Wells Marco Bruni seecon international gmbh Wells Find

Wells Marco Bruni, seecon international gmbh Wells

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Find this presentation and more on: www. ssswm. info. Contents 1. Introduction 2. How Can Wells Optimise my Local Water System? 3. Prospecting for Groundwater Sources 4. Different Types of Wells and their Characteristics 5. Basic Design and Construction Principles 6. Operation and Maintenance 7. Applicability 8. Advantages and Disadvantages 9. References Wells 3

Find this presentation and more on: www. ssswm. info. 1. Introduction Variability of the Groundwater Table Infiltration of water into an aquifer during the wet season Infiltration of water into an aquifer during the dry season Source: SMET & WIJK (2002) Wells 4

Find this presentation and more on: www. ssswm. info. 1. Introduction Groundwater Withdrawal from Wells by Means of Buckets or Pumps Source: http: //www. flickr. com/photos/foodforthepoor/61002 18694/sizes/z/in/photostream/ [Accessed: 17. 05. 2012] Source: IWMI (n. y. ); NE (n. y. ); WATER CHARITY (n. y. ); BAUMANN (2011) Rope & Bucket Wells 5

Find this presentation and more on: www. ssswm. info. 2. How Can Wells Optimise my Local Water System? Health Aspects A properly constructed well can improve a community’s water supply substantially. High quality drinking water No or just minor purification required Many low-cost and lowtech digging and drilling options available Source: BAUMANN (2011) Wells 6

Find this presentation and more on: www. ssswm. info. 3. Prospecting for Groundwater Sources Where Should I Look for Groundwater? • Villagers and members of the neighbouring communities can be a good source of information on the presence of shallow groundwater. • Also, certain types of vegetation (e. g. banana plants, bulrushes, sugar can, date palms) can indicate presence of groundwater (COLLINS 2000). • Often, existing wells in close proximity indicate the presence of groundwater. • If technical equipment is available, test borings can give detailed information on the groundwater level. Source: http: //thumbs. dreamstime. com/t humblarge_553/1288894832745 DF 3. jpg [Accessed: 18. 05. 2012] Wells 7

Find this presentation and more on: www. ssswm. info. 4. Different Types of Wells and their Performance Two Main Types of Wells Dug Wells Diameter: +/- 1. 2 m Length: 3 – 20 m Wells Drilled Wells Diameter: +/- 50 mm Length: 10 – 50 m (200 m) 8

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Location • Wells should not be constructed close to potential sources of contamination, e. g. pit latrines, livestock farming, fuel/pesticide/ fertiliser storage, etc. Source: BUCHANAN et al. (2010) • Well should be located in close proximity to the actual point of water use Wells 9

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Dug Well: Elements Well Head Well Shaft Intake Source: SMET & WIJK (2002) Wells 10

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Dug Well: Excavation • Excavation is done manually with pick and shovel • Lining is most often necessary to protect the well from collapsing and preventing subsequent contamination of the well • Materials for lining: prefabricated concrete rings, stones, bricks, masonry, etc. Wells Source: : http: //cloud. globalgiving. org/pfil/7109/Handdug_Well 2_Grid 7. jpg [Accessed: 14. 03. 2011] 11

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Drilled Well: Drilling a) Basic hand-drilling techniques Source: http: //www. nigerwaterforlife. org/images/upload/IMAG 0010. j pg [Accessed: 27. 03. 2012] b) High-tech machine-drilling Wells Source: http: //i 01. i. aliimg. com/photo/v 0/106324951/water_well_drilling_ and_borehole_rig_machine. jpg [Accessed: 17. 05. 2012] 12

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Drilled Well: Drilling – Many Different Techniques a) Basic Hand-drilling techniques e g u A n o i ss g n i r cu r e P b) Machine-drilling t Je g n i dg g n i t e in h c ing a M rill d Slu Source: ELSON & SHAW (1995) Source: WURZEL (2000) Wells 13

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Drilled Well: Completion of a well involve construction of a: • Well casing (prevents the well from collapse and seepage of contaminants). • Well screen (holds back sediments while allowing water to infiltrate the well) • Gravel pack (prevents the well screen from becoming clogged) • Sanitary seal & head works (prevents surficial contamination) Source: WATERAID (2008) Wells 14

Find this presentation and more on: www. ssswm. info. 5. Basic Design and Construction Principles Well Protection • Wells and aquifers are susceptible to contamination. Contaminants can either enter from the opening or from the sides of the excavation. • Water source protection involves: - Interdiction of all activities that can potentially cause contamination close to the well (e. g. pit latrines, livestock farming, fuel/pesticide/ fertiliser storage, etc) • Wellhead protection involves: - Drainage - Surficial seal: an apron - Impermeable lining (dug wells) or casing (drilled wells) - Securing functioning of the pump Wells Source: NABUUR (n. y. ) 15

Find this presentation and more on: www. ssswm. info. 6. Operation and Maintenance Dug Well • Structural maintenance includes: - Checking the apron for cracks, - Securing the inspection cover, Improving the yield by deepening or removing infiltrated sand particles, and the - Maintenance of the lifting device. • Equally, securing hygienic operation is essential. This involves: - Protection and cleaning of the area (e. g. fencing and covering), - Checking water quality and disinfecting if necessary, - Monitoring the effects of withdrawal on environment and surrounding areas, and - Educating water users in properation of the well. Wells 16

Find this presentation and more on: www. ssswm. info. 6. Operation and Maintenance Drilled Well • Drilled wells are easy to operate and basically not in need for maintenance. • However, as a drilled well always include a manual or mechanised pump, maintenance of the lifting is critical! Source: http: //www. edgeoutreach. com/sites/edgeoutreach. com/files/Haiti. HPRTrainers. j pg [Accessed: 18. 05. 2012] Wells 17

Find this presentation and more on: www. ssswm. info. 7. Applicability Drilled Well • Can serve as a water supply for a • Can serve as water supply for single households, for small rural community, depending on rural communities as for more the performance urban areas, depending on the • Low-tech solution particularly size of the well (depth & for rural communities diameter). • Manual drilling is applicable in alluvial soils up to 40 metres. • A pump must be available and frequently maintained Wells 18

Find this presentation and more on: www. ssswm. info. 8. Advantages and Disadvantages Dug Well Advantages: High degree of involvement of the local community during the whole process • Long construction phase • Dangerous excavation • Under supervision, no skilled workers are required • • Simple equipment sufficient for both • construction and maintenance Motorised pump (power source) often required to lower the water table during construction • Low cost for construction and O&M • Involvement of private sector possible (local well diggers) • Yield can be increased after construction • Reservoir included (large diameter) • Wells Disadvantages: Application restricted to regions with rather soft geological formation and relatively high groundwater levels • Alteration of groundwater level can adversely affect the surrounding environment • High susceptibility for contamination • People (i. e. children) can fall in if the well is uncovered 19

Find this presentation and more on: www. ssswm. info. 8. Advantages and Disadvantages Drilled Well Advantages: Wells Disadvantages: • Quicker and cheaper to sink than hand-dug wells • • Less susceptible to contamination Skilled staff and experts required for drilling • No dewatering during sinking required • Pump required, which needs appropriate operation and maintenance • Less lining material required • • Safer in construction and use Lower yield than hand-dug wells (smaller diameter) • The well itself needs barely maintenance • Overexploitation may lead to adverse effects on the environment • Many simple drilling techniques available suiting many geological conditions • Arsenic pollution may occur • More technical equipment and skills necessary for construction • No integrated storage capacity / recharge during periods of low abstraction 20

Find this presentation and more on: www. ssswm. info. 9. References BAUMANN, E. (2011): Low-cost Hand Pumps. St. Gallen: Rural Water Supply Network (RWSN). URL: http: //www. rwsn. ch/documentation/prcollector. 2009 -04 -05. 2482958002/skatdocumentation. 2011 -07 -01. 0268979788/file [Accessed: 02. 04. 2012]. BUCHANAN, B. ; DE LA CRUZ, N; MACPHERSON, J. ; WILLIAMSON, K. (2010): Water Wells that Last for Generations. Edmonton: Alberta Agriculture and Rural Development. URL: http: //www 1. agric. gov. ab. ca/$department/deptdocs. nsf/all/wwg 404 [Accessed: 23. 04. 2012]. ELSON, B. ; SHAW, R. (1995): Simple Drilling Methods. Leicestershire: Water, Engineering and Development Centre (WEDC), Loughborough University. URL: http: //www. lboro. ac. uk/well/resources/technical-briefs/43 -simple-drilling-methods. pdf [Accessed: 21. 03. 2012]. IWMI (n. y. ): Diesel pump in operation. Colombo: International Water Management Institute (IWMI). URL: http: //awmsolutions. iwmi. org/motorized-pumps. aspx [Accessed: 25. 04. 2012]. NABUUR (n. y. ): Protected dug well in Uganda. Amersfoort: Nabuur. URL: http: //www. nabuur. com/en/village/nakyerongosa/project/task/integrated-community-managed-water-hygiene-and-sanitationimprovem [Accessed: 15. 03. 2012]. NE (n. y. ): Solar Water Pump. Lahore: National Engineers (NE). URL: http: //www. ne. com. pk/uploads/images/Gallery/pump/DSCN 0054. jpg [Accessed: 26. 04. 2012]. SMET, J. (Editor); WIJK, C. van (Editor) (2002): Small Community Water Supplies: Technology, People and Partnership: Groundwater Withdrawal - Chapter 10. The Hague: International Water and Sanitation Centre (IRC). URL: http: //www. irc. nl/page/1917 [Accessed: 29. 02. 2012]. WATERAID (2008): Technology Notes. London: Wateraid. URL: http: //www. wateraid. org/documents/plugin_documents/technology_notes_2008. pdf [Accessed: 12. 03. 2011] WATER CHARITY (n. y. ): Deep-well hand piston pump including apron and drain in Wallalan, Upper Badibu District, Gambia. Crestline: Water Charity. URL: http: //appropriateprojects. com/images/jorgensen/7. jpg [Accessed: 02. 04. 2012]. WURZEL, P. (2001): Drilling Boreholes for Handpumps. St. Gallen: Swiss Centre for Development Cooperation in Technology and Management (SKAT). URL: http: //www. skat. ch/publications/prarticle. 2005 -09 -29. 5069774463/prarticle. 2006 -1102. 5180575226/skatpublication. 2006 -11 -02. 0404244520/file [Accessed: 22. 03. 2012]. Wells 21

Find this presentation and more on: www. ssswm. info. “Linking up Sustainable Sanitation, Water Management & Agriculture” SSWM is an initiative supported by: Created by: Wells 22