Saturday, September 22nd, 2007
Why open pit should be opposed in Bangladesh
Bangladesh does not afford to allow destruction of its surface and underground water resources, fertile land, rich biodiversity, peoples lives and livelihoods for open pit mine, which is not even technically possible. Open pit is unprecedented in a country like Bangladesh, nor this is the only way to utilize its coal resources. The causes to say NO to open pit in Bangladesh is summarized below:
Population
About 200,000 people from 150 villages will have to be evacuated from only one mine area. Within the coal vicinity area or nearby area there is no such barren land to allocate the people. It will be very difficult to relocate those people in a densely populated country like Bangladesh. Moreover, they will be deprived of their livelihoods. Moreover, millions of people in greater North Bengal will face sufferings for desertification as well as contamination of water resources and for loss of huge fertile land.
Water
Degradation of both surface water and groundwater is one of the major
problems with open-pit coal mining anywhere in the world.
Extraction of Phulbari or Barapukuria coal adopting open-pit mining method will be disastrous for the north-western region in particular and Bangladesh in general due to dewatering of arsenic contamination free pure drinking and irrigable groundwater from DupiTila formation to the tune of 800 million litres per day over a period of 38 years. Dewatering in the mining area will not only disturb the major aquifer, it will also damage the most potential and massive aquifer of north-western Bangladesh, making the area a desert-like place.
Potential and major groundwater reservoir of Bangladesh lies in the north-western region of Bangladesh covering greater Dinajpur and Rangpur districts. The groundwater resource of this region is the main aquifer of Bangladesh which is about 80-120 metres thick in the DupiTila formation and situated at about 10-12 metres below surface.
Mining operations will mainly consists of dewatering of aquifer, cleaning and top soil stripping, overburden removal, rehabilitation of mined out areas and overburden dumps. Coal seams ranging in total thickness between 20 and 65 metres are planned to be extracted from the upper and main coal seams. Aquifer dewatering will be continuous throughout the operation life of the mine.
To maintain dry working condition in open-pit mine, aquifers and aquitards need to be depressurised. Due to mine dewatering activities water level drawdown will form an irregular ellipsoidal shape with water level declines in excess of 10 kilometres from the mine. This would reduce groundwater availability to a large area of North Bengal, highly fertile and also a significant source of food supply of the country. Groundwater will also impact on biodiversity, wetlands and rivers in the large areas, will put the north-western region of Bangladesh to the threat of natural disaster, land subsidence, land sliding and earthquake.
Food Security
According to the Expert Committee, an area of 247 sq km outside the mining area will be affected through groundwater depletion. This is one of the few regions in Bangladesh that is not prone to floods or other natural catastrophes, and that it currently provides a significant portion of the country’s food supply. Desertification or contamination through the Open pit mine Project would therefore have serious impacts for the food security of the entire country.
Acid-mine-drainage and loss of renewable resources
Bangladesh has tremendous renewable energy sources in the form of wood (65 per cent of the total energy consumed), generated annually on its surface through the growth of vegetation. This is because of its fertile soil, regular rainfall and the energy of sunshine consumed by the plants together. The sunshine also consumed by the animals, directly and indirectly in many ways is difficult to quantify. The
energy of wind and water currents in the rivers and seas consumed by the ecosystem supports our economy in many ways but is never quantified.
Acid-mine-drainage (AMD) associated with overburden and its likelihood will contaminate both soil and water. AMD prevention and mitigation are costly activities, which have resulted in widespread environmental damage and bankruptcy of mining operations. The State of Pennsylvania (US), for example, spends more than $12 million each year to treat acid mine drainage from active and abandoned coalmines.
Most importantly, the water pumped out of a mine or surface water coming out of coal-waste pile is not suitable for human consumption. Most of the time, such water is loaded with dissolved heavy metals, including arsenic. Water from coal mines is acidic and cannot support any aquatic life, nor can be used for agricultural purposes without expensive treatment.
Technical Feasibility: M/S WARDELL Armstrong’s study
M/S WARDELL Armstrong, a reputed mining exploration and consulting company of the UK, conducted techno-economic feasibility study of Barapukuria coal deposit in 1987-1991. Wardell Armstrong very strongly rejected the idea of open-pit mining at Barapukuria. They have estimated removal of 8,000-10,000 litres of groundwater per second for the whole operational life of the mine (30 years) to dewater DupiTila aquifer for open-pit mining of Barapukuria coal deposit. Wardell Armstrong realised that the huge extraction of groundwater for such a long time from DupiTila aquifer may damage the most potential and major aquifer in the whole region. This is one of the reasons that Wardell Armstrong opted for underground mining at Barapukuria. Wardell Armstrong suggested 35-40 per cent coal recovery by adopting underground long-wall mining method. This is being practised all over the world.
Present recovery of 7-8 per cent recovery of coal from Barapukuria cannot be the basis of adopting open-pit mining at Phulbari. Coal recovery from Barapukuria may be increased to 35-40 per cent if ‘hydraulic stowing’ is undertaken. Moreover, if hydraulic stowing is conducted present subsidence that has occurred at Barapukuria could be minimised. Even if latest underground coal extraction technology is adopted coal recovery from Barapukuria may rise to 60-70 per cent. Present low recovery is due to the lacking of the authorities concerned. Therefore, present low recovery of Barapukuria coal cannot be cited as a supportive example for open-pit mining at Phulbari.
Rain
The top-soil will be removed and preserved once mining operation begins in a particular block. This top-soil will be preserved before it is brought back and spread on the top of the area filled. The top-soil will be utilized after completion of mining in one particular block which may take 3-5 years. It will be very difficult to preserve top-soil for such a long time in a country like Bangladesh. Top-soil may be washed away during monsoon.
At least 3-5 monsoon will be there before top-soil is used at the top of the filled out mining block. And the fertility of the top-soil will be lost during these 3-5 rainy seasons. During monsoon, already mined out area will be filled up by rain water, which is required to be pumped out again. During rainy season mining will be difficult and may have to be postponed to facilitate pumping water out of the mine to make it dry for mining. Thus 2-3 months in a year may be lost due to above reasons. Thus, uninterrupted supply of coal to the power station and other consumers will not be possible.
Depth
The coal seam lies below more than 200 meters from the surface. The overburden of Phulbari coal deposit is incompetent, unconsolidated and waterlogged. Technically open-pit coal mining should not be done below 150-200 metres. These are practiced in our neighbouring countries India and China. The unconsolidated and waterlogged bed above the coal seam will disturb the stability of the working ‘bench’ and installation of heavy equipments will be very difficult in the loose soils at intermediate depth for extraction of coal. During the rainy season the situation will be much more complicated.
Major Faults
Existence of major faults in the Phulbari coal basin indicates presence of highly disturbed zone. This will facilitate rapid drawdown of water table. This will disturb the stability of major aquifer in the region. Since major, massive and most potential water reservoir lies above the coal seams, open-pit mining will therefore definitely damage the major aquifer. There are agricultural lands, villages, township, forests, etc at the surface of the coal deposit. Rehabilitation, relocation and compensation by land in congested areas like Phulbari or Barapukuria will be very difficult. All these factors make open-pit mining in Bangladesh non-feasible and non-viable.
Technical Feasibility:BHP Australia’s Retreat
BHP Australia discovered Phulbari coal in 1997. BHP worked in Bangladesh for about eight years, spent millions of dollars on exploration and discovered a large coal deposit at Phulbari. BHP realized, after locating coal at a deeper depth, that open-pit mining at a depth of more than 130 metres would be unthinkable at Phulbari.
In a densely populated country like Bangladesh where coal seam lies beneath three valuable resources – water reservoir, agricultural land, township and villages – open-pit mining, damaging and destroying three important resources of Bangladesh, will be simply disastrous.
Considering the unconsolidated overburden and thick aquifers, open-cut mining was problematic even at a depth of 130 metres. After opening of the mine, the dump of already-mined coal and the overburden materials will have to be spread over large areas.
During heavy monsoon these materials will spread beyond the mining area, escape through rivers and distributaries and clog the river system up to the Bay of Bengal. Consider that sort of scenario and contemplate the environmental and ecological havoc that may befall Bangladesh. BHP decided not to proceed for open-cut mining mainly due to environmental reasons and, to a lesser extent, for geological, hydro-geological, and economic reasons.