Water in Highly Polluted Peruvian River Runs Crystal Clear since COVID-19 Lockdown Begun as Waste Drops by 90%

The Rímac River in Peru, the main supplier of water to the capital Lima, is normally a dumping ground for garbage and waste. But local officials have been reporting that its waters appear to be clearer since the country introduced its coronavirus lockdown.

Luis Enrique Yampufé Morales, a spokesperson for Peru's National Water Authority (ANA,) said that the increased transparency of the river is linked to the reduction of contamination from human activities since the lockdown began, Peruvian news outlet El Comercio reported.

According to Morales, the lack of dumping of garbage, construction materials or waste from businesses has meant that the waters near the mouth of the river in Peru's Callao region are almost as transparent as those nearer to the source in the Andes mountains.

"It is appreciated that the water is cleaner and more crystalline. There is recovery of vegetation and migration of birds, especially at the river mouth," Yampufé told El Comercio.

Yampufé announced that scientists would be collecting samples from the river on Thursday in order to assess how the water quality has changed.

According to evaluations conducted last year, the river has the highest number of parameters that do not comply with the ANA's Environmental Quality Standards due to the presence of certain metals and thermotolerant coliforms, a type of bacteria present in high numbers in human and animal feces that are a common indicator for monitoring water quality.

"The state of emergency has allowed us to observe the impact of human actions on water resources," Flor de María Huamani Alfaro, an ANA spokesperson, said in a statement.

"For this reason it is important that we become aware and consider that the water in our rivers and irrigated channels are for human and agricultural consumption, so they should not be areas for garbage dumping or clearing," she said.

Furthermore, the volume of solid waste from individuals and businesses that is reaching La Atarjea water treatment plant has been reduced by 90 percent, according to Francisco Dumler, chairman of the board of Sedapal—the utility company that operates the plant.

"When the isolation measures are over, we should encourage people not to throw more garbage," Dumler told El Comercio.

Rímac River
An image of the Rímac River, Peru. iStock

Aside from the decrease in waste dumping, Huamani Alfaro noted that the color of the river can also be affected by other factors, for example, the fact that it is currently the dry season, when the river is often less cloudy.

The Rímac River, which extends for about 127 miles, supplies around 80 percent of the water to the Peruvian capital Lima, which has a metropolitan area home to more than nine million people.

However, due to a lack of sanitary landfills, waste is often dumped illegally, often ending up in the river, which also receives large quantities of untreated effluent from human settlements and various industries, leading to high levels of pollution, according to the Food and Agriculture Organization of the United Nations.