Infrastructure Development Experiences and Options for Improvement

Transcription

1 Infrastructure Development Experiences and Options for Improvement Jens Thøgersen Danida, 7th December

2 Characteristics of Rural Sanitation Infrastructure Latrines and soak-away pits are household investments Latrine options to be affordable and comply with the local culture Promotion of various cultural acceptable latrine options, integrated with hygiene promotion essential Schools and health stations are often keys to success 2

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4 Different Rural Technologies Pit latrines with smooth floor/surface with or without vents Double Vault Composting (DVC) latrines long tradition in many parts of North Vietnam Pour-flush latrine Septic tank latrine Superstructure of locally available materials Drainage and soak-away pit 4

5 Challenges, Rural Areas Latrines low priority for poor and low-income households (especially men) Local institutions focus on improved water supply, not sanitation Local institutions reluctant to promote locally accepted pit latrines Wastewater disposal forgotten when establishing small piped water scheme 5

6 Solutions, Rural Areas Combine discussions on latrine options with discussions on hygiene and financing options Ensure that households decide on latrine type Financial options: loans / subsidies / self-financing Schools and health stations as entry points for promotion of household latrines and good hygiene Simple wastewater disposal / drainage to be an integrated part of any rural water supply option 6

7 Characteristics of Urban Wastewater & Drainage Infrastructure Collection of wastewater and drain water require big structures (pipes / drains) in most roads Treatment of wastewater require big land areas Establishing house connections often require drastic impacts on private property Urban drainage, wastewater collection and treatment require huge investments Difficult to make financially sustainable if investments shall be financed by tariffs 7

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10 Different Urban Technologies Wastewater collection system: Combined or separate Wastewater treatment: Low tech land demanding or high tech less land demanding Effluent: To recipient or use for agriculture or other purpose 10

11 Challenges Urban/Peri-urban Areas Worn out / inadequate / failing existing infrastructure Urban population growth / unplanned urban development Waste management? sanitation interrelation Climate change Financing of projects 11

12 Solutions, Urban Areas Innovative (temporary) solutions like small bore technology Need for flexible solutions particularly when urban development is difficult to predict Need for fast processing of projects to avoid that realities by-pass the projects before being implemented 12

13 Example: Saidabad WTP, Bangladesh Saidabad 1 planned 1989 and completed 2002, at that time water quality had already deteriorated to such extent so the plant couldn t handle the incoming water Saidabad 2 project been in the planning phase for 10 years 3 feasibility studies carried out and later overtaken by deteriorated raw water quality 4th feasibility study conclude that none of the studied options would be able to solve problem 100%. Recommended flexible solution solving the problem to the extent possible 13

14 Water Quality Problems Complaints of taste, smell and colour during dry season, possibly hygienic problems High ammonia concentration? not possible to disinfect? not possible to control algae nor to ensure hygienic quality of water Algae growth in canal? release of toxic and nuisance substances Diluted wastewater? high concentration of organic substances? high chlorine demand and appearance of nuisance substances 14

15 Ammonium concentration mgnh 3 -N/L Average Maximum 0 dec-02 dec-03 dec-04 dec-05 dec-06 dec-07 15

16 River flow Cross section Propellerpump to lift the water into the inlet canal, 1600 m3/tim, 0,15 mvp ca 2 kw Air supply max, 6000 Nm3 luft/tim, 250 mbar ca 65 kw Nitrificationsbassin to be tight, floating or fixed to the bottom Material can be steel plates or flexible Aeration system to be fixed on the walls or in the bottom of the canal but still removable for service. Plan 16

17 Climate Change Site specific; need climate adaptation strategy Different scenarios: More water, less water, less water but more intensive rainfall Need to over-dimension drainage capacity or improve treatment to recycle wastewater Separate collection systems may be more economically feasible when climate changes are taken into account Need to design wastewater treatment facilities to collect and use or burn methane developed in the anaerobic processes 17

18 Financing Projects Need for infrastructure investments possibly bigger than what is available from bilateral and multilateral donors and development banks Need for more private sector investments Need to develop new financing mechanisms to meet demand Danida s urban sanitation projects in Vietnam cost approx USD 200 per person served. Urban population increase with approx 100 million people every year!!! 18

19 Thank you for your attention 19