Usha Chaumar, a gregarious 40-something with an enormous grin, can pinpoint the exact day she stopped being one of the "untouchables," the Hindu caste that was supposedly abolished in 1950.
It was 2003, and Ms. Chaumar was on her way to work when Bindeshwar Pathak stopped her. She recalls being amazed that a "nicely dressed" man would even speak with someone like her: a manual scavenger. As such, it was her job to clean human waste, by hand, from homes that lack flushing toilets in this dusty town in the state of Rajasthan.
Usually, neighbors crossed the street when they saw her coming with the tools of her trade: a metal pan and wire brush. And even when she had finished her gut-churning work and scrubbed her body clean, she was treated as a pariah.
But Dr. Pathak asked her why she covered her face with her shawl and why she seemed ashamed to talk to him. At the time, Chaumar had no idea she was speaking to the man whose mission it was to end manual scavenging and who would eventually change her life.
Pathak founded an organization called Sulabh in 1970 to eradicate the practice by replacing unplumbed toilets with affordable flush ones, and by giving scavengers training for other jobs.
"Shopkeepers would drop the rice to me – they wouldn't touch me," Chaumar remembers, losing her smile for a moment. "And they made me put my money down, away from them. They threw water over it before taking it."
Today, she earns a living selling homemade pickles and embroidered cloths.
Manual scavenging was banned in India in 1993, by a law that forbids the construction of dry toilets and requires existing ones to be destroyed. But in India, such laws tend to be implemented slowly. There are thought to be several hundred thousand manual scavengers still working; a recent report found there were over 1,000 in Delhi alone.
Sulabh has built 1.2 million affordable hygienic toilets throughout India and helped 60,000 former manual scavengers move into other jobs.
All those jobs are held by members of the Valmiki community, a substratum of the Dalit caste – formerly known as untouchable – at the bottom of the ancient Hindu caste system. The term untouchable – along with, theoretically, the stigma attached to it – was made illegal by India's Constitution in 1950.
In Alwar, in 2003, Pathak set up a retraining program for the town's manual scavengers which has given more than 50 women vocational training. The center, where women learn to read and write, make clothes, and train as beauticians, is housed in a prosperous area of Alwar.
"At first they felt uncomfortable coming here, but we wanted to give them a different perspective," says Suman Chahar, who runs the center.
In one room, Lalita Nanda is making wicks for oil lamps in Hindu temples. The priests who buy them did not let Lalita into the temple until recently, she says, smiling.
One of the first things Pathak did with Alwar's scavengers was usher them into the town's biggest Hindu temple. He also took a group out to dinner at the Maurya Sheraton, a five-star hotel in Delhi.
The manager was so appalled he tried to stop the women entering. Pathak promised to pay for anything that was broken or stolen; nothing, of course, was; and as the party left, the manager apologized to them.
Sulabh's transformation of manual scavengers would not be possible without the other part of its work, the development of cheap hygienic toilet technology.
"The toilet is a tool of social change," declares Pathak, who defies the stereotype of the scruffy Gandhian activist dressed in rough-spun cotton. He is wearing, instead, a starched white pajama suit with a smart jacket; his hair is dyed black, and he wears a fine gold ring.
Born into a family of Brahmins – the highest of all the castes - in a village in Bihar, Pathak remembers, as a little boy, being intrigued by the notion that the ordinary-looking woman who sold kitchen utensils to his family could be "untouchable."
"So I touched her," he says, "Just to see. And my grandmother made me drink a mixture of cow urine, cow dung, and Ganges water." That combination is meant as both cleanser and punishment.
Later, Pathak joined a committee established to celebrate the centennial of Mahatma Gandhi's birth. During this period he was struck by what Mr. Gandhi had said about scavengers: "I may not be born again, but if it happens I will like to be born into a family of scavengers, so that I may relieve them of the inhuman, unhealthy, and hateful practice of carrying night soil."
Curious, Pathak went to live in a community of scavengers for three months. At this point, he says, he was not yet inspired by their cause. But two experiences changed this.
The first, he says, was when he saw a newly married girl being forced by her mother-in-law to clean human waste by hand. "I can't describe how awful her crying was," he says. The second was when he saw a small boy being attacked by a bull. People rushed to save him, but when someone cried out that he came from the Valamiki caste, they left him, and he was killed.
"These things still happen," says Pathak. "But we have everything we need to change things. It is so, so simple, if people only have the will."