Abstract: Chlorination is the use of chlorine as a disinfecting agent to eliminate bacteria from drinking water. During the late 19th and early 20th centuries, physicians and sanitary engineers only used chlorine on sewage or experimentally to treat water during outbreaks of typhoid fever, but not as a permanent measure. Experts and citizens alike distrusted chlorine due to the unpleasant odour and taste it added to water and safety concerns. After all, putting chemicals into the water was, for some, contrary to the idea that 'pure water' was better obtained by protecting watersheds than by treating an already polluted source. Chlorination was first adopted as a permanent water treatment technology in the United States in 1908, and from there, it spread worldwide, radically changing water management and reducing mortality and morbidity on an impressive scale. My talk will answer the question of why this technology, despite initial resistance, was adopted so quickly.

Bio: Edisson Aguilar Torres is a historian of technology and Latin America. His research explores the interconnection between state formation and the construction of small-scale infrastructure for water supply systems in the Colombian countryside during the 20th century, as well as the global history of water treatment technologies. His book manuscript, The Delegatory State: Water infrastructure, Community, and State Formation in 20th-century Colombia, challenges notions of the state as an overly centralising project that destroys local knowledge and practices by imposing large-scale infrastructures. Instead, it shows how the Colombian state decided to partially delegate water provision in rural areas to local communities, using a system that relied on state engineering, small-scale water supply systems, local management and maintenance, and Indigenous and peasant labour traditions. The rationale behind that decision combined ideals of citizenship participation with more practical concerns about the costs for the state of providing public goods directly. Insufficient investment, though, hindered full access to drinking water in the countryside, creating water inequalities that persist today. Pipes for the Community addresses the socio-technical system that came to dominate water supply in the Colombian rural areas as a way to understand the importance of small-scale technology in the landscape of modernity.