1. 2.5 A way forward … a tool for selecting sustainable sanitation arrangements
How to obtain all the information we need?
Learning objective: awareness that selecting a sustainable arrangement is more than just a matter of choosing between technical solutions
Jan-Olof Drangert, Linköping university, Sweden

2. Factors pushing the sanitation sector to develop towards sustainability
world population increase
high population densities in urban areas
increased consumption and chemical compounds
scarcity of phosphorus and other nutrients
Jan-Olof Drangert, Linköping university, Sweden
global warming
modernity and prestige
Private activity
Community concern

3. The role of sanitation in solving the looming water and nutrient crises and global warming
- save H2O (demand management) and prevent pollution of H2O
- use treated greywater to save on ground- and surface water
- sanitise nutrients (P, K and S) from households and restaurants
recycle nutrients and organics for food production and soil
restoration
- reduce emissions of CO2 and other greenhouse gases
Jan-Olof Drangert, Linköping university, Sweden

4. Many framework issues to consider
Challenges for the present sanitation arrangements
Policies, building codes and other regulations
New housing area, densification or retrofit
Landscape, soil and groundwater characteristics
Wind, temperature variation and rainfall pattern
Open areas (gardens etc.) and urban agriculture
Availability (intermittent supply?) and cost of water
Availability (intermittent supply) and cost of energy
Collection and recirculation of solid waste, organic waste in particular, etc.
Jan-Oloof Drangert, Linköping university, Sweden

5. Up to now the WC has set the standard, but from now on the resilience of nature will do so
El Grand Canal, Mexico City with ”treated” effluent
Wastewater and stormwater drainage in Bangalore, India
Courtesy of Ian Adler, IRRI-Mexico
J-O Drangert, Linköping university, Sweden 5

6. A new approach for sustainability
The discharged waste is an unlimited resource!
- if it is clean enough
The crucial question to ask is therefore:
”What comes out at the end of the sanitation system?”
There is no scarcity of natural resources for households
– only poor management of the natural resources we
already command!
Jan-Olof Drangert, Linköping university, Sweden 6

7. Where is sludge treated and where does it end up ?
Always start your investigation from the end of the process
Screen Sedimentation aeration clarifier outflow
Where is sludge treated and where does it end up ?
Where does the treated effluent flow ?
Jan-Olof Drangert, Linköping university, Sweden

8. Start from the end ! (centralised example)
Our thinking is now on global challenges as well as on local wishes for system performance and status
Sludge drying bed
We decide what quality we would like the final products to have.
CO2 & methane
gases
Dried sludge itself
percolating
leachate
J-O Drangert, Linköping university, Sweden 8

9. Treated greywater = clean water?
Jan-Olof Drangert, Linköping university, Sweden

10. Treatment results for small and large water utilities
More than 2,000 persons
Treatment results for small and large water utilities
Less than 2,000 persons
Jan-Olof Drangert, Linkoping university, Sweden 10

11. A holistic sanitation selection algorithm
ON/OFF
Is there an aim/policy of reuse or sustainability? no
Make alliances and find your way around
yes
Is there enough space and infiltration/evaporation capacity on site?
Is simplified sewerage affordable ?
Is wastewater quality a major concern/problem? no no
yes
On-site reuse of
safe wastewater no
yes
yes
yes
Is wastewater pollution caused by excreta?
Can the pollution be eliminated through source control ? no
greywater no
Is swale/open ditch possible?
yes
yes
yes
Is treatment on site effective & affordable?
yes
Is household organic waste sorted ? no
Is diversion of urine an affordable option ? no
yes
yes
yes
Is infiltration or other reuse safe ?
Is settled sewerage affordable ?
Can faecal matter be composted on site?
Can urine be stored and used on site?
yes
Compost and use nutrients on site
yes no
yes no
Is biological treatment affordable & safe?
yes
yes no no
Reuse of
polished water
yes
Energy for household
yes
Is biogas reactor feasible on site ?
Fertilise
garden no
problem
yes
Swale/fish pond
Jan-Olof Drangert,
Linköping University, Sweden
Collection & reuse off site

12. Time to search for technical solutions!

13. A new housing area in central Stockholm
Courtesy of Stockholm Water, Sweden

14. Some achievements in the new district
- Household water consumption down 40%
- Hot water use (35% of total water use) not measured yet,
but expected to decrease % (= energy saving)
- Eutrophication of the receiving lake reduced by 50%
- 60% of phosphorus and nitrogen returned to agriculture
- Green-house effect, acidification, and use of non-renewable
energy reduced by 30%
Improvements made by resource-saving installations,
rather than changes in individual behaviour – so far
Next step: residents become partners
Jan-Olof Drangert, Linköping university, Sweden

15. Self-contained housing complexWC
15 L
50 L
10 L
130 L
80 L
wetland
STP 130
70 L
55 L groundwater recharge
well water
80 L
groundwater
Jan-Olof Drangert, Linköping university, Sweden

16. A vision for sanitation arrangements
National and local governments provide guidelines for installation and operation of eco-friendly arrangements.
A single household or a housing company can find eco- friendly products in ordinary hardware shops and outlets for contractors.
Small and large contractors, plumbers and engineering firms, architects are familiar with the requirements of eco-friendly installations.   
Jan-Olof Drangert, Linköping university, Sweden 16