Wednesday, July 2, 2014

Sand mining is going to be new battleground.



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.











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