New Delhi | Jun 13, 2016:
The guidelines said that training of architects and engineers, new laws and regulations, and positive incentives are needed to initiate a shift for lowering our dependency on sand. Photo: HT To promote sustainable sand mining, the Union environment ministry has suggested tapping “alternative sources of sand and gravel” like sand that accumulates at the bottom of dams.
“Their use would address the problem of these aggregates accumulating which leads to reduced capacity of dams to store water and could result in the dams’ water intakes being blocked. Dams regularly release large amounts of water to flush out aggregates,” said the sustainable sand mining management guidelines 2016 released by the ministry of environment, forest and climate change (MoEFCC) last week.
The guidelines stressed on “reducing consumption of sand” and focusing on alternative sources of sand.
“Because sand is still very cheap—sand itself is freely accessible (and) only extraction and transportation costs need to be covered—there is little or no incentive to induce a change in our consumption. Despite the very high value of minerals found in the sand, it is mostly used for concrete or is buried under highways,” said the guidelines.
“Recycled building and quarry dust material can be a substitute for sand. Concrete rubble should be recycled to avoid using aggregates, at least for low-quality uses. Substitutes for sand are available. Quarry dust could be used to replace sand in general concrete structures,” it added.
The guidelines further said that training of architects and engineers, new laws and regulations, and positive incentives are needed to initiate a shift for lowering our dependency on sand.
“Renewable and recycled materials need to be targeted for building houses and roads. Use of manufactured sand (M-Sand) also needs to be promoted,” it added.
The guidelines also stressed that India’s national standard body, Bureau of Indian Standards, is taking steps to promote the usage of alternatives to sand and gravel.
“Bureau of Indian Standards, the national standards body of the country, considering the scarcity of sand and coarse aggregates from natural sources, has evolved number of alternatives which are ultimately aimed at conservation of natural resources apart from promoting use of various waste materials without compromising in quality,” the guidelines explained.
Some of the alternatives for sand that have evolved are use of slag, waste from steel industry; fly ash, waste from thermal power plants; crushed over-burnt bricks; and tiles, waste from clay brick and the tile industry, for plain cement concrete as an alternative to sand (natural aggregate).
In January 2016, Prakash Javadekar-led MoEFCC came out with a policy for mining of minor minerals with special emphasis on sustainable sand mining. Under the new policy, the Union government decentralized the process of granting environmental clearance for sustainable sand mining and mining of minor minerals. It created a District Environment Impact Assessment Authority for proper monitoring of sand mining.
(Source: http://www.livemint.com/)