Sand is indispensable for construction, roads and oil recovery – even as nations try to protect coasts and supplies.
By Susan Froetschel*
When powerful storms strike, like Typhoon Hato in southern China or Hurricane Harvey in Texas, the surging water scatters tons of sand – an essential ingredient required for the rebuilding soon to follow. Such storms add to growing global demand for sand with poor consequences for the economy and environment.
Sand is a main ingredient for concrete, roads and other construction materials and second only to water as the most used natural resource. Building booms, especially in emerging nations, increase world sand production with prices doubling since the end of the 20th century. In the 1990s, geologists described sand mining as a local business, with product transport more than 30 miles economically unfeasible. Supplies that once seemed endless are in demand with more cross-border trade.
The global market in construction aggregates was valued at more than $350 billion in 2016 with demand leading for sand, although recordkeeping on mining operations is relatively new for many nations. Sand dredging along waterways eliminates natural buffers, contributing to nearby erosion. The International Monetary Fund warns of environmental harm with no international conventions to regulate trade along with minimal enforcement of national regulations.
Sand varies in size and color with chemical composition linked to the geological origin of rocks and minerals weathered over centuries. Industries have preferences. The construction industry relies on river sand. Glass, ceramics, electronics and oil industries seek inland silica sand with high levels of quartz wth names like Northern White or Sierra Gold. Foundries use dune sand for casting automobiles and wind turbines. Corrosive marine sand must be rinsed free of salt before use in concrete, but works well for projects described as beach nourishment, replenishment or repair along the US coast and land reclamation in the South China Sea. China alternately dredges the South China Sea for sand while adding deposits to contested reefs to build new islands.
Water naturally alters coasts over time, and humans try to limit the damage for communities.
Satellite data and other tools document shifting coastlines due to rising seas and climate change, and mining nearby sand to expand distant beaches has become a sensitive issue. In Japan sand mining has been banned for river channels since the 1960s but continues in seabed locations. The California Coastal Commission denied permits for Mexico-based Cemex, effectively ending sand mining for Monterey County beaches by 2021.
Beach restoration is not a one-time fix. Added sand erodes faster than natural sand, and few beach projects last more than five years without ongoing maintenance and additions, explains geologist Don Barber. Billions of cubic yards of material are removed from sites around the globe annually to keep shipping lanes open. In the United States, the Army Corps of Engineers oversees dredging projects for widening channels for modern ships, stockpiling offshore supplies and protecting shorelines.
Panama City is one of many Florida communities that have added millions of cubic yards of sand to beaches over the last two decades. The sand comes from nearby offshore “borrow areas,” a mixture of sand, silt and water transported by pipelines. The cost of 2017 repairs, estimated at $17 million, is largely paid for by tourists with a “bed tax” on rentals. Some communities like Miami have used up their allotted offshore supplies and yet reject sand dredged from inland Florida as too dark and costly. Instead, they want white sand from the Bahamas and the Caribbean, which would require overturning a law prohibiting imported sand in beach restoration projects that receive federal funding.
Activists raise alarm about eroded shorelines and wildlife protection, and communities increasingly impose limits on sand mining and exports, such as opposing public funding to restore beaches that limit public access. The appearance of four sand mining barges off a beach in Suriname despite a ban demonstrates need for community vigilance.
Nowhere is the competition for sand perhaps more intense than in fast-growing Asia. Governments in Malaysia, Vietnam and Cambodia have limited exports of river sand, concerned by Singapore’s increasing its land mass by 20 percent since 2000. People in six countries that rely on the Mekong River worry about China’s plans to dynamite sections, among the many One Belt, One Road projects that both require and exploit sand. A judge in the Philippines this month urged the government to guard a Sandy Cay sandbar near Subi Reef, where China is reported to be dredging sand. Investigators in Cambodia discovered that up to $750 million worth of sand went missing after the UN Commodity Trade Statistics Database showed about 3 million tons leaving the country between 2007 and 2015 and more than 70 million tons of Cambodian sand entering Singapore during the same period. Cambodia imposed a permanent ban on exports in July.
Increasing restrictions contribute to illegal sand mines in India, Malaysia, Sri Lanka, Nepal, Bangladesh, South Africa, Tanzania, Botswana and the Philippines, reports Marius Dan Gavriletea for Sustainability.
Industries search for alternatives. The fracking industry is reducing use of sand with new chemicals and well designs. Alternatives to river sand include crushed and screened waste glass, crushed rock and granite dust, quarry dust, recycled copper slag and sea sand. Singapore, New Zealand, Australia, Germany, Japan, the United Kingdom and others manufacture sand with large crushing and sorting equipment.
Engineers dismiss desert sand as too fine for construction or beach improvements, forcing sand-rich nations like the United Arab Emirates to rely on Australian and British multinationals for supplies. Still, researchers experiment with additives like marble dust and treatments to make desert sand suitable for erosion control. Recycling is another option. Recycling rates of glass containers is 73 percent in the European Union and 34 percent in the United States, with every ton of recycled product eliminating the need for a ton of natural product. Concrete can also be recycled for select uses, suggests the Construction & Demolition Recycling Association.
Singapore is taking lessons from the Netherlands in building dikes and seawalls around low-lying tracts of land along with networks of drains and pumps. Indonesia, after losing small islands due to illegal sand mining, has contracted with the Dutch firm Boskalis to construct an artificial island off Jakarta.
The best defense may be restricting building in coastal zones and protecting native plants.
The world’s largest exporter is the United States, which began keeping statistics on sand mining in 1905 and a century later was shipping industrial grade product to almost every region of the world. The value of US production of construction sand and gravel is higher than that of gold or copper production. Collecting production data in many nations is challenging because of varying specifications and the informal nature of some sand-mining businesses. In 2002 at the World Summit on Sustainable Development, 193 nations concluded that that sand and other minerals are essential for economic and social development. Sand miners must build good relations with communities, emphasizing sustainability and reducing waste, suggests the National Stone, Sand & Gravel Association.
Unchecked sand mining, with more sand removed each year than what can be replaced by the natural processes occurring over the course of centuries, is unsustainable. The forces of globalization are altering coastlines and the sand-mining industry as much as storms and waves shape grains of sand.
*Susan Froetschel is managing editor of YaleGlobal Online and author of five mystery novels that examine globalization and public policies at the local level.