Environmental Engineer Deepthi Nagappa joins host Pavan Srinath to unpack what really happens to wastewater after we flush the toilet. The conversation explores how sewage treatment plants work, the difference between grey water and black water, what septic tanks actually do, and what nutrients like nitrogen and phosphorus do to our ecosystems.In the fifth episode of The WELL Labs Show, Deepthi takes us inside the science and engineering of wastewater treatment - from microbes and sludge to aeration tanks, filtration systems, and the operational challenges that determine whether an STP succeeds or fails.

Deepthi Nagappa⁠ is a Senior Research Associate in the Urban Water programme at WELL Labs, with expertise in water quality management, she has worked on lakes in and around Bengaluru, and on safe water reuse in decentralised STPs.Pavan Srinath is the Managing Partner for Communications and Development at WELL Labs. Pavan is a communications and public policy professional who has spent over 14 years working in Bangalore's not-for-profit sector.This episode is essential viewing for anyone working on urban water management, sanitation, environmental engineering, sustainability, or anyone curious about the invisible systems that keep cities clean and lakes alive. The WELL Labs Show features rich conversations on water, environment, land and livelihoods, from the people and partners of WELL Labs. Hosted by Pavan Srinath, each episode explores complex environmental and social issues and helps you understand the systems and the dynamics better. For all references and further readings related to the episode, visit https://welllabs.org/wastewater-treatment-explained-with-deepthi-nagappa/ Subscribe to the WELL Labs YouTube channel @welllabs and watch all episodes on the official playlist here.

Recording by Nabina Chakraborty, Vraj Acharya and Ritik Pathak. Video editing by Vraj Acharya. Graphics and artwork by Aparna Nambiar. Podcast production and management by Nabina Chakraborty and Pavan Srinath.