Illegal and
indiscriminate river sand mining is going to cause a large number of
environmental and social problems in World.
By
Dr. Nitish
Priyadarshi
Geologist.
This is Kanchi river which provides sands to Ranchi district.
This is Jumar River near Ranchi which now contains less sand deposit due to over exploitation.
Illegal sand mining is a scourge in states across India. The latest battle in Gautum
Buddh Nagar, Uttar Pradesh, where sub divisional magistrate (SDM) was suspended
from service, has served to highlight the plight of rivers ravaged.
Construction work on projects worth thousands of crores of rupees in Jharkhand has been affected by a sand crisis caused by the
on-again, off-again auction policy.
River sand is a product of natural weathering of rocks over a period of millions
of years. It is mined from the river beds. River sand is becoming a scarce
commodity now. River (Fresh water) sand is far superior for construction
purposes than any other sand used in construction.
Due to the crisis, prices of river sand have gone up to Rs.7,000 per truck
from Rs.3,000 per truck before the current round of auctions started and then
halted due to protests. This is because the raw material has to be brought from
outside the state.
It is unfortunate that the Jharkhand state is facing a sand crisis and
projects worth more than Rs.3,000 crore have been affected. This crisis has
been created by the state government. It is the duty of the state government to
facilitate licenses and environmental clearances. Construction work has been badly
affected in the state.
Illegal sand mining is adding to the plight of the Yamuna
river in the National Capital Region. It has not only changed the course of the
river but also made its riverbed unstable, thus disturbing the biodiversity of
the region.
While farmers from nearby villages claimed that people
involved in illegal sand mining intentionally prevent the natural flow of water
to take out more sand from a spot, experts claimed that it actually leads to
change in the course of river.
The Karnataka government has attempted a rare balancing act between the
needs of rivers and buildings for sand. This conflict between the environment
and development was addressed by issuing an order to the public works
department (PWD) on September 16, 2013 mandating the civil body to use only
manufactured sand (M-sand) instead of river sand for all its building
activities. A move widely seen as a good initiative aimed to plug the
demand-supply deficit in order to ease pressure on sand mining. Shifting of
PWD, one of the major consumers of sand in the state, to M-sand is bound to
ease prices of sand in the market and also curb illegal sand mining. Point to
be noted here is that M-sand is nothing but crushed rock, that too mostly
granite. Though it yields higher quality concrete, but the questions one needs
to ask are these: Are we really solving the environmental concerns? Isn’t it a
misplaced attempt as rocks are also minerals that need to be conserved?
As humans we’re a race that takes everything for granted, and that’s evident
in the way we’ve recklessly consumed most of our natural resources. Take a look
around, we haven’t spared much in the name of development. Whether it’s coal,
water, oil or even natural gas, we’ve managed to diminish it all. But did you
know that sand falls into this list as well? That it’s an extremely essential
natural resource being used everywhere, right from cement, concrete, glass,
computer parts, smart phones, toothpaste, cosmetics, paper, paint, tires and so
much more! But sand isn’t an unlimited resource. It’s in fact one of the most
consumed and underestimated resources in the world and with 70 per cent of
world beaches disappearing, we haven’t the slightest idea what the
repercussions will be in the future.
Ranchi city in Jharkhand State
receives sand from only Kanchi river now. Earlier sands of two more rivers were
used for construction. Now in both rivers the deposits of sands have been
affected due to over exploitation especially of Jumar river flowing north of
city.
Sand being so in demand (it’s fuelling the construction boom everywhere),
the industry has already consumed most of it available in quarries and rivers.
Sand from the deserts cannot be used for construction as the grains are rounded
and polished (due to winds) and do not stick together, which is essential for
construction. The industry has no option and is turning to the sea and beaches
to meet its insatiable demand. Illegal sand mining is already underway in 70
countries around the world.
Sand-rivers providing perennial water supply some
sand-rivers provide water throughout all the years due to the favourable
features of:
• The floor under the sand in a riverbed forms an upwards
dyke which traps water upstream of it. An underground reservoir is thereby
created from where water can be drawn. In Jharkhand state of India people residing near the banks of polluted
Damodar and Swarnarekha
River are more dependent
on river sands for drinking water than consuming directly from the river. They
dig the sand to trap clean water.
• Coarse sand and gravel in sand-rivers can trap and store
50 per cent of water in the voids between the solids of sand. Up to 35 per cent
of this water can be extracted. In other words, 350 litres of water can be
extracted from every cubic metre of sand.
Sand is not a sustainable resource and though it regenerates, it is being
consumed faster than its rate of creation. It takes 25,000 years to
create sand from the mountains and sand stone, which breaks down and flows down
little streams, down rivers to deltas and then gets carried to the ocean by the
waves and tides. Much of the sand never makes it to the ocean because of dams
which trap the sand. There are about 8,45,000 dams in the world. In the US alone there
are around 80,000 dams. In China,
it is estimated that by 2020 not one river will reach the sea. Thanks to these
dams, much of the sand that could reach the sea won’t do so.
Most of us think of sand as a
necessary ingredient for any beach vacation. Yet those seemingly insignificant
grains of silica surround our daily lives. Every house, skyscraper and glass
building, every bridge, airport and sidewalk in our modern society depends on
sand. We use it to manufacture optical fiber, cell phone components and
computer chips. We find it in our toothpaste, powdered foods and even our wine
(both the glass and the wine, as a fining agent)! Is sand an infinite resource?
Can the existing supply satisfy a gigantic demand fueled by construction booms?
What are the consequences of intensive beach sand mining for the environment?
By the end of the 21st century, beaches will be a thing of the past. That is
the alarming forecast of a growing number of scientists and environmental NGOs.
Sand has become a vital commodity for our modern economies. The worldwide
construction boom fuelled by emerging economies and increasing urbanization has
led to intensive sand extraction on land and in the oceans, with damaging
environmental impacts.
The construction industry requires massive amounts of sand for its
projects. Despite some legal framework prohibiting sand mining in most
states, the industry gets most of the sand by dredging rivers’ earthen
materials beyond a safe capacity. In almost every river where it is
viable, the ‘sand mafia’ purge the depths for profitable sand, amounting to an
illegal yearly turnover of Rs. 1000 crore. Despite its illegality, sand mining is perpetuated by various social and
economic dilemmas. First, it brings revenue to state government and
panchayats, which paves the way for corruption and conflict. Thus,
relationships between local politicians, contractors, and bureaucrats emerge to
create a power nexus capable of deterring community-based
resistance. The players in this nexus are infamously termed the’
sand mafia,’ by the media.
The case of Maharashtra epitomizes this
phenomenon. In September 2010, the Bombay High Court banned the
extraction of sand, due to its adverse environmental effects and detriment to
water supply. If this ruling had stuck, the real estate industry would
have suffered a loss of Rs. 2,000 crore. The High Court asked the
government to come up with a new policy on sand mining after the court
appointed Indian Institute of Technology submitted a report. On 20 Oct 2010,
State cabinet approved a new sand mining policy that empowers communities to
have a say on sand mining in their localities. The policy also bans use of
suction pumps in dredging but fails to ban mechanized dredging. Moreover, the
High Court directed the Maharashtra government not to award any contract or
allow any sand excavation to commence across the state "until and
unless" it first obtained environmental clearance as contemplated in its
latest policy decision.
The environmental reasons for this ban and others across India are
numerous. Sand acts as an aquifer, and as a natural carpet on the bottom of the
river. Stripping this layer leads to downstream erosion, causing changes
in channel bed and habitat type, as well as the deepening of rivers and
estuaries, and the enlargement of river mouths. As the river
system lowers, local groundwater is affected, which leads to water scarcities
aggravating agriculture and local livelihoods. In terms of legal measures,
ground water shortages have been noted as the patent problem with river sand
mining. Less considered in legal action, but centrally relevant, experts
also note substantial habitat and ecological problems, which include “direct
loss of stream reserve habitat, disturbances of species attached to stream bed
deposits, reduced light penetration, reduced primary production, and reduced
feeding opportunities”. key issues have not been resolved.
The rivers in Kerala have been subject to significant such degradation, and
serve as a good overview of the aforementioned problems. Major rivers
such as the Pampa,
Manimala, and Achankovil have been subject to such non-discretionary dredging
that there has been a sharp fall in ground water table levels. According
to one study, indiscriminate mining has lowered the Pampa an average of three to four metres, and
up to six metres in some areas.
Sand smuggling is continuing unabated in Krishna
district despite the ‘preventive measures’ by the official machinery since the
sand mafia is enjoying the support of the politicos.
While the government stopped the sand auctions due to legal and
administrative issues as well as pressure from the politicos for more than a
year, the sand mafia is minting money by transporting the sand from Krishna
river using trucks, mini trucks, passenger auto-rickshaws and even bullock
carts on both sides of the river Krishna in Krishna and Guntur districts.
Nearly 40 sand reaches are located along the Krishna
river in the district from Jaggaiahpet mandal upstream of Prakasam barrage to
downstream of the river in Avanigadda mandal in Diviseema.
Sand smuggling is a regular phenomenon in Ibrahimpatnam, Kanchikacharla,
Nandigama, Chandarlapadu, Jaggaiahpet, Penamaluru, Thotlavalluru, Challapalli,
Ghantasala, Pamarru and Avanigadda mandals of Krishna
district.
Besides, sand is also smuggled from rivulets of Munneru and Tammileru in Krishna district. The officials are facing a
challenging task of preventing the illegal sand quarrying. Most of the illegal
sand extracted from the reaches is used for construction activity particularly
in the construction of buildings, houses, and government projects.
In the Eastern Uttar-Pradesh, mechanized sand mining has resulted in soil
erosion and turned thousands of acres of land infertile and sand mafias are in
control of rivers like Chhoti Gandak, Gurra, Rapti and Ghaghara.
Indiscriminate sand extraction is likely to create environmental problems in
future. The contractors who get the rights for quarrying are exceeding their
limits in extracting more sand deep into the river beds.
This will create many environmental problems in future.
Collins et al. (1990) summarized the effects of sand and
gravel mining as listed below:
a) Extraction of bed material in excess of replenishment by
transport from upstream causes the bed to lower (degrade) upstream and
downstream of the site of removal.
b) Bed degradation can undermine bridge supports, pipe lines
or other structures.
c) Degradation may change the morphology of the river bed,
which constitutes one aspect of the aquatic habitat.
d) Degradation can deplete the entire depth of gravelly bed
material, exposing other substrates that may underlie the gravel, which could
in turn affect the quality of aquatic habitat.
e) If a floodplain aquifer drains to the stream, groundwater
levels can be lowered as a result of bed degradation.
f) Lowering of the water table can destroy riparian
vegetation.
g) Flooding is reduced as bed elevations and flood heights
decrease, reducing hazard for human occupancy of floodplains and the
possibility of damage to engineering works.
h) The supply of over bank sediments to floodplains is
reduced as flood heights decrease.
i) Rapid bed degradation may induce bank collapse and
erosion by increasing the heights of banks.
j) In rivers in which sediments are accumulating on the bed
(aggrading) in undisturbed condition, gravel extraction can slow or stop
aggradation, thereby maintaining the channel's capacity to convey flood waters.
k) The reduction in size or height of bars can cause
adjacent banks to erode more rapidly or to stabilise, depending on the amount
of sand and gravel removed, the distribution of removal, and on the geometry of
the particular bend.
l) Removal of gravel from bars may cause downstream bars to
erode if they subsequently receive less bed material than is carried downstream
from them by fluvial transport.
A worldwide sand rush is taking place. Sand is bagged by divers on the Maldives, it is towed from beaches to trucks by
mules in Morocco, excavated
from heavenly beaches by machines in the Philippines. In Indonesia dredge boats suck it up from the
bottom of the sea, in Vietnam
from the river Con. In Sierra Leone
workers excavate every grain from local beaches, while on the other side of the
Atlantic, in the Caribbean, sand thieves steal
entire beaches unnoticed.
Sand is a key raw material for the construction business. Building requires
tons of sand. Armoured concrete is two-thirds sand. The construction of a house
costs on average two hundred tons of sand. Thirty thousand tons are needed for
a one-kilometre stretch of motorway; twelve million tons for a nuclear plant.
After water, sand is the most-used material in the world.
Sand for Construction
Sand is an extremely needful material for the construction
but this important material must be purchased with all care and vigilance. Sand
which is used in the construction purpose must be clean, free from waste stones
and impurities. It is important to know what type of sand is beneficial for
construction purpose as sand is also classified into three different forms that
make it suitable for specific type of construction.
Sand is classified as: Fine Sand (0.075 to 0.425 mm), Medium Sand (0.425 to 2
mm) and Coarse Sand (2.0 to4.75 mm). However this classification of sand is
further has types of sand in particular and on that basis only they are being
incorporated in the construction. Read out the detailing of the types of sand:
Pit Sand (Coarse sand)
Pit sand is classified under coarse sand which is also called badarpur in
common language. This type of coarse sand is procured from deep pits of
abundant supply and it is generally in red-orange colour. The coarse grain is
sharp, angular and certainly free from salts etc which is mostly employed in
concreting.
River Sand
River sand is procured
from river streams and banks and is fine in quality unlike pit sand. This type
of sand has rounded grains generally in white-grey colour. River sand has many
uses in the construction purpose such as plastering.
Sea Sand
As the name suggest, sea sand is taken from seas shores and it is generally in
distinct brown colour with fine circular grains. Sea sand is avoided for the
purpose construction of concrete structure and in engineering techniques
because it contains salt which tends to absorb moisture from atmosphere and
brings dampness. Eventually cement also loses its action when mixed with sea
sand that is why it is only used for the local purpose instead of structural
construction.
There are different standards for the construction purpose which must be
checked and considered for the better construction. The requirement according
to which sand is chosen should be like:
- For plastering purpose the
overall fine sand used must not be less than 1.5 while silt is preferred
to not less than 4 percent.
- For brick work fine sand used
must not be less than 1.2 to 1.5 and silt is preferred is 4 percent
generally.
- Concreting work require
coarse sand in modulus of 2.5 to 3.5 with not less than 4 percent silt
content.
The coarse sand is used for constructing pillars and
underground tanks, while the medium sand is used for the first layer of
plastering and other works. The final finish of plastering includes the use of
fine sand. Pit coarse sand obtained from quarries is used in the construction
of houses in urban areas of Hyderabad.
It is filtered when required for specific uses in construction such as
plastering.
Like any other material, there are certain features that determine the quality
of sand. Good quality sand should not possess more than 4% of silt content. It
should have natural and crushed stone sand. It must be free from organic matter
and other dirt particles.
How to check the quality of sand.
Many of us do not know the quality, features, and
measurements of good sand. Many builders/suppliers make an advantage of this by
providing a cheap rate load and may tell that it is of good quality. However,
there are certain ways which help you in knowing the quality of sand. Take some
quantity of sand and put it in a glass of water. Shake it well and allow it to
settle. If a distinct layer of clay or impurities is formed at the top of the
sand, it can be considered as of low quality. The other way of assessing the
quality is to add sodium hydroxide or caustic soda to sand solution. The
presence of impurities in the sand is detected by the color change of the
solution. Clay and silt content present in the sand also affects its quality.
Here is another idea for assessing the quality of sand. When you rub the sand
sample between damp hands, clean sand will leave the hands slightly stained. If
the hands are left dirty, it indicates the presence of too much silt or clay in
the sand.
Dwindling sand supplies, rising prices and an increased demand have given
rise to a sand mafia. In many countries criminals collaborates closely with
corrupt governments and police. In over 8,000 places in India, for example, sand is
excavated illegally.
Forty percent of Morocco’s
sand trade involves illegal sand that is excavated and immediately sold on
construction sites. There, it is used unprocessed to make concrete, a guarantee
for future problems. The Moroccan government fears that most of its country’s
beaches are being transformed into a moonscape.
World status:
Singapore – With a booming economy, it has been accused of
importing illegally dredged sand from neighbouring states and smuggling sand
from poorer neighbouring countries to expand its coast line.
Many islands of Indonesia
have vanished.
USA- Sand mining in the USA
has resulted in erosion and a collapse of beachfront houses and properties.
With beaches disappearing, many places like Florida are artificially putting
sand back onto the beaches to attract tourists, but this not been fruitful
Maldives – Many islands have disappeared, there’s been a loss
of livelihood and rising water levels Dubai has extensively used and
extensively exhausted its own sand resources to build artificial beaches
and in construction, etc. Dubai
and many other such countries are buying and importing sand.
India
- After China
and the United States, India has the
world’s largest construction business.
India has a very strong sand
mafia which works in nexus with builders and politicians, especially in areas
like Navi Mumbai, and coastal districts of Thane, Raigad, Sindhudurg and
Ratnagiri and Gujarat and Goa. Sand mining and
dredging is rampant despite all directives against it.
A lack of any clear regulatory framework has aggravated the
environmental problems caused by river sand mining. In addition, sand prices
have increased several times over in recent years and this has driven the
exploitation of sand into fragile and remote places. This movement of sand
mining into marginal areas has not only exacerbated its impact on nature, but
has also caused more damage to weak rural roads.
If the demand for sand could be partly met from other
sources the environmental impact of river sand mining could be significantly
reduced. To see whether this is a possible course of action, alternatives to
river sand mining were identified and assessed. The following alternative
sources were highlighted: offshore sand, land based sand, dune sand and the
use of quarry dust. A river sand tax could also be introduced in order to
encourage the construction industry to move towards the use of offshore sand. But
sustainable mining is best option to protect the sands from over exploitation
because till today alternatives of sand is not available.
Mother Nature has its own way to counter coastal erosion via a natural
supply of sand. Most beach sand comes from rivers that bring it in from the
mountains. But exactly these rivers are being dammed up. That effectively stops
the migration of sand. Worldwide dams are stopping the supply of fresh sand and
are holding up one quarter of the sand supplies. River dredging is another
cause why half the sand that would normally reach the sea doesn’t succeed in
doing that.
References:
Collins,B. and Dunne,T. (1990). Fluvial Geomorphology and
River-Gravel Mining: A Guide for Planners, Case Studies Included. Special
Publication 98, California Department of Conservation, Division of Mines and
Geology.
