Despite the importance it holds to the local people of Puno and the surrounding Katari area for their daily supply of fish and drinking water, Lake Titicaca – at 3,810m, the world’s highest large lake – has been left largely to fend for itself when it comes to hygiene. In October 2016, tens of thousands of critically endangered Titicaca water frogs were found dead, their bodies overwhelmed by toxins in the water. It’s just one result of pollutants that have been flowing in increasing quantities into Cohana Bay, near the tourist spot of Copacabana, for decades.
The key culprit: the 1.2 million residents of El Alto, 60km to the southeast. As the city has rapidly grown (from only 95,000 inhabitants in 1976) so has its waste supply. A recent study led by the French National Institute for Sustainable Development (IRD) identified metals, pharmaceutical residues, nutrients (such as nitrate, phosphate, and ammonium), and faecal bacteria such as E. coli in the city’s wastewater – resulting in suffocating eutrophication, and making the lake unsuitable for consumption, or for the harvesting of fish. ‘The main source of contamination is El Alto, but agriculture, mining, and the increasing population is also contaminating the lake,’ explains Céline Duwig, a soil contaminants specialist at IRD.
“The local government has to work on separating industrial wastewater from domestic waste water. That means, obliging industries to treat their waste water, difficult when lots of industries are informal”
She points out that vast tin and silver mining has taken place on and off around the lake since the 1940s. To combat the problem, Peruvian President Pedro Pablo Kuczynski announced in January a $437million clean-up operation, including the installation of ten treatment plants on streams flowing into the lake. On a visit to the high altitude basin, he claimed he wanted to ensure, ‘the most beautiful lake in the world is [also] the cleanest lake in the world.’ It follows an agreement struck last year with Bolivian President Evo Morales – Lake Titicaca sits on the border between the two countries – to work together to clean up the lake.
This was published in the March 2017 edition of Geographical magazine.