Village
Technology
Handbook


Volunteers in Technical Assistance
1815 North Lynn Street
Arlington, Virginia 22209 USA

Village Technology Handbook

Copyright [C] 1988 Volunteers in Technical Assistance
All rights reserved. No part of this publication may be reproduced or transmitted
in any form or by any means, electronic or mechanical, including photocopy,
recording, or any information storage and retrieval system, without the written
permission of the publisher.

(This is the third edition of a manual first published in 1963, with the support of
the U. S. Agency for International Development, and revised in 1970, which has
gone through eight major printings.)

Manufactured in the United States of America.

Set in Times Roman type on an IBM personal computer, a gift to VITA from
International Business Machines Corporation, using WordPerfect software donated
by WordPerfect Corporation.

Published by: Volunteers in Technical Assistance
1815 North Lynn Street, Suite 200
Arlington, Virginia 22209 USA

10 9 8 7 6 5 4 3 2 1

Library of Congress Cataloging-in-Publication Data

Village technology handbook.

Bibliography: p. 413
1. Building--Amateurs' manuals. 2. Do-it-yourself work. 3. Home economics,
Rural--Handbooks, manuals, etc. I. Volunteers in Technical Assistance.
TH148.V64 1988 620'.41734 88-5700
ISBN 0-86619-275-1

Village Technology Handbook

Table of Contents

FOREWORD
NOTES ON USING THE HANDBOOK
ABOUT VITA
SYMBOLS AND ABBREVIATIONS

WATER RESOURCES

wr1.gif (393x393)



Developing Water Sources
Getting Ground Water from Wells and Springs
Ground Water
Flow of Water to Wells
Where To Dig a Well
Well Casing and Seal
Well Development
Tubewells
Well Casing and Platforms
Hand-Operated Drilling Equipment
Dry Bucket Well Drilling
Driven Wells
Dug Wells
Sealed Dug Well
Deep Dug Well
Reconstructing Dug Wells
Spring Development

Water Lifting and Transport
Overview
Moving Water
Lifting Water
Water Transport
Estimating Small Stream Water Flow
Measuring Water Flow in Partially Filled Pipes
Determining Probable Flow with Known Reservior Height and
Size and Length of Pipe
Estimating Water Flow from Horizontal Pipes
Determining Pipe Size or Velocity of Water in Pipes
Estimating Flow Resistance of Pipe Fittings
Bamboo Piping

Water Lifting
Pump Specifications: Choosing or Evaluating a Pump
Determining Pump Capacity and Horsepower Requirements
Determining Lift Pump Capability
Simple Pumps
Chain Pump for Irrigation
Inertia Hand Pump
Handle Mechanism for Hand Pumps
Hydraulic Ram
Reciprocating Wire Power Transmission for Water Pumps
Wind Energy for Water Pumping
Overview
Decision Making Process

Water Storage and Treatment
Cisterns
Cistern Tank
Catchment Area
Cistern Filter
Selecting a Dam Site
Catchment Area
Rainfall
Location
Water Purification
Boiler for Drinking Water
Chlorinating Wells, Springs, and Cisterns
Water Purification Plant
Sand Filter

HEALTH AND SANITATION

Sanitary Latrines
Overview
Privy Location
Privy Shelters
Privy Types
Pit Privy
Water Privy
Philippine Water-Seal Latrine
Thailand Water-Seal Privy Slab

Bilharziasis
The Parasites
Symptoms and Diagnosis
Treatment
Prevention

Ridding an Area of Bilharziasis

Malaria Control
Community Preventive Measures
Personal Preventive Measures
Treatment

Oral Rehydration Therapy
Dehydration--A Life-Threatening Condition
Treating or Preventing Dehydration

AGRICULTURE

Earth Moving Devices for Irrigation and Road Building
Drag Grader
Fresno Scraper
Barrel Fresno Scraper
Construction
Operation
Repairing the Barrel Fresno Scraper
Adapting for Heavy Duty
Float with Adjustable Blade
Buck Scraper
V-Drag
Multiple Hitches

Irrigation
Siphon Tubes
Using Tile for Irrigation and Drainage
Making a Concrete Tile Machine
Making the Tile

Seeds, Weeds, and Pests
Seed Cleaner
Seed Cleaning Sieves
Drying Grain with Wooden Blocks
Preparing the Blocks
Using the Blocks
Bucket Sprayer
Backpack Crop Duster
How the Duster Operates
Adjusting the Duster
Filling the Duster
Making Springs for the Duster

Poultry Raising
Brooder with Corral for 200 Chicks
Kerosene Lamp Brooder for 75 to 100 Chicks
Brooder for 300 Chicks

Bamboo Poultry House
House
Roof
Feeders
Nests
Poultry Feed Formulas

Intensive Gardening
The Soil
The Growing Beds
Fertilizing the Soil
Selection of Crops
Mulch

Silage for Dairy Cows

FOOD PROCESSING AND PRESERVATION

Storing Food at Home
How to Care for Various Kinds of Food
Dairy Foods
Fresh Meat, Fish, Poultry
Eggs
Fresh Fruits and Vegetables
Fats and Oils
Baked Goods
Dried Foods
Canned Goods
Leftover Cooked Foods
Food Spoilage
When is Food Spoiled?
Why Food Spoils
Containers for Food
Types of Containers
Care of Food Containers
The Storage Area
Good Ventilation
Keep the Storage Area Cool and Dry
Keep the Storage Area Clean

Keeping Foods Cool
Evaporative Food Cooler
Iceless Cooler
Window Box
Other Ways To Keep Foods Cool

Storing Vegetables and Fruits for Winter Use
Post Plank Cellar
Cabbage Pits
Storage Cones

Fish Preservation
Salting Fish
Preparing the Fish
Salting
Washing and Drying To Remove Excess Salt
Air Drying
Using Salted Fish
Smoking Fish

CONSTRUCTION

Concrete Construction
Overview
Importance of a Good Mixture
Aggregates: Gravel and Sand
Water
Calculating Amounts of Materials for Concrete
Using the "Concrete Calculator"
Using the Water Displacement Method
Using "Rule of Thumb" Proportions
Mixing Concrete
Making a Mixing Boat or Floor
Slump Tests
Making Forms for Concrete
Placing Concrete in Forms
Curing Concrete
Quick-Setting Concrete

Bamboo Construction
Preparing Bamboo
Splitting Bamboo
Bamboo Preservation
Bamboo Joints
Bamboo Boards
Bamboo Walls, Partitions, and Ceilings

Walls
Partitions
Ceilings

Stabilized Earth Construction
Overview
Soil Characteristics
Testing the Soil
Composition Test
Compaction Test
Shrinkage Test
Making Adobe Blocks
Making Compressed Earth Blocks and Tiles
Building with Stabilized Earth Blocks

Construction Glues
Casein Glue
Making Casein Powder
Mixing Casein Glue
Using Casein Glue
Liquid Fish Glue

HOME IMPROVEMENT

Simple Washing Machines
Plunger Type Clothes Washer
Making the Washer
Using the Washer
Hand-Operated Washing Machine
Making the Washing Machine
Using the Washing Machine

Cookers and Stoves
Fireless Cooker
Making the Fireless Cooker
Using the Fireless Cooker
Charcoal Oven
How To Build the Oven
How To Use the Oven
Portable Metal Cookstoves
Principles of Energy-Efficient Stoves
Cookstove Design
Producing the Cookstoves
Outdoor Oven

Home Soap Making
Two Basic Methods
Ingredients for Soap
Fats and Oils
Lye
Borax
Perfume
Water
Soap Making with Commercial Lye
Recipes
How To Make the Soap
How To Know Good Soap
Reclaiming Unsatisfactory Soap
Soft Soap with Lye Leached from Ashes
Leaching the Lye
Making the Soap
Larger-Scale Soap Making

Bedding
A Nest of Low-Cost Beds
How To Make a Mattress
Making the Mattress
Making a Rolled Edge

CRAFTS AND VILLAGE INDUSTRY

Pottery
Waste-Oil Fired Kiln
Cost Advantages of Waste Oil
Design of Kiln and Fire Box
Operating the Kiln
Small Rectangular Kiln
Construction
Firing
Salt Glaze for Pottery
Considerations
How To Fire the Pottery

 
Hand Papermaking
Papermaking Processes
Pre-processing
Pulping
Lifting, Couching, Stacking
Pressing and Drying
Sizing
Calendering

Sorting and Cutting
Making Paper in the Small Workshop
Pulping
Making the Sheets
Pressing and Drying
Sizing and Coating
Making Paper in the Micro-Factory

Candle Making
Making the Jigs
Preparing the Wax
Dipping the Candles

COMMUNICATIONS

Bamboo or Reed Writing Pens

Silk Screen Printing
Building the Silk Screen Printer
Printing
Preparing A Paper Stencil
Making Silk Screen Paint

Inexpensive Rubber Cement

REFERENCES

CONVERSION TABLES

Foreword

The Village Technology Handbook has been an important tool for development
workers and do-it-yourselfers for 25 years. First published in 1963 under the
auspices of the U.S. Agency for International Development, the Handbook has
gone through eight major printings. Versions in French and Spanish, as well as
English, are on shelves in bookstores, on desks in government offices and local
organizations, in school libraries and technical centers, and in the field kits of
village workers around the world. The technologies it contains, like the chain and
washer pump, the evaporative food cooler, and the hay box cooker, have been
built for technology fairs and demonstration centers throughout the developing
world-and more importantly, have been adopted and adapted by people everywhere.

Because the Handbook has been a faithful friend for so long, this revision was
approached with care. As even the best of friendships needs an occasional
reassessment, our question was how to update the book without damaging its
fundamental utility-to avoid throwing the baby out with the bath water.

We began by circulating sections of the book to VITA Volunteers with expertise
in the various technical areas. We asked them to take a good hard look at what
was presented and let us know what should be revised, updated, discarded,
replaced. The volunteers' replies affirmed what tens of thousands of users around
the world have recognized over the years, that the basic material was sound.
Where they suggested changes, additions, and deletions, we have done our best to
oblige.

Concurrently, we reviewed the comments that many of those users have sent to
us over the years. Comments on what worked, what caused trouble, and what
would be nice to have included. With so much going on in the development of
small-scale, village technologies, the latter category was extensive. But because so
much of the original book is still very applicable today, we opted to make the
additions and changes selectively. We made the decision to add to this volume
where it seemed most feasible, and to begin to compile a companion volume that
will cover a selection of those other technologies.

Since the Handbook is primarily intended for "do-it-yourselfers" in villages and
rural regions, most space still is allocated to the development of water resources
and to agriculture. And rather than simply replacing everything and starting over,
this new edition reorganizes some sections, updates several of the original
articles, and includes a number of new ones on frequently requested topics. The
new articles cover energy efficient stoves, the use of wind power to pump water,
stabilized earth construction, a novel ceramics kiln, small-scale candle and paper
production, high yield gardening, oral rehydration therapy, and malaria control. An
all-new reference section is also provided.

VITA is committed to assisting sustainable growth: that is, to progress, based on
expressed needs, that increases self reliance. Access to clearly presented technical
information is a key to such growth. VITA searches out, develops, and disseminates
techniques and devices that contribute to self suffiency. The Village
Technology Handbook is one such VITA effort to support sustainable growth with
easy to read technical information for the communities of the world.

VITA Volunteers are similarly committed to helping VITA help others, and many
of them were involved in this project, reviewing material in their technical fields.
VITA wishes to thank Robert M. Ross and David C. Neubert for reviewing the
sections on agriculture; Phil D. Weinert, Charles G. Burney, Walter Lawrence, and
Steven Schaefer, water resources and purification; Malcolm C. Bourne and Norman
M. Spain, food processing and preservation; Dwight R. Brown and William Perenchio,
construction; Charles D. Spangler, sanitation; Jeff Wartluft, Mark Hadley,
Marietta Ellis, Gerald Kinsman, and Peter Zweig, home improvement; Dwight
Brown and Victor Palmeri, crafts and village industries; and Grant Rykken,
communications.

Most especially, we would like to thank VITA Volunteer engineer and literacy
specialist Len Doak, who was coaxed out of retirement and away from the fishing
docks to coordinate the revision, sort out the comments, and pull the new pieces
together.

VITA staff who were involved included Suzanne Brooks, administrative support and
graphics; Julie Berman, administrative support; Margaret Crouch, editorial; and
Maria Garth, typesetting.

And finally, this effort has given all of us a new respect for Dan Johnson, one of
VITA's "founding fathers" and currently a member of the Board of Directors, who
devoted a year of his life to putting the original Handbook together a quarter of
a century ago. That so much of that work has stood the test of time is due in no
small measure to the care with which he and the other VITA Volunteers who
worked with him approached their task.

--VITA Publications
January 1988

Notes on Using the Handbook

INTRODUCTION

The Village Technology Handbook contains eight major subject sections, each containing
several articles. The articles cover both the broad topic areas such as
agriculture, as well as specific agricultural projects such as building a scraper.

If you are planning an entirely new project you would benefit by reading the entire
section through. If you are planning a specific project (such as building a
wind-driven water pump) only that article need be read.

The skills needed for each of the projects described vary considerably, but none
of the projects requires more than the usual construction and trade skills such as
carpentry, welding, or farming that are generally found in most modest sized villages.

When the materials suggested in the Handbook are not available, it may be possible
to substitute other materials. Be careful to make any changes in dimensions
made necessary by such substitutions.

If you need translations of articles from the Handbook, we ask that you let us
know. The book itself has been translated into English, French, and Spanish, and
some individual articles may be available in other languages.

The articles in the Handbook came from many sources. Your comments and suggestions
for changes, difficulties with any of the projects described, or ideas for
new articles are welcome. Those kinds of comments were a very important element
in preparing this revised edition, and we expect to rely on them in the
future as well. Please send your comments so that we may continue to share.

SUMMARY OF THE HANDBOOK BY SECTION

Section 1. Water

Water resources are so vital that extensive coverage is provided. Much of this
material is from the original, but it has been reorganized and updated. The
sequence of articles begins with principles of hydrology that explain where
underground water is likely to be found. This is followed by articles on types of
wells and how to make well drilling tools and how to drill or dig the wells.

Next come articles on practical methods to lift water from wells and to transport
it. Articles on several pumps and water piping occur here. A new article on wind-driven
pumps is in this section. A number of charts and tables help in the
calculation of pipe size and water flow.

Water storage and purification are the topics of the next series of articles. This
section is unchanged from the earlier edition, but several new references are
fisted.

Section 2. Health and Sanitation

Next to pure water, sanitation is one of the most critical health needs of any
society. This section begins with two brief articles on the principles for disposal
of human waste. These are followed by details of how to build various types of
latrines. Also included is an article on bilharziasis (schistosomiasis) and a new
articles on malaria control and oral rehydration therapy.

Section 3. Agriculture

Seven topics are covered, beginning with earth moving devices to level fields and
build irrigation ditches. This is followed by directions for an irrigation system
based on concrete tile, including how to make the tile in the field. A variety of
material on raising poultry is included, and a new article on small, high yield
gardens has been added.

Section 4. Food Processing and Preservation

The articles in this section describe storage and handling of different types of
food, evaporative coolers and other cold storage technologies, and a variety of
other storage and processing systems and devices. The section has been revised
and updated and new references have been added.

Section 5. Construction

Much of this section deals with construction of buildings and walls using concrete
or bamboo. A new article on stabilized earth construction has been added, and
instructions for making glues to use in construction are also included.

Section 6. Home Improvements

Washing clothes, cooking, making soap, and making bedding are covered here. An
important new addition is an article on the construction of an energy efficient
cookstove developed in West Africa. The stove has shown more than double the
fuel efficiency of the traditional open fire.

Section 7. Crafts and Village Industry

Traditional crafts that lend themselves to development as small businesses are
discussed in this section--pottery, hand papermaking, and candle making. Ceramic
kilns described include an alternative kiln design fueled by waste motor oil.

Section 8. Communications

This section remains unchanged from the original on the premise that while
changes, in communications could actually fill volumes on their own, there are
many places in developing areas where the simple technologies presented here are
still quite useful. Simple writing instruments and silk screen printing are discussed.
The skills and materials described should be available in most rural
villages.

SOURCES OF ADDITIONAL INFORMATION

Each article in the Handbook concludes with one or more source references. These
and other sources of information have been compiled into the new expanded
Reference section at the back of the book. VITA publications that are listed may
be ordered directly from VITA Publications, Post Office Box 12028, Arlington,
Virginia 22204 USA.

You may also request technical assistance from VITA Volunteer experts by writing
to VITA, 1815 North Lynn Street, Suite 200, Arlington, Virginia 22209 USA.

About VITA

Volunteers in Technical Assistance (VITA) is a private, nonprofit, international
development organization. It makes available to individuals and groups in developing
countries a variety of information and technical resources aimed at fostering
self sufficiency--needs assessment and program development support; by-mail and
on-site consulting services; information systems training; and management of long-term
field projects.

Throughout its history, VITA has concentrated on practical and workable technologies
for development. It has collected, organized, tested, synthesized, and
disseminated information on these technologies to more than 70,000 requesters and
hundreds of organizations in the developing countries. As the information revolution
dawned, VITA found itself in a leadership position in the effort to bring the
benefits of that revolution to those in the Third World who are traditionally
passed over in the development process.

Perhaps of greatest significance is VITA's emphasis on technologies that are
commercially viable. These have the potential of creating new wealth through
adding value to local materials, thereby creating jobs and increasing income as
well as strengthening the private sector. We have increasingly translated our
experiences in information management to the implementation of projects in the
field. This evolution from information to implementation to create jobs, businesses,
and new wealth is what VITA is really about. It provides missing links
without creating dependency.

VITA places special emphasis on the areas of agriculture and food processing,
renewable energy applications, water supply and sanitation, housing and construction,
and small business development. VITA's activities are facilitated by the
active involvement of thousands of VITA Volunteer technical experts from around
the world, and by its documentation center containing specialized technical
material of interest to people in developing countries.

VITA currently publishes over 150 technical manuals, papers, and bulletins, many
available in French and Spanish as well as English. Manuals deal with construction
or implementation details for such specific topics as windmills, reforestation,
water wheels, and rabbit raising. In addition, VITA Technical Bulletins present
plans and case studies of specific technologies to encourage further experimentation
and testing. The technical papers-"Understanding Technology"-offer general
introductions to the applications and necessary resources for technologies or
technical systems. Included in the series are topics that range from composting to
Stirling engines, from sanitation at the community level to tropical root crops.
Publications catalogues are available upon request.

VITA News is a quarterly magazine that provides an important communications
link among far-flung organizations involved in technology transfer and adaptation.
The News contains articles about projects, issues, and organizations around the
world, reviews of new books, technical abstracts, and a resources bulletin board.

VITA derives its income from government, foundation, and corporate grants; fees
for services; contracts; and individual contributions.

For further information write to VITA, 1815 North Lynn Street, Suite 200,
Arlington, Virginia 22209 USA.

Symbols and Abbreviations
Used in this Book

@ . . . . at
" . . . . inch
' . . . . foot
C . . . . degrees Celsius (Centigrade)
cc . . . . cubic centimeter
cm . . . . centimeter
cm/sec . . centimeters per second
d or dia . diameter
F . . . . degrees Fahrenheit
gm . . . . gram
gpm. . . . gallons per minute
HP . . . . horsepower
kg . . . . kilogram
km . . . . kilometer
l . . . . liter
l/pm . . . liters per minute
l/sec. . . liters per second
m . . . . meter
ml . . . . milliliters
mm . . . . millimeters
m/m. . . . meters per minute
m/sec. . . meters per second
ppm. . . . parts per million
R . . . . radius

Water Resources
<see image>

Developing Water Sources

There are three main sources of water for small water-supply systems: ground
water, surface water, and rainwater. The choice of the source of water depends
on local circumstances and the availability of resources to develop the water
source.

A study of the local area should be made to determine which source is best for
providing water that is (1) safe and wholesome, (2) easily available, and (3)
sufficient in quantity. The entries that follow describe the methods for tapping
ground water:

o Tubewells
- Well Casings and Platforms
- Hand-Operated Drilling Equipment
- Driven Wells

o Dug Wells
o Spring Development

Once the water is made available, it must be brought from where it is to where it
is needed and steps must be taken to be sure that it is pure. These subjects are
covered in the major sections that follow:

o Water Lifting and Transport
o Water Storage and Treatment

GETTING GROUND WATER FROM WELLS & SPRINGS

This section defines ground water, discusses its occurrence, and explains its
movement. It describes how to decide on the best site for a well, taking into
consideration the nearness to surface water, topography, sediment type, and
nearness to pollutants. It also discusses briefly the process of capping and sealing
the well and developing the well to assure maximum flow of water.

Ground Water

Ground water is subsurface water, which fills small openings (pores) of loose
sediments (such as sand and gravel) or rocks. For example, if we took a clear
glass bowl, filled it with sand, and then poured in some water, we would notice
the water "disappear" into the sand (see Figure 1). However, if we looked through

fig1pg4.gif (393x393)


the side of the bowl, we would see water in the sand, but below the top of the
sand. The sand containing the
water is said to be saturated. The
top of the saturated sand is called
the water table; it is the level of
the water in the sand.

The water beneath the water table
is true ground water available (by
pumping) for human use. There is
water in the soil above the water table, but it does not flow into a well and is
not available for use by pumping.

If we inserted a straw into the saturated sand in the bowl in Figure 1 and sucked
on the straw, we would obtain some water (initially, we would get some sand too).
If we sucked long enough, the water table or water level would drop toward the
bottom of the bowl. This is exactly what happens when water is pumped from a
well drilled below the water table.

The two basic factors in the occurrence of ground water are: (1) the presence of
water, and (2) a medium to "house" the water. In nature, water is provided by
precipitation (rain and snow) and surface water features (rivers and lakes). The
medium is porous rock or loose sediments.

The most abundant ground water reservoir occurs in the loose sands and gravels
in river valleys. Here the water table roughly parallels the land surface, that is,
the depth to the water table is generally constant. Disregarding any drastic
changes in climate, natural ground water conditions are fairly uniform or balanced.
In Figure 2, the water poured into the bowl (analogous to precipitation) is

fig2pg4.gif (393x393)


balanced by the water discharging out of the bowl at the lower elevation (analogous
to discharge into a stream).
This movement of ground water is
slow, generally just centimeters or
inches per day.

When the water table intersects the
land surface, springs or swamps are
formed (see Figure 3). During a

fig3pg5.gif (486x486)


particularly wet season, the water
table will come much closer to the
land surface than it normally does
and many new springs or swampy
areas will appear. On the other hand, during a particularly dry season, the water
table will be lower than normal and many springs will "dry up." Many shallow
wells may also "go dry."

Flow of Water to Wells

A newly dug well fills with water a meter or so (a few feet) deep, but after some
hard pumping it becomes dry. Has the well failed? Was it dug in the wrong place?
More likely you are witnessing the phenomenon of drawdown, an effect every
pumped well has on the water table (see Figure 4).

fig4pg5.gif (486x486)



Because water flows through sediments slowly, almost any well can be pumped dry
temporarily if it is pumped hard enough. Any pumping will lower the water level
to some degree, in the manner shown in Figure 4. A serious problem arises only
when the drawdown due to normal use lowers the water table below the level of
the well.

After the well has been dug about a meter (several feet) below the water table, it
should be pumped at about the rate it will be used to see if the flow into the
well is adequate. If it is not sufficient, there may be ways to improve it. Digging
the well deeper or wider will not only cut across more of the water-bearing layer
to allow more flow into the well, but it will also enable the well to store a
greater quantity of the water that may seep in overnight. If the well is still not
adequate and can be dug no deeper, it can be widened further, perhaps lengthened
in one direction, or more wells can be dug. The goal of all these methods is to
intersect more of the water-bearing layers, so that the well will produce more
water without lowering the water table to the bottom of the well.

Where to Dig a Well

Four important factors to consider in choosing a well site are:

o Nearness to Surface Water
o Topography
o Sediment Type
o Nearness to Pollutants

Nearness to Surface Water

If there is surface water nearby, such as a lake or a river, locate the well as
near to it as possible. It is likely to act as a source of water and keep the water
table from being lowered as much as without it. This does not always work well,
however, as lakes and slow-moving bodies of water generally have silt and slime
on the bottom, which prevent water from entering the ground quickly.

There may not seem to be much point to digging a well near a river, but the
filtering action of the soil will result in water that is cleaner and more free of
bacteria. It may also be cooler than surface water. If the river level fluctuates
during the year, a well will give cleaner water (than stream water) during the
flood season, although ground water often gets dirty during and after a flood. A
well will also give more reliable water during the dry season, when the water
level may drop below the bed of the river. This method of water supply is used
by some cities: a large well is sunk next to a lake or river and horizontal tunnels
are dug to increase the flow.

Wells near the ocean, and especially those on islands, may have not only the
problem of drawdown, but that of salt water encroachment (see Figure 5). The

fig5pg6.gif (540x540)


underground boundary between fresh and salt water generally slopes inland:
Because salt water is heavier than fresh water, it flows in under it. If a well
near the shore is used heavily, salt water may come into the well as shown. This
should not occur in wells from which only a moderate amount of water is drawn.

Topography

Ground water, being liquid, gathers in low areas. Therefore, the lowest ground is
generally the best place to drill or dig. If your area is flat or steadily sloping,
and there is no surface water, one place is as good as another to start drilling or
digging. If the land is hilly, valley bottoms are the best places to look for water.

You may know of a hilly area with a spring on the side of a hill. Such a spring
could be the result of water moving through a layer of porous rock or a fracture
zone in otherwise impervious rock. Good water sources can result from such
features.

Sediment Type

Ground water occurs in porous or fractured rocks or sediments. Gravel, sand and
sandstone are more porous than clay, unfractured shale and granite or "hard
rock."

Figure 6 shows in a general way the relationship between the availability of

fig6pg8.gif (540x540)


ground water (expressed by typical well discharges) and geologic material (sediments
and various rock types). For planning the well discharge necessary for
irrigating crops, a good rule of thumb for semi-arid climates-37.5cm (15") of
precipitation a year-is a 1500- to 1900-liters (400 to 500 U.S. gallons)-per-minute
well that will irrigate about 65 hectares (160 acres) for about six months. From
Figure 6, we see that wells in sediments are generally more than adequate.
However, enough ground water can be obtained from rock, if necessary, by
drilling a number of wells. Deeper water is generally of better quality.

Sand and gravel are normally porous and clay is not, but sand and gravel can
contain different amounts of silt and clay, which will reduce their ability to carry
water. The only way to find the yield of a sediment is to dig a well and pump it.

In digging a well, be guided by the results of nearby wells and the effects of
seasonal fluctuations on nearby wells. And keep an eye on the sediments in your
well as it is dug. In many cases you will find that the sediments are in layers,
some porous and some not. You may be able to predict where you will hit water
by comparing the layering in your well with that of nearby wells.

Figures 7, 8, and 9 illustrate several sediment situations and give guidelines on

fig7pg90.gif (540x540)


how deep to dig wells.

Aquifers (water bearing sediments) of Sand and Gravel. Generally yield 11,400
LPM (300 gpm) (but they may yield less depending on pump, well construction,
and well development.
Aquifers of Sand, Gravel, and Clay (Intermixed or Interbedded). Generally yield between
1900 LPM (500 gpm) and 3800 LPM (1000 gpm), but can yield more
--between 3800 LPM (1000 gpm) and 11,400 LPM (3000 gpm)-- depending
on the percentage of the constituents.
Aquifers of Sand and Clay. Generally yield about 1900 LPM (500 gpm) but may
yield as much as 3800 LPM (1000 gpm).
Aquifers of Fractured Sandstone. Generally yield about 1900 LPM (500 gpm) but
may yield more than 3800 LPM (1000 gpm) depending on the thickness of the
sandstone and the degree and extent of fracturing (may also yield less than
1900 LPM (500 and gpm) if thin and poorly fractured or interbedded with clay or
shale).
Aquifers of Limestone. Generally yield between 38 LPM (10gpm) but have been
known to yield more than 3800 LPM (1000 gpm) due to caverns or nearness
of stream, etc.
Aquifers of Granite and/or "Hard Rock." Generally yield 38 gpm (10gpm) and may
yield less (enough for a small household).
Aquifers of Shale. Yield less than 38 LPM (10gpm), not much good for anything
except as a last resort.

Nearness to Pollutants

If pollution is in the ground water, it moves with it. Therefore, a well should
always be uphill and 15 to 30 meters (50 to 100 feet) away from a latrine,
barnyard, or other source of pollution. If the area is flat, remember that the flow
of ground water will be downward, like a river, toward any nearby body of
surface water. Locate a well in the upstream direction from pollution sources.

The deeper the water table, the less chance of pollution because the pollutants
must travel some distance downward before entering ground water. The water is
purified as it flows through the soil.

Extra water added to the pollutants will increase their flow into and through the
soil, although it will also help dilute them. Pollution of ground water is more
likely during the rainy than the dry season, especially if a source of pollution
such as a latrine pit is allowed to fill with water. See also the Overview to the
Sanitary Latrines section, p. 149. Similarly, a well that is heavily used will
increase the flow of ground water toward it, perhaps even reversing the normal
direction of ground-water movement. The amount of drawdown is a guide to how
heavily the well is being used.

Polluted surface water must be kept out of the well pit. This is done by casing
and sealing the well and providing good drainage around the well cover.

Well Casing and Seal

The purpose of casing and seating wells is to prevent contaminated surface water
from entering the well or nearby ground water. As water will undoubtedly be
spilled from any pump, the top of the well must be sealed with a concrete slab to
let the water flow away rather than re-enter the well directly. It is also helpful
to build up the pump area with soil to form a slight hill that will help drain away
spilled water and rain water.

Casing is the term for the pipe, concrete or grout ring, or other material that
supports the well wall. It is usually impermeable in the upper part of the well to
keep out polluted water (see Figure 7) and may be perforated or absent in the

fig7pg9.gif (540x540)


lower part of the well to let water enter. See also "Well Casing and Platforms," p.
12, and "Reconstructing Dug Wells," p. 57.

In loose sediment, the base of the well should consist of a perforated casing
surrounded by coarse sand and small pebbles; otherwise, rapid pumping may bring
into the well enough material to form a cavity and collapse the well itself.
Packing the area around the well hole in the water-bearing layer with fine gravel
will prevent sand from washing in and increase the effective size of the well. The
ideal gradation is from sand to 6mm (1/4") gravel next to the well screen. In a
drilled well it may be added around the screen after the pump pipe is installed.

Well Development

Well development refers to the steps taken after a well is drilled to ensure
maximum flow and well life by preparing the sediments around the well. The layer
of sediments from which the water is drawn often consists of sand and silt. When
the well is first pumped, the fine material will be drawn into the well and make
the water muddy. You will want to pump out this fine material to keep it from
muddying the water later and to make the sediments near the well more porous.
However, if the water is pumped too rapidly at first, the fine particles may
collect against the perforated casing or the sand grains at the bottom of the well
and block the flow of water into it.

A method for removing the fine material successfully is to pump slowly until the
water clears, then at successively higher rates until the maximum of the pump or
well is reached. Then the water level should be permitted to return to normal and
the process repeated until consistently clear water is obtained.

Another method is surging, which is moving a plunger (an attachment on a drill
rod) up and down in the well. This causes the water to surge in and out of the
sedimentary layer and wash loose the fine particles, as well as any drilling mud
stuck on the wall of the well. Coarse sediment washed into the well can be
removed by a bailing bucket, or it may be left in the bottom of the well to serve
as a filter.

Sources:

Anderson, K.E. Water Well Handbook. Rolla, Missouri: Missouri Water Wells
Drillers Association, 1965.

Baldwin, H.L. and McGuinness, C.L. A Primer on Ground Water. Washington, D.C.:
U.S. Government Printing Office, 1964.

Davis, S.N. and DeWiest, R.J.M. Hydrogeology. New York: Wiley & Sons, 1966.

Todd, D.K. Ground Water Hydrology. New York: Wiley & Sons, 1959.

Wagner, E.G. and Lanoix, J.N. Water Supply for Rural Areas and Small Communities.
Geneva: World Health Organization, 1959.

Ground Water and Wells. Saint Paul, Minnesota: Edward E. Johnson, Inc., 1966.

Small Water Supplies, Bulletin No. 10. London: The Ross Institute, 1967.

U.S. Army. Wells. Technical Manual 5-297. Washington, D.C.: U.S. Government
Printing Office, 1957.

TUBEWELLS

Where soil conditions permit, the tubewells described here will, if they have the
necessary casing, provide pure water. They are much easier to install and cost
much less than large diameter wells.

Tubewells will probably work well where simple earth borers or earth augers work
(i.e., alluvial plains with few rocks in the soil), and where there is a permeable
water-bearing layer 15 to 25 meters (50 to 80 feet) below the surface. They are
sealed wells, and consequently sanitary, which offer no hazard to small children.
The small amounts of materials needed keep the cost down. These wells may not
yield enough water for a lane group, but they would be big enough for a family
of a small group of families.

The storage capacity in small diameter wells is small. Their yield depends largely
on the rate at which water flows from the surrounding soil into the well. From a
saturated sand layer, the flow is rapid. Water flowing in quickly replaces water
drawn from the well. A well that taps such a layer seldom goes dry. But even
when water-bearing sand is not reached, a well with even a limited storage
capacity may yield enough water for a household.

Well Casing and Platforms

In home or village wells, casing and platforms serve two purposes: (1) to keep
well sides from caving in, and (2) to seal the well and keep any polluted surface
water from entering it.

Two low-cost casing techniques are described here:

1. Method A (see Figure 1), from an American Friends Service Committee (AFSC)

fig1pg13.gif (600x600)


team in Rasulia, Madhya Pradesh, India.

2. Method B, from an International Voluntary Services (IVS) team in Vietnam.

Method A

Tools and Materials

Casing pipe (from pump to water-bearing layer to below minimum water table)-Asbestos
cement, tile, concrete, or even galvanized iron pipe will do
Sand
Gravel
Cement
Device for lowering and placing casing (see Figure 2)

fig2pg14.gif (540x540)


Drilling rig - see "Tubewell Boring"
Foot valve, cylinder, pipe, hand pump
The well hole is dug as deep as
possible into the water-bearing
strata. The diggings are placed near
the hole to make a mound, which
later will serve to drain spilled
water away from the well. This is
important because backwash is one
of the few sources of contamination
for this type of well. The
entire casing pipe below water level
should be perforated with many
small holes no larger than 5mm
(3/16") in diameter. Holes larger
than this will allow coarse sand to
be washed inside and plug up the
well. Fine particles of sand,
however, are expected to enter.
These should be small enough to be
pumped immediately out through
the pump. This keeps the well
clear. The first water from the new
well may bring with it large
quantities of fine sand. When this
happens, the first strokes should be
strong and steady and continued
until the water comes clear.

Perforated casing is lowered, bell
end downward, into the hole using
the device shown in Figure 2. When
the casing is properly positioned,
the trip cord is pulled and the next
section prepared and lowered. Since
holes are easily drilled in asbestos
cement pipe, they can be wired
together at the joint and lowered
into the well. Be sure the bells
point downward, since this will
prevent surface water or backwash
from entering the well without the
purifying filtration effect of the
soil; it will also keep sand and dirt
from filling the well. Install the
casing vertically and fill the
remaining space with pebbles. This
will hold the casing plumb. The
casing should rise 30 to 60cm (1' to
2') above ground level and be
surrounded with a concrete pedestal
to hold the pump and to drain
spilled water away from the hole.
Casing joints within 3 meters (10
feet) of the surface should be
sealed with concrete or bituminous
material.

Method B

Plastic seems to be an ideal casing material, but because it was not readily
available, the galvanized iron and concrete casings described here were developed
in the Ban Me Thuot area of Vietnam.

Tools and Materials

Wooden V-block, 230cm (7 1/2') long (see Figure 3)

fig3pg15.gif (145x437)


Angle iron, 2 sections, 230cm (7 1/2') long
Pipe, 10cm (4") in diameter, 230cm (7 1/2') long
Clamps
Wooden mallet
Soldering equipment
Galvanized sheet metal: 0.4mm x 1m x 2m (0.01.6" x 39 1/2" x 79")

Plastic Casing

Black plastic pipe for sewers and drains was almost ideal. Its friction joints could
be quickly slipped together and sealed with a chemical solvent. It seemed durable
but was light enough to be lowered into the well by hand. It could be easily
sawed or drilled to make a screen. Care must be taken to be sure that any plastic
used is non-toxic.

Galvanized Sheet Metal Casing

Galvanized sheet metal was used to make casing similar to downspouting. A
thicker gauge than the 0.4mm (0.016") available would have been preferable.
Because the sheet metal would not last indefinitely if used by itself, the well hole
was made oversize and the ring-shaped space around the casing was filled with a
thin concrete mixture which formed a cast concrete casing and seal outside the
sheet metal when it hardened.

The 1-meter x 2-meter (39 1/2" x 79") sheets were cut lengthwise into three
equal pieces, which yielded three 2-meter (79") lengths of 10cm (4") diameter pipe.

The edges were prepared for making seams by clamping them between the two
angle irons, then pounding with a wooden mallet to the shape shown in Figure 3.

The seam is made slightly wider at one
end than at the other to give the pipe a
slight taper, which allows successive
lengths to be slipped a short distance
inside one another.

The strips are rolled by bridging them over a 2-meter (79") V-shaped wooden
block and applying pressure from above with a length of 5cm (2") pipe (see Figure 4).

fig4pg15.gif (393x393)


The sheet metal strips are shifted from side to side over the V-block as they
are being bent to produce as uniform a surface as possible. When the strip is bent
enough, the two edges are hooked
together and the 5cm (2") pipe is slipped
inside. The ends of the pipe are set up
on wooden blocks to form an anvil, and
the seam is firmly crimped as shown in
Figure 5.

fig5pg15.gif (285x285)



After the seam is finished, any irregularities
in the pipe are removed by
applying pressure by hand or with the
wooden mallet and pipe anvil. A local
tinsmith and his helper were able to
make six to eight lengths (12 to 16
meters) of the pipe per day. Three
lengths of pipe were slipped together and soldered as they were made, and the
remaining joints had to be soldered as the casing was lowered into the well.

The lower end of the pipe was perforated with a hand drill to form a screen.
After the casing was lowered to the bottom of the well, fine gravel was packed
around the perforated portion of the casing to above the water level.
The cement grouting mortar used around the casings varied from pure cement to a
1:1 1/2 cement : sand ratio mixed with water to a very plastic consistency. The
grout was put around the casing by gravity and a strip of bamboo about 10
meters (33 feet) long was used to "rod" the grout into place. A comparison of
volume around the casing and volume of grouting used indicated that there may
have been some voids left probably below the reach of the bamboo rod. These are
not serious however, as long as a good seal is obtained for the first 8 to 10
meters (26 to 33 feet) down from the surface. In general, the greater proportion
of cement used and the greater the space around the casing, the better seemed to
be the results obtained. However, insufficient experience has been obtained to
reach any final conclusions. In addition, economic considerations limit both of
these factors.

Care must be taken in pouring the grout. If the sections of casing are not
assembled perfectly straight, the casing, as a result, is not centered in the well
and the pressure of the grouting is not equal all the way around. The casing may
collapse. With reasonable care, pouring the grout in several stages and allowing it
to set in-between should eliminate this. The grouting, however, cannot be poured
in too many stages because a considerable amount sticks to the sides of the well
each time, reducing the space for successive pourings to pass through.

This method can be modified for use in areas where the structure of the material
through which the well is drilled is such that there is little or no danger of
cave-in. In this situation, the casing serves only one purpose, as a sanitary seal.
The well will be cased only about 8 meters (26 feet) down from the ground
surface. To do this, the well is drilled to the desired depth with a diameter
roughly the same as that of the casing. The well is then reamed out to a
diameter 5 to 6cm (2" to 2 1/4") larger than the casing down to the depth the
casing will go. A flange fitted at the bottom of the casing with an outside
diameter about equal to that of the reamed hole will center the casing in the
hole and support the casing on the shoulder where the reaming stopped. Grouting
is then poured as in the original method. This modification (1) saves considerable
costly material, (2) allows the well to be made a smaller diameter except near the
top, (3) lessens grouting difficulties, and (4) still provides adequate protection
against pollution.

Concrete Tile Casing

If the well is enlarged to an adequate diameter, precast concrete tile with
suitable joints could be used as casing. This would require a device for lowering
the tiles into the well one by one and releasing them at the bottom. Mortar
would have to be used to seal the joints above the water level, the mortar being
spread on each successive joint before it is lowered. Asbestos cement casing
would also be a possibility where it was available with suitable joints.

No Casing

The last possibility would be to use no casing at all. It is felt that when finances
or skills do not permit the well to be cased, there are certain circumstances
under which an uncased well would be better than no well at all. This is particularly
true in localities where the custom is to boil or make tea out of all
water before drinking it, where sanitation is greatly hampered by insufficient
water supply, and where small-scale hand irrigation from wells can greatly
improve the diet by making gardens possible in the dry season.

The danger of pollution in an uncased well can be minimized by: (1) choosing a
favorable site for the well and (2) making a platform with a drain that leads
away from the well, eliminating all spilled water.

Such a well should be tested frequently for pollution. If it is found unsafe, a
notice to this effect should be posted conspicuously near the well.

Well Platform

In the work in the Ban Me Thuot area, a flat 1.75-meter (5.7') square slab of
concrete was used around each well. However, under village conditions, this did
not work well. Large quantities of water were spilled, in part due to the enthusiasm
of the villagers for having a plentiful water supply, and the areas around
wells became quite muddy.

The conclusion was reached that the only really satisfactory platform would be a
round, slightly convex one with a small gutter around the outer edge. The gutter
should lead to a concreted drain that would take the water a considerable
distance from the well. It is worth noting that in Sudan and other very arid areas
such spillage from community wells is used to water vegetable gardens or
community nurseries.

If the well platform is too big and smooth, there is a great temptation on the
part of the villagers to do their laundry and other washing around the well. This
should be discouraged. In villages where animals run loose it is necessary to build
a small fence around the well to keep out animals, especially poultry and pigs,
which are very eager to get water, but tend to mess up the surroundings.

Sources:

Koegel, Richard G. Report. Ban Me Thuot, Vietnam: International Voluntary
Services, 1959. (Mimeographed.)

Mott, Wendell. Explanatory Notes on Tubewells. Philadelphia: American Friends
Service Committee, 1956. (Mimeographed.)

Hand-Operated Drilling Equipment

Two methods of drilling a shallow tubewell with hand-operated equipment are
described here: Method A, which was used by an American Friends Service
Committee (AFSC) team in India, operates by turning an earth-boring auger.
Method B, developed by an International Voluntary Services (IVS) team in
Vietnam, uses a ramming action.

Earth Boring Auger

This simple hand-drilling rig can be used to dig wells 15 to 20cm (6" to 8") in
diameter up to 15 meters (50') deep.

Tools and Materials

Earth auger, with coupling to attach to 2.5cm (1") drill line (see entry on
tubewell earth augers)
Standard weight galvanized steel pipe:

For Drill Line:

4 pieces: 2.5cm (1") in diameter and 3 meters (10') long (2 pieces have
threads on one end only; others need no threads.)
2 pieces: 2.5cm (1") in diameter and 107cm (3 1/2") long

For Turning Handle:

2 pieces: 2.5cm (1") in diameter and 61cm (2') long
2.5cm (1") T coupling

For Joint A:

4 pieces: 32mm (1 1/4") in diameter and 30cm (1') long

Sections and Couplings for Joint B:

23cm (9") Section of 32mm (1 1/4") diameter (threaded at one end only)
35.5cm (14") Section of 38mm (1 1/2") diameter (threaded at one end
only)
Reducer coupling: 32mm to 25mm (1 1/4" to 1")
Reducer coupling: 38mm to 25mm (1 1/2" to 1")
8 10mm (3/8") diameter hexagonal head machine steel bolts 45mm (1
3/4") long, with nuts
2 10mm (3/8") diameter hexagonal head machine steel bolts 5cm (2")
long, with nuts
9 10mm (3/8") steel hexagonal nuts

For Toggle Bolt:

1 3mm (1/8") diameter countersink head iron rivet, 12.5mm (1/2") long
1 1.5mm (1/16") sheet steel, 10mm (3/8") x 25mm (1")

Drills: 3mm (1/8"), 17.5mm (13/16"), 8.75mm (13/32")
Countersink
Thread cutting dies, unless pipe is already threaded
Small Tools: wrenches, hammer, hacksaw, files
For platform: wood, nails, rope, ladder

Basically the method consists of rotating an ordinary earth auger. As the auger
penetrates the earth, it fills with soil. When full it is pulled out of the hole and
emptied. As the hole gets deeper, more sections of drilling line are added to
extend the shaft. Joint A (Figures 1 and 2) is a simple method for attaching new

fig1x200.gif (600x600)


sections.

By building an elevated platform 3 to 3.7 meters (10 to 12 feet) from the ground,
a 7.6-meter (25 foot) long section of drill line can be balanced upright. Longer
lengths are too difficult to handle. Therefore, when the hole gets deeper than 7.6
meters (25 feet), the drill line must be taken apart each time the auger is
removed for emptying. Joint B makes this operation easier. See Figures 1 and 3.

fig3x200.gif (600x600)



Joint C (see construction details for Tubewell Earth Auger) is proposed to allow
rapid emptying of the auger. Some soils respond well to drilling with an auger
that has two sides open. These are very easy to empty, and would not require
Joint C. Find out what kinds of augers are successfully used in your area, and do
a bit of experimenting to find the one best suited to your soil. See the entries on
augers.

Joint A has been found to be faster to use and more durable than pipe threaded
connectors. The pipe threads become damaged and dirty and are difficult to start.
Heavy, expensive pipe wrenches get accidentally dropped into the well and are
hard to get out. These troubles can be avoided by using a sleeve pipe fastened
with two 10mm (3/8") bolts. Neither a small bicycle wrench nor the inexpensive
bolts will obstruct drilling if dropped in. Be sure the 32mm (1 1/4") pipe will fit
over your 25mm (1") pipe drill line before purchase. See Figure 2.

fig2x20.gif (600x600)



Four 3-meter (10') sections and two 107cm (3 1/2') sections of pipe are the most
convenient lengths for drilling a 15-meter (50') well. Drill an 8.75mm (13/32")
diameter hole through each end of all sections of drill line except those attaching
to Joint B and the turning handle, which must be threaded joints. The holes
should be 5cm (2") from the end.

When the well is deeper than 7.6 meters (25'), several features facilitate the
emptying of the auger, as shown in Figures 3 and 4. First, pull up the full auger

fig4x200.gif (600x600)


until Joint B appears at the surface. See Figure 4A. Then put a 19mm (3/4")

fig4x21.gif (600x600)


diameter rod through the hole. This allows the whole drill line to rest on it
making it impossible for the part still in the well to fall in. Next remove the
toggle bolt, lift out the top section of line and balance it beside the hole. See
Figure 4B. Pull up the auger, empty it, and replace the section in the hole where
it will be held by the 19mm (3/4") rod. See Figure 4C. Next replace the upper
section of drill line. The 10mm (3/8") bolt acts as a stop that allows the holes to
be easily lined up for reinsertion of the toggle bolt. Finally withdraw the rod and
lower the auger for the next drilling. Mark the location for drilling the 8.75mm
(13/32") diameter hole in the 32mm (1 1/4") pipe through the toggle bolt hole in
the 38mm (1 1/2") pipe. If the hole is located with the 32mm (1 1/4") pipe resting
on the stop bolt, the holes are bound to line up.

Sometimes a special tool is needed to penetrate a water-bearing sand layer,
because the wet sand caves in as soon as the auger is removed. If this happens a
perforated casing is lowered into the well, and drilling is accomplished with an
auger that fits inside the casing. A percussion type with a flap, or a rotary type
with solid walls and a flap are good possibilities. See the entries describing these
devices. The casing will settle deeper into the sand as sand is dug from beneath
it. Other sections of casing must be added as drilling proceeds. Try to penetrate
the water bearing sand layer as far as possible (at least three feet-one meter).
Ten feet (three meters) of perforated casing embedded in such a sandy layer will
provide a very good flow of water.

Tubewell Earth Auger

This earth auger (Figure 5), which is similar to designs used with power drilling

fig5x22.gif (600x600)


equipment, is made from a 15cm (6") steel tube.

 
The auger can be made without
welding equipment, but some of the
bends in the pipe and the bar can
be made much more easily when
the metal is hot (see Figure 6).

fig6x23.gif (600x600)



An open earth auger, which is
easier to empty than this one, is
better suited for some soils. This
auger cuts faster than the Tubewell
Sand Auger.

Tools and Materials

Galvanized pipe: 32mm (1 1/4") in diameter and 21.5cm (8 1/2") long
Hexagonal head steel bolt: 10mm (3/8") in diameter and 5cm (2") long, with nut
2 hexagonal head steel bolts: 10mm (3/8") in diameter and 9.5cm (3 3/4") long
2 Steel bars: 1.25cm x 32mm x 236.5mm (1/2" x 1 1/4" x 9 5/16")
4 Round head machine screws: 10mm (3/8") in diameter and 32mm (1 1/4") long
2 Flat head iron rivets: 3mm (1/8") in diameter and 12.5mm (1/2") long
Steel strip: 10mm x 1.5mm x 2.5cm (3/8" x 1/16" x 1")
Steel tube: 15cm (6") outside diameter, 62.5cm (24 5/8") long
Hand tools

Source:

U.S. Army and Air Force. Wells. Technical Manual 5-297, AFM 85-23. Washington,
D.C.: U.S. Government Printing Office, 1957.

Tubewell Sand Auger

This sand auger can be used to drill in loose soil or wet sand, where an earth
auger is not effective. The simple cutting head requires less force to turn than
the Tubewell Earth Auger, but it is more difficult to empty.

A smaller version of the sand auger made to
fit inside the casing pipe can be used to
remove loose, wet sand.

The tubewell sand auger is illustrated in
Figure 7. Construction diagrams are given in

fig7x24.gif (600x600)


Figure 8.

fig8x25.gif (600x600)



Tools and Materials

Steel tube: 15cm (6") outside diameter and
46cm (18") long
Steel plate: 5mm x 16.5cm x 16.5cm (3/16" x 6
1/2" x 6 1/2")
Acetylene welding and cutting equipment
Drill

Source:

Wells, Technical Manual 5-297, AFM 85-23, U.S. Army and Air Force, 1957.

Tubewell Sand Bailer

The sand bailer <see figure 9> can be used to drill from inside a perforated well casing when a

fig9x26.gif (600x600)


bore goes into loose wet sand and the walls start to cave in. It has been used to
make many tubewells in India.

Tools and Materials

Steel tube: 12.5cm (5") in diameter and 91.5cm (3') long
Truck innertube or leather: 12.5cm (5") square
Pipe coupling: 15cm to 2.5cm (5" to 1")
Small tools

Repeatedly jamming this "bucket" into the well will remove sand from below the
perforated casing, allowing the bucket to settle deeper into the sand layer. The
casing prevents the walls from caving in. The bell is removed from the first
section of casing; at least one other section rests on top of it to help force it
down as digging proceeds. Try to penetrate the water bearing sand layer as far as
possible: 3 meters (10') of perforated casing embedded in such a sandy layer will
usually provide a very good flow of water.

Be sure to try your sand "bucket" in wet sand before attempting to use it at the
bottom of your well.

Source:

Explanatory Notes on Tubewells, Wendell Mott, American Friends Service Committee,
Philadelphia, Pennsylvania, 1956 (Mimeographed).

Ram Auger

The equipment described here has been used successfully in the Ban Me Thuot
area of Vietnam. One of the best performances was turned in by a crew of three
inexperienced mountain tribesmen who drilled 20 meters (65') in a day and a half.
The deepest well drilled was a little more than 25 meters (80'); it was completed,
including the installation of the pump, in six days. One well was drilled through
about 11 meters (35') of sedimentary stone.

Tools and Materials

For tool tray:

Wood: 3cm x 3cm x 150cm (1 1/4" x 1 1/4" x 59")
Wood: 3cm x 30cm x 45cm (1 1/4" x 12"x 17 3/4")

For safety rod:

Steel rod: 1cm (3/8") in diameter, 30cm (12") long
Drill
Hammer
Anvil
Cotter pin

For auger support:

Wood: 4cm x 45cm x 30cm (1 1/3" x 17 3/4" x 12")
Steel: 10cm x 10cm x 4mm (4" x 4" x 5/32")

Location of the Well

Two considerations are especially important for the location of village wells: (1)
the average walking distance for the village population should be as short as
possible; (2) it should be easy to drain spilled water away from the site to avoid
creating a mudhole.

In the Ban Me Thuot area, the final choice of location was in all cases left up to
the villagers. Water was found in varying quantities at all the sites chosen. (See
"Getting Ground Water from Wells and Springs.")

Starting to Drill

A tripod is set up over the approximate location for the well (see Figure 1). Its

fig1x28.gif (600x600)


legs are set into shallow holes with dirt packed around them to keep them from
moving. To make sure the well is started exactly vertically, a plumb bob (a string
with a stone tied to it is good enough) is hung from the auger guide on the
tripod's crossbar to locate the
exact starting point. It is helpful
to dig a small starting hole before
setting up the auger.

Drilling

Drilling is accomplished by ramming
the auger down to penetrate the
earth and then rotating it by its
wooden handle to free it in the
hole before lifting it to repeat the
process. This is a little awkward
until the auger is down 30cm to
60cm (1' to 2') and should be done
carefully until the auger starts to
be guided by the hole itself.
Usually two or three people work
together with the auger. One
system that worked out quite well
was to use three people, two
working while the third rested, and
then alternate.

As the auger goes deeper it will be
necessary from time to time to
adjust the handle to the most
convenient height. Any wrenches or
other small tools used should be
tied by means of a long piece of
cord to the tripod so that if they
are accidentally dropped in the
well, they can easily be removed.
Since the soil of the Ban Me Thuot
area would stick to the auger, it
was necessary to keep a small
amount of water in the hole at all
times for lubrication.

Emptying the Auger

Each time the auger is rammed
down and rotated, it should be
noted how much penetration has
been obtained. Starting with an
empty auger the penetration is
greatest on the first stroke and becomes successively less on each following one
as the earth packs more and more tightly inside the auger. When progress
becomes too slow it is time to raise the auger to the surface and empty it.
Depending on the material being penetrated, the auger may be completely full or
have 30cm (1') or less of material in it when it is emptied. A little experience
will give one a "feel" for the most efficient time to bring up the auger for
emptying. Since the material in the auger is hardest packed at the bottom, it is
usually easiest to empty the auger by inserting the auger cleaner through the slot
in the side of the auger part way down and pushing the material out through the
top of the auger in several passes. When the auger is brought out of the hole for
emptying, it is usually leaned up against the tripod, since this is faster and easier
than trying to lay it down.

Coupling and Uncoupling Extensions

The extensions are coupled by merely slipping the small end of one into the large
end of the other and pinning them together with a 10mm (3/8") bolt. It has been
found sufficient and time-saving to just tighten the nut finger-tight instead of
using a wrench.

Each time the auger is brought up for emptying, the extensions must be taken
apart. For this reason the extensions have been made as long as possible to
minimize the number of joints. Thus at a depth of 18.3 meters (60'), there are
only two joints to be uncoupled in bringing up the auger.

For the sake of both safety and speed, use the following procedure in coupling
and uncoupling. When bringing up the auger, raise it until a joint is just above
the ground and slip the auger support (see Figures 2 and 3) into place, straddling

fig2x290.gif (393x393)


the extension so that the bottom of
the coupling can rest on the small
metal plate. The next step is to put
the safety rod (see Figure 4)

fig4x30.gif (594x594)


through the lower side in the
coupling and secure it with either a
cotter pin or a piece of wire. The
purpose of the safety rod is to
keep the auger from falling into
the well if it should be knocked
off the auger support or dropped
while being raised.

Once the safety rod is in place,
remove the coupling bolt and slip
the upper extension out of the
lower. Lean the upper end of the
extension against the tripod between
the two wooden pegs in the front legs, and rest the lower end on the tool
tray (see Figures 5 and 6). The reason for putting the extensions on the tool tray

fig5x310.gif (393x393)


is to keep dirt from sticking to the lower ends and making it difficult to put the
extensions together and take them apart.

To couple the extensions after emptying the auger, the procedure is the exact
reverse of uncoupling.

Drilling Rock

When stone or other substances the auger cannot penetrate are met, a heavy
drilling bit must be used.

Depth of Well

The rate at which water can be taken from a well is roughly proportional to the
depth of the well below the water table as long as the well keeps going into
water-bearing ground. However, in
village wells where water can only
be raised slowly by handpump or
bucket, this is not usually of major
importance. The important point is
that in areas where the water table
varies from one time of year to
another the well must be deep
enough to give sufficient water at
all times.

Information on the water table
variation may be obtained from
already existing wells, or it may be
necessary to drill a well before any
information can be obtained. In the
latter case the well must be deep
enough to allow for a drop in the
water table.

Source:

Report by Richard G. Koegel, International Voluntary Services, Ban Me Thuot,
Vietnam, 1959 (Mimeographed).

Equipment <see figure 7>

fig7x32.gif (486x486)



The following section gives construction details for the well-drilling equipment
used with the ram auger:

o Auger, Extensions, and Handle
o Auger Cleaner
o Demountable Reamer
o Tripod and Pulley
o Bailing Bucket
o Bit for Drilling rock

Auger, Extensions, and Handle

The auger is hacksawed out of standard-weight steel pipe about 10cm (4") in
diameter (see Figure 8). Lightweight tubing is not strong enough. The extensions

fig8x34.gif (600x600)


(see Figure 9) and handle (see Figure 10) make it possible to bore deep holes.

fig9x34.gif (600x600)



fig10x35.gif (600x600)



Tools and Materials

Pipe: 10cm (4") in diameter, 120cm (47 1/4") long, for auger
Pipe: 34mm outside diameter (1" inside diameter); 3 or 4 pieces 30cm (12") long,
for auger and extension socket
Pipe: 26mm outside diameter (3/4" inside diameter); 3 or 4 pieces 6.1 or 6.4 meters
(20' or 21') long, for drill extensions
Pipe: 10mm outside diameter (1/2" inside diameter); 3 or 4 pieces 6cm (2 3/8")
long
Hardwood: 4cm x 8cm x 50cm (1 1/2" x 3 1/8" x 19 3/4"), for handle
Mild steel: 3mm x 8cm x 15cm (1/8" x 3 1/8" x 6")
4 Bolts: 1cm (3/8") in diameter and 10cm (4") long
4 Nuts

Hand tools and welding equipment

In making the auger, a flared-tooth cutting edge is cut in one end of the 10cm
pipe. The other end is cut, bent, and welded to a section of 34mm outside-diameter
(1" inside-diameter) pipe, which forms a socket for the drill line
extensions. A slot that runs nearly the length of the auger is used for removing
soil from the auger. Bends are made stronger and more easily and accurately when
the steel is hot. At first, an auger with two cutting lips similar to a post-hole
auger was used; but it became plugged up and did not cut cleanly. In some soils,
however, this type of auger may be more effective.

Auger Cleaner

Soil can be removed rapidly from the auger with this auger cleaner (see Figure 11).

fig11x36.gif (486x486)


Figure 12 gives construction details.

fig12x36.gif (600x600)



Tools and Materials

Mild steel: 10cm (4") square and 3mm (1/8") thick
Steel rod: 1cm (3/8") in diameter and 52cm (20 1/2") long
Welding equipment
Hacksaw
File

Demountable Reamer

If the diameter of a drilled hole has to be made bigger, the demountable reamer
described here can be attached to the auger.

Tools and Materials

Mild steel: 20cm x 5cm x 6mm (6" x 2" x 1/4"), to ream a well diameter of 19cm
(7 1/2")
2 Bolts: 8mm (5/16") in diameter and 10cm (4") long
Hacksaw
Drill
File
Hammer
Vise

The reamer is mounted to the top of the auger with two hook bolts (see Figure 13).

fig13x37.gif (600x600)


It is made from a piece of steel 1cm (1/2") larger than the desired well
diameter (see Figure 14).

fig14x38.gif (600x600)



After the reamer is attached to the
top of the auger, the bottom of the
auger is plugged with some mud or
a piece of wood to hold the
cuttings inside the auger.

 
In reaming, the auger is rotated
with only slight downward pressure.
It should be emptied before it is
too full so that not too many
cuttings will fall to the bottom of
the well when the auger is pulled
up.

Because the depth of a well is
more important than the diameter
in determining the flow and
because doubling the diameter
means removing four times the
amount of earth, larger diameters
should be considered only under
special circumstances. (See "Well
Casing and Platforms," page 12.)

Tripod and Pulley

The tripod (see Figures 15 and 16), which is made of poles and assembled with

fig15390.gif (393x393)


when it extends far above ground; (2) to provide a mounting for the pulley (see Figures 17 and 19)

fig17400.gif (600x600)


place for leaning long pieces of casing, pipe for pumps, or auger extensions while
they are being put into or taken out of the well.

When a pin or bolt is put through the holes in the two ends of the "L"-shaped
pulley bracket (see Figures 15 and 18) that extend horizontally beyond the front

fig18390.gif (393x393)


formed.

To keep the extensions from falling when they are leaned against the tripod, two
30cm (12") long wooden pegs are driven into drilled holes near the top of the
tripod's two front legs (see Figure 19).

fig19x41.gif (600x600)



Tools and Materials

3 Poles: 15cm (3") in diameter and 4.25 meters (14') long
Wood for cross bar: 1.1 meter (43 1/2") x 12cm (4 3/4") square
For pulley wheel:
Wood: 25cm (10") in diameter and 5cm (2") thick
Pipe: 1.25cm (1/2") inside diameter, 5cm (2") long
Axle bolt: to fit close inside 1.25cm (1/2") pipe
Angle iron: 80cm (31 1/2") long, 50cm (19 3/4") webs, 5mm (3/16") thick
4 Bolts: 12mm (1/2") in diameter, 14cm (5 1/2") long; nuts and washers
Bolt: 16mm (5/8") in diameter and 40cm (15 3/4") long; nuts and washer
2 Bolts: 16mm (5/8") in diameter and 25cm (9 7/8") long; nuts and washers
Bore 5 places through center of poles for assembly with 16mm bolts

Bailing Bucket

The bailing bucket can be used to remove soil from the well shaft when cuttings
are too loose to be removed with the auger.

Tools and Materials

Pipe: about 8.5cm (3 3/8") in diameter, 1 to 2cm (1/2" to 3/4") smaller in
diameter than the auger, 180cm (71") long
Steel rod: 10mm (3/8") in diameter and 25cm (10") long; for bail (handle)
Steel plate: 10cm (4") square, 4mm (5/32") thick
Steel bar: 10cm x 1cm x 5mm (4" x 3/8" x 3/16")
Machine screw: 3mm (1/8") diameter by 16mm (5/8") long; nut and washer
Truck innertube: 4mm (5/32") thick, 10mm (3/8") square
Welding equipment
Drill
Hacksaw
Hammer
Vise
File
Rope

Both standard weight pipe and thin-walled tubing were tried for the bailing
bucket. The former, being heavier, was harder to use, but did a better job and
stood up better under use. Both the
steel bottom of the bucket and the
rubber valve should be heavy
because they receive hard usage.
The metal bottom is reinforced
with a crosspiece welded in place
(see Figures 20 and 21).

fig20420.gif (393x393)


When water is reached and the
cuttings are no longer firm enough
to be brought up in the auger, the
bailing bucket must be used to
clean out the well as work
progresses.

For using the bailing bucket the pulley is mounted in the pulley bracket with a
16mm (5/8") bolt as axle. A rope attached to the bailing bucket is then run over
the pulley and the bucket is lowered into the well. The pulley bracket is so
designed that the rope coming off the pulley lines up vertically with the well, so
that there is no need to shift the tripod.

The bucket is lowered into the well, preferably by two people and allowed to drop
the last meter or meter and one-half (3 to 5 feet) so that it will hit the bottom
with some speed. The impact will force some of the loose soil at the bottom of
the well up into the bucket. The bucket is then repeatedly raised and dropped 1
to 2 meters (3 to 6 feet) to pick up more soil. Experience will show how long
this should be continued to pick up as much soil as possible before raising and
emptying the bucket. Two or more people can raise the bucket, which should be
dumped far enough from the well to avoid messing up the working area.

If the cuttings are too thin to be brought up with the auger but too thick to
enter the bucket, pour a little water down the well to dilute them.

Bit for Drilling Rock

The bit described here has been used to drill through layers of sedimentary stone
up to 11 meters (36') thick.

Tools and Materials

Mild steel bar: about 7cm (2 3/4") in diameter and about 1.5 meters (5') long,
weighing about 80kg (175 pounds)
Stellite (a very hard type of tool steel) insert for cutting edge
Anvil and hammers, for shaping
Steel rod: 2.5cm x 2cm x 50cm (1" x 3/4" x 19 3/4") for bail
Welding equipment

The drill bit for cutting through stone and hard formations is made from the 80kg
(175-pound) steel bar (see Figures 22 and 23). The 90-degree cutting edge is hard-surfaced

fig22440.gif (393x393)


handle) for attaching a rope or
cable is welded to the top. The bail
should be large enough to make
"fishing" easy if the rope breaks. A
2.5cm (1") rope was used at first,
but this was subject to much wear
when working in mud and water. A
1cm (3/8") steel cable was substituted
for the rope, but it was not
used enough to be able to show
whether the cable or the rope is better. One advantage of rope is that it gives a
snap at the end of the fall which rotates the bit and keeps it from sticking. A
swivel can be mounted between the bit and the rope or cable to let the bit
rotate.

If a bar this size is difficult to find or too expensive, it may be possible,
depending on the circumstances, to make one by welding a short steel cutting end
onto a piece of pipe, which is made heavy enough by being filled with concrete.

In using the drilling bit, put the pulley in place as with the bailing bucket, attach
the bit to its rope or cable, and lower it into the well. Since the bit is heavy,
wrap the rope once or twice around the back leg of the tripod so that the bit
cannot "get away" from the workers with the chance of someone being hurt or
the equipment getting damaged. The easiest way to raise and drop the bit is to
run the rope through the pulley and then straight back to a tree or post where it
can be attached at shoulder height or slightly lower. Workers line up along the
rope and raise the bit by pressing down on the rope; they drop it by allowing the
rope to return quickly to its original position (see Figure 24). This requires five

fig24x46.gif (393x393)


to seven workers, occasionally more. Frequent rests are necessary, usually after
every 50 to 100 strokes. Because
the work is harder near the ends
of the rope than in the middle, the
positions of the workers should be
rotated to distribute the work
evenly.

A small amount of water should be
kept in the hole for lubrication and
to mix with the pulverized stone to
form a paste that can be removed
with a bailing bucket. Too much
water will slow down the drilling.

The speed of drilling, of course,
depends on the type of stone
encountered. In the soft water-bearing
stone of the Ban Me Thuot
area it was possible to drill several meters (about 10 feet) per day. However,
when hard stone such as basalt is encountered, progress is measured in centimeters
(inches). The decision must then be made whether to continue trying to
penetrate the rock or to start over in a new location. Experience in the past has
indicated that one should not be too hasty in abandoning a location, since on
several occasions what were apparently thin layers of hard rock were penetrated
and drilling then continued at a good rate.

Occasionally the bit may become stuck in the well and it will be necessary to use
a lever arrangement consisting of a long pole attached to the rope to free it (see Figure 25).

fig25x47.gif (437x437)


Alternatively, a windlass may be used, consisting of a horizontal pole
used to wrap the rope around a vertical pole pivoted on the ground and held in
place by several workers (see Figure 26). If these fail, it may be necessary to

fig26x47.gif (437x437)


rent or borrow a chain hoist. A worn rope or cable may break when trying to
retrieve a stuck bit. If this happens, fit a hook to one of the auger extensions,
attach enough extensions together to reach the desired depth, and after hooking
the bit, pull with the chain hoist. A rope or cable may also be used for this
purpose, but are considerably more difficult to hook onto the bit.

Drilling Mechanically

The following method can be used for raising and dropping the bit
mechanically:

o Jack up the rear wheel of a car and replace the wheel with a small
drum (or use the rim as a pulley).
o Take the rope that is attached to the bit, come from the tripod on
the pulley, and wrap the rope loosely around the drum.
o Pull the unattached end of the rope taut and set the drum in
motion. The rope will move with the drum and raise the bit.
o Let the end of the rope go slack quickly to drop the bit.
It will probably be necessary to polish and/or grease the drum.

Dry Bucket Well Drilling

The dry bucket method is a simple and quick method of drilling wells in dry soil
that is free of rocks. It can be used for 5cm to 7.5cm (2" to 3") diameter wells in
which steel pipe is to be installed. For wells that are wider in diameter, it is a
quick method of removing dry soil before completing the bore with a wet bucket,
tubewell sand bailer, or tubewell sand auger.

A 19.5-meter (64') hole can be dug in less than three hours with this method,
which works best in sandy soil, according to the author of this entry, who has
drilled 30 wells with it.

Tools and Materials

Dry bucket
Rope: 16mm (5/8") or 19mm (3/4") in diameter and 6 to 9 meters (20' to 30')
longer than the deepest well to be drilled
3 Poles: 20cm (4") in diameter at large end and 3.6 to 4.5 meters (12' to 15') long
Chain, short piece
Pulley
Bolt: 12.5mm (1/2") in diameter and 30 to 35cm (12" to 14") long (long enough to
reach through the upper ends of the three poles)

A dry bucket is simply a length of pipe with a bail or handle welded to one end
and a slit cut in the other.

The dry bucket is held about 10cm (several inches) above the ground, centered
above the hole location and then dropped (see Figure 1). This drives a small

fig1x49.gif (600x600)


amount of soil up into the bucket. After this is repeated two or three times, the
bucket is removed, held to one side and tapped with a hammer or a piece of iron
to dislodge the soil. The process is repeated until damp soil is reached and the
bucket will no longer remove soil.

To make the dry bucket, you will need the following tools and materials:

Hacksaw
File
Iron rod: 10mm (3/8") or 12.5mm (1/2") in diameter and 30cm (1') long
Iron pipe: slightly larger in diameter than the largest part of casing to be put in
the well (usually the coupling) and 152cm (5') long

Bend the iron rod into a U-shape small enough to slide inside the pipe. Weld it in
place as in Figure 2.

fig2x49.gif (486x486)



File a gentle taper on the inside of the opposite end to make a cutting edge (see Figure 3).

fig3x49.gif (393x393)



Cut a slit in one side of the sharpened end of the pipe (see Figure 2).

Source:

John Brelsford, VITA Volunteer, New Holland, Pennsylvania

Driven Wells

A pointed strainer called a well point, properly used, can quickly and cheaply
drive a sanitary well, usually less than 7.6 meters (25') deep. In soils where the
driven well is suitable, it is often the cheapest and fastest way to drill a sanitary
well. In heavy soils, particularly clay, drilling with an earth auger is faster than
driving with a well point.

Tools and Materials

Well point and driving cap (see Figure 1):

fig1x50.gif (486x486)


usually obtainable through mail order houses
from the United States and elsewhere
Pipe: 3cm (1") in diameter
Heavy hammer and wrenches
Pipe compound
Special pipe couplings and driving arrangements
are desirable but not necessary

Driven wells are highly successful in coarse sand where there are not too many
rocks and the water table is within 7 meters (23') of the surface. They are usually
used as shallow wells where the pump cylinder is at ground level. If conditions
for driving are very good, 10cm (4") diameter points and casings that can
accept the cylinder of a deep well can be driven to depths of 10 - 15 meters (33'
to 49'). (Note that suction pumps generally cannot raise water beyond 10 meters.)

The most common types of well points are:

o a pipe with holes covered by a screen and a brass jacket with holes. For
general use, a #10 slot or 60 mesh is recommended. Fine sand requires a
finer screen, perhaps a #6 slot or 90 mesh;

o a slotted steel pipe with no covering screen, which allows more water to
enter but is less rugged.

Before starting to drive the point, make a hole at the site with hand tools. The
hole should be plumb and slightly larger in diameter than the well point.

The joints of the drive pipe must be carefully made to prevent thread breakage
and assure airtight operation. Clean and oil the threads carefully and use joint
compound and special drive couplings when available. To ensure that joints stay
tight, give the pipe a fraction of a turn after each blow, until the top joint is
permanently set. Do not twist the whole string and do not twist and pound at the
same time. The latter may help get past stones, but soon will break the threads
and make leaky joints.

Be sure the drive cap is tight and butted against the end of the pipe (see Figure 2).

fig2x51.gif (600x600)


check with a plumb bob to see that the pipe is vertical. Test it occasionally
and keep it straight by pushing on the pipe while driving. Hit the drive cap
squarely each time or you may damage the equipment.

Several techniques can help avoid damage to the pipe. The best way is to drive
with a steel bar that is dropped inside the pipe and strikes against the inside of
the steel well point. It is retrieved with a cable of rope. Once water enters the
well, this method does not work.

Another way is to use a driver pipe, which makes sure that the drive cap is hit
squarely. A guide rod can be mounted on top of the pipe and weight dropped over
it, or the pipe itself can be used to guide a falling weight that strikes a special
drive clamp.

The table in Figure 3 will help identify the formations being penetrated. Experience

fig3x52.gif (600x600)


is needed, but this may help you to understand what is happening. When
you think that the water-bearing layer has been reached, stop driving and attach
a handpump to try the well.

Usually, easier driving shows that the water-bearing level has been reached,
especially in coarse sand. If the amount of water pumped is not enough, try
driving a meter or so (a few feet) more. If the flow decreases, pull the point
back until the point of greatest flow is found. The point can be raised by using a
lever arrangement like a fence-post jack, or, if a drive-monkey is used, by
pounding the pipe back up.

Sometimes sand and silt plug up the point and the well must be "developed" to
clear this out and improve the flow. First try hard, continuous pumping at a rate
faster than normal. Mud and fine sand will come up with the water, but this
should clear in about an hour. It may help to allow the water in the pipe to drop
back down, reversing the flow periodically. With most pitcher pumps this is easily
accomplished by lifting the handle very high; this opens the check valve, allowing
air to enter, and the water rushes back down the well.

If this does not clear up the flow, there may be silt inside the point. This can be
removed by putting a 19mm (3/4") pipe into the well and pumping on it. Either
use the pitcher pump or quickly and repeatedly raise and lower the 19mm (3/4")
pipe. By holding your thumb over the top of the pipe on the upstroke, a jet of
muddy water will result on each downstroke. After getting most of the material
out, return to direct pumping. Clean the sand from the valve and cylinder of the
pump after developing the well. If you have chosen too fine a screen, it may not
be possible to develop the well successfully. A properly chosen screen allows the
fine material to be pumped out, leaving a bed of coarse gravel and sand that
provides a highly porous and permeable water-gathering area.

The final step is to fill in the starting borehole with puddle clay or, if clay is
not available, with well-tamped earth. Make a solid, water-proof pump platform
(concrete is best) and provide a place for spilled water to drain away.

 
Source:

Wagner, E.G. and Lanoix, J.N. Water Supply for Rural Areas and Small Communities.
Geneva: World Health Organization, 1959.

DUG WELLS <see figure 1>

fig1x54.gif (600x600)



A village well must often act as a reservoir, because at certain hours of the day
the demand for water is heavy, whereas during the night and the heat of the day
there is no call on the supply. What is suggested here is to make the well large
enough to allow the water slowly percolating in to accumulate when the well is
not in use in order to have an adequate supply when demand is heavy. For this
reason wells are usually made 183 to 213cm (6' to 7') in diameter.

Wells cannot store rainy season water for the dry season, and there is seldom any
reason for making a well larger in
diameter than 213cm (7').

The depth of a well is much more
important than the diameter in
determining the amount of water
that can be drawn when the water
level is low. A deep, narrow well
will often provide more water than
a wide shallow one.

Remember that tubewells are much
easier to construct than dug wells,
and should be used if your region
allows their construction and an
adequate amount of water can be
drawn from them during the busy
hours (see section on Tubewells).

Deep dug wells have several
disadvantages. The masonry lining
needed is very expensive. Construction
is potentially very dangerous;
workers should not dig deeper than
one and a half meters without
shoring up the hole. An open well
is very easily contaminated by
organic matter that falls in from
the surface and by the buckets
used to lift the water. There is an
added problem of disposing of the
great quantity of soil removed from
a deep dug well.

Sealed Dug Well

The well described here has an
underground concrete tank that is
connected to the surface with a
casing pipe, rather than a large-diameter
lining as described in the
preceding entry. The advantages are
that it is relatively easy to build,
easy to seal, takes up only a small
surface area, and is low in cost.

Many of these wells were installed in India by an American Friends Service
Committee team there; they perform well unless they are not deep enough or
sealed and capped properly.

Tools and Materials

4 reinforced concrete rings with iron hooks for lowering, 91.5cm (3') in diameter
1 reinforced concrete cover with a seating hole for casing pipe
Washed gravel to surround tank: 1.98 cubic meters (70 cubic feet)
Sand for top of well: 0.68 cubic meters (24 cubic feet)
Concrete pipe: 15cm (6") in diameter, to run from the top of the tank cover to at
least 30.5cm (1') above ground
Concrete collars: for joints in the concrete pipe
Cement: 4.5kg (10 pounds) for mortar for pipe joints
Deep-well pump and pipe
Concrete base for pump
Tripod, pulleys, rope for lowering rings
Special tool for positioning casing when refilling, see "Positioning Casing Pipe,"
below
Digging tools, ladders, rope

A villager in Barpali, India, working with an American Friends Service Committee
unit there, suggested that they make a masonry tank at the bottom of the well,
roof it over, and draw the water from it with a pump. The resulting sealed well
has many advantages:

o It provides pure water, safe for drinking.

o It presents no hazard of children falling in.

o Drawing water is easy, even for small children.

o The well occupies little space, a small courtyard can accommodate it.

o The cost of installation is greatly reduced.

o The labor involved is much reduced.

o There is no problem of getting rid of excavated soil, since most of it is
replaced.

o The casing enables the pump and pipe to be easily removed for servicing.

o The gravel and sand surrounding the tank provide an efficient filter to
prevent silting, allow a large surface area for percolating water to fill the
tank, and increase the effective stored volume in the tank.

On the other hand, compared to a well where people draw their own buckets or
other containers of water, there are three minor disadvantages: only one person
can pump at a time, the pump requires regular maintenance, and a certain amount
of technical skill is required to make the parts used in the well and to install
them properly.

A well is dug 122cm (4') in diameter and about 9 meters (30') deep. The digging
should be done in the dry season, after the water table has dropped to its lowest
level. There should be a full 3 meter (10') reaccumulation of water within 24
hours after the well has been bailed or pumped dry. Greater depth is, of course,
desirable.

Spread 15cm (6") of clean, washed gravel or small rock over the bottom of the
well. Lower the four concrete rings and cover into the well and position them
there to form the tank. A tripod of strong poles with block and tackle is needed
to lower the rings, because they weigh about 180kg (400 pounds) each. The tank
formed by the rings and cover is 183cm (6') high and 91.5cm (3') in diameter. The
cover has a round opening which forms a seat for the casing pipe and allows the
suction pipe to penetrate to about 15cm (6") from the gravel bottom.

The first section of concrete pipe is positioned in the seat and grouted (mortared)
in place. It is braced vertically by a wooden plug with four hinged arms to brace
against the sides of the wall. Gravel is packed around the concrete rings and over
the top of the cover till the gravel layer above the tank is at least 15cm (6")
deep. This is then covered with 61cm (2') of sand. Soil removed from the well is
then shoveled back until the shaft is filled within 15cm (6") of the top of the
first section of casing. The next section of casing is then grouted in place, using
a concrete collar made for this purpose. The well is filled and more sections of
casing added until the casing extends at least 30cm (1') above the surrounding
soil level.

The soil that will not pack back into the well can be used to make a shallow hill
around the casing to encourage spilled water to drain away from the pump. A
concrete cover is placed on the casing and a pump installed.

If concrete or other casing pipe cannot be obtained, a chimney made of burned
bricks and sand-cement mortar will suffice. The pipe is somewhat more expensive,
but much easier to install.

Source:

A Safe Economical Well. Philadelphia: American Friends Service Committee, 1956
(Mimeographed).

Deep Dug Well

Untrained workers can safely dig a deep sanitary well with simple, light equipment,
if they are well supervised. The basic method is outlined here.

Tools and Materials

Shovels, mattocks
Buckets
Rope--deep wells require wire rope
Forms--steel, welded and bolted together
Tower with winch and pulley
Cement
Reinforcing rod
Sand
Aggregate
Oil

The hand dug well is the most widespread of any kind of well. Unfortunately, in
many places these wells are dug by people unfamiliar with good sanitation
methods and become infected by parasitic and bacterial disease. By using modern
methods and materials, dug wells can safely be made 60 meters (196.8') deep and
will give a permanent source of pure water.

Experience has shown that for one person, the average width of a round well for
best digging speed is 1 meter (3 1/4'). However, 1.3 meters (4 1/4') is best for
two workers digging together and they dig more than twice as fast as one person.
Thus, two workers in the larger hole is usually best.

Dug wells always need a permanent lining (except in solid rock, where the best
method is usually to drill a tubewell).

The lining prevents collapse of the hole, supports the pump platform, stops
entrance of contaminated surface water, and supports the well intake, which is
the part of the well through which water enters. It is usually best to build the
lining while digging, since this avoids temporary supports and reduces danger of
cave-ins.

Dug wells are lined in two ways: (1) where the hole is dug and the lining is built
in its permanent place and (2) where sections of lining are added to the top and
the whole lining moves down as earth is removed from beneath it. The second
method is called caissoning; often a combination of both is best (Figure 2.)

fig2x58.gif (600x600)



If possible, use concrete for the lining because it is strong, permanent, and made
mostly of local materials. It can also be handled by unskilled workers with good
speed and results. (See section on Concrete Construction).

Masonry and brickwork are widely used in many countries and can be very
satisfactory if conditions are right. In bad ground, however, unequal pressures can
make them bulge or collapse. Building with these materials is slow and a thicker
wall is required than with concrete. There is also always the danger of movement
during construction in loose sands or swelling shale before the mortar has set
firmly between the bricks or stones.

Wood and steel are not good for lining wells. Wood requires bracing, tends to rot
and hold insects, and sometimes makes the water taste bad. Worst of all, it will
not make the well watertight against contamination. Steel is seldom used because
it is expensive, rusts quickly, and if it is not heavy enough is subject to bulging
and bending.

The general steps in finishing the first 4.6 meters (15') are:

o set up a tripod winch over cleared, level ground and mark reference points
for plumbing and measuring the depth of the well.

o have two workers dig the well while another raises and unloads the dirt
until the well is exactly 4.6 meters (15') deep.

o trim the hole to size using a special jig mounted on the reference points.

o place the forms carefully and fill one by one with tamped concrete.

After this is done, dig to 9.1 meters (30'), trim and line this part also with
concrete. A 12.5cm (5") gap between the first and second of these sections is
filled with pre-cut concrete that is grouted (mortared) in place. Each lining is
self-supporting as it has a curb. The top of the first section of lining is thicker
than the second section and extends above the ground to make a good foundation
for the pump housing and to make a safe seal against ground water.

This method is used until the water-bearing layer is reached; there an extra-deep
curb is constructed. From this point on, caissoning is used.

Caissons are concrete cylinders fitted with bolts to attach them together. They
are cast and cured on the surface in special molds, prior to use. Several caissons
are lowered into the well and assembled together. As workers dig, the caissons
drop lower as earth is removed from beneath them. The concrete lining guides the
caissons.

If the water table is high when the well is dug, extra caissons are bolted in place
so that the well can be finished by a small amount of digging, and without
concrete work, during the dry season.

Details on plans and equipment for this process are found in Water Supply for
Rural Areas and Small Communities, by E. G. Wagner and J. N. Lanoix, World
Health Organization, 1959.

Reconstructing Dug Wells

Open dug wells are not very sanitary, but they can often be rebuilt by relining
the top 3 meters (10') with a watertight lining, digging and cleaning the well and
covering it. This method involves installation of a buried concrete slab; see Figure 3

fig3x60.gif (600x600)


for construction details.

Tools and Materials

Tools and materials for reinforced concrete
A method for entering the well
Pump and drop pipe

Before starting, check the following:

o Is the well dangerously close to a privy or other source of contamination? Is
it close to a water source? Is it desirable to dig a new well elsewhere
instead of cleaning this one? Could a privy be moved, instead?

o Has the well ever gone dry? Should you deepen it as well as clean it?

o Surface drainage should generally slope away from the well and there should
be effective disposal of spilled water.

o What method will you use to remove the water and what will it cost?

o Before entering the well to inspect the old lining, check for a lack of
oxygen by lowering a lantern or candle. If the flame remains lit, it is
reasonably safe to enter the well. If the flame goes out, the well is dangerous
to enter. Tie a rope around the person entering the well and have two
strong workers on hand to pull him out in case of accident.

Relining the Wall

The first job is to prepare the upper 3 meters (10') of the lining for concrete by
removing loose rock and chipping away old mortar with a chisel, as deep as
possible (see Figure 4). The next task is to clean out and deepen the well, if that

fig4x62.gif (600x600)


is necessary. All organic matter and silt should be bailed out. The well may be
dug deeper, particularly during the dry season, with the methods outlined in "Deep
Dug Wells." One way to increase the water yield is to drive a well point deeper
into the water-bearing soil. This normally will not raise the level of water in the
well, but may make the water flow into the well faster. The well point can be
piped directly to the pump, but this will not make use of the reservoir capacity
of the dug well.

The material removed from the well can be used to help form a mound around the
well so water will drain away from the opening. Additional soil will usually be
needed for this mound. A drain lined with rock should be provided to take spilled
water away from the concrete apron that covers the well.

Reline the well with concrete troweled in place over wire mesh reinforcement.
The largest aggregate should be pea-sized gravel and the mix should be fairly rich
with concrete, using no more than 20-23 liters (5 1/2 to 6 gallons) of water to a
43kg (94 pound) sack of cement. Extend the lining 70cm (27 1/2") above the
original ground surface.

Installing the Cover and Pump

Cast the well cover so that it makes a watertight seal with the lining to keep
surface impurities out. The cover will also support the pump. Extend the slab out
over the mound about a meter (a few feet) to help drain water away from the
site. Make a manhole and space for the drop pipe of the pump. Mount the pump
off center so there is room for the manhole. The pump is mounted on bolts cast
into the cover. The manhole must be 10cm (4") higher than the surface of the
slab. The manhole cover must overlap by 5cm (2") and should be fitted with a
lock to prevent accidents and contamination. Be sure that the pump is sealed to
the slab.

Disinfecting the Well

Disinfect the well by using a stiff brush to wash the walls with a very strong
solution of chlorine. Then add enough chlorine in the well to make it about half
the strength of the solution used on the walls. Sprinkle this last solution all over
the surface of the well to distribute it evenly. Cover the well and pump up the
water until the water smells strongly of chlorine. Let the chlorine remain in the
pump and well for one day and then pump it until the chlorine is gone.

Have the well water tested several days after disinfection to be sure that it is
pure. If it is not, repeat the disinfection and testing. If it is still not pure, get
expert advice.

Sources:

Wagner, E.G. and Lanoix, J.N. Water Supply for Rural Areas and Small Communities.
Geneva: World Health Organization, 1959.

Manual of Individual Water Supply Systems, Public Health Service Publication No.
24. Washington, D.C.: Department of Health and Human Services.

SPRING DEVELOPMENT

Springs, particularly in sandy soil, often make excellent water sources, but they
should be dug deeper, sealed, protected by a fence, and piped to the home. Proper
development of a spring will increase the flow of ground water and lower the
chances of contamination from surface water. If fissured rock or limestone are
present, get expert advice before attempting to develop the spring.

Springs occur where water, moving through porous and saturated underground
layers of soil (aquifer), emerges at the ground surface. They can be either:

 
o Gravity seepage, where the water bearing soil reaches the surface over an
impermeable layer, or

o Pressure or artesian, where the water, under pressure and trapped by a hard
layer of soil, finds an opening and rises to the surface. (In some parts of
the world, all springs are called artesian.)

The following steps should be considered in developing springs:

1) Observe the seasonal flow variations over a period of a year if possible.

2) Determine the type of spring-seepage or artesian-by digging a small
hole. An earth auger with extensions is the most suitable tool for that
job. It may not be possible to reach the underlying impermeable layer.

3) Have chemical and biological tests made on samples of the water.

Dig a small hole near the spring to learn the depth of the hard layer of soil and
to find out whether the spring is gravity seepage or pressure. Check uphill and
nearby for sources of contamination. Test the water to see if it must be purified
before being used for drinking. A final point: Find out if the spring runs during
long dry spells.

For gravity-fed springs, the soil is usually dug to the hard, underlying layers and
a tank is made with watertight concrete walls on all but the uphill side (see Figures 1 and 2).

fig1x650.gif (600x600)


The opening on the uphill side should be lined with porous
concrete or stone without mortar, so that it will admit the gravity seepage water.
It can be backfilled with gravel and sand, which helps to keep fine materials in
the water-bearing soil from entering the spring. If the hard soil cannot be
reached easily, a concrete cistern is built that can be fed by a perforated pipe
placed in the water-bearing layer of earth. With a pressure spring, all sides of
the tank are made of watertight reinforced concrete, but the bottom is left open.
The water enters through the bottom.

Read the section in this handbook on cisterns before developing your spring. No
matter how the water enters your tank, you must make sure the water is pure by:

o building a complete cover to stop surface pollution and keep out sunlight,
which causes algae to grow.

o installing a locked manhole with at least a 5cm (2") overlap to prevent
entrance of polluted ground water.

o installing a screened overflow that discharges at least 15cm (6") above the
ground. The water must land on a cement pad or rock surface to keep the
water from making a hole in the ground and to ensure proper drainage away
from the spring.

o arranging the spring so that surface water must filter through at least 3
meters (10') of soil before reaching the ground water. Do this by making a
diversion ditch for surface water about 15 meters (50') or more from the
spring. Also, if necessary, cover the surface of the ground near the spring
with a heavy layer of soil or clay to increase the distances that rainwater
must travel, thus ensuring that it has to filter through 3 meters (10') of
soil.

o making a fence to keep people and animals away from the spring's immediate
surroundings. The suggested radius is 7.6 meters (25').

o installing a pipeline from the overflow to the place where the water is to be
used.

Before using the spring, disinfect it thoroughly by adding chlorine or chlorine
compounds. Shut off the overflow to hold the chlorine solution in the well for 24
hours. If the spring overflows even though the water is shut off, arrange to add
chlorine so that it remains strong for at least 30 minutes, although 12 hours
would be much safer. After the chlorine is flushed from the system have the
water tested. (See section on "Superchlorination.")

Sources:

Wagner, E.G. and Lanoix, J.N. Water Supply for Rural Areas and Small Communities.
Geneva: World Health Organization, 1959.

Manual of Individual Water Supply Systems, Public Health Service Publication No.
24. Washington, D.C.: U.S. Department of Health and Human Services.

Acknowledgements

John M. Jenkins III, VITA Volunteer, Marrero, Louisiana
Ramesh Patel, VITA Volunteer, Albany, New York
William P. White, VITA Volunteer, Brooklyn, Connecticut

Water Lifting and Transport

OVERVIEW

Once a source of water has been found and developed, four basic questions must
be answered:

1. What is the rate of flow of the water in your situation?
2. Between what points must the water be transported?
3. What kind and size of piping is needed to transport the required flow?
4. What kind of pump, if any, is necessary to produce the required flow?

The information in this section will help you to answer the third and fourth
questions, once you have determined the answers to the first two.

Moving Water

The first three entries in this section discuss the flow of water in small streams,
partially filled pipes, and when the height of the reservoir and size of pipe are
known. They include equations and alignment charts (also called nomographs) that
give simple methods of estimating the flow of water under the force of gravity,
that is, without pumping. The fourth tells how to measure flow by observing the
spout from a horizontal pipe.

Four entries follow on piping, including a discussion of pipes made of bamboo.

You will note that in the alignment charts here and elsewhere, the term "nominal
diameter, inches, U.S. Schedule 40" is used along with the alternate term, "inside
diameter in centimeters," in referring to pipe size.

Pipes and fittings are usually manufactured to a standard schedule of sizes. U.S.
Schedule 40, the most common in the United States, is also widely used in other
countries. When one specifies "2-inch Schedule 40," one automatically specifies the
pressure rating of the pipe and its inside and outside diameters (neither of which,
incidentally, is actually 2"). If the schedule is not known, measure the inside
diameter and use this for flow calculations.

Lifting Water

Next, several entries follow the steps required to design a water-pumping system
with piping. The first entry in this group, "Pump Specifications: Choosing or
Evaluating a Pump," presents all the factors that must be considered in selecting
a pump. Fill out the form included there and make a piping sketch, whether you
plan to send it to a consultant for help or do the design and selection yourself.

The first pieces of information needed for selecting pump type and size are: (1)
the flow rate of water needed and (2) the head or pressure to be overcome by
the pump. The head is composed of two parts: the height to which the liquid must
be raised, and the resistance to flow created by the pipe walls (friction-loss).

The friction-loss head is the most difficult factor to measure. The entry "Determining
Pump Capacity and Horsepower Requirements" describes how to select the
economic pipe size(s) for the flow desired. With the pipe(s) selected one must
then calculate the friction-loss head. The entry "Estimating Flow Resistance of
Pipe Fittings" makes it possible to estimate extra friction caused by constrictions
of pipe fittings. With this information and the