A city’s success is measured by what happens within its boundaries, yet its greatest consequences often unfold beyond them. Urban indicators tell us how well a city serves its residents but reveal little about the biological and chemical legacy it leaves downstream.
The Municipal Performance Index 2020, which scored city governance nationwide, scores sanitation and solid waste management average 48.22, water and wastewater just 38.06 and health at 26.72 the lowest of any services parameter it measures.
The economic activity of an urbanising city fundamentally reshapes and alters the volume, composition, and toxicity of the waste they generate. Today’s sewage carries residues of antibiotics, antidepressants, hormones, industrial solvents, heavy metals and microplastics, contaminants for which many conventional wastewater treatment plants were never designed. Their persistence has transformed rivers into conduits of emerging public health risks.
The challenge, therefore, is not simply what cities discharge, but how far the consequences of those discharges travel. The remaining wastewater does not disappear at the city’s edge. It becomes part of irrigation networks, groundwater recharge, fisheries and food systems that sustain millions living downstream. A city’s wastewater is not the end of its metabolism; it is the beginning of its health footprint. It is this continuum of downstream consequences that, we argue, constitutes a city’s urban health footprint, a policy lens for making visible the cumulative health externalities that cities export but rarely account for.
This blind spot is increasingly difficult to ignore. According to the Central Pollution Control Board (CPCB), India’s urban centres generate over 72,000 million litres of sewage every day, yet only around 28% is actually treated before being discharged into rivers and water bodies. India has rightly recognised the need to strengthen urban wastewater infrastructure. Under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) scheme, the Union Government funds for sewerage and septage projects nationally, adding roughly 5,792 Million Litre per Day (MLD) of treatment capacity. However, implementation has lagged behind ambition. As of mid-2026, only 104 projects (18%) had been completed, while 398 remained under implementation and several were yet to be tendered, prompting the Government to extend the mission until March 2027.
Municipal bodies manage sewerage, pollution control boards regulate effluent, public health agencies monitor disease, and agricultural departments oversee food systems. Yet responsibility for the health risks that move from city sewers to rivers, food systems and ultimately people falls through institutional cracks. Making these downstream health externalities visible is the first step towards governing them.
For decades, we have measured cities by what they produce: jobs, infrastructure, growth and services. The harder question now is, how do we measure what we leave behind?
