Land subsidence or the sinking under of land, is almost an everyday occurrence in Bhowra Colliery of Jharia Coal field (JCF) in Dhanbad, Jharkhand. This happens, among other reasons, due to the coal burning underground which weakens the top soil, writes Ashok Kumar in Youth ki Awaaz.
Blessed with prime coking coal deposits and scores of underground infernos (coal fire) raging in the coalfield, land subsidence is triggered every other day in this densely populated district.
According to the government owned BCCL (Bharat Coking Coal Limited), which operates most of the mines in Dhanbad district, 2016 marks the centenary of the first land-subsidence triggered by an underground inferno in Bhowra colliery.
According to Ashok Kumar, ever since, land-subsidence has claimed several lives in the district over the years. The situation is hazardous for the BCCL exactly for these reasons.
For the record, JCF is the one of the most exploited coalfields in India, with mining going on there since over a century. Why? Because of its valuable metallurgical grade coal reserves. Mining in JCF was initially in the hands of private entrepreneurs who had limited resources and a lack of desire for scientific mining. The mining methods were both opencast as well as underground and caused extensive damage.
Opencast mining (where a pit or tunnel is dug into the ground) blocks were never back filled, leaving them open like a well, seen even today in the form of abandoned mines. According to DGMS (Directorate General of Mines Safety) mining laws, after mining, the pit dug for extracting coal should be back filled with the same soil, removed earlier before mining. But here in JCF, such abandoned mines were never back filled. So you have a large expanse of land peppered with gaping dangerous, deep pits.
On top of that, extraction of thick coal layers beneath the surface at shallow depths has damaged the ground surface; subsidence and pot-holes and cracks reach up to the surface, increasing chances of spontaneous heating of coal seams or the upper beds of coal that are mined.
“Once underground coal seams are exposed to oxygen they catch fire (since methane trapped underneath comes into contact with oxygen); the fires may continue to burn for several years, depending on the availability of coal and oxygen,” Dr. Gurdeep Singh, formerly with the Indian School of Mines and now vice chancellor of Vinoba Bhave University, Hazaribagh told YKA.
“Coal-fires and subsidence have occurred in all parts of the world. India, USA, Indonesia, South Africa, Australia, China, Germany… however, their nature and magnitude differ.” In Jharia, they occur mainly because “coal was extracted using unscientific methods in the past,” Dr. Singh told YKA. “JCF has been the epitome of unplanned, unscientific mining ever since the first mining activity began here in 1894. Today, people of the region are paying for it” he adds.
Today, out of the 77 fires identified, 67 still rage in JCF, engulfing an area of around 9 square km of the JCF, according to BCCL. So far, 595 affected sites have been identified in the area. The families that reside in the nearly 65,000 houses to be vacated, do not know when they might be swallowed by the earth beneath their feet.
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Sourced from Youth Ki Awaaz, Featured image courtesy: jharia.jharkhand.org.in