concentration of minerals like fluoride, that is pumped up by borewells,” Saikia further said.

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It is, however, not a hopeless situation and the key lies in revisiting and fine-tuning traditional methods. For instance, in Tapatjuri, the Public Health and Education Department (PHED) has put red-crosses on hand-pumps, indicating contamination. The villagers are now dependent on the PHED water supply from nearby rivers. (IANS)

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Experts Claim, Climate Change Can Affect Food, Water Security

Lauding IIT-Mandi for hosting the workshop, Rajeevan said the Himalayas were one of the world's sensitive hotspots to climate change along with the Artic region.

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Ramesh P. Singh, workshop Coordinator and visiting faculty at IIT-Mandi, said: "We have to understand climate change and its impact as it is very important for the future generations." Pixabay

Climate change can affect the food, water and energy security of a region, Ministry of Earth Sciences Secretary M. Rajeevan said here on Friday.

“Climate is changing and global warming is happening due to the release of greenhouse gases. In many parts of the world, including India, the effects of climate change are being seen especially in mountain regions like Mandi,” he said.

He was speaking at the Indian Institute of Technology-Mandi that hosted an International Workshop on Climate Change and Extreme Events in the Indian Himalayan Region.

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In many parts of the world, including India, the effects of climate change are being seen especially in mountain regions like Mandi,” he said. Pixabay

The workshop was aimed at understanding the effects of climate change, melting of glaciers, increased frequency of extreme events, atmospheric pollution and pollution due to the burning of crop residue in the Himalayan region and applications of remote sensing.

Lauding IIT-Mandi for hosting the workshop, Rajeevan said the Himalayas were one of the world’s sensitive hotspots to climate change along with the Artic region.

“The Himalayan region is experiencing increasing variability in weather in the last many years. This could lead to further snow accumulation over this region and more research is needed to understand this phenomenon. By studying data, there is also evidence that the number of extreme warm days and nights has increased in this Himalayan region, which are clear effects of global warming.”

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The workshop was aimed at understanding the effects of climate change, melting of glaciers, increased frequency of extreme events, atmospheric pollution and pollution due to the burning of crop residue in the Himalayan region and applications of remote sensing. Pixabay

In his presidential address, IIT-Mandi Director Timothy A. Gonsalves said: “We have 15 professors from six different disciplines in IIT-Mandi who are working on climate change. This workshop saw the participation of faculty from various disciplines and is an example of the inter-disciplinary and collaborative environment on campus.”

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Ramesh P. Singh, workshop Coordinator and visiting faculty at IIT-Mandi, said: “We have to understand climate change and its impact as it is very important for the future generations.”

The workshop has participation from all over India, besides Europe, and the US with over 90 speakers from across India. (IANS)