High water table sanitation

1. High water table sanitation Session 2 Technical options for high water table sanitation WTS2

2. Objectives of session • Be able to list 4 of the 7 technical options available to solve the problem of providing sanitation in high water table locations. • Be able to discuss the advantages and disadvantages of each option. • Be able to identify which option to apply when in an emergency situation. WTS2

3. Group work • Identify options to solve problems of pit collapse and ground water pollution? • Focus on: • First phase of an emergency. • Situation when the water table is within 4 metres of the ground surface (not concerned with flooding or when water table is above ground level). • Work in groups and report back with ideas in 10 minutes. WTS2

4. 1st Phase Emergency Options For High Water Table Locations • Open defecation fields • Shallow trench or pit latrines • Raised pit latrines • Containers • Ecological sanitation • Pollute groundwater (use conventional pit or deep trench latrines) • Relocate site WTS2

5. Design considerations • Technical • Financial constraints • Socio-political issues • Mandate of agency • Operation and Maintenance and • Socio-cultural issues WTS2

6. Socio-cultural issues • Important to listen to internally displaced persons/users. • Build on previous practices. • Consider people who live near/around the camp (if any). WTS2

7. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

8. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

9. Water table (WT) at or above ground level (GL) • Consider cause of flood? • If necessary relocate site • Involves dismantling existing camp and organising transport to a new location. WTS2

10. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

11. Groundwater not used for water supply? Remember - It is better to pollute groundwater than have pollutants on the ground surface - in ponds, drains and water courses. • Can use conventional pit latrines or deep trench latrines. • But only if pits can be dug. WTS2

12. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

13. Ecological sanitation (Eco-San) or open system to soakaway Source: Harvey, 2007 Double-vault urine-diverting latrine or compost latrine Image courtesy of WEDCC: Peter Harvey WTS2

14. Example: Elevated compost latrines in Dominican Republic • Used in second-phase response to flood-affected communities. • The latrines had to be elevated, as the water-table was less than 1m below ground-level. • Composting latrines were deemed appropriate as there were other latrines of this design in the area. • Other solution involving desludgeable tanks was not considered sustainable. • 210 latrines were built, some for individual families and some shared between three to six families. • Sanitation and hygiene promotion work before, during and after the construction was extensive and latrines were generally used properly and kept clean. Source: Harvey, 2007 WTS2

15. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

16. WT is between GL and 2.5m. Options where the groundwater is used as a water supply and the water table is within 2.5 metres of the ground level: • Open defecation fields; • Containers; • Relocate site; and • Ecosanitation. WTS2

17. Containers This option includes the use of: • Bucket latrines; • Packet latrines e.g. peepoo bags; • Cess pits; or • Chemical toilets. WTS2

18. Bucket/container latrines WTS2

19. Example: Bucket latrines in Wajir, north-east Kenya Situation • Groundwater table is high. • Water supply is from shallow wells because deep aquifer is saline. • To avoid pollution of groundwater people use bucket latrines. • Poor management of transport and disposal. Outcome • Resulted in surface contamination and major pollution problem! WTS2

20. Example: Chemical toilets in the Dominican Republic Source: Harvey, 2007 WTS2

21. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

22. Where WT is between 2.5m and 3.5m below GL. Options when groundwater is used as a water supply and water table is between 2.5 metres and 3.5 metres below ground level: • Shallow pit or trench latrines; or • Raised pit latrines. WTS2

23. Raised pit latrines Source: Harvey, 2007 Source: Franceys, Pickford and Reed, 1992. WTS2

24. Site is flooded and it is impossible to dig a pit or construct a hygienic latrine of any kind. Relocate site or consider appropriate flood sanitation measures – see other modules. Is WT at or above GL? Yes No Can a deep pit latrine be dug in the wet soil? Is groundwater used for water supply? OK to pollute groundwater so use conventional pit latrines or deep trench latrines. No Yes No Yes Are people accustomed to using Eco-San? Yes Consider using same Ecological Sanitation system that users are familiar with. How to select the right option? No Is depth to WT over 2.5 m.? • Select from: • Open defecation fields; • Containers; • Relocate site No Yes Is depth to WT over 3.5 m.? No • Select from: • raised pit latrine; or • shallow pit or trench latrine. Yes Use conventional pit latrines or deep trench latrines. WTS2

25. Where WT is over 3.5 metres below GL Options when groundwater is used as a water supply and water table is over 3.5 metres below ground level: • Can use conventional pit latrines or deep trench latrines. • Ensure bottom of pit is 1.5 metres above water table. • When the water table is deeper than 3.5 metres it does not generally conflict with sanitation provision. WTS2

26. Group work In groups of at least 2 people take one of the specificallyhigh water table sanitationoptions and discuss; • Advantages and disadvantages • Include how well it solves the problems? • And also privacy, safety, access for the vulnerable, cultural appropriateness. • Be ready to present back to the group in 10 minutes WTS2

27. Raised pit latrines • Advantages • Allows use of pit type technology. • More hygienic and will last longer than open field or shallow latrine options. • Can be built with local materials. • Disadvantages • Not suitable if water table within 2.5 metres of GL. • Moderately resource intensive - takes time to construct and requires reasonable level of skilled labour. • Moderately costly. • Poor access for disabled. WTS2

28. Containers • Advantages • Bucket latrine option relatively easy to implement. • Options do not require digging of pits or trenches. • Can be used regardless of water table level. • Disadvantages • Bucket latrines require handling of fresh excreta. • Peepoo bags require users to change defecation behaviour. • Chemical toilet option is very expensive. • Need to transport and dispose of excreta (probably by burial off-site where water table depth is lower). WTS2

29. Pollute groundwater • Advantages • Can use conventional pit and trench latrines. • Simple technology – familiar to users. • Excreta does not need to be handled. • Relatively low cost (note - cost increases with pit depth). • Disadvantage • Ground water must not be used for water supply. WTS2

30. Eco-San composting toilets • Advantages • Does not pollute groundwater. • Provides useful compost. • Disadvantages • Resource intensive – takes considerable time, skill and materials to construct. • Very costly option. • Only recommended if users are accustomed to using method. • Poor access for disabled. WTS2

31. Relocate site • Advantages • Enables selection of site where adequate and safe water and sanitation services can be provided. • Does not pollute groundwater. • Disadvantages • Stressful for displaced persons. • Logistically complex to organise. • Very costly option. WTS2

32. Hygiene promotion • Important to promote good hygiene practise alongside all sanitation interventions. • Handwashing; • Personal hygiene; • Menstrual hygiene management. WTS2

33. Monitoring and evaluation • Critical to carry out monitoring and evaluation of latrine usage. • Monitor: • Usage and cleanliness • Acceptability of facilities to users • Health impact • Evaluate and report back findings then design and implement changes. • Feed learning into Phase 2 design. WTS2