Is dilution the solution to pollution? Municipal sewerage systems in late nineteenth century San Francisco and London

Abstract

This article explores the historical development of wastewater management planning in two cities: San Francisco and London. Both cities constructed their municipal sewerage networks in the late 1800s, and both cities designed these networks as combined systems, which carry storm water and sewer water in the same pipes. Due to differences in political and public attitudes towards sewage management and to the relative status of engineers versus scientists, London and San Francisco followed different processes in the development of municipal sewer systems. While London entertained a science-based approach that yielded innovative ideas in biological sewage treatment, San Francisco retained a traditional engineering approach that favored sewage conveyance over treatment. Though both cities eventually adopted similar combined sewer systems that have left challenging urban infrastructure planning legacies, London's experimental methods a century ago provide a useful model for infrastructural problem-solving today, as planners attempt to accommodate growing urban populations with infrastructure solutions that achieve multiple public benefits. San Francisco and London are both ripe for new wastewater planning experiments that expand upon nineteenth century British notions of biological treatment, incorporating ecological, social, and economic benefits into municipal wastewater management.