Peruvian authorities said last week that some 173 different types of pollutant are being discharged into the Rímac River, the main source of potable water for the country’s capital, Lima, and the nearby port city of Callao.
The pollutants, which originate from domestic, industrial, agricultural and mining sources, are severely damaging the Rímac’s water quality between Lima’s Ricardo Palma Bridge and the Atarjea water treatment plant, official state news agency Andina quoted Deputy Minister of Construction and Sanitation Francisco Dumler Cuya as saying.
“In addition to contamination caused by metals, levels of organic and bacteriological waste are also high, and in the majority of cases, exceed the maximum permissible limits established in national environmental quality standards for water,” Dumler said.
According to the deputy minister, one of the worst affected areas is the Huaycoloro River, an affluent to the Rímac; the contaminated waterway contains high levels of heavy metals, arsenic and other pollutants that are carried downstream to the Rímac, causing operational problems for the nearby Atarjea plant.
The 160-kilometer-long Rímac -- known locally as the “Río Hablador” after the Quechua word “rimaq,” meaning “talking” -- is considered by experts to be one of the most polluted waterways in the world, and has to be regularly dredged and cleaned to guarantee water supply to Lima and Callao’s 9 million residents.
Dumler said Sedapal, the state-owned public utility that serves Lima and Callao, carries out regular physicochemical and microbiological analysis of the Rímac and other nearby waterways to assess the impact of contamination on water quality.
The company operates 29 monitoring stations from Lake Tiktiqucha in Lima province to the Atarjea plant, including locations at the Santa Eulalia, Aruri, Blanco and Huaycoloro river basins, the deputy minister said.
In a separate statement, Sedapal Chief Executive Marco Vargas Medina acknowledged the high levels of contamination affecting the Rímac and its affluents, but guaranteed the quality of potable water destined for households in Lima and Callao.