**4. The untold story of pits in urban India**

A flushable toilet has come to symbolize modern urban population living in India and throughout the world. More than 80% of Indians living in metropolitan areas have access to solitary or communal bathrooms. Instead of being linked to a sewer network, most of these toilets are pour-flush and joined to a pit or septic systems. In the absence of pipes to remove fecal waste from pits and tankers, it ought to be transferred by non-waterborne methods. Until about the mid-2000s, most pit cleaning work was done by hand. Waste is discarded distant from households in the castebased practice of manual "scrounging" after being scraped out of dried, unsewered lavatories. Due to recurring sanitation employee fatalities as well as the vile aspect of manual scouring, the Indian government approved the "Prohibition of Employment as Manual Scavengers and their Rehabilitation Act" in 2013. For collection, a water tank with a sturdy, leak-proof design is a requisite [20].

The basic treatment system, or septic tank, lowers the biochemical oxygen demand (BOD) by 30 to 50 percent on average while minimally affecting the pathogens and nutrient content. The wastewater from the tank therefore has to be remedied further, either with underground dispersion systems or impenetrable secondary and tertiary treatment methods. Conventional septic tank systems, also known as "septic systems," include a septic tank and a subsurface dispersal mechanism, like a soak pit and dispersion trench. The soak pit plan has obstacles due to costs, close communication with the septic tank, and associated activities.

Due to a shortage of consistent desludging solutions, families opt for bigger septic tanks which needs less frequent desludging. However, 67% of pit latrines larger than 2000 L only have one compartment, rendering them inefficient for their intended use. The construction of a subsurface dispersion system in addition to the onsite repair of the basic unit would be required in order to handle wastewater through soak pits under these circumstances [21].
