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Submarine Tailings Disposal
What is STD?
STD is Submarine Tailings Disposal - the disposal of dangerous mine waste into the ocean. This waste disposal is polluting coastal environments at several operating STD mines in the Asia Pacific. It has been imposed on a number of communities in the region without their informed consent.
What are tailings? Tailings are simply mining waste. In a typical metal mining operation, tailings consist of crushed rock and ore, after most of the target metals have been removed. Mine tailings are often toxic, and if not contained, are harmful to the environment.
In STD, mines pipe their tailings to the ocean, then run another pipe out into coastal waters, where the tailings spill out over the sea floor, and may disperse in coastal currents. Off the island of Sumbawa in Indonesia, an enormous pipe releases 160,000 tons of tailings per day into coastal waters.
STD is used more and more by mining companies from rich countries in their operations in poorer countries, where they can often get around environmental restrictions and are not accountable to local communities. STD is effectively illegal in the USA, Canada and Australia. The world's biggest mining companies like Newmont, Placer Dome, Rio Tinto and BHP are based in these wealthy countries. Yet these same companies are operating or planning STD at mines throughout the Asia-Pacific region that would clearly not be permitted in their own countries.
STD costs less than land-based disposal because it does not require the construction of dams or long-term responsibility for the effects of tailings. As far as the mining company is concerned, once the waste is released into the sea, it is "out of sight, out of mind".
STD is being promoted by the mining industry as the safest method of getting rid of its wastes. Affected communities in Indonesia, the Philippines, Papua New Guinea and elsewhere don't believe this. Their lives depend on the coastal waters, and they report that mining companies dumping waste in the ocean have hurt their livelihoods and their health.
There are few independent laboratory or field studies into the environmental impacts of STD. Most of the information which does exist about STD is written by or for the mining companies using the technique. In addition to this, companies often refuse to release the information to the public.
Mine waste on the loose
The aim of an STD operation is to have the tailings travel from the mouth of the underwater pipe in a continuous current to the sea floor. That's the theory. In practice, it is inevitable that substantial quantities of mine waste will separate from the main tailings flow and form plumes of waste that will spread out across the ocean. Different currents can carry these plumes into surface waters. The mine waste that reaches the sea floor doesn't necessarily stay there. It is almost certain that deepsea currents will move tailings away from the disposal area. Deep-sea storms and turbulence can stir settled waste up. But the most serious problem is related to upwelling. Upwelling is the term used to describe the movement of deep ocean water to the surface of the sea. This usually occurs along the coastline, and under normal circumstances is one of the most productive marine processes because it provides food, for fish and other animals. Upwellings are often the site of the best fishing. Unfortunately, upwelling can also bring mine waste back to the surface of the ocean, where it is most dangerous to marine life.
Smothering
A major deep-water impact of STD is typically the smothering of hundreds of square kilometers of seafloor under hundreds of millions of tons of tailings. The exact impact of this in many operations can only be guessed, since proper scientific research has not been done. But miners admit that those sea floor organisms which don't simply die from being buried under mine waste will instead become contaminated with toxic metals to an unknown extent. Miners dismiss these organisms as unimportant since they live deep under the sea. But these animals form part of the ocean's food chain, and more mobile predators that feed on them can carry the toxic metals further afield and upwards, acting as a biological "pump" mechanism to bring contamination to shallower waters.
Fisheries
People living on the coasts of the archipelagos of Southeast Asia and the South Pacific depend on the sea for their livelihood. STD has been linked to toxic contamination in fish and eventually deters them from entering dumping areas. Fish catches and local incomes then decline drastically. STD also wipes out bottom-dwelling fish and other organisms, and affects coral ecosystems, potentially threatening rare species and adding to the decline of coral reefs worldwide.
One example of a toxin that can enter the marine environment when STD is used is ammonia. This chemical, which is used in nickel plants, can be deadly to marine life, or in smaller amounts can damage fish's gills, interfere with reproduction and stunt growth. The toxic metals in tailings often include mercury, cadmium, nickel, chromium and arsenic. Apart from direct toxicity, fine particles of mine waste make water muddy, which interferes with fishing, and with the breeding and migration of many species of fish that depend on clear water.
Fish that can be caught are hard to sell because of health fears in the market. Communities without other economic resources are forced to eat contaminated fish. Not only are local communities impoverished, but strong evidence suggests they suffer serious health damage, ranging from skin disease to paralysis.
For more information, please contact:
Igor O'Neill
Workphone: +62 21 794 1672
Mobile: +62 81 286 12 286
Created: 01 Jan 1970 | Last updated: 20 Oct 2004
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