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

Glossary

apron - A slightly sloped concrete pad which surrounds the well and helps prevent contaminated surface water from finding its way back into the well.

aquifer - A water-bearing layer (stratum) of permeable rock, sand, or gravel.

artesian well - A well that reaches water which, from internal pressure, flows up like a fountain.

bit - The piece which operates at the bottom end of the tool string to loosen the soil or rock to deepen the hole.

bottom plug - A concrete slab across the bottom of a well which can act to prevent anything from entering the well or allow only water to enter.

bottom section - That part of the well that extends beneath the water table.

brake post - An anchored cylindrical object which can act as a friction brake for rope wrapped around it. casing - Metal pipe used to reinforce a drilled well.

cement - A gray powder used as an ingredient in mortar and concrete.

concrete - A hard strong building material made by mixing cement, sand and gravel with sufficient water to cause the cement to set and bind the entire mass.

consolidated ground formation - Any of the various kinds of rock; hard rock; examples: granite. contaminate - To make impure or unclean.

curb - A part of the well lining that extends out from the dining into the surrounding soil, helps to hold it in place and prevents it from sliding down.

cutting ring - A sharp edged ring used on the bottom of a lining that is being sunk into place to make sinking easier.

development - See well development.

drive cap - A strong protective covering, screwed on to the top of a metal casing pipe and then struck to drive the pipe into the ground.

drop pipe - That section of pipe in a deep well pump assembly which extends between the pump cylinder and the pump body.

foot valve - A valve at the bottom of the suction pipe which prevents the water pulled up into it by the cylinder from flowing back into the well.

form - The structure or material around or in which concrete will exactly conform to.

ground water - Water deep enough in the ground so that it cannot be drawn off by plants or evaporated out through the ground surface; accumulates in quantity in aquifers from which it can be drawn out of the ground through wells.

grout seal - Mortar or concrete used to fill in a space to make it waterproof.

head wall - A short wall which extends above the ground level around a well.

hydrologic cycle - Continual natural cycle through which water moves from oceans to clouds to ground and ultimately back to oceans.

impermeable - A substance through which water cannot penetrate.

intake section - That part of the bottom section through which water enters the well.

laterite - A residual product of rock decay that is red in color; prevalent in Africa; difficult to penetrate but has little strength for construction purposes.

level - (Adj.) perfectly horizontal; (noun) a device used to establish a perfectly horizontal line.

lining - Masonry wall built to reinforce dug well hole walls.

lining ring - A hollow circular column, usually made of concrete, which is used to reinforce a dug well.

middle section - That part of the well between the ground surface and the water table.

mold - Form used in the construction of linings and lining rings.

percussion - The act of tapping sharply.

permeability - The speed which water can move through a certain type of soil or rock. Water will move much faster through sand than it will through clay so the sand is said to be more permeable. platform - See apron. plumb - Perfectly straight down or up.

pump cylinder - That part of the pump in which the piston and cup seals slide to move water. sinking method - Any technique used to dig or drill a well. stable ground - Firm soil; not likely to cave in.

suction pipe - That part of the pump assembly which extends beneath the cylinder into water.

surface recharge - The amount of water that soaks down through the ground to reach an aquifer in a certain length of time.

surface water - Water that is found on the ground surface in puddles, streams, rivers, lakes or oceans.

surge plunger - A device that can be inserted into the casing pipe and is moved up and down to develop the well.

swivel connection - A device used to connect two pipes or hoses and which permits one or both to turn freely.

tool string - The entire length of equipment and connections operated in the hole to sink a drilled well.

top section - That part of the well above the ground surface.

transpiration - The passage of water vapor from plants into the atmosphere.

unconsolidated ground formation - any type of soil other than hard rock; examples: sand, gravel, clay.

valve - A structure that permits the movement of fluid in one direction only.

water source - Any place where people could possibly come to gather water; for example a well, spring, river, lake, reservoir, public tap, private home faucet.

water table - The upper limit of that portion of the ground which is wholly saturated with water.

watertight seal - An impermeable material used to prevent water from moving from one area to another.

well development - The process of rearranging the soil particles around the intake section of a well to permit easier and better water flow into the well.