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