The Marcopper mining disaster was one of the Philippines' largest mining disasters to date. The disaster occurred on the Philippine island of Marinduque a province of the Philippines located in the MIMAROPA region in Luzon.
On 24 March, 1996, the Marcopper Mine on Marinduque made global news due to a Mining accident at their Marinduque mine. The incident involved the Marcopper Mining Corporation which has been carrying out open-pit copper mining since the 1970s. When the company finished one of its operations in Marinduque, it plugged up the old pit with a concrete fixture to allow the pit to act as a disposal lake for mining waste. In August 1995, a significant leak was discovered in the pit's drainage tunnel. This subsequently fractured. The accident discharged tailings into the Makulapnit-Boac (Boac) river system. The disaster resulted in the release of over 1.6 million cubic meters of tailings along 27 km of the river and the coastal areas. The impact on the river and the people who depend on it for their livelihoods was massive. The rush of tailings displaced river water which inundated low-lying areas, destroying crops and vegetable gardens and clogging irrigation channels to rice fields. The release left the Boac River virtually dead. The effects of the incident were so devastating that a UN assessment mission declared the accident to be a major environmental disaster.The Tapian pit contained around 23 million metric tons of mine waste. Officials of the DENR (Department of Environment and Natural Resources) claim that they did not know of the presence of the drainage tunnel measuring 2.6 kilometres long and 1 metre wide which was found underneath, which leads to the Makulapnit and Boac river system.
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