Coal Reserves and Mining in Odisha

Geological Setting and Distribution

The coal deposits of Odisha occur exclusively within the Lower Gondwana sedimentary sequence of the Permian age (approximately 250-300 million years ago), deposited in fault-bounded rift basins that developed within the Precambrian crystalline basement. The Mahanadi Valley coalfields, the southernmost extension of the great Damodar Valley belt of Indian coalfields, consist of two major basins: the Talcher Coalfield and the Ib Valley Coalfield. These coalfields are separated by the Mahanadi River and its floodplain. The coal-bearing formations — the Karharbari, Barakar, and Raniganj formations — are predominantly composed of sandstones, shales, carbonaceous shales, and coal seams, representing a cyclical sequence of fluvial and lacustrine deposition in a tropical peatland environment.

The Talcher Coalfield, covering approximately 1,800 square kilometres in Angul, Dhenkanal, and adjacent parts, is the single largest coalfield in Odisha and one of the largest in India. The Ib Valley Coalfield covers approximately 500 square kilometres in Jharsuguda and Sundargarh districts. Total coal reserves in Odisha are estimated at over 79 billion tonnes, of which about 27 billion tonnes are in the proven category — representing about 24 per cent of India’s total coal reserves.

Coal Quality and Characteristics

The coals of Odisha are nearly entirely of the non-coking (thermal) grade, with high ash content (25-45 per cent), moderate moisture (6-15 per cent), low to medium sulphur (0.4-0.8 per cent), and calorific values ranging from 3,500 to 6,100 kilocalories per kilogram. The high ash content is a characteristic feature of Indian Gondwana coals and results from the intermixing of mineral matter during peat accumulation. These coals are classified primarily as Grade F to Grade G+ (now designated as G5 to G13 under the revised classification), suitable for thermal power generation, captive power plants, and brick kilns. The low sulphur content is an advantage from an emissions perspective. However, the high ash content necessitates beneficiation (coal washing) for efficient utilisation, and the washeries in the coal belt process raw coal to reduce ash content before dispatch to distant power plants. Coking coal, essential for steelmaking via the blast furnace route, is virtually absent in Odisha, and steel plants in the state import coking coal from Australia, Mozambique, and other sources, blending it with domestic thermal coal in certain processes.

Mining Operations

Coal mining in Odisha is overwhelmingly carried out by Mahanadi Coalfields Limited (MCL), a subsidiary of Coal India Limited, headquartered at Sambalpur. MCL operates approximately 20 open-cast and 4 underground mines across the Talcher and Ib Valley coalfields, producing over 160 million tonnes of coal annually — making it the second-largest coal-producing subsidiary of Coal India after South Eastern Coalfields Limited. The major open-cast projects include the Bharatpur, Ananta, Jagannath, Bhubaneswari, and Kaniha mines in Talcher, and the Lakhanpur, Samaleswari, and Orient mines in the Ib Valley.

Mining is predominantly by open-cast methods, using large-capacity electric rope shovels, dumpers, and draglines. The stripping ratio — the volume of overburden that must be removed per tonne of coal — ranges from 1.5:1 to 5:1 depending on the depth and multiplicity of the coal seams. The open-cast mines are enormous in scale, with some pits extending several kilometres across and to depths exceeding 200 metres. Underground mining, once more common, has declined due to higher costs and safety challenges, although some underground mines continue to operate, particularly in the Orient area.

The Talcher Power Hub

The Talcher coalfield’s location at the centre of Odisha ensures that transportation costs for pit-head power plants are minimal, making the Talcher region one of the most cost-effective locations for thermal power generation in India. The National Thermal Power Corporation’s (NTPC) Talcher Super Thermal Power Station (3,000 MW) and Talcher Kaniha plant (460 MW) are the largest coal-fired power stations in Odisha. The NTPC Talcher Thermal Power Station (460 MW, one of India’s oldest, commissioned in 1968) is being replaced with a new 2,600 MW ultra-supercritical unit. The Talcher Fertilizer plant, being revived as a coal gasification-based urea plant with an investment of over Rs 13,000 crore, represents a strategic initiative to utilise coal for non-power applications. Numerous independent power producers (IPPs) — including GMR, Jindal, and others — operate captive power plants along the coal belt. The Ib Valley in Jharsuguda has also attracted major power generation, with the OPGC (Odisha Power Generation Corporation) Ib Thermal Power Station and various captive plants. This concentration of power generation has made Odisha a power-surplus state, exporting electricity to other states through the national grid.

Environmental and Social Impacts

Coal mining and combustion have left a severe environmental footprint in the mining districts. The open-cast mines displace vast quantities of overburden, which is dumped in external and internal dumps that cover thousands of hectares, destroy agricultural land, and alter drainage patterns. Coal washeries generate enormous volumes of slurry, often discharged into local water bodies. Air pollution from mining activities — including dust from blasting, loading, and transportation, and fly ash from thermal plants — has created a public health crisis in the Talcher and Ib Valley belts, with high rates of respiratory illnesses reported among the local population. Groundwater depletion from mine dewatering has dried up wells in surrounding villages. The displacement of communities, including significant numbers of tribal and traditional cultivator households, has been a persistent source of grievance. While Coal India and the State Government have implemented rehabilitation and resettlement packages, the quality of implementation has been inconsistent. The recent emphasis on renewable energy and India’s net-zero commitments signal a future where thermal coal mining will need to be gradually phased down, a transition that will have profound implications for the economy and communities of Odisha’s coal belt.