Collection area for the mined coal Rivers and streams flow through some of their dark, damp chambers, lending an other – worldly beauty to the caves that pockmark the state, the roofs of which sometimes hang so low that explorers have to crawl on all fours to get through.
There is much to explore in these caves, be it from the diverse life forms or the geomorphological features which are records and proof of climatic changes through the ages. However, these treasures in the Jaintia Hills of Meghalaya may be forever lost even before they are fully appreciated because of the rampant coal mining in the area which has about 40 million tones of coal reserves.
The Jaintia Hills, one of the seven districts of Meghalaya occupies the eastern part of the state. It covers an area of 3819 kms which is 17.03% of the total geographical area of the state. The Jaintia Hills district of Meghalaya is a major coal producing area and places like Sutnga, Lakadong, Musiang – Lamare, Khliehriat, Ioksi, Ladrymbai, Byrwai, Chyrmang, Bapung, Jarain, Shkentalang, Lumshnong and Sakynphor being the main coal bearing areas of the district (according to the book ‘Geography of North East’). The coal in the area is found imbedded in sedimentary rocks, sandstones and shale of the Eocene age. The three coal seams vary from 30 to 212 cms in thickness.
While the government has no idea how it is going to control it, indiscriminate mining has begun to threaten the famed Krem Liat prah – Um Lm – Labi cave system in Jaintia Hills, the longest in India at 30.9 km. Jaintia Hills is part of the Meghalaya plateau made of rocks belonging to the Archean (2.4 – 4 billion years ago and Tertiary periods (65 million to 2.588 million years ago). Meghalaya has the largest concentration of caves in the subcontinent, about a thousand caves were discovered in the past decade and most of these are yet to be explored and mapped.
Over the years, 118 cave passages, stretching across 148 km, have been mapped on the Nongklieh – Shnongrim ridge, 60 kms from Jowai town in Jaintia Hills. Cave sediments and stalagmites – conical limestone pillars rising from the floor – represent an undisturbed chronological repository of records of climatic change which can stretch back to one million years. Caves hold the key to understanding world climatic changes. Taken in their totality, the caves of Meghalaya should be considered national and archaeological heritage sites that call for concerted protection at both the national and state levels.
Besides being geologically important, these caves are rich in bio – diversity, teeming with fish, salamanders, spiders, woodlice and millipedes, which have adapted to the cave environment – they have no eyes, are white and have long antennae. The caves are also home to three bat species – the Long Winged Bat, Dobson’s Long Tongued Fruit Bat and the Kashmir Cave Bat. The number of bats has reduced significantly, which is alarming because they control pests. Their current population is between 3,000 and 5,000.
Coal extraction in Jaintia Hills is done by primitive mining method commonly known as ‘rat – hole’ mining. In this method, the land is first cleared by cutting and removing the ground vegetation and then pits ranging from 5 to 100 m are dug vertically into the seam for extraction of coal, which is brought into the pit by using conical baskets or a wheel barrow. The coal is taken out of the pit and dumped on a nearby unmined area, from where it is carried to the larger dumping areas, from where it is carried to the larger dumping places near highways for its trade and transportation. The entire process of mining is done manually employing small implements. Most of the mining activities are small scale ventures controlled by individuals who own the land. A large amount of soil runs off and gets swept inside the caves and coats the stalagmite and calcite formations with mud. In many areas, sandy clear underground streams are getting replaced by torrents of mud.
Coal seams, 30 cms to 212 cms thick, occur embedded in sedimentary rocks, sandstone and shale of the Eocene age (54 – 38 million years ago). During mining, large amounts of shale are brought to the surface as mine spoil and as by – products of coal cleaning. Iron pyrites in shale decompose when exposed to air and water and produce sulphuric acid and ferrous hydroxide. These flow into the surface and underground water, making it unsuitable for aquatic life. Then there is another threat; increased flooding of the caves. Mining may be partly responsible for this as water gets accumulated in the excavate pits and seeps into the caves. Higher water levels inside the caves erode sediments. Coincidentally, caves are adjacent to huge reserves of coal and limestone.
The water bodies of the area are the greatest victims of the coal mining. The problems of water quality degradation and its adverse impacts on availability of potable and irrigation water, soil quality, agricultural productivity and bio – diversity in the area have been attracting increasing attention of the people.
The main characteristics of the coal found in Jaintia Hills are its low ash content, high volatile matter, high calorific value and comparatively high sulphur content. The coal is mostly sub – bituminous in character. The physical properties which characterize the coal of Jaintia Hills districts are that it is hard, lumpy, bright and jointed except for the coal from Jarain which comes in both soft and hard types. The composition of the coal which was revealed through chemical analysis indicates moisture content between 0.4% to 9.2%, ash content between 1.3% to 24.7%,and sulphur content between 2.7% to 5.0%. The calorific value ranges from 5,694 to 8,230 kilo calories per kilogram.
The extraction of coal creates a variety of impact on the environment before, during and after the mining operation. The extent and nature of the impact can range from minimal to significant damage depending on a range of factors associated with ongoing mining processes as well as post mining management of the affected landscapes. The sensitivity of the local environment also determines the magnitude of the problems. Usually, an ecologically fragile environment has been found highly vulnerable, attracting long term ecological impact.
Mining operations in Jaintia Hills have undoubtedly brought wealth and employment opportunities in the area. However, simultaneously, it has led to extensive environmental degradation. Large scale denudation of forest cover, scarcity of water, pollution of the air, water and soil and degradation of agricultural lands are some of the conspicuous environmental implications of coal mining. Besides these, the caving in of the ground and subsidence of land and haphazard dumping of coal and overburdening have deteriorated the aesthetic beauty of the landscape.
Historically, coal mining has been a very dangerous activity and the list of historical coal mining disasters is a long one. Open cut hazards are principally mine wall failures and vehicular collisions. Underground mining hazards include suffocation, gas poisoning, roof collapses and gas explosions. Chronic lung diseases such as pneumoconiosis (black lung) were once common in miners leading to reduced life expectancy. The miners work in really dangerous conditions without proper safety measures, thus endangering themselves while extracting this black fuel. Another hazard which is regularly faced is exposure to black damp which is a mixture of carbon dioxide and nitrogen which can cause suffocation.
Improvements in the methods of mining such as the longwall method of mining, placement of hazardous gas monitors, gas drainage and ventilation will reduce the risks of rock falls, explosions and unhealthy air quality if implemented. These precautions, if implemented by the mine owners, will reduce the danger to the lives of the miners and improve their overall health.
Water in mining areas generally varies from brownish to reddish colours. Siltation of coal particles, sand, etc, Acid Mine Drainage and formation of iron hydroxide are some of the major causes of change in water colour. Many miners continue to die annually, either through direct accidents in the mine or through adverse health consequences from working under poor conditions.
Formation of iron hydroxides is mainly responsible for orange or red colour in the mining areas. Iron hydroxide is a yellowish insoluble material commonly formed in water bodies of the coal fields. It is this material that stains streams and is responsible for the red to orange colour of the water. When elevated levels of iron are introduced into natural waters, the iron is oxidized and hydrolyzed, thereby forming precipitates of iron hydroxides.
Layers of rock and earth above the coal removed during mining commonly contain traces of iron, manganese and alluminium and can also contain other heavy metals. These metals can be dissolved from mining sites through the action of acid runoff or can be washed into streams as sediment. Most of the water bodies in the coal mining areas of Jaintia Hills have been found to contain high concentrations of various metals. Many of these metals, though commonly found, can be toxic to fish and other aquatic organisms when present in high dissolved ratios.
Meghalaya is a dream come true. It is a cheerful territory of splendid beauty in terms of landscape, flora and fauna. This God given beauty will get lost if the state is left to the whims and fancies of people whose sole intention is to get rich, regardless of the consequences. Is this beauty something we can willingly sacrifice in the pursuit of wealth?