OK Tedi environmental disaster on Fly River

The Fly is 1,050 kilometers (650 mi) long, the second longest river in Papua New Guinea, after the Sepik. The Fly is the largest river in Oceania, the largest river in the world without a single dam in its catchment area and ranks globally as the 25th largest river in the world by flow. It originates in the Victor Emanuel Range branch of the Star Mountains and flows through the southwestern lowlands before emptying into the Gulf of Papua in a large plain. 

The Ok Tedi environmental disaster caused severe environmental damage along 1,000 kilometers (620 mi) of the Ok Tedi and Fly rivers in the Western Province of Papua New Guinea between 1984 and 2013 The lives of 60,000 people have been disrupted. One of the worst man-made environmental disasters, it is the result of dumping about two billion tons of untreated mining waste into Ok Tedi from the Ok Tedi mine, an open pit mine in the Western Province of Papua New Guinea. 

In 1999, BHP reported that 90 million tons of mining waste had been dumped into the river every year for more than ten years and was destroying villages, agriculture and fishing downstream. Mine waste has been deposited along 1,000 kilometers (620 mi) of Ok Tedi and the River Fly below its confluence with Ok Tedi, and over an area of ​​100 square kilometers (39 sq mi). BHP CEO Paul Anderson said the Ok Tedi mine was "incompatible with our environmental values ​​and the company should not have gotten involved". Erosion caused in river system every year, approximately 1,588 square kilometers (613 square miles) of forest are dead or under stress. Up to 3,000 square kilometers (1,200 sq mi) is likely to be damaged, an area equivalent to the US state of Rhode Island or the Danish Island of Funen after heavy rains, mine waste was washed away in the area. surrounding rainforest, swamps, and streams, and left 30 square kilometers of dead forest. Thick grey mud from the mine is visible throughout the Fly River system, although its impact downstream is less severe. 

The chemicals from the residue killed or contaminated the fish, although they were still eaten by people in the surrounding villages. However, the number of fish decreases closer to the beak. The huge amount of mining waste dumped into the river exceeds its load capacity. This spill caused the riverbed to rise by 10m, resulting in a relatively deep and slow-flowing river becoming shallower and developing rapids, disrupting native transport routes. Flooding caused by the uplift of the riverbed has left a thick layer of polluted mud on the floodplain between the plantations of taro, banana and sago palm which are the staple food of the local people. About 1300 square kilometers were damaged in this way.