This article interrogates the epistemological conditions of Charles Liernur’s pneumatic sewage system in order to shed light on the changing relation between soils and Dutch society in the nineteenth century. The first section discusses the relation between hygienism, soil and sewage. The second section unearths how Liernur’s design related to the agricultural chemistry of Justus Liebig. Through the epistemologies and the mediating technologies that are operationalized by hygienists and chemists, soils are made governable. The final section of this article discusses the struggle to commercialise the urban waste collected by Liernur’s system, highlighting the difference between governable and governed soils.