With regard to education, traditional environmentally-related issues have been intertwined with courses in natural sciences, which could entail opportunities as well as difficulties. The study concerns two knowledge matters that are usually divided into two different subject traditions - water and justice. In this article, we focus on the way teachers consider instruction within the frameworks of these two discourses and how teaching is related to sustainable development. The findings suggest that water and justice are two examples that are suitable for the problematisation of sustainable development with respect to holistic education. Current educational policies in Sweden advocate a tendency towards a more closed and subject-centred discourse, which means that the ability to successfully teach about sustainable development is made even more problematic.