Manual scavenging persists because the caste system treats the handling of human waste as the permanent, inherited duty of specific sub-castes rather than a job anyone might do. The stigma attaches to the person's birth identity, so even those who leave the work remain socially marked as 'untouchable', which is why abolishing the task alone does not dissolve the status.
The book records women from scavenging communities who clean dry latrines by hand each morning, scraping human excrement into baskets they carry on their heads to disposal sites, often for payment in leftover food rather than cash. Their own testimonies describe the daily nausea, the social avoidance, and the generational entrapment of daughters inheriting the same baskets.
India formally outlawed manual scavenging and the construction of dry latrines by statute, yet the practice continued widely because local officials, municipalities, and railways remained among the employers and faced no consequences. The gap shows that a prohibition becomes decorative when the state that passed it is itself a violator and no accountability mechanism bites.
Viewing everyday sanitation systems (dry latrines, open drains, sewer lines without machines) as physical arrangements that presuppose a disposable human cleaner reveals how caste is built into bricks and pipes, not just attitudes. What looks like a technical lack of investment is instead a social choice that someone of a fixed birth will always be available to do by hand what equipment could do.