The Brihanmumbai Municipal Corporation (BMC) currently engages 4,357 labourers to clean 54,600 manholes and open sewage lines manually, using iron rods and spliced bamboo sticks.
Once inside, there is nothing but darkness. The sewage worker could pass out from inhaling a toxic gas, or be carried away in the rush of water and waste.
The 'shittiest job' in the world: some of the drainage lines are deep enough to accommodate a double decker bus.
The work requires no special skill, just a pair of arms and legs and the courage to descend into hell. Once they're below, they're disconnected from the world above.
There are 21 million people in Mumbai who generate 7,000 tonnes of waste daily. That waste, if not cleared, could lead to outbreaks including cholera, dysentery and typhoid.
Clearing garbage is back-breaking work and the tools are primitive. There are scars where the pole digs into Jadhav's shoulders.
Can we acknowledge the contribution the sewage workers make to our health and wellbeing, at the cost of their own survival?
No human being should have to work in such dehumanising conditions. But 30,000 men in Mumbai do.
Dead babies, roadkill, sanitary napkins, shards of glass, medical waste, diapers full of shit - there is nothing these manual scavengers don't touch with their bare hands every day.
Abusive, full of self-hatred and contempt for life, the bitterness they live with is perhaps more toxic than the sewage they are covered in each day.
It's on the failing strength of their shoulders that we make promises of a Clean India. Their bodies that carry tonnes of trash to the dumping ground. Their lives that pass in a toxic haze.
Hiraman's wife refused to be photographed, saying she would have nothing to do with any friend of the rakshas (devil) who gives her Rs 150 a month to run the house. Hiraman keeps asking her to shut up. She keeps threatening to leave.
By the time the worker from this family reaches home, alcohol turns him into a tormentor - 'a demon' who abuses and beats his wife and children.
Kamble's wife, a domestic worker, occasionally gets food from her employer to take home. But home, where they live with their three children, is a tiny space under a staircase.
It's the most despicable kind of reservation: jobs in all categories of 'conservancy' work are reserved for scheduled castes. It's also a daily reality for 20-25 members of a family to live one on top of the other in a hole in the wall.
If the worker marries, his wife gets the job. Remarriage is out of question for the widows of sewage workers. If they do remarry, they'd lose their jobs and kholis.
Sewage workers pay an unspeakable price - the complete loss of dignity. They begin to see themselves as garbage - worthy of nothing, not even a little respect.
Dumping ground sites are their workplace - but the concept of even basic amenities like a canteen for a cup of chai, or a bathroom to wash the filth off their bodies, or just a chair to sit on, does not exist. These 'luxuries' are to be acquired on your own.
The Hell Divers: 12 lakh men who die to keep us clean
These photographs don't document a hidden reality. They document what we walk past, drive past, look past every single day.
They document the hellish existence of 30,000 Mumbai men who clean the sewers of your and our filth.
They document the subhuman existence of others - 12 lakh faceless men - who live their lives underground, in manholes and sewers. In garbage dumps and gutters.
They document the army on whose shoulders we promise a Swachh Bharat.
Men who descend into a world of toxic gases, slime, faeces and unspeakable filth armed with no protective gear - not even water for washing the slime off their bodies.
Men who live, on average, to age 45 - 20 years less than the national average - because of exhaustion, toxicity and poverty.
Men whose children see no prospect but to follow in these same footsteps because caste and poverty have decided their fate for them.
Photographer Sudharak Olwe took these heartbreaking images for what he has made his personal mission: documenting the inhuman existence of these faceless men. His book In Search of Dignity and Justice is a vital first step to rescuing future generations from certain death as they follow their fathers into the same subterranean hell.
You can read the full account here: Bharat Ratnas: the Clean India army every Indian should meet