Karnataka sacrifices stones to conserve river sand

State mandates use of manufactured sand in public works, which would result in over-exploitation of another minor mineral and damage to the environment

By Avikal Somvanshi
Published: Wednesday 18 September 2013

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, 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. Addressing media on the issue, law and parliamentary affairs minister of Karnataka, T B Jayachandra, said the demand for sand is about 3.3 million tonnes a month in the state while the supply is just 800,000 to 900,000 tonnes.

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. Depending on the supply-demand and distance factors, the price of sand currently varies from Rs 30,000 to Rs 60,000 a truck-load. according to Jayachandra. Maintaining that several private firms have come forward to set up M-sand manufacturing units at Bidadi near Bengaluru, he said that once M-sand was made popular the demand for the river sand would reduce and also solve environmental concerns.

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?

History's quicksand
Construction boom along with mega infrastructure developments like Namma Metro Project of Bangaluru has complicated the whole demand-supply situation of sand. According to construction industry estimates, to build a 100 sq m structure, around 22 cubic metre of sand is needed. Over-exploitation of local rivers for sand mining and active intervention of the Karnataka High Court forced Karnataka to regulate and monitor sand mining since 2009 through a sand mining policy. The policy was revised in 2011 following further directives of the high court on illegal sand mining.

Further complications have been added by sand lorry owners. They have been going on frequent strikes since 2010 to protest restrictions imposed on movement of sand lorries in the state. All these factors together have pushed sand prices more than fivefold. It was Rs 7,000 to Rs 8,000 a truck-load a few years ago. Karnataka’s construction industry has been severely hit by this increase. Confederation of Real Estate Developers’ Associations of India (Credai) has been contemplating challenging the National Green Tribunal’s (NGT’s) ban on sand mining without environment clearance in the court. terming it as arbitrary and anti-growth.

Earlier trial and error
Shortage of river sand in the state has prompted development multiple alternatives even before M-sand. “Filtered” sand was one of the most popular alternatives which come under scanner of state Lokayukta for being dangerous for construction activities. “Filtered” sand is soil washed in a sieve, which rids it of impurities; then the clean sediment or “silica sand” is used for construction. The Lokayukta in his May, 2008 report said “filtered” sand does not have binding force and buildings constructed using it may last only eight to 10 years. The report, suo moto in nature, was prompted by the collapse of a building in Bengaluru in October 2008. Four persons were injured and another 100 construction workers had a providential escape when part of a 15-storey concrete structure which was under construction crashed at Whitefield. Use of filtered sand, and possibly lack of proper soil testing played a role in this collapse, the Lokayukta said.

M-sand industry
M-sand is crushed aggregates produced from hard granite stone which is cubically shaped with grounded edges, washed and graded with consistency to be used as a substitute for river sand. M-sand produced under strict industrial control and manufactured to meet BIS standards has proven to produce stronger concrete compared to river sand.  Fears raised by “filtered” sand seemed to have been answered by M-sand. All the four southern states have recognised it as a substitute for river sand, and have been promoting its use over the years. Karnataka has been the most pro-active of the lot. In fact, the 2011 sand policy encourages establishment of M-sand units by giving it top priority while allotting quarries.

To further incentivise M-sand, need for a joint policy has arisen as stone crushing is governed by a different law. Jayachandra informed that a secretary-level committee, comprising those from mining and industry departments, among others, was formed last week to work on a comprehensive draft on mining and stone-crushing policy, and it would submit recommendations within a month. "Once the committee submits its report, the state government's 2011sand policy would be replaced with the new and comprehensive document to deal with the problem," he said. The new minor mineral policy would also provide solutions, mainly relating to getting clearance from the forest as well as environmental agencies for the stone crushing units.

Stoned logic
Stone quarrying and crushing has long been associated with high environmental damage and air pollution concerns. In fact, court directives regarding environmental concerns related to stone crushers of the state pre-dates sand mining concerns. The Karnataka High Court's 1998 order to relocate all stone crushers to a designated “safer” zone in order to keep a check on pollution hasn’t been completely implemented yet. The Karnataka State Pollution Control Board (KSPCB) has been slapping closure notices on stone crusher units to control the menace. Following a Supreme Court directive, 3,700-odd crusher units across Karnataka were shut last year.

M-sand is not the same as quarry dust and should not be confused as a by-product or waste of stone quarry. Therefore, to meet 2.4-2.5 million tonne per month shortage of sand in the state at least 2.4-2.5 million tonnes extra virgin granite have to be mining in the state, assuming an impossible 100 per cent efficiency in M-sand manufacturing system. If one goes by the trend, for every state of art M-sand manufacturing unit, 100 or so informal small scale and highly inefficient units will crop up. This is lot more of stone mining and crushing in an already stressed state.

Real solutions on offer
The dilemma for the construction sector is acute, but solutions are not far to look for. At a workshop-cum-exhibition organised by the Karnataka Engineers’ Federation in Bangaluru on last Saturday, sand was the chief topic of discussion. Jindal Steel mooted the idea of producing artificial sand from the slag left after manufacturing steel as the best alternative to sand.

The company estimated that by 2020, 70 million tonnes of slag could be stacked. And instead of treating it as a waste material, it can be put to good use. Approximately 500 tonnes of slag is produced from the manufacture of every 1,000 tonnes of steel. The sand made from such slag costs about Rs 100 per tonne on site (in Bellary and Hospet), considerably less than the river sand. The charges to transport the sand to Bangaluru will, however, gobble up all the savings. Jindal Steel even claimed that KSPCB has okayed the use of such sand.

Way forward
Converting industrial waste like slag into alternative to river sand has its own complications but is still a more viable solution to explore. Even though scientifically sound and internationally practised alternative to river sand, this cannot be adopted in India. Reason being the standards in India require the sand to be of “natural” origin only. Thus, the easier way out is to promote M-sand and filtered sand which are made of natural material even if not environmental sound. But if the worries of construction industry have to be soundly addressed then we need to rise above these quick fixes and ask BIS to revise its standards and issue new guidelines for safe induction of recycled sand into the construction industry.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.