In a time when we fear overstepping the planet boundaries, circular economy appears as important for a sustainable society. Promising economic and environmental gain, it is promoted by political bodies as well as business companies. In the circular economy trash turns into valuable treasures; waste is recycled and filled with economic and cultural value. In an ongoing project the transformations of biological waste are examined in urban contexts. This paper explores the flows of waste water in a municipal organization, from “shit” to new commodities on the market. Where are the leaks in this supposed circular economy? How is economic and environmental value added to/removed from sewage during the process? Through the methodology of “trash-tracing”, we follow how waste water is valued, from flushed down from toilet to its end-up products: biogas and fertilizer. The study is based on an ethnography of wastewater management in a Swedish municipality, including interviews with twenty “waste workers” and observations of a treatment plant, a land fill site and a biogas plant. During the transformation of wastewater into products conflicts appear between 1) public and private logics; 2) environmental and economic gain; 3) nature and society. In these conflicts valuation processes of waste are ongoing, branding the municipality as sustainable city, employing new waste workers, but with limited economic and environmental value in the final products. We discuss the inherent conflicts of the circular economy as well as methodologies to explore societal infrastructure through a micro-perspective on culturally hidden phenomena such as waste water.