That was probably two generations ago?

Scavengers in manholes [India Stinking?] Frontline has a review of Gita Ramaswamy's book India Stinking: Manual Scavengers in Andhra Pradesh and their work.

Many anachronistic devices and systems have yielded to modern, expensive gadgets or tools in the name of public good. But behind the question of doing away with the existing system of human waste disposal - manual scavenging - one can see a deep-rooted prejudice against Dalits, on whom the hierarchical caste Hindu society has thrust this obnoxious occupation only because they are born into this segregated social group. Dalits are asked to lift human excreta from private and community dry latrines using mostly a tin plate and carry it in buckets or as headload to be dumped elsewhere.

Now a quote from an 'India Shining' book:

"I am a liberal, and above these caste distinctions", said my host, turning to me, "but I cannot tolerate the sight of a lower caste girl sitting beside a Brahmin boy. I saw it with my own eyes on a bus in Delhi the other day. Mind you, the boy was the son of a Supreme Court judge."

"What is wrong with them sitting on the bus together?" I asked artlessly.

"What's wrong -- she is unclean!" said my Rajput host, rising imperiously from the charpai and assuming the dignity of a retired transport commsissioner."They used to carry muck on their heads."

"That was probably two generations ago", I said, impatience showing in my voice.