“OCTOPUS” principle reduces wastewater management costs through network optimization and clustering

Sanitation and wastewater management are integral to the United Nations Sustainable Development Goal 6 (SDG 6: clean water and sanitation). However, a significant portion (50%–80%) of global wastewater is currently being discharged without proper treatment. A main hurdle in wastewater management are the substantial costs required to achieve SDG 6 that constitute both of the investment costs but also the long-term operation and maintenance costs of treatment facilities. To realize safe sanitation across the globe, we developed the OCTOPUS design that identifies settlement groups where individual treatment plants are merged into a large one. This merging can lower the actual treatment costs. To gauge the global impact, we applied OCTOPUS to over 4.1 million settlements across 140 countries, encompassing more than 2,600 administrative regions. The results demonstrate that over 20% of these regions could achieve cost savings exceeding 10% compared to the conventional approach of having a single treatment plant per settlement.