2.2 Major changes over time Urbanisation and manufacturing are independent factors underlying most changes of our sanitation systems Source: Rathnabharathie and Kariyawasam, 2007 Learning objective: to become aware of the long-term impacts of society on sanitation systems and origins of change

Was the strong link between the water and sanitation in the 20th century a brief detour in human history? Most common Parenthesis? What will come next ? agriculture + sanitation water + sanitation agriculture + sanitation All rural Essentially urban Jan-Olof Drangert, Linkoping University, Sweden

Urine-diverting toilet in the 1860s and sanitation footprints 1910 faeces vent pipe urine collector 60km Stock- holm urine bowl (broken) urine funnel Jan-Olof Drangert, Linkoping University, Sweden

How pipes gradually took over waste transport Period Solid street- waste kitchen- faeces urine Wastewater 1800 1870 1900 1950 1970 2000 Solid waste Excreta Earth pits for all household waste and content emptied in garden or on nearby farm Disposed of in streets or in yard Latrine buckets of metal Disposed of in streets or in yard Urine and greywater to a septic tank/waste pit or straight to water body Container for solid waste Black (WC)- and greywater in pipe to water body without any treatment Solid waste incinerated Some garbage sorted Wastewater treatment plants being built Sorting of garbage and reuse Some sludge applied on farmland Scenario 1: grinder for kitchen waste, increased mixing of waste and incineration Scenario 2: garbage sorted in more fractions, which are treated separately and used in production of new products Jan-Olof Drangert, Linkoping University, Sweden

The history of management of water and used water over the 20th century and beyond 1970 2000 Supply Management Demand    Reuse Priority 1: provide water no longer the only concern Priority 1: reduce water volume and emerging interest in wastewater Pri 1: wastewater quality Jan-Olof Drangert, Linköping University, Sweden

Mexico City now has 20+ million people MC Latest opened water source 1 KM 100 KM Next? 2 KM 200 km Courtesy of Ian Adler, International Renewable Resources Institute, Mexico Jan-Olof Drangert, Linköping University, Sweden

What we have seen so far ….. More pipes and more mixing of various flows has been the mantra for a long period But of late, there is a slow shift in focus from supply issues to what happens to water and waste materials after they are used New focus: to improve the way we deal with excreta, organic solid waste and wastewater in order to treat and use these resources again The future sources of water and nutrients will come from reusing water and waste materials Jan-Olof Drangert, Linköping University, Sweden