Cover Image
close this book Wells construction: hand dug and hand drilled
View the document Acknowledgments
View the document Introduction
close this folder Section one: Planning
close this folder Chapter 1: Introduction to wells planning
View the document A. Overview
View the document B. The need for adequate water supply
View the document C. Involving the local community
View the document D. Selecting the most appropriate water source
View the document E. Site choice
View the document F. Preventing water contamination
View the document G. Types of wells
View the document H. Well sections
View the document I. Materials
View the document J. Tools and equipment
View the document K. Sinking method
View the document L. Preparation for construction
View the document M. Planning
close this folder Section two: Hand dug wells
View the document Chapter 2: Introduction to hand-dug wells
View the document Chapter 3: Well design
View the document Chapter 4: Supplies
View the document Chapter 5: Lowering and raising workers and equipment
View the document Chapter 6: Digging
View the document Chapter 7: The middle section: overview of lining techniques
View the document Chapter 8: Construction of the middle section
View the document Chapter 9: Construction of the bottom section
close this folder Section three: Drilled wells
View the document Chapter 10: Introduction to drilled wells
View the document Chapter 11: Drilling and casing techniques
View the document Chapter 12: Construction: hand rotary and hand percussion methods
View the document Chapter 13: Construction: sludger method
View the document Chapter 14: Construction: driven and jetted
View the document Chapter 15: The bottom section
close this folder Appendices
View the document Appendix I: Conversion factors and tables
View the document Appendix II: Vegetation as an index of ground water
View the document Appendix III: Uses of dynamite in hand dug wells
View the document Appendix IV: Cement
View the document Appendix V: Leveling and plumbing the mold
View the document Appendix VI: Pipe
View the document Appendix VII: Pumps
View the document Appendix VIII: Water treatment in wells
View the document Appendix IX: Rope strength
View the document Glossary
View the document Annotated bibliography

B. The need for adequate water supply

A new properly built well can provide people with more and better water. But the new well itself may have little or no impact on the surrounding community's health if the well users do not know how to make effective use of the water.

It is important to learn the water needs of a local population in order to construct an appropriate water source. In all locales an adequate supply of clean water is essential for maintaining and improving health. Many of the most common and serious diseases in developing countries are closely related to the amount and quality of water people use. Without an adequate supply of clean water, little can be done to control diseases that spread through contaminated water supplies.

In order to ascertain local needs, you must consider two limiting aspects to the provision of water: 1) the quality of the water and 2) the quantity of water available locally.

Good quality water does not contain chemicals and bacteria which are hazards to health and life. The quality of water can be assured by:

• locating the site to avoid possible water contamination;

• proper construction of the well or any other water source, to protect the water supply from contamination;

• initial and periodic water treatment, usually with chlorine, to kill dangerous bacteria (see Appendix VIII, Water Treatment);

• education of the local users so that they can maintain the purity, or at least prevent the gross contamination of their water.

The quantity of water is often more difficult to ensure. Especially in a rural setting, access (distance) to water will often limit the amount that can be used by each individual, because of the time needed to convey it. Quantity, however, has a direct bearing on health.

Five liters per person per day is considered the minimum consumption level, although desert dwellers exist on less. More than 50 liters per person per day, it has been estimated, gains no further health benefits. Twentyfive liters per person per day may become an acceptable goal in places where piped connections to individual houses are not feasible. Wherever possible, water use beyond minimum-level consumption should be encouraged. Consumption will rise under the following circumstances:

• new well construction to provide a water source closer to a group of people, who will then presumably be able to gather more water in the same amount of time that they previously were able to do;

• education of local users toward a greater use of water, especially for hygienic purposes (bathing, washing clothes and cooking utensils).

The quantity of water needed may also be significantly affected by the number of livestock that require water and by whether the water is to be used for garden irrigation.