This paper examines the governmentality of colonial Hong Kong throughout the 1980s and 1990s, focusing on the implementation of the Livestock Waste Control Scheme (1987–1997), the production of normative waste treatment knowledge, the spatial control of farming practices and the resulting subjectivity in the construction of the ‘environmentally friendly farmer’ identity. These themes are examined by analysing archival materials and conducting in-depth interviews with two Pig Farmers Association representatives and 19 pig farmers. This paper argues that the colonial government of Hong Kong relied on environmental ordinances and zoning regulations, livestock waste demonstration projects and socially constructed perceptions of olfactory acceptability as major technologies of governance in the creation of ‘environmentally friendly’ pig farmers. Through being exposed to these technologies, pig farmers learned and internalised a particular concept of what constitutes appropriate animal waste management and treatment. This paper shows how the concept of being ‘environmentally friendly’ contributes to the creation and use of ‘good farming’ subjectivities when modernising pig farmers’ waste management practices.