When people in the Patagonian village of El Chaltén saw untreated waste flowing into waterways and found the sewage plant was faulty, they grew increasingly concerned about the health risks from pollution in two glacier-fed rivers, the Fitz Roy and Las Vueltas.

The incident in 2016 led Marie Anière Martínez, a conservationist with the Patagonian environmental organisation Boana, and Lorena Martínez, a Los Glaciares national park official,to form a group to investigate water contamination at the Unesco world heritage site.

Last year, they secured a landmark court ruling against water pollution in the Argentinian national park. Supported by the Escazú agreement,a regional treaty on environmental rights,residents filed a collective lawsuit,forcing authorities to acknowledge failures in waste management and commit to upgrading systems by January 2025.Yet despite this victory, the pollution persists and activists are still calling for more robust enforcement.”What have the authorities done to prevent environmental damage?” asks Marie Anière Martínez.

Nestled in a 135-hectare (330-acre) valley in the shadow of Mount Fitz Roy, El Chaltén is home to up to 2,900 people during high season in the area, which is a paradise for hikers exploring Patagonia’s spectacular trails.

Los Glaciares protects part of the southern Patagonian ice field – a massive freshwater reservoir in South America. Spanning 600,000 hectares of lakes,forests and glacier-fed rivers,the national park includes the las Vueltas

Patagonia’s Paradise Lost: Sewage,Bacteria and a Fight to Save a Pristine Landscape

Like many in the village,Paula Chaparro,a mountain guide,has been involved in monitoring the water and public advocacy over pollution for more than a decade. “We don’t know how, over time, sewage discharges into the river can impact ecosystems,” she says. “The pollution goes beyond the village and affects the entire course of the Las Vueltas River to Lake Viedma.”

The activists are now supporting new legal action against the national parks administration for roadworks and other projects carried out in protected areas without environmental assessments.

During the legal process, Karina Soledad Esquius and fellow biologists from the National University of Mar del Plata sampled water from 82 watercourses in the north of Los Glaciares park.

In November 2023, they found multiresistant bacteria in the water. “In most of the environments sampled, the water quality is very good, but we found multiresistant Escherichia coli [E coli] near the confluence of the Vueltas and Fitz Roy rivers, close to the sewage treatment plant,” says María soledad Domínguez, the biologist responsible for the analysis. “Of 27 isolates, five showed resistance to three different families of commonly used antibiotics.”

El Chaltén Struggles with Wastewater Management Amidst Tourism Boom

el Chaltén, the popular trekking destination in Argentine patagonia, is facing significant challenges in managing its wastewater. Rapid tourism growth has outpaced the town’s infrastructure, leading to concerns about pollution in the Las Vueltas River. The company responsible for wastewater treatment says it is working to increase capacity, with two plants currently operating and a third under construction. last year, they invited bids for a grease and oil separation system for the El Chaltén plant.

The situation is intricate by the lack of a comprehensive environmental plan during the town’s expansion.Melina Lorenti, a lawyer specializing in environmental issues, points to this as a critical oversight. “The big mistake is that El Chaltén expanded rapidly without an environmental framework in place,” she states.

While a study is underway to assess pollution levels in the Las Vueltas River, Adrián Alonso Durán, the municipal director of environmental policy, admits the results are currently inconclusive and require further data collection. He also acknowledges the limitations of the existing treatment plant.”It has a fairly small capacity and does not operate at full capacity during peak tourist seasons,” Durán explains. This suggests the plant is often overwhelmed, possibly releasing untreated or partially treated wastewater into the river.

The lack of adequate wastewater treatment poses a threat to the river’s ecosystem and the overall environmental health of the region, raising concerns about the long-term sustainability of tourism in El chaltén.