Mining in India
India is endowed with huge resources of many
metallic and non-metallic minerals. Since independence in 1947, there has been
a rapid growth in the mineral production both in terms of quantity and value.
Currently, India produces as many as 87 minerals, which include 4 fuel, 10
metallic, 47 non-metallic, 3 atomic and 23 minor minerals (including building
and other materials).
The mining activities are extremely poorly regulated.
As early as 1948, the founding fathers of the constitution realized this need
for proper regulation. During the Constitutional debates, they said,
“Industrialisation has brought in its wake an ever-increasing demand for
mineral resources. These resources are non-replenishable and mostly scarce.
Proper control over regulation and development of mines and minerals is
therefore, a matter of national concern.[i]”
Today over 80,000 mines operate illegally as against nearly 10,000 legitimate
leases. Only a third of the legal mines actually report to the Indian Bureau of
Mines, the regulator and only a tenth of them is inspected.
The concerns of ecological damage and
environmental impacts and the consequent effects on people are therefore
receiving less attention than it deserves. The Ministry of Statistics and Plan
Implementation (MOSPI) states that, “Mining, unless properly regulated, can
have adverse environmental and social consequences. On the one hand, mining
disturbs the soil, water and ecological regimes and on the other hand, unless
accompanied by proactive measures to promote inclusiveness through social
education, health and other interventions, it can lead to alienation of the
local population and assume socially unacceptable dimensions. Issues of
Technology for zero waste or low waste mining, relief & rehabilitation,
mine closure which otherwise leads to land degradation are important issues
which require continuous attention[ii].”
Typically mining takes place either by
digging through the surface or by digging under the surface and are called
open-cast mining and underground mining respectively. While underground mining
does not show visible signature of destruction of land, but eventually the area
is affected either because of subsidence or the area getting parched for not
being able to retain the moisture. Thus,
mining is one of the most destructive of human economic activities. Therefore
it is often called a “surgery of mother earth” to remove materials for human
use. We will only highlight the biophysical impacts of mining in this module.
Mining and Impact on Land
Mining devours a large area of land. The total
area under mining and abandoned after mining is exactly not known. The total
land under mining is estimated to be greater than 1.30 million hectares. Land
under coal mining and abandoned coal mines alone is around 0.36 million
hectares[iii].
The impact of mining on land is not
restricted to the mining lease are alone. The amount of land affected depends
on the topography, the quality of the mineral and the depth at which the
mineral is available.
The amount of material to be removed before
reaching the mineral is called the “overburden”. More the overburden more land
is required for dumping this material. Coal occurs in layers called “coal-seam”
in between other sedimentary rocks such as sandstone and shale. Often several
hundred meters of rocks are to be removed before reaching a coal-seam and after
mining every seam, again the intervening rocks have to be removed. The
proportion of coal to overburden can be as high as 1:5 but in general it is
never below 1:2. This means that land is required to store the waste materials
which will be twice as much as the coal we mine and upto five times. This
requires a large area of land as the dumping of these materials has to be
scientific and in low angles that will not allow it to slide and affect adjoin
areas. In several cases this is over twice the area involved in mining. If the
region of mining has an undulating topography with steep slopes more area will
be required for storing the overburden materials.
The quality of the mineral found also impacts
the land area required. In we have a poor quality of mineral the amount of
material required to be mined will be higher. Again if we look at the example
of coal, most Indian coal deposits have 30-40 percent of non-coal material
along with it. So when the coal is burnt in a thermal power plant to produce
electricity we are left with 30-40 percent of the material used as ash. We once
again need more land to dump this ash. Over the life-time of a thermal power
plant, ash dumps require more land than the actual plant itself.
The amount of materials mined for securing
small quantities of metals is generally not understood by common people. For
example to get one tonne of aluminium nearly 6 tonnes of rock has to be mined.
In case of precious metals the ratios are
staggering. A gold ring weighing 5 grams would have required mining of nearly
6-8 tonne of rock. In case of diamond it is still higher. It is for this reason
that these metals are expensive. Uranium mining for instance requires almost 30
tonnes for a gram. This means that we require large land areas to place these waste
materials.
|
Average Viable
Quantity to Mine
|
|
|
Decade
|
Grams/Tonne
|
|
1881-1900
|
47.50
|
|
1901-1910
|
28.00
|
|
1911-1920
|
18.19
|
|
1921-1930
|
19.60
|
|
1931-1940
|
15.40
|
|
1941-1950
|
12.43
|
|
1951-1960
|
7.15
|
|
1961-1970
|
5.35
|
|
1971-1980
|
7.38
|
|
1981-1990
|
3.50
|
|
1991-2000
|
2.20
|
|
2001-2010
|
1.80
|
|
Compiled by Environics Trust from various sources, 2014
|
|
As we go into the future, many of our shallow
deposits would have been used and we would need to dig deeper and also use
poorer quality of deposits to meet our needs.
If we look at gold mining over the past we
find that in the last century the amount of gold required for mining profitably
has dropped significantly and proportionately the amount of overburden and
waste generated has increased many times over.
The land area required is one aspect but the
quality and type of land being used for mining and dumping of overburden and
waste adds another dimension to the impact on land.
Mining alters the topography of the land and
along with the manner in which the overburden is dumped completely changes the
initial contours. This has impact on the local slopes and alters the drainage
pattern in the area. We will look at the impacts it has on water in a later
section. If mining takes place in forested areas, agricultural lands and common
lands of people the impacts are not limited to just losing the land area.
Mining and Impact on Forests and Agricultural Lands
It is estimated that over 164,000 hectares of
forests have already been lost to mining activities. Considering the fact that
in future we will be mining in the last of the original forests the impact is
going to be larger and far reaching.
The forests not only completely disappear
because of mining, but with the initiation of mining in a densely forested area
the quality of the forest are also degraded. The forest cover density reduces
and because of the various activities going in the area the forests are
fragmented.
The Bellary district in Karnataka which has
become infamous for its iron ore mining has suffered severe loss of
agricultural land in the last decade. Between 2005-2010 nearly 43000 hectares
of agricultural land was lost due to mining including some irrigated lands.
Dr Patra
Himansu Sekhar and Sethy Kabir Mohant[iv] of the Department of Geography of the Utkal
University undertook a study to understand the impact on forests because of
iron ore mining in Keonjhar through comparison of Satellite images of three
periods - 1990, 2000 and 2012 provided insights regarding the changes in land
use pattern especially in the forest land during these years.
The results of land use / land cover
assessment were based on visual interpretation from satellite data. The land
coming under forest refers to land with a tree canopy cover of more than 10
percent and area of more than 0.5 ha. Forests are determined both by the
presence of trees and the absence of other predominant land uses within the
notified forest boundaries. Forest was classified into three categories on the
basis of crown density viz; dense, open and degraded. After observation of
percent change analysis, it was found that maximum deforestation occurred in
the vicinity of iron ore mining areas.
The dense forests exhibit crown density of
more than 40%. Periodic analysis of dense forest shows that it covered an area
of 5255.18 Ha (16.70 % of the total area) during 1990, 3123.67 ha (9.93 % of
the total area) during 2000 and 1527.51 ha (4.85 % of total area) during 2012. Dense
forest shows a decrease of 40.56 % in area during 1990 to 2000 while this
decreased by 51.09%, between 2000-2012. It has been found out that most of the
iron ore mining activities are taking place in the vicinity of dense forests because
most of the iron resources are located with the hilly terrain covered with
forest.
Therefore, decrease in the area of dense
forests is attributed to the removal of trees to initiate iron mining
activities and development of mining infrastructure. Open forest exhibit crown
density in between 40% to 10%. It is easily identified on FCC image by its
light red - pinkish colour, smooth - medium texture, contiguous to non contiguous
pattern with irregular outline. Open forest covered an area of 3567.89 ha
(11.34 % of total study area) in 1990, 5673.44 ha (18.03 %) in 2000 and 7430.88
Ha (23.62%) in 2012. Open forests exhibit overall increasing pattern by 59.01 %
during 1990 to 2000 and 30.97% during 2000 to 2012. Similarly area under forest
plantation category was found at 256.24 ha (.81% of total area) during 1990,
which was reduced to 202 ha (0.64%) in 2000 and 179.17 (0.56%) during 2012. The
land coming under land with shrub was 2707.24 Ha (8.60%) in 1990, 3808.63 (12.10%)
during 2000 and 5810.32 (18.47%) during 2012.
This shows that it is not only the forest
area that is lost for mining but the quality of forests is deteriorated when
mining activity begins in an area with dense forests. It is estimated that over
ten thousand hectares of forests would have been affected so far by iron ore,
chromite and manganese mining in Keonjhar District alone.
The second example is from a study undertaken
by Dr Mukesh from the Indian Instiute of Remote Sensing in Chhattisgarh. His
assessment includes how not only forest areas are affected but adjoining
agricultural lands are also severely affected. He found through his analysis of
the Manendragarh area around 18.54% of the forest has been converted to barren lands
followed by around 43.81% as degraded forest. The forest immediate near to the
mining has been totally converted to non forest. However, a trend of impact of
mining could be seen as gradient in the southern and northeastern side. The
forest type is predominantly sal and sal mixed which harbours most the
medicinal and rich species in the state. In the region very less area has been
converted to agriculture, which could be help in concluding that major of the
changes are due to mining activity. Further he found around 85.75 % of
agriculture area has been totally changed to barren where as very least
affected area is 13.30% of total agriculture.
While it is very difficult to assess the
quantum of agricultural land involved in the total land degradation a sample
survey undertaken by Sribas Goswami[v]
and his colleague in the Raniganj coalfield indicates that agricultural land
has generally been 18-55 percent of land degraded in a project. The quantum of
agricultural land involved increases with mining entering into a relatively new
area, whereas when the project is on an area where mining activities are
already in full swing, the quantum of agricultural land involved may be
smaller. A reasonable estimate may be that 35-40 percent of the total land
involved may be agricultural land, which means around 10,000 ha of agricultural
land involves in the Raniganj coalfield during the process of mining upto 2012.
Dr Nitish Priyadarshi who has been studying
the impacts of mining in Jharkhand over decades points out that “Feeding
minerals to meet the nation’s insatiable appetite has taken its toll on the
state- rampant mining for decades has turned large tracts of forests into
wastelands. During the 80’s, coal companies acquired thousands of hectares of
forests in Jharkhand for mining operation in Damodar valley. In Singhbhum
district a similar devastation of forest lands happened for extracting iron
ore. According to the Forest Survey of India’s State of Forest Report,
during an assessment published in 1997, Jharkhand had 2.6 million ha of forest.
In 1999, it had 2.2 million ha, a loss of 0.4 million ha of forest cover. The
forest cover in the Damodar valley coalfield, once 65 per cent, stands at only
0.05 per cent today.
Saranda, once so dense that even the sun’s rays couldn’t penetrate it, has Asia’s largest Sal (Shorea robusta) forests and is an important elephant habitat. Today, uncontrolled mining for iron ore, both legal and illegal, is destroying not just the forest, but also the wildlife, apart from the livelihoods of the local tribal communities. The impact on the forests has been significant. According to the state of forest reports, between 1997 and 1999, about 3,200 ha of forest were lost in the Singhbhum region. Between 2001 and 2003 some 7,900 ha of dense forests were lost in the East and West Singhbhum districts. Saranda too has been affected, and further degradation will have serious consequences for its considerable biodiversity[vi].”
Saranda, once so dense that even the sun’s rays couldn’t penetrate it, has Asia’s largest Sal (Shorea robusta) forests and is an important elephant habitat. Today, uncontrolled mining for iron ore, both legal and illegal, is destroying not just the forest, but also the wildlife, apart from the livelihoods of the local tribal communities. The impact on the forests has been significant. According to the state of forest reports, between 1997 and 1999, about 3,200 ha of forest were lost in the Singhbhum region. Between 2001 and 2003 some 7,900 ha of dense forests were lost in the East and West Singhbhum districts. Saranda too has been affected, and further degradation will have serious consequences for its considerable biodiversity[vi].”
Impact on Water
|
Open cast mining/quarrying
/excavation not intersecting ground water table
|
|
Affecting
natural surface water regime
Affecting
ground water recharge regime
|
|
Open cast
mining/excavation intersecting ground water table
|
|
Pumping of
ground water
Declining of
water table
Affecting
natural surface water regime
Affecting
ground water recharge regime
Affecting
natural springs
|
|
Underground mining
|
|
Affecting
ground water recharge regime
Shallow
aquifers
Deep aquifers
Affecting
ground water flow direction
Affecting
ground water recharge
|
|
CBM/ Underground Coal
Gasification
|
|
Ground water
resource/potentials-drying of upper aquifers
|
The impacts of mining on water occur from
small scale quarrying to deep underground mining and in the new areas of Coal
Bed Methane extraction and proposed Underground Coal Gasification. Mining and
allied industries are major guzzlers of water and biggest destroyers of natural
storage capacity and the most important cause for deterioration of water
quality. The future of water resources is seriously at stake.
|
Water Forfeited to Mining from
a part of Clearances Granted in 2007
(123 MINES)
|
|
|
Total Water Required (L)
per day
|
136305970
|
|
136MLD
|
|
|
ML per yr
|
40800
|
|
1020
|
|
In an analysis of a cross-section of 123
mining projects which were granted environmental clearance by the Ministry of
Environment and Forests in 2007, a startling 136 Million Litres Per Day has
been forfeited for Mining that could serve the entire country for a day at the
official rural norms for supply. If we were to extrapolate to all the mines in
the country, water forfeited to mining operations each year would be atleast a
week’s national actual consumption.
Considering that this is only consumption for
mining operations, if we calculate the needs for downstream beneficiation and
industries and at the permanent loss of aquifer storages, natural drainage
systems and water rendered unusable by downstream pollution, the damage is
colossal.
It is clear that intersection of water table
by the mining industries must be considered seriously as in several places the
major resources lies beneath the water table.
The breaching of the ground water table must be subject to stricter
regulation as the very basis of survival of the local communities is sacrificed
at this stage. Merely to say that the mine water is put to “gainful” use can
lead to unsustainable management of the aquifer. While this may include several
uses such as water supply to adjacent area, utilization for dust suppression by
the industry, utilization by the mining industry for its different purposes,
supplying to local communities, to water supply agencies, utilization for artificial
recharge etc, it will be tantamount to mining water.
Water is used in coalmines for several
functions including washing, spraying, in tailing -ponds and for coal
preparation. This can cause a conflict with other water users and environmental
requirement. Mines can dewater groundwater aquifers some distance from shafts
or pits, which reduce the water table in the area adversely affecting other
activities including agriculture. The major source of water pollution due to
mining include pumped out mine water, spent water from coal handling plants,
dust extraction and dust suppression systems, wash offs from overburden dumps,
workshops and domestic effluents and effluents from washery. Chronic leaks from
waste dumps or direct disposal of waste in the water bodies result in severe
pollution of ground and surface water. Water pollution can affect the area even
after the closure of the mine if the pits are not filled properly. Water in
contact with the left over coal in the pits becomes toxic and unfit for any
use. Also run off from abandoned waste dumps and pits, becomes acidic resulting
in soil erosion, and contamination in the water bodies. Several examples of
such pervasive impacts are seen in coalfields of Jharkhand, Orissa, West
Bengal, Maharashtra, Uttar Pradesh, Madhya Pradesh, Maharashtra and Andhra
Pradesh[vii].
In East Parej Open Cast Coal Mines operated
by Coal India’s Central Coalfields Limited, which had the distinction of
receiving World Bank Funds for Environmental and Social Mitigation, the land
which used to be an agriculture land providing income and livelihood to people
is now turned into a huge pile of dumps and pit holes. Such unkempt dumping
without any proper topsoil conservation plan and regeneration action plan,
leads to greater devastation of surrounding areas. Along with destroying the
scenic beauty of the area, these huge piles of dump are destroying the
regeneration capacity of Parej. The Environmental Management Plan has a
provision of providing guarding sump around the over burden dump, so that any
accumulation in these guarding sump can check waste or soil erosion from these
dumps. In reality, CCL has not invested money or attention on these aspect.
Mine waste collected during overburden removal is simply strewn and allowed to
seep into underground water aquifers. Since mining started in the region,
malaria incidence has increased. Water
resources in the region and wells provided to PAPs in Pindra and Premnagar
blocks are found to be highly contaminated and unhygienic for drinking, and
scarcity has aggravated the problem for them. People in Parej are left with no
other option but to use these contaminated and unhygienic water sources for
drinking and water collected in mine pits for bathing, resulting in higher rate
of skin diseases in the region. Mining
operations in the region, apart from affecting the general surface structure of
the region by means of huge overburden dumps and pit holes like lunar craters,
is also disturbing the underground as well as stream flow in the region. This
disturbance results into collection of water in mine sump or pit holes created
by abandoned open cast mines instead of flowing into natural ponds or streams
Fortunately many of the coal deposits are not
associated with pyrite and acid mine drainage is not a severe problem. However,
there are a few mines with acid mine drainage problems, a significant example
being the coal mines in Meghalaya. The Jaintia Hills District of Meghalaya is a
major coal producing area with an estimated coal reserve of about 40 million
tonnes. Sutnga, Lakadong, Musiang-Lamare, Khliehriat, Loksi, Ladrymbai, Rymbai,
Byrwai, Chyrmang, Bapung, Jarain, Shkentalang, Lumshnong, Sakynphor are the
main coal bearing areas of the District. 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 cm in thickness. 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. Large
scale denudation of forest cover, scarcity of water, pollution of air, water
and soil and degradation of agricultural lands are some of the conspicuous
environmental implications of coal mining. Besides, caving in of the ground and
subsidence of land and haphazard dumping of coal and overburden has
deteriorated the aesthetic beauty of the landscape. The water in coal mining
areas has been found highly acidic. The pH of streams and rivers varies between
2.31 to 4.01. This indicates serious condition of the water bodies of the area
that hardly can support any aquatic life such as fish, amphibians and insects.
Contamination of Acid Mine Drainage (AMD) leads to acidity or low pH of the
affected water bodies. Acidic water is a matter of primary concern since it can
directly be injurious to aquatic organisms. It also facilitates leaching of
toxic metals into the water that could be hazardous to aquatic life, directly
or can disturb the habitat after precipitation. Most of the water bodies in the
coal mining area of Jaintia Hills have been found containing high concentration
of various metals. Many metals, though common, can be toxic to fish and other
aquatic organisms thus reducing the overall fish population. Besides, water was also found turbid and
coloured due to suspended precipitates of iron hydroxides. Silt, fine sand,
mud, coal dust and similar materials form a covering over the bottom and
disrupt the benthic habitat. In addition they reduce the availability of oxygen
and light for aquatic life. Dissolved oxygen is essential for sustaining higher
life forms in water. It is an important parameter to assess water quality.
Dissolved oxygen was found to be low in water bodies of coal mining areas, the
lowest being 4.24 mg/L in river Rawaka and stream Metyngka of Rymbai.[viii]
Impact on Air Quality
Surface coal mining creates more air
pollution problems with respect to dust than underground mining. An
investigation was conducted by Prof Ghose and Dr Majee[ix] to evaluate the characteristics of the
airborne dust created by surface coal mining in the Jharia Coalfield. Work zone
air quality monitoring was conducted at six locations, and ambient air quality
monitoring was conducted at five locations, for a period of 1 year. Total
suspended particulate matter (TSP) concentration was found to be as high as
3,723 microg/m(3), respirable particulate matter (PM10) 780 microg/m(3), and
benzene soluble matter was up to 32% in TSP in work zone air. In ambient air,
the average maximum level of TSP was 837 microg/m(3), PM10 170 microg/m(3) and
benzene soluble matter was up to 30%. Particle size analysis of TSP revealed
that they were more respirable in nature and the median diameter was around 20
micron. Work zone air was found to have higher levels of TSP, PM10 and benzene
soluble materials than ambient air. They concluded that more stringent air
quality standards should be adopted for coal mining areas and due consideration
should be given on particle size distribution of the air-borne dust while
designing control equipment.
The Comptroller and Auditor General while
evaluating the environmental situation in the iron ore mining area in Bellary
found respiratory diseases have dramatically increased because of poor air
quality. The problem with air quality in small stone quarries and crushers used
for building materials has become a huge problem with a large number of workers
suffering from the deadly disease of silicosis.
Brief Conclusion
The mining activities in India are causing
severe ecological degradation and affecting health of workers and people around
the mining areas. Unless stringent regulations are implemented, the damage will
be irreversible. The ecosystems have only certain levels of resilience and when
stretched beyond this, they cannot recover.
[i] Mining Matters – Environics
Trust, 2012
[ii]
http://mospi.nic.in/Mospi_New/upload/SYB2014/CH-15-MINING/Mining.pdf
[iii] Looking Back to Look Ahead:
Green India 2047 edited by R.K Pachauri & P.V.Sridharan
[v] International Research Journal
of Geology and Mining (IRJGM) (2276-6618) Vol. 4(6) pp. 154-162, September,
2014
[vi]http://nitishpriyadarshi.blogspot.in/2012/05/effects-of-mining-on-environment-in.html
[vii] Environics Trust, Water in
Mining Areas, 2008
[viii] Sumarlin Swer & Singh
O.P:Proceedings of the National Seminar on Environmental Engineering with
special emphasis on Mining Environment, NSEEME-2004, 19-20, March 2004; Eds.
Indra N. Sinha, Mrinal K. Ghose & Gurdeep Singh
[ix] Journal of Scientific and
Industrial Research, Volume 62, September, 2003
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