Pitfalls and Pipelines - Philippine Indigenous Peoples Links

82 Pitfalls and Pipelines: Indigenous Peoples and Extractive Industries
1.3.3 Mining and the Impacts of Climate
Change
There are serious considerations about mining impacts
that it is predicted will be made worse by more extreme
weather and climate change. Some threaten the safety of
surrounding communities and may threaten the viability of
mining projects as well.
Waste Management: Tailings Dams
The safety of tailings dams is an area of particular concern
because of the potential seriousness of breaches.
Mine tailings are these days most commonly held behind
tailings dams. Most dams are currently constructed with excavated
earth. All are built to a cost calculation based on the
risks of dam failure prediction of extremes of future weather.
The biggest tailings dam currently in the Philippines is, according
to its constructor, Lepanto Consolidated, built on a
calculation to withstand a one in 500 year weather event. 51 As
there is, however, an increase in extreme weather events due
to climate changes, the odds of such an event occurring are
increasing. In the past a disturbing number of the more than
3,500 tailings dams said to be in existence globally suffered
serious incidents of breach or leakage. 52 For example, according
to a partial listing by PIPLinks, in the Philippines there
has been a serious incident on average once every two years
or more over the last 25 years. 53
Where heavy unseasonal rains may occur, mine sites are
particularly vulnerable to rapid run off sometimes including
washing of exposed earth and even toxic materials into
river and marine systems. The cost of the safe management of
waste containment may have to escalate steeply; even prohibitively.
In some regions it may prove necessary to impose no
go zones for tailings dams. Zones to be affected may include
the typhoon/cyclone zones of Southeast and South Asia and