An old man in a loincloth squats on the banks of the sacred Ganges River scrubbing his clothes. Nearby, sewage gushes from a pipe as water buffaloes contentedly wallow in the river's murky waters.
Upstream, a bright-eyed woman clad in a fuchsia sari stands waist-deep, pouring a stream of the river's holy water from a brass pot and reciting prayers while a plastic bag of garbage washes up on the shore.
This river is known to Hindus as goddess Ganga, one of the main arteries at the heart of India's spiritual and physical life, who provides a lifeline of fresh water to the 400 million people who live on her banks.
Starting Wednesday and for the next six weeks, legions of devout Hindus will celebrate the "Ardh Kumbh Mela" or Half Grand Pitcher festival in the city of Allahabad, at the confluence of the Ganges and Yamuna rivers. Allahabad is one of four spots where Garuda, the winged steed of the Hindu god Vishnu, is said to have rested during her battle with demons over a pitcher of divine nectar.
But chronically high levels of pollution have turned this river goddess into a potential killer. For the nearly 75 million pilgrims – setting the record for the world's largest gathering of people – who will travel here to bathe their sins away, sip the river water, or cremate their dead, the "holy dip" is believed to usher them more quickly into a state of nirvana.
Leading Indian environmentalists claim the $100 million Ganga Action Plan (GAP), launched 20 years ago to treat sewage dumped in the river, has failed. They blame poor planning, corruption, lack of technical knowledge, and a gross miscalculation of the volume of waste from Varanasi, a teeming city of around 1.2 million people, which they say has left pollution levels worse than ever.
Kicked off in 1986 by former Prime Minister Rajiv Gandhi, the GAP aimed to divert and treat the waste and bring the quality of water up to bathing standards. However, in Varanasi, where raw sewage spews into the river from 30 sources, levels of fecal coliform bacteria are up to 3,000 times the accepted Indian standard and 1.5 million times the safe level for drinking.
The river's destitute state is no mystery to the hordes of fervent devotees. This year, hundreds of Hindu holy men have threatened to commit mass suicide during the festival to protest what they say is a lack of government action, the Daily Telegraph reported last week.
Among the devotees completing the daily dawn ablutions before the festival was Veer Bhadra Mishra. Clad in a white cotton dhoti, the tall, silver-haired priest cups his hands and lifts the water to his mouth. But he leaves out one part of the ritual – he does not drink it. As the mahant, or spiritual and administrative head of Varanasi's second largest temple, he believes the water is holy. But as a professor of hydraulics and a leading campaigner to clean up the Ganges, he knows it is not pure.
The 66-year-old has been campaigning to clean the river since 1982, when he founded the Swatcha Ganges Abhiyaan (Campaign for a Clean Ganges) organization, an effort that combines his knowledge of the spiritual with the scientific.
"On a practical level 400 million people rely on this water. Spiritually for practising Hindus, the river is a medium of life. We want to touch our mother, submerge our bodies in the water, sip the waters. But we only have human bodies. If the river is polluted they will die, and with them their heritage, culture and faith," he says.
"The Ganga is the silken thread which binds this country together. What will happen if it breaks?"
Mishra says GAP has categorically failed. "The planning was hasty and unscientific. They did not know how many million litres of sewage flowed into the river, what the organic content of the water was, or whether there were chemical pollutants in the water." Varanasi produces about 39 million gallons of sewage per day, but can treat only about 26 million litres.
Each day, samples of the water are tested in the campaign's laboratories. The tests reveal a toxic cocktail of industrial chemicals, pesticides, heavy metals and arsenic quite apart from the refuse, corpses and animal carcases that float past chanting pilgrims. Ninety per cent of the pollution comes from sewage.
The treatment plants are crippled by poor maintenance as well as electric power cuts. For the five months of the monsoon the pumps cannot function at all due to flooding.
With the help of William Oswald, an engineering professor at the University of California at Berkeley, Mishra came up with an alternative solution. Oswald's scheme would use gravity to divert the waste downstream into a series of treatment ponds built on wasteland outside the Varanasi city limits, using bacteria and algae to eliminate chemical and biological pollutants.
The plan was unanimously approved by the city council eight years ago, yet the state and central governments turned it down.
Ujjwal Raman Singh, minister of environment for the state of Uttar Pradesh, insists the level of organic matter has gone down despite more domestic sewage being pumped into the river. But he admits there are shortcomings.
"Money was not properly utilized," he says. "There was a faulty bidding system, global tenders were not allowed, and money was instead given to petty contractors who did not have a clue about the technical or financial know-how to deal with the matter."
He says the solution lies in more electric-powered plants, but that will require more government financing.
Some residents blame the state. Sanjay, a silk weaver, says, "The government takes the money but the river never gets cleaner. If we complain to the local administration they ignore us."
Others blame the local population. "The government can't do anything unless the people change," says Varanasi guest house owner, M.P. Sahi. "Until people learn not to throw corpses in the river or empty their rubbish there, and factories stop their pollution, nothing will change."
For Mishra, who founded the Swatcha Ganges Abhiyaan (Campaign for a Clean Ganges) organization, the battle to change the attitudes of both the authorities and the people continues. He says his campaign has been a bit like a game of snakes and ladders: When it has gained speed, a snake comes and swallows it up.
"But one day," he says, "I will dodge all the snakes and save mother Ganges."