Engineering sustainable sewage systems

Urban sewage collection is part of an infrastructural system developed during the past century to increase convenience and hygienic standards in households. With the attention on sustainable development growing during the 1980s-1990s, Swedish municipal sanitation professionals began to pay attention to recycling of the nutrients in the sewage. The attempt in this paper is to draw together important thoughts from studies of professions, of communication and of sanitation and other infrastructural sociotechnical systems in an effort to better understand current efforts to increase sustainability in the sewage system in Sweden. It is argued that the momentum of a large sociotechnical system like the sewage network makes it difficult to change the system. However, with the focus on sustainability and on recycling of nutrients, sanitation professionals express an increased need to communicate with users and other actors, in order to reduce harmful substances in the system. In two Swedish municipalities, two different methods to improve the quality of the sewage were tried; source separation of toilet sewage water, and intensive information to households about proper use of the current system. In the former case, existing social and organizational structures were preserved, while the latter case caused increased collaboration with other municipal staff as well as households and other actors.