Pollution in the environment emerges as a legal and technical object on the one hand, and as a repository of social and cultural beliefs on the other. What happens when we trouble the idea that these belong to different domains and think about seemingly divergent meanings of pollution together? In this article, I draw from anti-caste and anti-racist work to explore this question. Extending critical urban scholarship on environmental politics, I attend to formations of caste and religion alongside judicial and political discourse on preventing pollution to the river Ganga in North India. In our present moment, on the banks of the sacred river, extremist leaders mobilize regulations to target minoritized Muslim and Dalit communities in Kanpur’s leather industry. I argue that the roots of these actions lie in an environmental petition from the mid-1980s which transformed urban environmental governance in North India, as the court decoupled questions of environmental protection from economic and social justice. I suggest that the analytic of regional racial formations helps us grapple with uneven socio-spatial landscapes in postcolonial cities and sharpens our understanding of environmental injustices by moving beyond fixed categories of difference.