Linda Strande

1. Introduction Click to copy section linkSection link copied! Nonsewered sanitation (NSS) is essential to meeting the sanitation needs of billions of people. Indeed, 58% of the global population is not connected to sewers. (1) Reliance on NSS spans dense urban neighborhoods in low- and middle-income countries (LMICs), where NSS can account for 60–90% of sanitation systems, to rural communities in high-income countries (HICs), where 5–30% rely on onsite systems.

Abstract Half of the world’s population is now served by non-sewered sanitation, yet the field remains fragmented, with a focus on individual research agendas, and prevalence of imprecise terminology that hinders scientific learnings and leads to misconceptions. The field is at a decisive juncture, with scientific knowledge taking off that holds the potential to fulfil the urgent need for inclusive sanitation in a rapidly urbanizing world.

Special Issue Published as part of the Environmental Science & Technology virtual special issue “Accelerating Environmental Research to Achieve Sustainable Development Goals”. Improvements in urban sanitation in the 19th and 20th centuries in Europe and North America resulted in significant inhibition of the spread of infectious disease. Subsequently, centralized waterborne sanitation was ranked as one of the top medical and engineering achievements of the 20th century.