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Generic Code of Practice for

Cost Effective Boreholes Consultation Draft 2

Rural Water Supply Network Code of Practice

Cost-Effective Boreholes

June 2010

1

Code of Practice for


Executive Summary

The Generic Code of Practice for Cost-Effective Boreholes aims

to raise the level of professionalism in rural water supply pro-

grammes that include water well drilling so that:

Policies and practices that bring about cost-effective bore-

hole provision are adhered to and fully supported.

Country systems and procedures are developed and used,

with strong institutions.

Performance of the drilling sector is routinely monitored

and evaluated and reported on in a transparent manner.

The document sets out four general and nine specific principles

for borehole drilling covering: community selection, planning

and coordination, operation & maintenance, groundwater re-

sources, drilling enterprises, procurement, contract manage-

ment, supervision, siting, drilling technology, borehole design

and construction, well development, pumping test, water quality

analysis, data and databases as well as monitoring and evalua-

tion.

The document provides a framework for the analysis of the

strengths and weaknesses of existing procedures. It can be used

to develop a national protocol for cost-effective borehole provi-

sion and by international organisations to determine whether

they are working in accordance with best international practices.

Table of Contents

Executive Summary 1

1 Introduction 2

2 General Issues 3

3 Principles for Cost-Effective Boreholes 4

Principle 1 Professional Drilling Enterprises and Consultants 4

Principle 2 Procurement 5

Principle 3 Contract Management, Supervision and Payment 6

Principle 4 Borehole Siting 7

Principle 5 Construction Method 8

Principle 6 Borehole Design and Construction 9

Principle 7 Data and Information 10

Principle 8 Database and Record Keeping 11

Principle 9 Monitoring and Evaluation 11

Annex 1 Bills of Quantities 12

Annex 2 Categorisation of Risk and Payment Structures 13

Annex 3: Sample borehole designs 14

Annex 4. Suggested Format for Borehole Completion Record18

Definitions For the purpose of the Code of Practice for Cost-Effective Bore-

holes, the key terms are defined as follows:

Borehole - a hole which is drilled in the ground and lined for

the abstraction of groundwater.

Borehole design - choosing the depth, diameter and lining

materials of the borehole and the drilling technique to be used.

Borehole development - the act of cleaning a borehole by

flushing or other means until the water from the hole is clean

and free of fine materials.

Borehole siting - the selection of the optimal location of the

boreholes by either hydrogeological and/or geophysical means

to ensure the design yield.

Community Selection Process - the process by which commu-

nities are selected to benefit a borehole fitted with pump.

Data - all facts about a borehole collected before and during,

drilling, borehole development, completion and pumping test.

Drilling contractor is a private company engaged in the drilling

of boreholes for water supply boreholes.

Drilling technology - the method of construction and equip-

ment used in making the borehole.

Monitoring - the periodical checking of the functionality of

boreholes, pumps and pad and community management of the

water source.

Operation and maintenance - running and repairing a bore-

hole, pumps and pads and so that the pump works at all times

throughout its designed life and the general area of the well is

kept clean.

Planning at Community level – a pre-project assessment of

existing water and socioeconomic situation of the community to

determine sustainable water facility.

Procurement - the process of selecting a drilling contractor or

hydrogeological consultant to undertake a particular service or

construction.

Quality Control - ensuring that the pumps and spare parts

supplied adhere to the specifications.

2

Code of Practice for Cost-Effective Boreholes

1 Introduction

In accordance with the Paris Declaration on Aid Effectiveness

external support organisations and donors should increasingly

support national, Government led water and sanitation pro-

grammes. Unfortunately, the fragmentation of donor support in

the past, coupled with weak Government institutions mean that

national standards and procedures with respect to water well

drilling are often lacking. Alternatively, if standards and proce-

dures have been defined, then adherence and enforcement

tends to be poor. In many developing countries, concerns have

been raised about the varying construction quality of drilled

water wells as well as apparently high costs.

The term “cost-effective” means optimum value for money in-

vested over the long term. In order for drilled water wells (sub-

sequently referred to as boreholes) to be cost-effective they

need to be appropriately specified, properly sited and drilled

using suitable equipment. Where the private sector is used,

competent procurement and contract management procedures

need to be followed. Drillers, as well as supervisors need to op-

erate in a professional manner to ensure adequate construction

quality.

Boreholes are drilled to function for their intended lifespan (in

the range of 10 to 30 years). Thus, the lowest cost borehole is

not always the most cost-effective, particularly if construction

quality is compromised to save money. Cheap drilling can lead

to premature failure of the borehole or contamination of the

water supply. Boreholes which are abandoned by the users due

to poor construction quality are clearly not cost effective.

This document sets out a Generic Code of Practice for Cost-

effective Boreholes (COP) based on best international practice. It

recommends procedures to be followed, defines minimum

standards and sets out reporting requirements with respect to

the provision of boreholes.

The purpose of the COP is to raise the level of professionalism

of borehole drilling so that:

Policies and practices that bring about cost-effective bore-

hole provision are adhered to and fully supported.

Country systems and procedures are developed and used,

with strong institutions.

Performance of the drilling sector is routinely monitored

and evaluated and reported on in a transparent manner.

The COP provides a menu of ideas to be considered by practi-

tioners and policy makers as they try to improve the cost-

effectiveness of borehole provision. It provides a systematic

framework to identify in-country, or organisational strengths

and weaknesses with respect to the provision of boreholes. Es-

sentially it provides a lens through which to examine the poli-

cies, standards and practices for borehole drilling in a particular

country, or for a specific programme.

The intention is that the COP is used as a basis for the devel-

opment of a national protocol1 for cost-effective borehole pro-

vision and that international organisations use it to determine

whether they are working in accordance with best international

practices.

Analysis of existing strategies, procedures, guidelines and ca-

pacity in a particular country or organisation against the COP

enables key areas for improvement, donor support, knowledge

exchange and technical assistance to be identified.

It is envisaged that national governments together with their

major development partners will develop a country-specific

protocol1 which takes into account the guidance set out in this

COP. Ideally the protocol should be adhered to by all sector

players as they plan and implement water supply programmes

that include borehole drilling. They would thus all work accord-

ing to common and well accepted procedures.

This document sets out four general issues, which relate to all

water supply development interventions, and nine specific prin-

ciples for borehole drilling (Box 1). These principles are critical in

order to achieve cost-effective borehole provision. For each

country (and more locally) some of the principles will be more

critical than others. Thus country-specific protocols will differ

accordingly.

In terms of context, geology varies widely, as do approaches to

improving rural water supply. In some countries emergency

situations prevail, others are in transition or reconstruction and

some are implementing long-term development interventions.

In some countries water supply programmes are undertaken

through numerous projects while others implement a few pro-

grammes or even a single national programme. The capacity of

the public sector as well as the maturity and professionalism of

the private sector also varies considerably.

Determining the importance of each principle and how to

address it is the responsibility of in-country stakeholders;

primarily national Government in collaboration with its devel-

opment partners. Country assessments and studies can enable

the strengths as well as critical areas for improvement to be

identified. The development of a national protocol1 requires a

partnership between national Government through the lead

Ministry for water supply, and other stakeholders in country.

There is need for extensive dialogue and consensus-building to

prioritise the principles and determine how to address the key

issues. The process of developing a national protocol1 and en-

suring that it is adhered to is not a one-off event but is an on-

going process spanning several years.

1 In some countries the protocol is referred to as a strategy or a

code of conduct.

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Box 1 Summary of Code of Practice for Cost-effective Boreholes

General Issues Principles for Cost Effective Boreholes

1. Community Selection

2. Planning and Coordination

3. Operation & Maintenance

4. Groundwater Resources

1. Professional Drilling Enterprises

2. Procurement

3. Contract Management, Supervision and Payment

4. Borehole Siting

5. Construction Method

6. Borehole Design and Construction

7. Data and Information

8. Database and Record Keeping

9. Monitoring and Evaluation

Full adherence to the COP set out in this document requires

strong national systems as well as public and private institutions

with sufficient capacity in terms of finance, personnel, skills and

equipment. Such systems and capacity can only be built over

time and efforts are required to ensure that they are main-

tained. Existing capacities need to be considered when develop-

ing a country-specific protocol. Where these capacities are

weak, Government and other water sector stakeholders should

prepare an action plan for addressing them over a realistic time

period.

Chapter 2 of this document summarises the general issues for

rural water supply programmes. The nine principles for Cost

Effective Boreholes are set out in chapter 3, each with a more

detailed explanation. The annexes of this document provide

relevant guidance materials and references.

2 General Issues

The issues set out below relate directly to other national strate-

gies for rural water supply, decentralisation and water resources

management. Although emergency situations may require

short-term solutions with immediate results, the subsequent

transition to a development situation should also be considered.

General Issue 1. Community Selection

The process of community selection for improved water

supplies is well-defined and transparent. In countries where

there is some form of decentralisation, this process is led by

local government.

National systems for prioritisation and community selection

(e.g. demand responsive; pro-poor; equitable access) are ad-

hered to by all agencies involved in rural water supplies.

General Issue 2. Planning and Coordination

Planning and coordination of water supply infrastructure

improvements is undertaken by the lowest appropriate

level of Government (e.g. District or Ward).

All donors, NGOs and other Government institutions must in-

form local Government and consult with them from the plan-

ning of investments through to infrastructure development.

Local Government should develop a workplan which coordi-

nates the social components (i.e. sensitisation, mobilisation and

training) with borehole siting and construction works. Potential

contractors must be informed of the workplan. Efforts should be

made to consolidate the plans and tenders for borehole con-

struction by water, education and health departments at local

level. Multi-year development plans at local government level

can form the basis for multi-year contracts.

General Issue 3. Operation and Maintenance

The long term operation and maintenance requirements for

the full lifetime of the technology should be fully consid-

ered during the planning stage.

At a bare minimum, there is need for a national operation and

maintenance strategy which ensures that:

water users, caretakers, mechanics, suppliers and local Gov-

ernment have the right equipment and skills and are aware

of their roles and responsibilities in relation to others;

a clear process of community contribution or full payment

for construction is adhered to by all stakeholders working in

a particular area/district/country;

collection of user fees for maintenance (and possibly re-

placement) is adhered to by all stakeholders working in a

particular area;

there is a reliable supply chain for spare parts;

a robust and adequately financed system of follow-on sup-

port to water users is in place.

In addition, it is essential that a quality control mechanism for

handpumps and spare parts is in place and adhered to. This

should include pre-shipment inspection, certification as well as

consignee end inspection.

If water users do not fulfil their obligations with respect to op-

eration and maintenance then re-training and improvement of

management should be undertaken rather than new construc-

tion.

General Issue 4. Groundwater Resources

Measures are taken to manage and monitor groundwater

resources and protect vulnerable resources from over-

exploitation.

Water quality should be checked for bacteriological and chemi-

cal contamination in accordance with national guidelines (e.g.

arsenic, nitrate, fluoride, iron, manganese). Users should be

aware of the risks associated with consumption of water from

highly contaminated sources. Specific follow-up of vulnerable

resources should be undertaken.

4


3 Principles for Cost-Effective Boreholes

Each of the following nine sections comprises an overall prin-

ciple (in bold), followed by sub-principles and further details.

It is anticipated that the national protocol will follow this over-

all structure, modifying principles as appropriate and even

adding or removing specific principles where necessary.

Principle 1 Professional Drilling Enterprises and

Consultants

Borehole construction and supervision is undertaken by

professional and competent organisations which adhere to

national standards and are regulated by the public sector.

Construction of boreholes and installation of pumps should

normally be undertaken by local private sector firms rather

than by Government or donor agencies.

Subsidised drilling by public/state drilling enterprises and

NGOs should be avoided. If considerable drilling is undertaken

directly by the public sector or private sector drilling capacity

is weak, stakeholders should develop a strategy for achieving

local private sector involvement in a time-bound manner.

Drilling enterprises and consultants should be registered and

issued with a licence or permit. This should be renewed on an

annual basis provided that permit conditions are met, includ-

ing the submission of drilling completion reports as specified.

A national drillers association should exist and be active in

discussing and expressing drillers concerns.

The public sector has tended to undertake the construction of

boreholes in many countries. However, the preferred option is

for construction to be undertaken by the local private sector

so as to improve efficiency and foster competition. Govern-

ment and donor support agencies as well as NGOs are thus

encourage to provide support which builds up the private sec-

tor, rather than to purchase state-owned drilling equipment.

If the local private sector is particularly weak, the asset base

and capacity can be built by the use of lease to purchase

mechanisms over a period of one to three years. Such mech-

nisms should be considered as they enable the capital cost of

drilling equipment to be progressively recovered over time

from contract payments.

In cases where support agencies have already supplied drilling

equipment there is need to ensure that there is support in the

form of spare parts, tools, management support and training,

for a ten-year period, following the rig commissioning.

If support agencies provided drilling rigs to Government

within the last seven years, a rig information management

system (Box 1) should be established, utilised and reported on.

Box 1. Outline for Rig Information Management System

A rig information management system (RIMS) is a simple da-

tabase which enables information regarding the utilisation,

maintenance and repair of drilling equipment to be recorded,

stored and analysed. It enables drilling programme managers

to monitor equipment productivity, track equipment use and

reduce misuse or abuse. A RIMS does not replace a national

borehole database, as it does not include all the necessary

information. Tt records the following:

Details of drilling rigs, compressors and support vehicles.

All equipment has a unique identification number and de-

scription.

List of the Region/State, Local Government and Village/

Community of operation. Each State and Local Govern-

ment has a unique identification code.

Details of each borehole drilled (i.e. location with GPS ref-

erence, borehole identification number, start date, com-

pletion date depth drilled, drilling time and idle time on

site).

Distance travelled (initial mobilisation as well as between

each individual site).

Down time (due to idleness, maintenance and repair).

The software needs to enable the following queries to be run:

Information on drilling activities for particular equipment,

state, district, community or period of time.

Information on maintenance and repair activities for par-

ticular equipment.

The RIMS software must be able to generate standard reports

and allow for the backup and restoration of data.

1. Professional Drilling

Enterprises and

Consultants

Competent Local Private Sector

Avoid Subsidised NGO or State Drilling Enterprises

Registration and Licencing of Drilling Enterprises

and Consultants

Drillers Association

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Principle 2 Procurement

Procurement procedures ensure that contracts are

awarded to experienced and qualified consultants and

drilling contractors.

Procurement should be through national government systems

rather than under direct contract to the donor or support or-

ganisation. If these systems are particularly slow or weak, a mix

of approaches should be used in order to improve the national

systems and at the same time receiving results in the field.

The engagement of construction companies for water well

provision should be through a national (or local) competitive

bidding process, involving pre-qualification. Engineers‟ est-

mates should be used to avoid contracts being awarded to

tenders below the cost price.

Procurement should be for a multi-borehole package, in a

sensibly defined geographic area, preferably with similar

hydrogeology. In countries where there are already a good

number of drilling companies, lots could be for a high number

of boreholes (e.g. 50). However, in countries where there is

need to promote new drilling companies, smaller lots should

be considered.

In order to draw upon and build in-country capacity, and en-

able smaller enterprises to compete with larger companies,

mechanisms of awarding role-over packages to a “driller‟s

pool” should be considered.

Procurement should not necessarily be limited to one year

contracts.

In-country tender and contract award procedures, i.e. the con-

stituted public procurement system, should be utilised and

strengthened where weak. In order to ensure that contracts

are awarded to experienced and qualified consultants and

drilling contractors a process of pre-qualification, tender and

contract award is recommended:

Human resource needs and equipment capability re-

quirements should be clearly defined. These should be in

line with well design and contract size.

A transparent and thorough pre-qualification process

based on the company profile, equipment and staff skills,

turnover, experience and past performance as well as ad-

herence to national regulations with respect to drilling

permits, licensing as well as membership of national pro-

fessional associations. Pre-qualification, which can be un-

dertaken every one to three years, should include visits to

the drilling company premises and, if possible, their on-

site operations during and after completion. The list of

pre-qualified contractors should be published.

Tender documents, drawings and specifications should be

based on the findings of the siting and endorsed by Local

Government and other key stakeholders prior to tender-

ing.

Definition of required outputs (locations, depths, drilling

conditions) at the tender stage. If this is not possible then

an open negotiated agreement on costs as set out in the

bill of quantities (Annex A1.1) should be undertaken.

In the absence of reliable information on drilling condi-

tions in a particular area, a tender meeting should be held

whereby a hydrogeologist who is intimate with drilling

conditions in the area describes the “categories of risk”.

This is discussed further under Principle 4 on Siting.

The tender or award process involving the submission of a

method statement should only be open to pre-qualified

contractors.

A clear and transparent contract award process.

Contracts packaging in terms of boreholes within close prox-

imity is intended to reduce mobilisation costs and to facilitate

contract supervision. It is advisable to package ten or more

wells together, bearing in mind that when too many wells are

in a package (e.g. hundreds) this can exclude small local con-

tractors.

Packaging can be a particular challenge in countries operating

in a highly decentralised manner. However, innovative solu-

tions such as rolling budget allocations from one year to the

next or drilling every 2 to 4 years in order to bulk up the num-

ber should be considered. Contracting out wells of similar

depth and hydrogeology in one lot facilitates the use of

smaller, less costly rigs where appropriate.

A mechanism to enable small companies to participate is to

award role-over packages to a driller‟s pool, i.e.:

Pre-quality a number of contractors.

Following the bidding process, identify contractors to be

part of the drillers pool for a specified term.

Negotiate and set drilling prices for an agreed area.

Award small roll-over packages of say 20 to 30 boreholes

to several contractors in the driller‟s pool. The drillers can

undertake the work consecutively.

As roll-over packages are completed, subsequent pack-

ages can be awarded depending on performance.

Such a mechanism enables contractors to work for more con-

tracts as high quality and timely construction wins new work.

Contractors with multiple rigs can take on several packages;

those with one rig can work according to their capacity. The

client has control over works being implemented.

Multi-borehole package in one geographic area with

similar hydrogeology and risk of dry borheoles stated.

Try to include works for water, health and education

departments.

Roll-over package for more than one year

2. Procurement National Partner Systems

Local Competitive Bidding Process

Pre-qualification

6


Principle 3 Contract Management, Supervision and

Payment

Adequate arrangements are in place to ensure proper con-

tract management, supervision and timely payment of the

drilling contractor.

Normally contract management and supervision should be

based on systems and personnel of Government although

additional expertise can be brought in to cover capacity gaps

with a view to building expertise over the long term.

Contract documents need to be straightforward and readily

understandable by drillers.

Payment for construction works should be timely.

A defects liability period should be upheld whereby a financial

retention (of the order of 10%) is held in an insurance bond,

bank guarantee or cash.

Ideally a robust legal framework that supports compensation,

financial retention mechanisms, and audit and compliance

procedures is required.

Expertise and personnel for the design, management, supervi-

sion and scheduling of drilling programmes is essential to en-

sure that wells drilled are of high quality and that drilling costs

are reasonable. Waiting time at the drill site while decisions

are taken can raise the overall drilling costs considerably. Pro-

ject planning should ensure that drilling in the rainy season is

avoided.

Contracts for water well drilling can be paid according to bills

of quantities (Annex 1) or as a lump sum. Although lump sum

contracts are simpler to manage, with less scope for manipula-

tion, it is still essential that supervision is competent. Overall,

the contract must ensure that it is in the driller‟s interest to

construct a high-quality borehole. Lump sum contracts are

more appropriate under conditions where there is no payment

for dry wells. However this requires a categorisation of the

risks of drilling a dry borehole and appropriate payment

mechanisms, such as set out in Annex 2. Contracts may either

bundle the pump installation with the borehole construction

or handle this separately, e.g. more localised procurement and

installation by local mechanics.

In cases where performance bonds from a bank can only be

secured through cash, it is preferable that Contracts insist on

insurance bonds from a reputable company.

Proper supervision is a good investment which provides high

quality construction, ensures wells are not drilled deeper than

necessary and prevents holes from being abandoned prema-

turely. There is need for regulation of drilling supervision. Wa-

ter well drilling works should preferably be supervised full time

by skilled and qualified personnel in order to ensure high

quality construction. Part time supervision should only be un-

dertaken for lump sum contracts, for which it is essential that

supervision of the pumping test is undertaken and the yield as

well as borehole depth measured.

Staff of partner organisations (with adequate financial and

human resources), or private sector consultants should under-

take drilling supervision. Supervisors need to be well-trained

and operate independently from the driller in terms of finance

and logistics. Remoteness should not be an excuse for not

undertaking supervision. Typical problems of poor drilling su-

pervision are:

Driller claims bore is deeper than reality

Borehole of smaller diameter than specified is drilled

Borehole drilled deeper than necessary as driller is paid

against a bill of quantities and tries to maximise revenue.

Incorrect screen placement

Insufficient /poor specification gravel

Lack of grout

Not enough development

Driller claims well successful, but in reality it is dry.

Community monitoring of the construction and supervision

should also be considered. If properly trained, communities

can, for example monitor the number of casing pipes installed,

number of bags of cement used by the contractor and pres-

ence of the supervisor.

It is not uncommon for boreholes which are signed off as suc-

cessful go dry within a short time due to poor construction.

Thus a defects and liability clause, with about 10% retention of

contract value, needs to be included in the Contract and en-

forced. Toward the end of the 12-month period, under the

terms of the Contract, supervisors are obliged to visit each

completed site for the final sign off, which includes confirma-

tion of viability with the water users. It is essential that the

Contract clearly stipulates who is responsibility for pump qual-

ity within the warranty period.

Payment for works should be made within one month of com-

pletion and should not extend to more than three months.

Delays for longer than this are not acceptable for drillers to

maintain their liquidity (cash flow) and should incur pen-

alty/interest payments.

Third party monitoring, paid for by the client but undertaken

by an independent trained professional following construction

can also be undertaken as a control mechanism. This requires

a well-defined and consistent checklist for every water-well

drilled, with the results published.

In cases where the required legal framework and public insti-

tutions to underpin contract management procedures are

weak, there is need for considerable emphasis on building the

required systems through legislation and improving capacity.

3. Contract Management,

Supervision and Payment

Proper Contract Management

Proper Supervision by Pofessionals & use National Systems

Straightforward and Understandable Contract Documents

Timely Payment

Defects Liability Period

Robust Legal Framework

7



Principle 4 Borehole Siting

Appropriate siting practices are utilised.

Prior to preparing any well construction contract, a hydro-

geological desk study and field reconnaissance need to be be

carried out and the method of siting boreholes agreed upon,

based on expert opinion.

The risk of drilling an unsuccessful borehole should be catego-

rised. In proven areas where the geology is well understood

and borehole success is high (say over 70%), it may not be

necessary to site wells using geophysical survey techniques.

The final site selection needs to take community preferences

with respect to convenience into account.

Determining the best site for a borehole requires considera-

tion of technical, social and institutional issues. The siting

process should show which groundwater conditions dominate

the project area and enable the borehole(s) design to be

specified. Professional siting involves desk and field reconnais-

sance, and makes full use of existing data. In order to deter-

mine the best place for a borehole seven factors are of par-

ticular importance:

Sufficient yield for the intended purpose: The ground-

water aquifer should have a sufficient yield for a rural wa-

ter supply handpump (around 0.3-0.5 l/sec), for a small

town water supply (1-10 l/sec), or for a larger scale need

such as a significant irrigated area. This information is

sometimes available from documents or can be derived

performing a pump test.

Sufficient renewable water resources for the intended

purpose. Although a well may be capable of delivering a

certain yield in the short to medium term, if the ground-

water is not regularly replenished by infiltration from rain-

fall or river flow, then that yield will not be sustained over

the long term. It is important therefore to evaluate the

likely recharge to the aquifer, and how this might vary

with time. This judgement can be based on a water bal-

ance of an area calculated in a conceptual water model.

Appropriate water quality for the intended purpose.

Different water uses impose different water quality re-

quirements. Domestic water must be free of disease

pathogens (which are carried in human excreta) and low

in toxic chemical species such as arsenic or fluoride. When

using groundwater for irrigation the level of salinity has to

be checked. Well siting must therefore take account of

know-ledge of the occurrence of such undesirable sub-

stances.

Proximity to the point of use. Within the constraints of

geology, groundwater resources and groundwater quality,

wells should ideally be sited as close as possible to the

point of use. This means that walking distances to collect

water from rural point sources (eg handpump wells) and

energy costs for piped supplies should be minimised. If

not known, detailed interviews within the community

should be undertaken to get this information before per-

forming the siting.

Access by construction and maintenance teams. In the

case of wells constructed by heavy machinery, access by

drilling rigs, compressors and support vehicles is crucial.

Even when lighter equipment is used, vehicle access for

construction and for maintenance is important. Site se-

lection must therefore take account of these needs.

Avoidance of interference with other groundwater

sources and uses. In areas where some groundwater de-

velopment has already taken place, the construction of a

new well can lead to increased drawdown1 in existing

sources. This in turn can lead to greater pumping (en-

ergy) costs in both the existing well and the new well, re-

duced yields, changes in groundwater quality and poten-

tial conflict. In an early phase of the siting process possi-

ble interferences and risks for derogation have to be de-

scribed and discussed. In high risk situations possible al-

ternative siting areas should be evaluated.

Avoidance of interference with natural groundwater

discharges. In a similar way, the construction of a well

too near to natural springs, watercourses or wetlands can

lead to a reduction of water levels, potentially drying up

these important water sources and ecosystems and affect-

ing uses and users dependent upon them. The intrusion

of salt water due to too high abstraction of groundwater

near the coast could lead to irreversible decline of water

quality.

If skills for borehole siting are lacking in the country, efforts

should be made to build long-term capacity in this regard.

As part of borehole siting, the risk of drilling a dry borehole

should be categorised, e.g. high, medium and low risk as set

out in Annex 2.

In the case of boreholes which are to be fitted with hand-

pumps, geophysical techniques (e.g. resistivity, conductivity)

are rarely required once the general hydrogeology of a given

area is known. Drilling small exploratory boreholes (e.g. with a

small hand auger) can also be a suitable siting method for

shallow wells in certain conditions.

Engagement with the community to agree on the well location

is essential and requires some negotiation to explain technical

constraints while taking community preferences into consid-

eration. In general the community would be expected to indi-

cate three preferred boreholes sites in their locality, in order of

priority.

4. Borehole siting Hydrogeological Desk Study and Field Reconnaissance

Categorisation of risk and use of geophysical survey

technique only where appropriate.

Community Preference Considered for Site Selection

8


Principle 5 Construction Method

The construction method chosen for the borehole is the

most economical, considering the design and available

techniques in-country. Drilling technology needs to match

borehole design.

Well depths should not be unnecessarily over-specified or un-

der-specified.

A stepped approach to technology selection should be fol-

lowed. Firstly very low cost methods, including hand dug wells

and manual drilling, are considered before mechanised drilling

if they are feasible.

Subsequently, the use of small rigs which provide specified

diameter and well depth and can reach remote locations should

be considered.

It is important that well depths are not properly specified.

Stakeholders should avoid over-specifying depths and diame-

ters on a „just in case‟ basis, in order to then over-specify the

drilling rig required. This results in the mobilisation of excess

equipment and raises costs. However, excessive under-

specification is also a problem. Tendencies can be analysed by

comparing specifications with actual drilled depths.

Tender and contract documents should enable the least expen-

sive, but suitable drilling equipment to compete against larger,

more expensive rigs. Tenders should specify the final product

(i.e. the drilled water well) and thus avoid over-specifying the

drilling equipment. Small, low cost mechanised rigs drill at lower

cost than large rigs, can often be transported on the back of a

four-wheel drive pickup or single axle trailer and can reach

more locations, particularly where road networks are poor. If

stakeholders do not know about small mechanised drilling

technologies, explicit efforts should be made to raise awareness.

It should however be noted that drilling with a smaller rig may

be slower, and will thus require longer supervision. This needs

to be fully considered when considering contract management

and supervision requirements.

Hand dug and manually drilled wells are an option in specific

environments (soft formation and shallow groundwater). In ar-

eas where such techniques can provide water wells in significant

numbers, they should be fully considered. However, borehole

verticality needs to be good enough to enable the installation

and operation of the specified handpump, and wells need to be

deep enough to sustain supplies in prolonged dry periods and

successive dry years. There is need for the use of appropriate

quality control.

Dissemination of information, exchange visits, pilot projects,

support to the local private sector, and in-country studies may

be necessary in areas where hand dug wells or manual drilling

techniques are not well known about or not common.

The three conventional mechanised drilling techniques to

achieve boreholes suitable for hand-pumps are mud-circulation

boring, air-percussion boring or combination boring (mud-

circulation drilling through collapsible over-burden to rock, then

air percussion drilling).

In order to improve the availability of spare parts for drilling

equipment in countries with low levels of industrialisation the

private sector should be encouraged to partly standardise on

their drilling equipment. However, final decisions lie within the

hands of the private contractors, and the danger of creating a

monopoly for suppliers needs to be considered. It may be eas-

ier to discuss such practices with a drillers association (if it ex-

ists).

Proper specification of well depths.

5. Construction Method

Stepped approach to technology selection with very low

cost methods (hand dug wells and manual drilled wells)

considered first.

Appropriate drilling rig selection.

9



Principle 6 Borehole Design and Construction

The borehole design is cost-effective, designed to last for a

lifespan of 10 to 30 years, and based on the minimum speci-

fication to provide a borehole which is fit for its intended

purpose.

Minimum specification for „fit for purpose“ well in terms of yield,

diameter, depth, casing and screen, gravel pack/formation

stabiliser, verticality, drilling additive and sanitary seal. Over-

design of boreholes, especially excessive depth or diameter, is

wasteful and should be avoided.

The sustainability of the groundwater resource is fully

considered. The procedures for well development and for

pumping test are agreed upon and clearly specified in the

drilling contract.

The drilled well must be developed until the water is free of

solids and fine materials (fines) and any turbidity for a

continuous period of 30 minutes.

Pumping test requirements for a handpump should be realistic

and not over-specified.

Water quality testing for specified chemicals is undertaken,

particularly for areas at risk and boreholes serving institutions.

A fit for intended purpose design is summarised below. In the

case of motorised systems (if deemed cost-effective), design

must account for the precise requirements of the system.

In terms of yield for a handpump, 1m3/hour is sufficient

although this may be dropped to 400 litres/hour in areas

where groundwater is difficult to find. Wells should only be

drilled to the required depth for this yield. However, ex-

pected variations in the level of the water table should also

be considered. It should allow for expected drawdown, sea-

sonal fluctuations, multi-year trends and deterioration in

well efficiency. Yield requirements for motor pumps depend

on the system design, which is based on user requirements

and can be significantly higher than that of a hand pump.

Handpump borehole diameter requirements and the small

diameter pumps now on the market mean that 4”

(~100mm) internal diameter cased boreholes are usually

sufficient for the handpump cylinder and rising main. Nor-

mally uPVC casing/screen is stipulated which has a mini-

mum internal diameter of 103mm and an outside diameter

of 113mm. Motor-pumped boreholes can completed with a

cased pump housing of 5” nominal diameter to permit

space for an electro-submersible pump.

Depth: In locations where superficial weathered formations

are likely to be of a sufficient thickness, permeability and

storage to support the required yield, and deal with fluctua-

tions in the water level, the use of a relatively shallow well

(screened and gravel packed), constructed by a small drill-

ing rig may be cost effective.

Plain casing and screen: In locations where boreholes are

drilled into stable basement formation, it is possible to

make savings by casing the collapsing formation only.

However, the interface between the collapsing formation

and hard formation must be sealed (e.g. with grout). Plastic

(pVC) casing and screen should be used in preference to

steel where wells are less than 100-120m in depth. In fine

sands it may be necessary to use geo-textile materials (filter

socks) for the screen.

Gravel pack/formation stabiliser should have a proper

grading with a quality of >95% silica. It needs to be in-

stalled slowly and carefully, preferably with a “tremmie

pipe” and funnel.

Verticality needs to be specified (<100mm for every 30m),

as a condition of the borehole being denoted as successful.

Verticality should be such that a standard hand-pump cyl-

inder can be lowered into the borehole without meeting

any resistance).

Chemical foam and biodegradable mud should be utilised

as drilling additives in preference to bentonite and other

non-degradable mud. Bentonite should not be used as a

drilling mud once the drilling progresses below the water

table.

A sanitary seal is essential. It requires that the annulus is

backfilled (with drilling spoil) and then sealed with grout to

a depth of at least 4m. It is essential that no contaminated

water (e.g. from the surface or from pit latrines) can leak

into the borehole or the aquifer. A cement platform which

drains pumped water away from the borehole is required.

Annex 3 sets out sample borehole designs for the major hydro-

geological formations.

Well development must be undertaken before the driller

moves to the next site. If the screen and gravel pack area is not

properly flushed well efficiency can drop and the screen can

block over time. Well development is best undertaken with

compressed air thoroughly applied to all of the screened areas.

The borehole should be flushed until it is free of fines and tur-

bidity for a continuous period of 30 minutes. Chlorine can be

introduced before well development to help break down the

drilling polymer. Once the lifted water is clear, then the amount

of water being voided from the well by the air-lift should be

quantified and the measured “airlifted yield” recorded.

Pumping test is undertaken to establish well efficiency and

assess well yield. Requirements appropriate for a hand pump

are continuous pumping for 3 to 6 hours. It can be done only

until stable pumping water level is achieved for a constant rate

of discharge. Normally, the discharge rate should be at least

double the specified national minimum discharge for a success-

ful borehole. Recovery should be measured for half the pump-

ing time. In the case of motorised wells, more comprehensive

drawdown and recovery tests should be undertaken (e.g 24-

hour pumping tests).

Water quality analysis in line with national guidelines should

be undertaken and results submitted to the appropriate author-

ity. On site testing should be used when possible.

6. Borehole Design and

Construction Appropriate well development

Minimum specification for „fit for purpose“ well in terms of yield,

diameter, depth, casing and screen, gravel pack/formation

stabiliser, verticality, drilling additive and sanitary seal

Suitable pumping test requirements

Water Quality Analysis

10


Principle 7 Data and Information

High quality hydrogeological and borehole construction

data for each well is collected in a standard format and

submitted to the relevant Government authority.

The data to be gathered during borehole drilling is specified in

the drilling contract and responsibilities for data collection be-

tween the contractor and the supervisor are clear.

Information, in the form of a national borehole completion re-

port should be submitted to the appropriate government au-

thority after drilling (even in the case of dry boreholes).

Renewal of drilling licences should be linked to the submission

of borehole completion reports.

Each borehole drilled in the country should have its own dedi-

cated identification number.

Government, and other water sector stakeholders should collate

data on borehole drilling programmes annually, and make the

reports available to the public.

Formats for borehole completion records need to include in-

formation on the location, drilling operation, casing and well

completion, lithology, well development and pumping test and

water quality. Annex 4 provides a recommended format for

borehole completion records. It is essential that this information

is submitted to the appropriate centralised Government author-

ity and that each project does not merely hold on to its own

data.

The importance of regulation and licensing of drilling contrac-

tors is noted under principle 1. As a condition of annual drillers

licence renewal, it is recommended that it is made obligatory for

drillers to submit a bound compilation of their Completion Re-

ports of annual output for the preceding year to the appropriate

authority.

Each borehole dedicated identification number should be

stamped onto a metal plate on the hand-pump base and also

engraved into the pump platform. In order to avoid the un-

planned and unmonitored drilling of boreholes, permits should

be issued by the appropriate authority.

In terms of information on drilling programmes by Government

and other stakeholders, the key areas to be reported include:

Programme outputs (with associated costs) in terms of

skills, knowledge and organiational capacity raised as well

as numbers of people trained.

Boreholes drilled, i.e. numbers, well depths, and locations

(with borehole numbers and GPS references annexed).

Supervision summary.

Price of each well, with details on what is included and ex-

cluded, (e.g. profit and overheads, siting, mobilisation, drill-

ing, supervision, handpump, training of the community). In-

clude an explanation of how costs are derived (e.g. cost of

package of 10 wells in a particular contract package divided

by 10). Information needs to be structured in a way that en-

ables comparisons between regions and /or districts to be

carried out.

Details of private sector involvement including names of

companies, contract summary and amount, date paid for

construction and defects liability payment.

Findings of monitoring and evaluation missions.

Specify data requirements and responsibilities

Submit borehole completion log to authority

Unique borehole identification number

Annual reports on drilling programmes

available to the public

7. Data and Information

Drilling licence renewal linked to submission

of completion reports

11



Principle 8 Database and Record Keeping

Storage of hydrogeological data is undertaken by a central

Government institution with records updated, information

made freely available and used in preparing subsequent

drilling specifications.

A national (or state level) database of all borehole drilling re-

cords should be established and kept up-to-date. If no such

national database exists, sector stakeholders should keep and

archive records of all borehole drilling work undertaken until it

is established.

The data from all drilling programmes and projects in the coun-

try should feed into this database.

Data from the database should be made freely available.

The cumulative knowledge of groundwater resources provided

by adequate and accessible data archives greatly enhances the

chances of successful drilling and borehole construction. Bore-

hole logs, completion reports and pumping test data (as speci-

fied in the drilling contract) must always be submitted to the

relevant national (and/or) local authority. Information from “dry”

or unsuccessful boreholes is just as important as that from the

unsuccessful ones.

There is need for specific key data to be abstracted from the

drilling completion reports and entered onto a national data-

base for borehole drilling. Such a database needs to be properly

established, kept up to data, be readily accessible to all, and

ensure that there is no duplication of data entry (i.e. by using an

individual borehole identification number and GPS information).

If there is no national database, drilling data should be archived

by sector stakeholders until such a mechanism, with responsible

agent, is established. Government and external support organi-

sations should be encouraged to enforce data gathering, estab-

lish groundwater databases and build the national capacity in

this regard.

It is internationally accepted that to assess progress and status

of national groundwater development and guide future plan-

ning, it is necessary to maintain good records of borehole drill-

ing, and index and archive original documents so that they can

be readily accessed. Records should include:

Pre-qualification and tender evaluation reports.

Reports of community mobilisation and training.

Schedules of construction supervision.

Monitoring reports.

Principle 9 Monitoring and Evaluation

Regular visits to completed boreholes are made to monitor

their functionality in the medium as well as long term with

the findings published.

The monitoring and evaluation systems of Government should

be utilised (and strengthen if necessary) rather than the devel-

opment of parallel systems.

Monitoring of the use of the borehole and pump functionality,

including analysis and action-taking should be undertaken at: 6

months, one year, five years and ten years after construction at

a miminum.

The findings of the monitoring work should be made public.

It is essential that the procedures for monitoring and evaluation

as set out by Government are respected, and/or improved, with

all information collected communicated to the relevant authori-

ties.

Monitoring of water source functionality should include the

collection of information on revenue collection, management,

reasons for breakdown and user response. Findings should in-

form national policies with respect to infrastructure develop-

ment as well as operation and maintenance. Actions taken

should be in line with national policies.

Use national monitoring and

evaluation systems 9. Monitoring

and Evaluation

Monitor use and functionality

at least: 6 months, 1 year, 2

years, 5 years and 10 years

after installation

Publish monitoring reports.

8. Database and

Record Keeping National database of all drilling

records (or archive all records)

All drilling programmes, projects

and works feed into the database

Information from database is

freely available and used

12


Annex 1 Bills of Quantities

Tables A1.1 and A1.2 provide two sample BoQs.

Table A1 Sample of Bill of Quantities for 10 wells - Long Version

Description Qty Unit Unit Price

Total Price

1 Borehole Siting 1 Each

2 Establishment of Base Camp

3 Mobilisation and demobili-sation of equipment and personnel

500 km

4 Set up of rig and move be-tween sites

400 km

5 Drilling borehole of 5” di-ameter in soft overburden

200 m

6 Drilling borehole of 5” di-ameter in basement rock

300 m

7 Supply, install and withdraw temporary casing

10 each

8 Sampling and Borehole Log-ging

10 Each

9 Supply and installation of 110mm (4 inches) diameter, uPVC casings of 10 bar pres-sure rating.

400 m

10 Supply and installation of 110mm (4 inches) diameter, uPVC screens of 10 bar pres-sure rating. (Slot size 0.5)

100 m

11 Supply and place approved filter pack around casings and screens

90 m

12 Borehole cleaning & devel-opment till water is silt free

20 hour

13 Test Pumping 5 each

14 Provide and place cement grout

5 each

15 Water Quality Analysis and borehole disinfection

5 each

16 Installation of handpump and accessories.

5 each

17 Completion Reports – Spiral bound copies

15 Each

18 Waiting (or standing) Time hour

Sub-total

18 Overheads and profit -15%

Value Added Tax (VAT)- 20%

Total

In Table A1.2, items have been streamlined and the margin

(profit plus overheads) is incorporated into the rates for the

various items. Note that BoQs are not problem-free. We have

found examples where there is no item included for moving

between the drill sites, or where the specified drilling depths,

casing and screen do not make any sense!

Table A1.2 Sample of Bill of Quantities (BoQ) (Streamlined Version)

Description Qty Unit Unit Price

Total Price

1 Mobilisation 1 LS

2 Moving between sites 5 LS

3 Drilling 200 m

4 Casing and Completion 400 m

5 Gravel Pack and Development 100 m

6 Test Pumping 5 LS

7 Backfill and well completion (including water quality analy-sis)

5 LS

8 Installation of handpump and accessories.

5 each

9 Completion Reports – Spiral bound copies

15 each

Sub-total

Value Added Tax (VAT)- 20%

Total

13



Annex 2 Categorisation of Risk and Payment Structures

It may be possible to classify the drilling potential for different parts of the country, or within a particular location into the follow-

ing categories:

Category Success

Rate* Assumptions Proposed Payment Arrangements

A

High

Success

> 90%

Geophysical survey not

necessary. Drilling at any

site has a high chance of

success. First preference of

community is likely to be

successful.

The risk of dry drilling is denoted as small and dry bores are not paid to

the contractor, under any circumstance. Driller is to survey select site

within the areas nominated by the community and his unit rates is to in-

clude the risk of dry bores.

B

Moderate

Success

70 - 90%

The drillers themselves may

elect to survey (either

themselves or by their ap-

pointed hydro-geologist)

and select the actual dill

sites within the given pre-

ferred areas of community.

Government guidelines for

siting should be followed.

In some cases it is advis-

able to specify a minimum

drilling depth in the Con-

tract.

Limited payment is made to the Contractor for dry bores to a certain

depth, according to formula set out below:

1st bore success: 100% paid; move to new location.

If 1st bore dry: No payment

2nd bore success: 100% paid, move to new location.

If 2nd bore dry: 50% (of a productive borehole) paid

3rd bore success: 100% paid, move to new location

If 3rd bore dry: 50% (of a productive borehole) is paid move to next

community

In the exceptional event of three dry bores, then no further drilling is un-

dertaken in this community at this juncture. In effect this community lo-

cale will now become a Category C risk and requires expert hydro-

geological survey to be commissioned by the Employer in order to ascer-

tain define site(s) for any further drilling.

C

Low

Success

< 70%

Client to commission inde-

pendent siting including

use of geophysics (Resistiv-

ity profiling and Electro-

magnetic (EM) assessment.

Sites selected and contrac-

tor drills to minimum depth

indicated

The employer has determined the actual site and depth; payment is made

for both wet and dry bores.

*The suggested percentages applied above can be varied to suit, for example 85%, 55-85% and 55% respectively.

A maximum of three dry boreholes may be made in any one community under the above arrangement, in accordance with their

preferred sites. Subsequently it is time to cease “random” drilling and undertake geophysical investigations.

14


Annex 3: Sample borehole designs

15



16


17



18


Annex 4. Suggested Format for Borehole Completion Record

Contents

1. General

2. Drilling Operation

3. Casing and Well Completion

4. Well Development and Pumping Test Summary

5. Water Quality

6. Lithology

6a. Lithological Logging

6b. Abbreviations for Lithological Logging

6c. Photograph of Generalised Lithology

7. Pumping Test Details

7a. Step Drawdown Test

7b. Constant Rate Test

7c. Recovery Test

8. Water Quality Analysis Parameters (full list)

19



1. General

Water Well Reference No: Use: Community Household/Private Compound Health Facility Education Facility Company Premises Test Well Other

Location: Owner Name:

Owner Address: Coordinates/GPS Refer-ence:

Long. E Lat. N

Financing Programme/Project/Private:

Well Permit No. Date Issued: Issuing Authority

Name of Driller: Driller’s License No:

Address of Driller:

Sketch Map Approximate Scale:

2. Drilling Operation

Start Date: Total Depth: m Drilling method(s):

Percussion Mud Rotary Air Rotary DTH

Equipment make: __________________

Hand Drilled (specify type) __________________

Main Water Strike: m

Completion Date: Static Water Level: m

Dynamic Water Level: m

Drilling Diameter: inch mm Average Penetration Rate: m/h

From To Diameter (inch/mm) Method Penetration Rate (m/h)

m m

m m

m m

m m

m m

m m

m m

m m

m m

20


3. Casing and Well Completion

Casing Material: _____________________

Casing Joints: Threaded Glue and Socket

Bottom Plug: Yes No

Height above ground level: ______________m

Plain casing and Screen installation: inch mm

Screen Open Area (%) ______

Casing

From To Diameter (inch/mm) Type

m m

m m

m m

m m

m m

m m

Screen

From To Diameter (inch/mm) Type Slot Size

m m

m m

m m

m m

m m

m m

Gravel

From To Size Volume used

m m

m m

Backfill and Grout

From To Diameter (inch/mm) Type

Alignment/Verticality Test Remark

Well head and Platform

Well Cap: Yes No

Apron:

Concrete slab

Drainage

Soak-away Pit

Fence

Pump:

Stand

Fitted around casing

Welded on Casing

Pump Type:____________________________________

Comments: _______________________________________________________________________________________

21



4. Well Development and Pumping Test Summary

Development:

Air-lift

Over-pumping

Surging

Backwashing

Jetting

Duration _____________hr

Comments: ___________________________________

______________________________________________

Pumping Test:

Air-lift capacity evaluation

Constant Rate Test (CRT)

Step Drawdown Test

Duration _________hr

Discharge ________l/s

Dynamic water level: _________m

Comments: ___________________________________

______________________________________________

5. Water Quality Summary

Sample taken: Yes No

Date____________

Chemical Quality:

pH:_______________

Laboratory: __________

(for more parameters see separate sheet) Physical Quality:

Clear

Turbid

Other (please specify) __________________

Colour_______ Taste_______ Turbidity______NTU

Temp. ______˚C TDS______mg/l EC_______µS-cm

Bacteriological Quality:

Faecal coliform: ____________cfu per 100ml

Laboratory: __________

Comments: _________________________________________________________________________________

22


6a. Lithological Logging

Water Well Reference No:

Location: Owner Name:

Owner Address: Coordinates/GPS Reference: Long. E Lat. N

Financing Programme/Project/Private:

Well Permit No. Date Issued: Issuing Authority

Name of Driller: Driller’s License No:

Well Logged by:

Depth (m)

Description Colour* Grain size* Texture* Degree of weathering*

Stratigraphic unit (if

known)*

Remarks (e.g. mineralogy,

drilling, water)

Penetration rate

(min/m)

Discharge EC TDS

Data to be recorded at a minimum of 1 meter intervals- add more sheets if required

* See below for codes

23



6b. Abbreviations for Lithological Logging

Colour (use combinations if needed)

Gr - grey Gn - green Br-brown Or – orange

Bg-beige Rd-red Pk- pink Wt – white

Shade

L-light M-medium D-dark

Grainsize

VF - very fine F - fine M - medium C – coarse VC - very coarse

Texture (use more than one as applicable)

D - Dense, hard F - fractured U- unconsolidated PC- partly consolidated

L - laminated H- homogeneous C - clast supported M- matrix supported

Degree of weathering

F-fresh L-light M-moderate D-deeply

Formation / Stratigraphic unit (if known - add codes based on the local stratigraphic nomenclature)

6c Photograph of Generalised Lithology

(Sample photograph from Zambia)

24


7. Pumping Test Details

7a. Constant Rate Test (note that 3 to 6 hours is sufficient of a handpump supply)

Water Well Reference No: Water Well Name:

Start Test Date: Time of Day

Static Water Level before the Test m

Data in this table is for: Pumping Well/ Observation Well (Tick Appropriate)

Reference Point

Average Discharge ( l/sec) Obs Well No. Distance (m) Depth (m)

Time Water Level Discharge (Q) Remark

Real Time Hrs Min

Depth of Water Drawdown

Container Method Flow Meter TDS, Temperature, pH and

any other observation (m) (m) (l/s or m3/h) (l/s or m3/h)

0

0.5

1

2

3

4

5

6

7

8

9

10

12

14

16

18

20

25

0.5 30

35

40

45

50

1 60

70

80

1.5 90

100

110

2 120

135

150

165

25




Real Time Hrs Min (t)

Depth of Water

Drawdown (S)



3 180

195

210

225

4 240

255

270

285

5 300

315

330

345

6 360

26


7b. Step Drawdown Test (for mechanized borehole supply)


Start Test Date: Time of Day:

Static Water Level before Test: m

Pump Intake: m

Reference Point Pumping Well/ Observation Well (Tick Appropriate)

Average Discharge: l/sec Obs Well No. Distance m Depth m


Real Time Hrs Min

Depth of Water Drawdown



0

0.5

1

2

3

4

5

6

7

8

9

10

12

14

16

18

20

25

0.5 30

35

40

45

50

1 60

70

80

1.5 90

100

110

2 120

135

150

165

27





Depth of Water

Drawdown (S)



3 180

195

210

225

4 240

255

270

285

5 300

315

330

345

6 360

375

390

405

7 420

435

450

465

8 480

495

510

525

9 540

555

570

585

10 600

615

630

645

11 660

675

690

705

12 720

735

750

765

13 780

795

810

28




Depth of Water

Drawdown (S)

Container Method Flow Meter

TDS, Temperature, pH and any other observation

(m) (m) (l/s or m3/h) (l/s or m3/h)

825

14 840

855

870

885

15 900

915

930

945

16 960

975

990

1005

17 1020

1035

1050

1065

18 1080

1095

1110

1125

19 1140

1155

1170

1185

20 1200

1215

1230

1245

21 1260

1275

1290

1305

22 1320

1335

1350

1365

23 1380

1395

1410

1425

24 1440

29



7c Recovery Test


Start Test Date: Time of Day:

Water Level Before the Test m Pumping Well/ Observation Well (Tick Appropriate)

Reference Point

Time Water Level Time Water Level

Real Time Hours Minutes

Depth of Water

Residual Drawdown

Real Time Hours Minutes

Depth of Water

Residual Drawdown

m m m m

0 8.5

0.5 9

1 9.5

2 10

3 10.5

4 11

5 11.5

6 12

7 13

8 14

9 15

10 16

12 17

14 18

16 19

18 20

20 21

25 22

0.5 30 23

35 24

40 26

45 28

50 30

1 60 32

70 34

80 36

1.5 38

100 40

110 42

2 44

2.25 46

2.5 48

2.75 50

3 52

3.5 54

4 56

4.5 58

5 60

5.5 62

6 64

6.5 66

7 68

7.5 70

8 72

9 74

30


8. Water Quality Analysis Parameters (full list)

Water Well Reference No:

Constituents Unit Concentration

Suspended solids mg/l

Colour TCU

Turbidity NTU

TDS mg/l

pH

Hardness (CaCO3) mg/l

Calcium (Ca) mg/l

Magnesium (Mg) mg/l

Sodium (Na) mg/l

Potassium (K) mg/l

Chloride (Cl) mg/l

Total Alkalinity mg/l

Bicarbonate mg/l

Carbonate mg/l

Sulphate mg/l

Nitrate mg/l

Flouride mg/l

Iron mg/l

Manganese mg/l

Zn mg/l

Copper mg/l l

Arsenic mg/l

Lead mg/l

Aluminium mg/l

Cadmium mg/l

Cyanide mg/l

Mercury mg/l

Ammonia mg/l

Hydrogen Sulphide mg/l

Faecal Coliform Count/100ml

Total Plate Count Count/100ml

Field Measurements

Temperature 0C

pH

Electrical Conductivity

References and Further Reading

Adekile, D and Kwei, C. 2009. The Code of Practice for Cost-Effective Boreholes in Ghana – Country Status Report, Consul-

tancy Report for RWSN/UNICEF

Adekile, D and Olabode O. 2008. Report on comparison of Cost-Effective borehole drilling in the Project Sates and other

Programmes. Consultancy Report for UNICEF Nigeria Wash Section.

Armstrong, T. 2009. The Code of Practice for Cost-Effective Boreholes in Zambia – Country Status Report, Consultancy Re-

port for RWSN/UNICEF

Ball, P. Solutions for Reducing Borehole Costs in Rural Africa. Field Note RWSN/WSP

Carter, RC. 2006. Ten-step Guide Towards Cost-effective Boreholes. Field Note RWSN/WSP

Danert, K. 2009. Learning from UNICEF’s Experiences of Water Well Drilling, UNICEF Internal Document

Duffau, B. and Ouedraogo, I. 2009. Optimisation du Cout des forages – Raport de Mission, Consultancy Report for

RWSN/UNICEF

MacDonald, A, Davies, J, Calow R and Chilton J. 2005. Developing Groundwater. A guide for Rural Water Supply, ITDG Pub-

lishing

Potential Forthcoming Documents (aid Memoire)

Water Well Drilling Short Contract

Field Note on Drilling Supervision

Overview of light and medium drilling rigs

Authors and Reviewers Contact

Kerstin Danert, Tom Armstrong, Dotun Adekile, Bruno Duf-

fau, Inoussa Ouedraogo and Clement Kwei are the authors

of the Generic Code of Practice for Cost-Effective Bore-

holes.

The report has been peer reviewed by Peter Harvey

(UNICEF), Ron Sloots (WE Consult), Richard Carter

(WaterAid), John Chilton (British Geological Survey) and

XXXXX (to be completed after the third review.

Note Dew Point input XXXXX.

The Rural Water supply Network (RWSN) is a global

knowledge network for promoting sound practices

in rural water supply.

RWSN Secretariat Phone: +41 71 228 54 54

SKAT Foundation Fax: +41 71 228 54 55

Vadianstrasse 42 Email: [email protected]

CH-9000 St.Gallen Web: www.rwsn.ch

Switzerland

Development of the Code of Practice

The preparation of this document was led by Dr Kerstin

Danert of Skat who managed a UNICEF/USAID funded pro-

ject to develop a Code of Practice for Cost-Effective Bore-

holes. The project included a review of the history of

UNICEF‟s involvement in borehole drilling, followed by

country studies in Burkina Faso, Ghana and Zambia. Ongo-

ing work to develop national drilling protocols, better un-

derstand the drilling sector and professionalise private

drilling enterprises in Nigeria, Uganda and the Sudan was

also drawn upon for the work.

The Generic Code of Practice was extensively reviewed

through consultations with UNICEF, XXXXXXX