Lake Chinchaycocha, Peru’s second largest lake, is threatened by growing contamination of its waters by mine tailings, reported daily El Comercio on Friday.
The lake, which constitutes central Peru’s largest water reserve, is dying little by little because of mining-related activity and contamination, said Junín Regional President Vladimiro Huaroc Portocarrero, during a regional assembly of mayors and community leaders.
Many species, such as the Junín flightless grebe and the giant frog, are on the verge of extinction, Huaroc added, and the water is becoming unusable for human or agricultural use.
Located more than 13,000 feet above sea level, Lake Chinchaycocha, which is also known as Lake Junín, is famous for attracting the greatest concentration of Andean birds in America, including the Junín flightless grebe, a slender bird similar to a duck.
With its narrow pointed beak, the grebe feeds on small fish caught by diving in the icy depths of the lake. But, its inability to fly has trapped it in a habitat damaged by pollution, and populations are down to an alarming 50-70 birds from a reported 1 million in the 1980s. Most bird species of the lake have suffered a dramatic decline in numbers, which is attributed to the prolonged contamination of the waterbody.
In response to the central government’s inaction, the mayor of Junín, Percy Chagua Huaranga, has called for drastic and immediate action.
“The Municipality of Junín, taking into account the serious contamination of (Lake) Chinchaycocha, has decided to file a complaint in Cerro de Pasco (one of Peru’s main mining areas),” said Chagua, so that it may be determined by the Public Prosecutor’s Office if mining companies are complying with their Environmental Management Programs, or PAMAs.
PAMAs have somewhat contributed to reducing the problem of mining wastes, as drainage fields have been set up and wastewater has begun to be recycled. However, the terms of many of these programs have expired, and companies have solicited extensions.
Lawbreakers should be sanctioned and their mining activities should be suspended, added Chagua, who pointed fingers at Volcan, El Broval, and Aurex, three companies he believes are “top polluters and environmental offenders.”
Lake Chinchaycocha, which is undergoing a process of eutrophication, is extremely contaminated by mining waste, especially in the northeastern section. Since at least 1933, there has been an inflow of mining residues into the lake, which has affected the fish and bird fauna.
“The problem is the pollution. The fish are dying and the birds and frogs have nothing to eat. Even the algae die off and float on the surface so the light can’t get through. Then they start to decompose,” said Francisco Tueros Aldana, a local fisherman.
And, though agriculture is sparsely developed in the area surrounding the lake due to its high elevation, water quality studies have detected the presence of agricultural insecticides in the lake.
Decomposition of submerged vegetation and discharge of wastewater from the towns of Junín and Carhuamayo are also important sources of contamination, and have lowered the available oxygen and increased the phosphorous load in the lake.
Several tributaries, including the Yahuarmayo, the Mararychaca, the Condorcocha, and the Huascán Rivers, converge into Lake Chinchaycocha, also carrying significant quantities of mining wastes loaded with heavy metals and other toxic substances.
In Peru’s highlands, several lakes and rivers are also polluted by tailings and mercury, a substance often used by informal miners.
