India, May 27 -- In the afternoon sun near Munirka along the Outer Ring Road, Mahendra Singh removes his shirt and trousers, stripping down to his underwear before stepping into a stormwater drain. With a rusted shovel, he scoops out dark, foul-smelling sludge-a mix of silt, plastic, and broken glass-and passes it to his co-worker Raj Kumar. Neither man wears gloves, boots, or any protective gear.

Along a 100-metre stretch from the spot, there are multiple heaps of filth as over 50 workers toil to clear choked storm drains ahead of monsoon. This scene, repeated across hundreds of sites in Delhi, is part of the Capital's annual pre-monsoon desilting drive.

To be sure, the drains being cleaned are not classified as sewage lines, but as st...