SWITCH Training Kit: Module 3C – Sustainable wastewater management

Module 3: Exploring the options

SWITCH Training Kit

Module 3C: Sustainable wastewater management

An overview

SWITCH Training Kit: Module 3C – Sustainable wastewater management

The issues facing urban wastewater management

Environmental impacts

Population growth Urbanisation

Energy costs

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Links between urban wastewater management and other areas of the water sector

Stormwater management

Water supply

Water treatment

Water quality

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Links between wastewater management and other sectors of urban management

FarmingParks, gardens and recreation

Local economic development

Energy

Housing

Health

SWITCH Training Kit: Module 3C – Sustainable wastewater management

The conventional approach

• Wastewater network to collect all wastewater streams from individual buildings

• Combined sewers

• Centralised treatment

• Discharge of treated effluent to receiving water bodies and disposal of sludge by-product

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Drawbacks of the conventional approach to urban wastewater management

• Pollution risk

• Cost

• Carbon emissions

• Failure to make use of resources

• Non-flexible

SWITCH Training Kit: Module 3C – Sustainable wastewater management

A more sustainable approach

• Separating wastewater flows such as urine, blackwater, greywater, industrial wastewater and stormwater at source

• Employing appropriate treatment methods (including natural systems) for different wastewater flows

• Reusing wastewater for different purposes

SWITCH Training Kit: Module 3C – Sustainable wastewater management

• Urine diversion toilets• Greywater reuse systems• Constructed wetlands• Soil Aquifer Treatment (SAT)• Waste stabilisation ponds• Bio-energy production

A more sustainable approach

Non-conventional wastewater treatment and reuse options include:

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Urban ecohydrology

Source: Zalewski, Wagner, (2008)

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Benefits of non-conventional wastewater management solutions

• Increased access to sanitation• Water savings • Flexibility to change • Reuse of nutrients for agriculture • Financial savings • Energy recovery • Improved treatment

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Why non-conventional wastewater management solutions are more sustainable

Improved sanitation coverage

Amenity value

Creation of renewable resources

Low investment and maintenance costs

Reduced risk of contaminated effluent being discharged to the environment

Reduced carbon emissions

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Examples of non-conventional wastewater management options

SWITCH Training Kit: Module 3C – Sustainable wastewater management

Acknowledgements

Ralph Philip and Barbara Anton ICLEI – Local Government’s for Sustainability

based on the joint efforts of the following SWITCH partners:J.M. Cai (Chinese Academy of Sciences), Y, Feng (Hamburg University of Technology), Y. Hu (Hamburg University of Technology), W.H. Ji (Chinese Academy of Sciences), K. Kujawa (Wageningen University), A. Mels (Wageningen University), R. Otterpohl (Hamburg University of Technology), A. Roman (Hamburg University of Technology), M. Sanz (UNESCO-IHE), M. Snel (IRC International Water and Sanitation Centre), N. Stoll (Hamburg University of Technology), F. Tettenborn (Hamburg University of Technology), R. van Veenhuizen (ETC Foundation), E. von Münch (UNESCO-IHE), M. Winker (Hamburg University of Technology), A. Adin (Hebrew University of Jerusalem), A. Aharoni (Mekorot), G. Amy (UNESCO-IHE), H. Cikurel (Mekorot), D.J. Conran (University of Birmingham), A. Drobniewska (University of Lodz), P.A. Ellis (University of Birmingham), W. Fratczak (University of Lodz), R.B. Greswell (University of Birmingham), K. Izydorczyk (University of Lodz), C. Lydon (University of Birmingham), M.O. Rivett (University of Birmingham), D. Rousseau (UNESCO-IHE), S.K. Sharma (UNESCO-IHE), H. van Bruggen (UNESCO-IHE), I. Wagner (University of Lodz), M. Zalewski (University of Lodz)The UNESCO-IHE led SWITCH project runs from Feb. 2006 to Jan. 2011 and is part-financed by Directorate General Research of the European Commission under the Sixth Framework Programme. For more information see www.switchurbanwater.eu

This presentation has been produced as part of the SWITCH Training Kit by: