El Salto de Juanacatlán was once a majestic waterfall where locals would fish, bathe, and play. Today the air stinks of sulphur, yellow-tinged water cascades over the rocks, and clouds of bright white foam collect at the foot of the falls before drifting downstream.
After years of watching the authorities fail to acknowledge the seriousness of the problem, desperate locals are now intensifying their calls for action. They claim it is already too late for 628 locals who they say the pollution has killed in the last eight years. That includes 72 deaths in 2015, the worst year to date.
"My mother and two sisters died of cancer," said Samuel Álvarez, a pensioner with white stubble and few teeth, as he ambled down the town's uneven streets on his morning walk. "We used to live right next to the river and I think it was caused by them inhaling the industrial fumes every night."
The devastation of El Salto began in the 1970s as industries began to congregate in the now decrepit town located on the southeastern outskirts of Guadalajara, the second-largest city in Mexico and the capital of the state of Jalisco.
Today El Salto is home to over 300 businesses, including local and multinational electronics firms, automotive factories, chemical plants, pharmaceutical labs, and food and beverage companies. Many are suspected of illegally discharging toxic waste into the river, which also absorbs sewage from Guadalajara.
A 2015 report by the National Water Commission found that the Río Santiago, which winds 349 miles across western Mexico and through El Salto, is the country's most heavily polluted river.
A 2011 study by Jalisco's State Water Commission and the Mexican Institute of Water Technology detected 1,090 different pollutants in the river. They included arsenic, mercury, chromium, and hormone disruptors that can cause cancerous tumors, birth defects, and other developmental disorders.
"People have adapted to this Dantesque scene"
Activists claim Jalisco health officials have sought to play down the link between pollution and health problems in the region.
"In every home here there's someone who's died or fallen ill," said 58-year-old Enrique Enciso Rivera, who founded the environmental group Un Salto de Vida in 2005. "Instead of searching for the solution, the state has done everything possible to hide the problem."
The town's decline is the subject of a documentary due for release in Mexico later this year titled Resurrection.
"It's an image out of science fiction," said director Eugenio Polgovsky. "The toxic white foam slowly advancing for miles, and the clouds that land on people's rooftops, converting into particles that everyone breathes in."
Polgovsky added that he was further struck by the way locals have grown accustomed to what has happened to their once picturesque town.
"Little by little it's become something normal, people have adapted to this Dantesque scene," he said. "Some children even play in the foam, painting themselves foam sombreros and moustaches, obviously unaware of the dangers."
El Salto did get some government attention after an eight year old fell into a coma and then died in 2008. Miguel Ángel López Rocha had slipped into the river while playing on its bank and ingested a fatal dose of arsenic.
Widespread outrage prompted the government to build El Ahogado, the region's biggest wastewater treatment plant that was inaugurated in 2012.
But even Dr Rodolfo Montaño, from Jalisco's environmental secretariat, recently admitted that it only has the capacity to treat up to 75 percent of the sewage and industrial waste that flows into the river.
"We're sick of impunity, we're sick of the incompetent people in government"
The official added that efforts to fight the pollution are undermined by insufficient funds and the division of responsibility between different municipal governments, as well as the state and federal level water and environmental bodies.
He said that Jalisco has so far complied with about half of the 43 recommendations he accepted were directed at state authorities within the 100 recommendations made by the Jalisco Human Rights Commission in 2009 related to pollution of the river. He insisted it is not viable to build a hospital, as the Commission wanted, but that the state authorities have opened smaller clinics and deployed mobile teams to help detect cases of cancer and other diseases.
Local activists, however, have been fiercely critical of the government's efforts.
Raul Muñoz, president of El Salto's Citizen's Committee in Defence of the Environment, said that as well as documenting 628 fatalities caused by pollution in the last eight years, activists have also detected 2,678 locals who have suffered health problems. These include renal insufficiency, cancer, leukaemia, skin diseases, and digestive and respiratory infections.
Muñoz, who blames his own son's skin cancer and his daughter's three miscarriages on the pollution, said patience was running out.
"We're sick of impunity. We're sick of the incompetent people in government," he said, adding that local activists are now seeking the intervention of national institutions. "We want action now. We want solutions, we don't want our children to become the next statistics."
Water policy experts believe the solution is simply for the authorities to enforce the existing regulation that prohibits dangerous discharges in the river. However, Dr Raúl Pacheco-Vega, from the CIDE think tank, warned this will not happen until Mexico begins hiring and training more personnel to enforce these standards.
"We have amazing regulation, excellent standards and very strong environmental and water laws, but nobody complies with those," he said. "No regulatory body at municipal, state or federal level has the capacity to deal with that much industrial pollution."
'" grew up with all this pollution, unable to stand the foul odors every night"
While few residents are optimistic about El Salto's future, some take heart from the emergence of a younger generation of activists who are injecting a new sense of energy into the struggle.
Several local high school students appeared at a recent press conference on World Environment Day to draw attention to those who will be worst affected by its continued decline.
"I grew up with all this pollution, unable to stand the foul odors every night. I don't like it and I'd hate for it to get much worse in years to come," said 18-year-old Stacie Ruíz, who directed a bleak short film envisaging El Salto in the year 2049. "What will happen to us in a couple of decades? What are we going to leave for our children?"
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