The world’s largest and perhaps most destructive mining industry is rarely discussed. Approximately 85 percent of all material mined from the earth is a simple and widely available resource: sand. Because it is so cheap and readily available, it is mined by everyone from guy with a shovel, to multi-million dollar machine operations. The majority of sand is used to make concrete, but the displacement of sand leads to the catastrophic destruction of coastal, sea bed and river ecosystems and topography.
The United Nations Environment Program estimates that 40 billion tons of sand are mined every year, but since the market is corrupt, hidden and decentralized there have been no comprehensive studies to date. In order to get a rough number, the United Nation’s used global cement production and sales figures to approximate how much sand is collected. For example, every ton of cement requires six to seven tons of sand and gravel in order to make concrete.
The environmental impact
Sand mining, especially when done without regulation or oversight, can damage rivers, cause beach erosion and destroy coastal ecosystems. At least 24 Indonesian islands disappeared off the map just to build Singapore.
Since sand dredging occurs primarily for construction purposes, miners target river and coastal ecosystems where the sand is ideal. River sand is particularly perfect for concrete because it is coarse and does not contain salt that would otherwise corrode metal and other building materials. In addition to disturbing riverbed and river bank ecosystems, altering the flow and capacity of rivers can cause drought or disastrous flooding– though rarely recognized as a contributing factor.
In Kerala, India, flooding was found to be partially caused by sand dredging that took 40 times more sand out of the river bed than the river could naturally replace.
Dredging sea grass habitat can also cause sediment to drift for miles causing both coastal erosion and smothering ecosystems like coral reefs. Erosion, land subsidence and the introduction of heavy machinery and vehicles into delicate habitats also threatens the integrity of nearby infrastructure such as roads and bridges.
One study found that every ton of sand taken from a river in California cost taxpayers $3 in infrastructure damage.
Cities’ demand for sand
Development and urbanization are expanding rapidly in every corner of the world to accommodate an exponentially growing population and our insatiable rates of consumption and expansion. According to the United Nations, the number of people living in cities is more than four times what it was in the 1950s. Over 50 percent of the world’s population now lives in urban areas with nearly three billion additional people expected to migrate to cities in the next 30 years.
In addition to new buildings, sand is also used for land expansion projects. In China, it is a common practice to dump sand on top of coral reefs to speed the process of building land. Dubai is also famous for its man-made islands, which required millions of tons of sand.
Singapore has added over 50 square miles of land in the past four decades and more skyscrapers in the last 10 years than all of New York City— a feat that required over 500 million tons of sand. The creation of Singapore was so rapid that Indonesia, Malaysia and Vietnam all banned the export of sand, but miners simply moved to Lake Poyang on the Yangtze River. The WWF calls this Lake the largest sand mine in the world, but it is tragically also Asia’s largest destination for migratory birds. Sand dredging activities have more than doubled the river’s capacity in certain areas, draining parts of the lake and reducing key fisheries.
The scale of the problem is enormous and the consequences of moving massive amounts of life-and land-sustaining material from one place to another is glaring but the world remains functionally oblivious, blinded by the desire for new buildings and up-and-coming neighborhoods.
Can sand dredging be done sustainably?
River ecologists suggest that sand dredging in rivers should only be done up to a pre-determined quota that allows the river to annually replenish sediment. However, this sustainable number will never equal humanity’s unsustainable need for development.
There are a number of suggestions to improve the sustainability of the industry, but none are perfect:
Offshore sand mining
Britain now sources much of its sand further offshore in order to protect river and coastal ecosystems, however, much of this sand is only used for land reclamation projects where the salt content is not a concern.
Sandy bottom reservoirs
Another untapped source is the sand that collects at the bottom of reservoirs. Dredging reservoirs could not only provide sand but also helps to expand storage capacity. Ecologists, however, argue that this sand should technically be put back into the rivers that feed into reservoirs.
Recycling glass and rubble
Rubble from demolished buildings can be used to produce concrete, reducing the need for fresh sand. Glass can also be recycled, which again reduces the need for sand.
Mining on flood plains
Limited mining on floodplains, rather than riverbanks and riverbeds, is thought to be less destructive. However, floodplains also have fragile ecosystems. In Australia, floodplains are home to rare carnivorous plant species that are now at risk from mining activities.
Replacing sand in concrete
Ash from incinerators and dust from stone quarries can be used in the production of concrete to reduce the demand for sand.
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