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GOVERNMENT OF SIERRA LEONE

Republic of Sierra Leone Ministry of Water Resources

Principles for Borehole Construction and Rehabilitation in Sierra Leone

May 2014

To be completed

Republic of Sierra Leone Ministry of Water Resources


May 2014

Republic of Sierra Leone: Ministry of Water Resources


To be completed

Acknowledgments



Contents

Foreword ....................................................................................................................................i

Acronyms and Abbreviations ..................................................................................................... ii

Introduction ............................................................................................................................... 1

Roles and Responsibilities in Borehole Construction and Rehabilitation ................................. 3

Principle 1: Professionalism .................................................................................................. 5

Principle 2: Siting .................................................................................................................. 6

Principle 3: Technology Selection and Construction Method ............................................... 8

Principle 4: Procurement ...................................................................................................... 9

Principle 5: Construction ..................................................................................................... 10

Principle 6: Supervision ...................................................................................................... 11

Principle 7: Water Quality Testing ...................................................................................... 13

Principle 8: Contract Management ..................................................................................... 14

Principle 9: Data ................................................................................................................. 15

Principle 10: Monitoring ........................................................................................................ 16

Appendix

1: Template for Memorandum of Understanding: Community leaders, District Council, the contractor and NGO (if an NGO is involved) and Land Owner .................................. 17

2: Recommended Structure for Site Selection Report ......................................................... 18

3: Sampleboreholespecifications ........................................................................................ 20

4: Sample Contract (for one borehole) ................................................................................. 23

5: Project Checklist for the Driller ......................................................................................... 33

6: Checklists of Drilling Steps for the Supervisor ................................................................. 34

7: Borehole Completion Record ........................................................................................... 41

iRepublic of Sierra Leone: Ministry of Water Resources


To be completed

Lamin K.S. SoumaDirector, Water Directorate,

Ministry of Water Resources, Sierra Leone

Foreword

ii Republic of Sierra Leone: Ministry of Water Resources


Acronyms and Abbreviations

1Republic of Sierra Leone: Ministry of Water Resources


Introduction

The National Water and Sanitation Policy (2010), objective 3.1.4 is to “have systematic and

sustainable development and use of groundwater resources”. This includes the develop-ment and dissemination of procedures and guidelines governing groundwater development and management. Sierra Leone has considerable untapped potential for borehole drilling which is starting to be exploited.

These Principles for Borehole Construction and Rehabilitation in Sierra Leone are in line with good international practices but take into account Sierra Leone’s context. A step-wise ap-proach is needed to introduce and adopt these principles. Ultimately, all stakeholders oper-ating in the country must respect these principles and adhere to all the mandatory aspects.

Boreholes in Sierra Leone must be constructed to be “cost-effective”. This means optimum value for money invested over the long term. Boreholes are drilled to function for a lifespan of 20 to 50 years. The lowest cost borehole is not always the most cost-effective, particularly if construction quality is compromised to save money. Poor construction quality including lack of proper borehole development can lead to premature failure of the borehole or contamina-tion of the water supply. Boreholes that are subsequently abandoned by the users as a result are not cost-effective.

In order for boreholes to be cost-effective they need to be properly sited, appropriately de-signed and specified, and then constructed and completed using suitable methods and equipment. Where the private enterprises undertake the drilling, procurement and contract management procedures need to be followed and supervision needs to be undertaken in a professional manner. Drillers, whether private, public or NGO, as well as supervisors need to ensure adequate construction quality.

The Principles for Borehole Construction and Rehabilitation in Sierra Leone have been drafted and agreed in 2013/14. At this time Sierra Leone is undergoing considerable institutional re-form. For example, posts within Government are being filled and new staff members are being oriented and trained. At the time of drafting these Principles, the institutional arrangements and legal basis to certify drillers and hydrogeologists or to collate and process borehole drill-ing data were not yet in place. It is envisaged that these principles will be amended as the

2 Republic of Sierra Leone: Ministry of Water Resources


institutional framework changes, and would form the basis of a “Code of Practice for Borehole Construction” or equivalent, with a number of legally binding aspects.

The principles are in line with the stages of a project cycle for Rural and Small Town WASH programming (Table 1). They specifically focus on stage 3 – site selection and construction.

TABLE 1: STAGES OF RURAL AND SMALL TOWNS WASH DEVELOPMENT, REHABILITATION AND MAINTENANCE THAT RELATE TO BOREHOLES

Stage Provisions/Principles

1. Coordination, Planning and ReportingProvisions to be detailed in another guideline

2. Community sensitisation, technology choice & mobilisation

Provisions to be detailed in another guideline

3. Site Selection and Construction

Provisions set out in:n Technical Guidelines for the

Construction and Maintenance of Hand Dug Wells

n Principles for Borehole Construction and Rehabilitation

n Handpump installation guidelines

4. Community or Private-Sector Management and Finance/Sustainability Compact

Provisions to be detailed in another guideline

5. Monitoring & Post-construction SupportProvisions to be detailed in another guideline

6. Guidelines for Water Quality MonitoringProvisions to be detailed in another guideline



Roles and Responsibilities in Borehole Construction and Rehabilitation

The roles and responsibilities for the different stakeholders involved in borehole construc-tion and rehabilitation are as follows.

n The Community members are the end users of the water supply. They must be included in the process of technology selection and siting so that the finished water point can meet their needs. There are cases where the Community is involved in supervision, but they should not be responsible for technical or contractual details unless their capacity has been built extensively.

n The Client is the organisation, household or community that is contracting out the borehole construction. Their responsibility is to fulfil regulatory requirements and ensure that they have well trained Supervisors present on site for the full duration of drilling operations.

n Note that even if district local government is not the client, it is still important for them to be involved in the process. District local government should attend a pre-mobilisation meet-ing, commencement of drilling and the end of the construction, including pump testing.

n The Funding Organisation pays for the borehole. It may be the Client (see above) or an-other organisation such as an international development partner or NGO. The funding organisation should not impose conditions that create perverse incentives or undermine the long-term sustainability of the finished borehole (e.g. by insisting that the cheapest bid is accepted regardless of quality). It should work within national or local government systems.

n The Regulator (once established) issues permits and licences for siting, supervision, drill-ing or abstraction. Legal requirements should be established by the Client early on to avoid delays.

n The Project Manager is responsible for a wider project. The siting and drilling will usually be just one component within a project, comprising community training/mobilisation, pump technology choice, water point design and construction, and establishing or strengthening a rural water supply service.



n The Supervisor is sometimes called the ‘Rig Inspector’. Supervision is usually done either by the Client’s staff or by a consultant. The Supervisor may be a hydrogeologist, an engi-neer, or a technician. Although the Driller and the Supervisor work together to deliver the product, their roles are different. The Supervisor’s responsibility is to ensure that the Driller adheres to the technical specification, makes all the required measurements, keeps all records accurately and ensures that health and safety procedures are adhered to. Annex 6 provides a checklist for the supervisor.

n The Driller, or Contractor, is the organisation that physically does the drilling. Sometimes, this will be an independent private sector company. In other cases, it will be an in-house team working for a government agency or NGO. The Driller’s responsibility is to drill the borehole as specified. Each Driller should have a designated ‘Record Taker’ who should remain on site at all times, with the duty to collate all the measurements and complete all the forms. Annex 5 provides a detailed checklist for the driller.



PRINCIPLE 1:

1.1 The siting, supervision and construction of drilled boreholes in Sierra Leone is under-taken by competent government/NGO staff, consultants and contractors.

1.2 Enterprises that are registered in Sierra Leone are to be given priority when tendering for siting, supervision and drilling services in the country.

1.3 Once regulations are in place, all government/NGO staff and consultants that under-take siting, supervision must be registered and accredited by the appropriate author-ity/institution/association.

1.4 Once regulations for licencing are in place, all contractors and NGOs that undertake siting, supervision and drilling must be registered and licenced by the appropriate authority/institution/association.

1.5 All external support agencies that finance borehole drilling programmes in Sierra Le-one must support the local drilling industry and the development of local skills, for example through appropriate lots of work, payment schedules and on-job training or mentoring.

Professionalism



PRINCIPLE 2:

2.1 For all boreholes, a hydrogeological desk study must be carried out and the detailed method for siting agreed.

2.2 For all boreholes, the risk of drilling a dry hole should be assessed.

2.3 Geophysical equipment should be used if it considerably improves the likelihood of successful drilling.

2.4 Community preference must be considered when siting a borehole. The process for community involvement is set out in the Memorandum of Understanding that is signed between the community leaders, the District Council, the contractor and NGO (if an NGO is involved) and land owner (Annex 1). If the preferred sites are not suitable for technical reasons, this must be explained to the community. Alternative drilling sites or alternative technology options need to be proposed to the community for consideration.

2.5 For all public/community boreholes, the ownership of the land selected must be deter-mined prior to the finalisation of site selection. The consent of the owners to use the land for the borehole and allow access indefinitely must be set down in writing. If compensa-tions are agreed they must be settled before commencement of any construction work.

2.6 There should be easy access for construction and maintenance equipment for the borehole.

2.7 The site must be accessible all year round to all people in the community. If possible the borehole should be centrally located within the community. If this is not possible the borehole should not be more than 500 m from the community. For schools and health centres the boreholes must be located within the premises. Household bore-holes should preferably be located within the compound of the homestead.

2.8 In order to ensure that the borehole is hygienic, it is mandatory to site it beyond the minimum distance from existing water points and contaminants (Table 2). It must be located up stream of any possible pollutants. It must not be sited where it could be flooded or in depressions with poor drainage. The site must not be liable to erosion and it must not be in an area where pesticides or fertilisers are being used.

Siting



TABLE 2: MINIMUM DISTANCE (M) FROM BOREHOLE

Existing structures Minimum distance from borehole (m)

Existing public water points (well/borehole) 20

Other existing water wells or boreholes 10

Latrines/Septic tank/soak way 30

Streams, canals, irrigation ditches 20

Buildings 3

Approved or informal solid waste dump, burial ground, lubricant depot 500

Coastline 100

2.9 A short report by the agency/consultant who undertakes the siting must be prepared for the client for each borehole explaining the reason for the selection of the final site (or sites) selected (Annex 2).

2.10 In the case of borehole rehabilitation, an assessment must be carried out to diagnose the problem and establish whether it is worth rehabilitating or not. It is essential to as-sess the following points:

n The duration the borehole worked for before breaking down. If it worked for several months before it broke down it is likely that it can be rehabilitated but if it stopped working only after a few days after construction it might be due to poor construction and may be difficult to rehabilitate.

n Whether the source has failed due to a problem with the pump, or with the borehole itself.

n In case of siltation:

– whether this is due to inadequate borehole development – which could be re-done;

– or whether this is due to poor construction such as inappropriate gravel packing and/or the wrong screen slot size. In such cases, it may not be worth rehabilitat-ing the borehole.

n The distance of the borehole to any potential contaminants should be checked. If the distance is less than that provided in Table 2, it must not be rehabilitated.

Borehole camera inspection, pumping test and water quality test can aid deciding whether a borehole could be rehabilitated or not.



PRINCIPLE 3:

Technology Selection and Construction Method

3.1 The most cost-effective construction method for providing an all-year water supply of the desired quantity and quality should be considered first. Groundwater sources can be a hand dug well, a manually drilled borehole or a machine drilled borehole, depending on the geology and hydrogeology of the area as well as community prefer-ences.

3.2 The technology selection must be undertaken in consultation with the community in line with National Guidelines on Community Mobilisation (by May 2014 these had not been developed).

3.3 In the case of a decision to go ahead with drilling, the specifications for borehole design must ensure that the well is “fit for purpose”. The borehole diameter, casing di-ameter and well depth must be designed to meet the requirements for the deliverable borehole yield. Annex 3 sets out sample borehole specifications.



PRINCIPLE 4:

Procurement

4.1 Procurement procedures for siting, supervision and drilling contracts must ensure that contracts are awarded to competent consultants and drilling contractors. Once regu-lations are in place, only registered and accredited consultants and contractors will be eligible to tender.

4.2 Procurement for siting, supervision and drilling contracts should be undertaken through national systems where these are deemed sufficiently rigorous and transpar-ent. NGOs and certain donor projects may have their own procedures. However it is essential that they adhere to the Principles for Borehole Construction and Rehabilita-tion.

4.3 Sierra Leone intends to support a strong, local drilling industry. In order to do this, bid-ding mechanisms need to ensure that they can participate in the tender process such as appropriateness of lot size.

4.4 Borehole siting and drilling specifications must be completed prior to the procurement of borehole construction, so that realistic cost estimates can be prepared by all par-ties.

4.5 In order to keep drilling equipment mobilisation costs down, drilling contracts pack-ages should, where feasible, be for multiple boreholes, preferably in reasonably close proximity.



PRINCIPLE 5:

Construction

5.1 Boreholes are to be constructed to be cost-effective, with an expected lifespan of 20 to 50 years. Construction must adhere to specifications with respect to diameter, depth, casing and screen, gravel pack/formation stabiliser, verticality, drilling additive and sanitary seal.

5.2 Procedures for borehole development as set out in the drilling specifications must be adhered to. The drilled borehole must be developed until the water is free of solids, and fine materials. (fines) and turbidity for a continuous period of 30 minutes.

5.3 Procedures for pumping test, as set out in the drilling specifications as set out in the contract are adhered to.

5.4 All aborted boreholes must be backfilled with drilling material and sealed according to the specifications.



PRINCIPLE 6:

Supervision

6.1 Full time supervision is the preferred option in Sierra Leone. There should be a trained and experienced supervisor on the site from when the contractor mobilises his equip-ment to the site through construction/rehabilitation and completion to demobilisation. Annex 6 provides a detailed checklist for drilling supervisors. The responsibilities of the supervisor are:

a) Make sure that the roles and responsibilities of all stakeholders are clear to the community and that the MoU between the Community leaders, District Council, the contractor and NGO (if an NGO is involved) and Land Owner has been signed (Annex 1).

b) Introduce the contractor to the community, making sure that the contractor can be contacted by the community. Discuss the work schedule with all parties, agreeing changes and recording them as necessary.

c) Cross-check that the site selected for the borehole adheres to Principle 2. In the case of a problem, the Project Manager should be consulted.

d) Ensure that all safety measures are adhered to.

e) Ensure that the design specifications are adhered to.

f) Decide when to stop the excavation in case hard formation is struck and/or the borehole cannot be drilled deep enough to ensure sufficient water throughout the year, or in case of other reasons.

g) Ensure that all the required data are collected in the approved format (Annex 7)

h) Ensure that records are submitted to the appropriate authorities.



6.2 Part time milestone supervision. If the Supervisor cannot be on site full time, he/she should visit the construction site at crucial stages (milestones) of the drilling process. These stages must be carried out in the presence of the Supervisor. Consequences of not abiding by them must be stated in the contract document. The milestones are:

n mobilisation

n check siting/site selection

n termination of drilling

n lining of the borehole

n borehole development

n pumping test

n sanitary seal

n demobilisation

n platform construction and pump installation (note that this may be delegated to another enterprise, government department or NGO staff, depending on the con-tract).



PRINCIPLE 7:

Water Quality Testing

7.1 The water quality for all boreholes must be tested in accordance with the Guidelines for Water Quality Monitoring (still under development).

7.2 The procedures to be followed in the case of poor water quality are set out in the Guidelines for Water Quality Monitoring (still under development).



PRINCIPLE 8:

Contract Management

8.1 Management of the siting, supervision and drilling contract is in line with national sys-tems where these have been established.

8.2 Contract documents are straightforward and understandable.

8.3 Drilling construction is paid for according to a bill of quantities (Annex 4), with pay-ment for dry boreholes being made according to the work done.

8.4 The defects liability period must be specified for each borehole.

8.5 In case of disputes between the client and contract, communication and arbitration procedures are clearly set out in the contract.

8.6 Payments are timely, with interest paid in case of delays, as specified in the contract.



PRINCIPLE 9:

Data

9.1 Once a borehole numbering system for Sierra Leone has been established, all new boreholes drilled are to be numbered accordingly, in a manner that can be clearly distinguished for ten to twenty years.

9.2 All signed borehole drilling records (Annex 5) are to be submitted to the District Coun-cil and Ministry of Water Resources.

9.3 Once the regulatory framework for drilling construction is established, renewal of drill-ing registration and accreditation is to be linked to the submission of drilling records (also referred to as drilling logs).

9.4 Over the coming years, the Ministry of Water Resources will establish a database for all drilling records. The data will feed into Sierra Leone’s Groundwater Mapping work, thus ultimately improving the understanding of the geology and hydrogeology of the country.

9.5 The drilling database, once in place will be available to the public.



PRINCIPLE 10:

Monitoring

10.1 Regular visits to water users with completed boreholes are made by local government staff to monitor the water user committees and functionality of the water points after six months and then at least once per year.

10.2 Post-construction monitoring activities and reporting are undertaken by local govern-ment and NGO staff in accordance with the National WASH Monitoring Guidelines (not yet developed).



APPENDIX 1:

Template for Memorandum of Understanding: Community leaders, District Council, the contractor and NGO (if an NGO is involved) and Land Owner

To be developed in consultation with organisations who have already set out similar

procedures.



APPENDIX 2:

Recommended Structure for Site Selection Report

The recommended structure (table of contents) of a site selection report is set out below.

1. Introduction

1.1 Background – client, contractor, date commissioned, date completed, location and purpose of report

1.2 Summary of the scope of work or terms of reference (cross reference to annex)

2. Methodology

2.1 Desk study – maps, satellite imagery, reports and other literature reviewed, hydrogeological model

2.2 Field work – geological/hydrogeological reconnaissance, geophysical methods used, if any

3. Findings

3.1 Previous work carried out by other workers, if any

3.2 Description of the physical characteristics of the project location

n Vegetation and climate

n Topography

n Drainage – major and minor

n Geology – description of the rock types, geological structures, weathering pattern and products

n Hydrogeology – discussion of borehole and well data; water bearing potential of the rock types, summary of aquifer types



3.3 Geophysical survey

n Detailed description of work carried out with sketches showing data collection points and major landmarks

n Results of the survey; reasons for selection of particular sites for drilling

4. Conclusion and recommendation

Bibliography

Appendix 1: Site photographs

Appendix 2: Statement of works or Terms of Reference by the client

Appendix 3: Geophysical data – VES curves, EM graphs



APPENDIX 3:

Sample borehole specifications

Sample Well Design (un-consolidated formation to depth of 100-120mm; at greater depths use steel casing)

uPVC plain casing (4" nominal diameter)Natural Ground Level

Sanitary seal

Backfill to 5m from ground level Unconsolidated Formation

BackfillRest Water Level (RWL)

Screen

Bottom plug Not to Scale

Depth of sanitary seal 5m from ground level

*See glossary for definition of gravel pack and formation stabiliser

Gravel Pack or Formation Stabiliser inserted to a minimum of 3m above slotted casing

Gravel pack or formation

stabiliser*: Drilling diameter needs to accommodate 2-4" thick gravel pack,

or thinner formation stabiliser. The thickness of the gravel pack depends

on the nature of the formation. A thick (3-4") annulus will be required in the case of very fine materials such as

mica, which will require a larger drilling diameter (7-10"). Alternatively, it may be possible to use a geotextile

filter sock depending on the risk of biofouling.

The pump should be positioned at the correct level above the screened section, taking into account the

drawdown and seasonal variations. This is generally 2m below the lowest

dynamic water level.

Drilled diameter: 7 to 8" if gravel pack needed; can be 5 to 6" if

formation stabiliser used.

Casing diameter must accommodate the external diameter of the pump

cylinder.

Plain casing for sump (1.5m)

Gravel Pack or Formation Stabiliser

Water bearing zone



Sample Well Design (semi-consolidated formation with risk of collapse to 100-120m; at greater depths use steel casing)


Sanitary seal

Backfill to 5m from ground level


Water bearing zone

Screen


Overburden/Unstable

Bedrock

Consolodated

Formation/Stable Bedrock


Drilled diameter: 7 to 8" if gravel pack needed; can be 5 to 6" if formation

stabiliser used.


cylinder.

Formation Stabiliser inserted to a minimum of 3m above slotted casing






Gravel pack or formation stabiliser*: Drilling diameter needs to

accommodate 2-4" thick gravel pack, or thinner formation stabiliser. The

thickness of the gravel pack depends on the nature of the formation. A thick (3-4") annulus will be required in the case of very fine materials such as

mica, which will require a larger drilling diameter (7-10"). Alternatively, it may be possible to use a geotextile filter sock

depending on the risk of biofouling.




Sample Well Design (consolidated formation – casing and screen in bedrock - 100-120m; at greater depths use steel casing)


Sanitary seal

Backfill to 5m from ground level


Screen


Drilled diameter: 7 to 8" if gravel pack needed; can be 5 to 6" if formation

stabiliser used.



cylinder.




Overburden/Unstable

Bedrock

Gravel pack or formation stabiliser*: Drilling diameter needs to

accommodate 2-4" thick gravel pack, or thinner formation stabiliser. The

thickness of the gravel pack depends on the nature of the formation. A thick (3-4") annulus will be required in the case of very fine materials such as

mica, which will require a larger drilling diameter (7-10"). Alternatively, it may be possible to use a geotextile filter sock

depending on the risk of biofouling.

Formation Stabiliser inserted to a minimum of 3m above slotted casing



Consolodated

Formation/Stable Bedrock




APPENDIX 4:

Sample Contract (for one borehole)

Contract for the Drilling of 1 No Borehole at

___________________________________

of ___________________________ District

Between

____________________________________

AND

____________________________________



Form of Agreement

This Agreement made the ________________________ day of ______________________

between the ___________________________________ of _________________________

(Hereinafter called the Employer) of the one part, and ______________________________

of _______________________________________________________________________

(Hereinafter called the Contractor)

(if a joint venture or consortium list the all the partners with the lead partner first)

Whereas the Employer desires that the following works should be provided and executed by the Contractor, i.e.

construction of a borehole, and has accepted a tender by the Contractor for the provision, execu-tion and maintenance of such Works under the direction and to the reasonable satisfaction of the Employer in the sum of:

(hereinafter called the Contract Sum)

Now this Agreement is witnessed as follows:

1. In this Agreement, words and expressions shall have the same meanings as are respec-tively assigned to them in the Conditions of Contract hereinafter referred to, and they shall be deemed to form and be read and construed as part of this Agreement.

2. In consideration of the payments to be made by the Employer to the Contractor as hereinaf-ter mentioned, the Contractor hereby covenants with the Employer to execute and complete the Works and remedy any defects therein in conformity in all respects with the provisions of the Contract.

3. The Employer hereby covenants to pay the Contractor in consideration of the execution and completion of the Works and the remedying of defects wherein the Contract Price or such other sum as may become payable under the provisions of the Contract at the times and in the manner prescribed by the Contract.

The parties have therefore caused this Agreement to be executed in the presence of witnesses on the date stated above.

The Common Seal of the Employer _________________________________________________

Witnessed by _____________________________ Signature _____________________________

Sealed and Delivered by the Contractor _____________________________________________

Witnessed by _____________________________ Signature _____________________________

Binding Signature of Employer _____________________________________________________

Binding Signature of Contractor ____________________________________________________



Technical Specifications

1. Project description/Scope of Work

The project consists of the construction of 1 no borehole in ____________________ community, _____________________ district, Sierra Leone.

The Contractor shall nominate one key person who shall be responsible for the assignment on behalf of the Contractor and shall be the Contractor’s site representative. This person shall dem-onstrate the different aspects of drilling as may be directed by the Supervisor. The person should therefore be a competent hydrogeologist or drilling engineer with at least 10 years field experience and fluent in the English language.

2. Work schedule

The Contractor, on acceptance of the contract, shall submit a comprehensive work schedule which should fall within the agreed period of contract execution to the Project Manager for approval be-fore mobilization of men, materials and equipment to site. It shall so include the pre-mobilisation meeting. This schedule shall be subject to the approval of the Supervisor.

On the _______________________, the Contractor’s representative shall, in the company of the Supervisor, visit the beneficiary community to take over the site.

3. Mobilization

3.1 Inspection of materials and equipment

The Contractor shall present to the Supervisor the list of equipment and samples of materials to be used on the project. The Contractor is not allowed to start the work until the equipment and materi-als have been checked and approved by the Supervisor.

3.2 Contractor’s Staff

The Contractor shall be fully operational with the drilling unit and installation crew by the _______________________. Adequate safety equipment such as safety helmets, hard-toed boots and gloves shall be available for the use of the drilling crew while on site.

3.3 Contractor’s equipment

The Contractor shall provide all plant and equipment, including drilling plant, tools, materials and everything else necessary for the proper completion of the drill hole and collection of the samples. The contractor’s drilling equipment shall have the capacity to construct 110 mm diameter lined boreholes, including gravel packs to depths of up to 60 m.

The Contractor shall arrange for transportation and security of all equipment and staff as neces-sary for proper completion of the contract.

3.4 Site instruction

The Supervisor shall from time to time issue instructions to the Contractor through the Contractor’s site representative. The instruction shall be in writing and shall be signed as received by the Con-tractor’s representative, who shall, without any delay, carry out the instruction issued.

4. Drilling

The Contractor shall ensure that the rig is set up at the exact point indicated by the Supervisor. The Contractor shall also take all precautions to ensure the safety of all staff, community members and equipment deployed to the project.



The Contractor shall be responsible for selecting the appropriate drilling procedure for the geol-ogy of the location. The diameter of the drilled hole must be adequate to accommodate the final borehole casing diameter as instructed by the Supervisor plus a minimum annular space of 50 mm. The Contractor may choose to either drill a hole of adequate diameter on the first pass or to drill a small diameter test hole, then ream to the desired size. Regardless of the procedure adopted by the Contractor, payment shall only be for the drilled hole at the appropriate size, i.e. additional payment for reaming shall not be allowed.

4.1 Drilling technique

The drilling method, drilling plant, drilling fluids and fluid additives are subject to approval of the Supervisor.

It is the responsibility of the Contractor to start drilling at a diameter which will allow the hole to be completed at the specified diameter. Extra casing of a larger diameter to achieve the depth is considered to be part of the Contractor’s equipment and shall not be reimbursed for its use.

Temporary steel or PVC casing shall be installed in the borehole where needed to protect the walls from caving, either suspended by a ground bearing bracket or correctly anchored in the underly-ing hard rock.

4.2 Drillingfluidsandadditives

The drilling fluids and additives shall consist of water, bio-degradable drilling mud, weight materi-als (barite or equivalent), fluid loss control materials, and foam. The selection, supply and use of drilling additives shall be the responsibility of the Contractor. Toxic or dangerous substances that may adversely affect the quality of the water shall not be added to the drilling fluid.

The Contractor shall be responsible for maintaining the quality of the drilling fluid to assure the protection of the aquifer and other potential water bearing formations and ensure that good repre-sentative samples of the formation material are obtained.

4.3 Collection of drill cuttings

The Contractor shall collect representative samples of the formation penetrated at 2.0 m intervals. Samples shall be caught in a bucket placed in the drilling fluid return at the top of the surface cas-ing and the sample allowed to settle out.

The penetration of the bit shall stop when the bottom of the sampling interval (that is every 2.0 m) is reached for such time as is required for all the cuttings to move from the last drilled section of the hole to the sampling point. Drill cuttings shall be placed in containers provided by the Contractor as approved by the Supervisor. Sample containers shall be steel boxes, divided into compartments approximately 100 mm by 100 mm square and 100 mm deep. At each drill site, the Contractor shall have sufficient sample containers to accommodate all of the samples collected in a hole, and they shall be kept available for inspection until the Supervisor agrees they can be disposed of.

4.4 Driller’s daily report

During the drilling, completion and development of each borehole, the Contractor shall maintain a detailed driller’s report. The report shall give a complete description of all formations encountered, number of meters drilled, number of hours spent drilling, shutdown due to breakdown, length and type of casing and screen set, and such other pertinent data as requested by the Supervisor. The Contractor shall provide to the Supervisor a copy of the daily driller’s report duly signed by both the driller and the Supervisor.



In addition, the Contractor shall measure and monitor during the drilling:n the depth of the borehole as it progressesn the static water or mud level in the boreholen the different depths of water strikes and aquifersn the penetration rates at various strata or change of tools

The data shall be presented in a format previously approved by the Supervisor.

4.5 Payment for drilling

The Contractor shall be paid unit prices per metre in accordance with the depth drilled as set out in the Bill of Quantities. The unit prices per meter shall include all costs associated with the drill-ing, drilling water, drilling additives, surface casing, collection of drill cuttings, gravel packing and development, and preparation of daily drilling reports. The Contractor shall be paid in accordance with the actual depth drilled on the rates set out in the Bill of Quantities. The depths given in the Bill of Quantities are indicative only.

4.6 Payment schedule

As the Contract is intended for demonstration and training purposes, the Contractor shall on com-pletion of the drilling be paid the full sum of the works certified by the TempaSupervisor as having been carried out by the Contractor as in the Bill of Quantities.

5. Borehole

The final depth of the borehole and all other relevant depths involved in the design of the borehole shall be determined from measurements made by the Contractor and the Supervisor. The Super-visor shall instruct the Contractor on the depth at which to terminate the hole, the intervals to be cased and screened, the appropriate screen slot opening, and the formation stabilizer or gravel pack size if required, to ensure completion of a sand-free borehole:

The borehole will consist of PVC casing and screen. The casing and screen shall have an inside diameter of 103.4 mm and an outside diameter of 110 mm and a wall thickness of 3.3 mm. The casings and screens shall be joined by threaded joints. The bottom of the casing columns shall be closed with a bail plug.

The entire casing and screen assembly shall be installed straight and vertical in the borehole. A maximum deviation of 0.5% will be allowed.

All permanent borehole casings, screens and fittings shall be new. Payment shall be on a per metre basis for the supply and installation of casing and screen in accordance with the Bill of Quantities.

5.1 Gravel packing

A gravel pack shall be installed in the annulus space around the screen. The pack should consist of coarse sand or well-graded river gravel. Under no condition should rock chippings be used. The material should be free from shale, mica, clay, dirt or organic impurities of any kind.

The gravel pack should have a minimum thickness of 50 mm and shall cover the entire screen length and rise to a minimum of 6 m above the top of the screen. The gravel pack should be care-fully introduced into the hole by means of a tremie pipe to avoid bridging.

Where the formation is considered stable and not in need of support, the Contractor, with the ap-proval of the Supervisor may elect to case only the upper part of the borehole, leaving the lower part (aquifer horizon) of the borehole uncased and without gravel packing.



6. Borehole development and site completion

6.1 Development

The Contractor shall develop the borehole by a combination of jetting with water and surging with air, simultaneously rotating the jetting tool and slowly raising and lowering it through the length of all screens. The development shall continue until the borehole is judged by the Supervisor to be free of sand.

The Contractor shall develop the borehole with great care to avoid any damage to the casings, the screens or the formation resulting from application of excessive pressures or inappropriate tech-niques during the development.

The Contractor shall be paid the unit price for borehole development as in the Bill of Quantities.

6.2 Backfillingandgrouting

The Contractor shall place an impervious clay plug at least 1 m thick directly on top of the gravel or filter pack. The exact level shall be indicated by the Supervisor. The annular space on top of the clay plug shall be backfilled with the drill cuttings up to 6 m below ground level. Surface soil shall not be used for backfilling. The backfill may be placed by pouring the material down from the surface, taking due caution to prevent bridging.

The last 6 m of annular space shall be filled with neat cement grout consisting of Portland cement mixed with not more than 25 l of water per 50 kg of cement.

The Contractor shall be paid the unit price for backfilling and placing the grout seal as in the Bill of Quantities.

6.3 Abandonment of unsuccessful borehole

After the development process, the borehole may be abandoned for reasons not resulting from any action or omission of the Contractor. This may occur because of inadequate yield, unsuitable water quality or excessive depth of the water level. Under these circumstances, the Contractor may attempt to retrieve the casing and screen from the abandoned borehole, but shall do so at his/her own expense.

6.4 Pump testing

The Contractor shall conduct a pumping test on the borehole a constant yield and continuous pumping of 1 m3/h for a period of 4 hours.

Where there is a possibility of the discharge water circulating back into the aquifer, the Contractor shall provide a minimum of 60 m of flexible hose to carry the water away.

6.4.1 Recovery

Immediately after the pumping test has been completed, the Contractor shall measure the water-level recovery in the borehole over a minimum period of at least 2 hours unless the water level has recovered to the original level by that time.

6.4.2 Measuring drawdown and recovery of water level

During the pumping and recovery periods, the Contractor shall measure the water level in the borehole using a calibrated electronic sensing device. The water level measurements are to be



taken in accordance with the schedule indicated by the Supervisor. The Contractor shall analyse the results of the pumping test for the specific capacity of the borehole and report the results on forms supplied by the Supervisor.

The Contractor shall be paid a lump sum price for the 6-hour pumping test in accordance with the Bill of Quantities.

6.5 Water quality analysis

During the pumping test, the Contractor shall collect water samples, securely corked and suitably labelled, from the borehole as indicated by the approved laboratory. The samples shall be col-lected from the pump flow direct into the container, without being allowed to settle first. Each label shall indicate the name of contractor, borehole number, date and time of sampling. The information shall be entered into a form to be provided by the Course supervisor.

The Contractor shall have test carried out in a laboratory approved by the Supervisor to determine the following parameters:

Colour Total hardnessOdour SilicaElectric Conductivity ChloridepH FluorideTaste NitrateTurbidity SulphateTemperature Dissolved gases (CO2, H2S, O2)Arsenic Manganese

Biological parameters shall comprise faecal coli form counts.

The samples thus collected should reach the authorized water testing laboratory within 6 hours from the time of collection from the borehole. Otherwise fresh samples shall be taken.

The contractor shall be paid for each set of samples tested as in the Bill of Quantities.

6.6 Borehole disinfection

Immediately after the pumping test has been completed, the Contractor shall undertake final disin-fection of the borehole by introducing sufficient chlorine compound into the borehole to achieve a concentration of 20 mg/l of free chlorine in the water i.e. 0.2% chlorine is used for every 100 litres of water in the borehole column.

The chlorine shall be applied uniformly throughout the entire depth of water in the borehole. The chlorine solution shall be introduced into the borehole through a tremie pipe extending to the bot-tom of the borehole and the pipe raised and lowered to achieve uniform distribution of the solution. All accessible portions of the borehole above the water level shall also be wetted with a chlorine solution.

6.7 Criteria for a successful borehole

For the borehole meeting to be accepted as successful it shall meet the following criteria other-wise it shall be declared abortive and abandoned. The Contractor may be requested to re-drill the abortive borehole if the reasons for being abortive are due to actions or inactions of the Contractor.



6.7.1 Borehole minimum yield

Unless otherwise agreed by the Supervisor, the minimum acceptable yield on the borehole shall be 1 m3/hour sustained over the 6-hour pumping test period.

Providing the Contractor has followed the appropriate procedures in the completion of the bore-hole, and having been so certified by the Supervisor, the Contractor shall not be held responsible for the abandonment of a borehole because of inadequate yield. However, if failure to obtain an adequate yield is caused by actions or inactions on the part of the Contractor, he/she will be re-sponsible for reconstructing the borehole in the proper manner at his/her own cost.

Where possible, the Contractor shall endeavour to maximize the yield from the borehole. Failure to properly exploit the aquifer potential through, for example, insufficient development or inadequate aquifer penetration and screening even when the yield of the completed borehole exceeds the minimum may be cause for rejecting the borehole and requiring the Contractor to reconstruct the borehole at his/her own cost.

6.7.2 Sand content

The sand content of the water shall not be more than 10 ppm by volume. The Contractor shall be responsible for ensuring that the borehole meets the criteria for sand content. If a borehole must be abandoned because of excessive sand content, the Contractor shall be responsible for construct-ing another borehole at his/her own cost.

6.7.3 Turbidity

The Contractor shall measure the turbidity of the water for each borehole. The turbidity of the water shall not exceed 10 NTU. In some circumstances, excessive turbidity may be due to the char-acteristics of the water-bearing formation and thus beyond the control of the Contractor. Where excessive turbidity is caused by actions or inactions by the Contractor, he/she will be responsible for reconstructing the borehole in the proper manner at his/her own cost.

6.7.4 Alignment and plumbness

The Contractor shall continuously monitor the weight on the drilling bit to ensure that the borehole is drilled and cased straight and vertical. The Contractor shall furnish all labour, tools and equipment to carry out a test for verticality as may be instructed by the Supervisor. Payment shall be on the unit rate as in the Bill of Quantities.

6.7.5 Chemical and bacteriological water quality

The Supervisor shall determine whether or not the chemical and bacteriological quality of the water is adequate to serve as a potable water supply. The Contractor shall take due caution to prevent contamination of the borehole. If the borehole has become contaminated because of an action or inaction on the part of the Contractor, the Contractor shall bear the responsibility for disinfection of the borehole and, if necessary, the construction of a new borehole at his/her own cost.

6.8 Temporary capping

Prior to leaving a borehole unattended at any time, the Contractor shall place a temporary cap on the borehole casing which shall consist of a purpose-made pipe fitted to the top of the casing.

6.9 Construction of concrete pad

The Contractor shall construct a concrete pad around the borehole casing sticking above the ground and continuous with the underlying 6 m cement grout in the borehole annulus described in



6.3. The pad shall be 1 m by 1 m. The concrete shall be cast over a layer of compacted hard core with a minimum thickness 200 mm above the ground and continuous with the underlying cement grout. The drainage channel shall be 6 m long, sloping away from the pad. The Contractor shall ensure that the sides of the pad are straight by properly anchoring the forms. Straightness shall be determined by running a stringline from one corner to the next and measuring the deviation of the pad from the line. Deviations greater than 12.5 mm shall not be acceptable. The top of the pad shall be trowelled to a smooth surface. Edges shall be used to ensure smooth, rounded edges to the pad.

6.9.1 Concrete mix

The concrete used for the pad shall be prepared by mechanical mixers capable of pouring a pad in a single batch using normal Portland cement with a mixture of fine and coarse aggregate. The concrete mix shall be in the ratio 1:2:4 (cement, fine, coarse aggregate).

Water used for mixing concrete and for curing shall be obtained from a borehole source and shall be equal to potable water in physical and chemical properties.

The fine aggregate shall consist of sand having clean, hard, strong, durable, uncoated grains free from dust, soft or flaky particles of shale, alkali, organic matter, loam, or other deleterious sub-stances. Fine aggregate shall be well-graded and have grain sizes within the range of 0.15 mm to 9.5 mm.

The coarse aggregate shall consist of crushed rock or other approved materials of similar charac-teristics having clean, hard, strong, durable, uncoated particles free from soft, friable, thin, elon-gated or laminated pieces, alkali, organic or other deleterious matter. Coarse aggregate shall be well graded and shall consist of grain sizes in the range 2.4 mm to 40.0 mm.

Because high temperatures prevail in the Contract area, the Contractor shall keep the surface of the concrete pad moist for a period of 72 hours after the concrete has been placed or use a curing compound approved by the Supervisor.

Payment for each pad shall be as provided for in the Bill of Quantities.

7. Demobilization, handing over & defects liability

7.1 Handing over

On completion of the works at the site, the Contractor shall remove all his/her equipment and materials from the site, cover all settlement pits, seal any abandoned borehole and as much as possible restore the site to what it was like originally before construction started. An inspection of the works shall be carried out by the Supervisor and the community representative in the presence of the Contractor’s representative. On being satisfied that the works carried out are in accordance with the contract agreement and technical specification, a completion certificate shall be issued and signed by the Supervisor and community representative, and the site handed over to the com-munity.

7.2 Defects liability

The defects liability period shall be 6 months from the date of handing over. During this period any defects on the functioning of the works shall be put right by the Contractor at his/her own expense. 10% of the total contract sum shall be retained by the Client until the defects liability period is over, after which the Contractor shall be paid the amount retained. If, however, the Contractor fails to put right any defects on the works as instructed by the Supervisor, he/she shall forfeit the amount retained.



8. Bill of Quantities

All the quantities in this Bill of Quantities are provisional. The contractor shall be paid for actual quantities used.

Bill of quantities for the Drilling of 1 No. Borehole at _______________ in _______________ District

Item Description Unit Quantity Rate Amount

1 Mobilisation

1a Mobilisation and demobilisation (including site clearance)

No

2 Borehole Drilling

2a Drilling overburden on the basement complex for installation of 110mm diameter PVC casing

m

2b Drilling in crystalline rock for the installation of

110mm diameter PVC casing m

2c Lost temporary casing m3 Borehole Completion

3a Supply and install 110mm OD threaded PVC casing

m

3b Supply and install 110mm OD threaded PVC screen

m

3c Supply and install gravel pack as directed No

3d Backfill borehole annulus No

3e Supply cement and install 6m deep sanitary seal No

3f Develop boreholes by jetting, surging and airlifting

No

4 Pumping Test

4a Carry out 3 hour pumping test on each hole No5 Water quality analysis No

5a Collect water samples and carry out water quality

Analysis No6 Disinfect borehole

6a Disinfect borehole as directed No7 Supply and installation of handpump

7b Supply and install India Mark II handpump on the completed borehole with 50 mm PVC rising main

No

8 Construct concrete pad

8a Construct standard circular concrete pad as well as soakaway

No

9 Idle time

9a Idle time caused by the Employer or any of his representatives

Hr

10 Total



APPENDIX 5:

Project Checklist for the Driller

Step Checklist

1. Pre- contract � Driller’s equipment approved

� Driller’s personnel approved

� Driller’s field operation observed

2. Pre-Mobilisation Meeting � Contract checked

� Questions asked and clarifications made

3. Mobilisation � Community has been mobilised

� Programme of work submitted and approved

� Materials checked and approved

� Driller has been shown the site

� Data collection forms approved

� Filing system set up

4. Siting � Geophysical equipment checked and approved

� Siting supervised

� Report submitted and approved

5. Drilling � Rig location approved

� All safety measures taken

� Samples are collected and kept

� Drilling completed

� Borehole logged

6. Borehole design � Casing and screen installation approved

� Gravel pack installation approved

� Sanitary seal approved

7. Borehole development � Water sample checked for sand content

� Pumping test carried out

� Borehole disinfected

� Water quality analysed

� Borehole successful or abortive

8. Demobilisation � Site restored to its original state

� Circulation pits backfilled

� Abandoned borehole sealed

� All pieces of equipment removed from site

� Rubbish disposed of properly

9. Complete documentation � The Driller has carried out all tests and submitted the reports.



APPENDIX 6:

Checklists of Drilling Steps for the SupervisorChecklist 1: Pre-contract checklist

Name of contractor

Name of Supervisor

Date

Equipment Checklist

� Drilling rig Year of Manufacture:

Manufacturer:

Lifting capacity:

� Raise mast.

� Start and run for an hour without problem.

� Check for oil leaks and get any fixed before giving approval.

� Compressor Year of Manufacture:

Manufacturer:

� Start and run for an hour without problem.

� Mud pump and generator � Check rating against estimated borehole depths.

� Test pumps and generator.

� Water tanker � Check for leaks.

� Support trucks � Check that the Driller has the necessary working support vehicles.

� Drill pipes � Check that there are adequate lengths of drill pipes to drill the deepest hole.

� Drill bits (and hammer depending on the type of drill rig)

� Correct diameter.

� Right drill bits available for likely ground conditions.

� Check condition.

� Geophysical surveying equipment � Geophysical equipment working correctly

� Personnel competent in use of geophysical surveying equipment

Personnel Checklist

� Drilling manager Years of experience:

Experience of similar assignments:

� Hydrogeologist Qualifications:

Years of experience:

Experience of similar assignments:

� Rig operator Years of experience:

� Driver Years of experience:

� Mechanic Years of experience:

� Rig assistants Number of assistants:

Years of experience:

� Record Taker Years of experience:



Checklist 2: Siting

Village Name/Site Name

District

Name of Supervisor

Date

Activity Checklist

� 1. Water User priorities and land ownership – based on Community engagement

1

� Proximity between site selected & point of use in meters:

� Is there access for all water users, especially women and most disadvantaged in the community?

YES / NO

� Has the land ownership been determined? YES / NO

� Have access rights for users and maintenance teams been confirmed verbally?

YES / NO

� Have access rights for users and maintenance teams been confirmed in writing?

YES / NO

� 2. Geophysical survey � Is a geophysical survey necessary? YES / NO

� If a geophysical survey is necessary, has it been carried out? YES / NO

� 3. Geological favourability - based on hydrogeological assessment

� Do you expect there to be sufficient yield for the intended purpose?

YES / NO/ Don’t Know

� Do you expect that there are sufficient renewable water resources for the intended purpose?

YES / NO

� Do you expect the water quality will be adequate for the intended purpose?

YES / NO

� Has interference with other groundwater sources such as springs of other pumps been avoided

YES / NO

� What is the chance of success? HIGH (>75%) / MEDIUM (50-75%) LOW (<50%)

� 4. Contamination risk � Have all the national criteria for minimum distance from the borehole been met?

YES / NO

� Are there any other contamination risks? YES / NO

� 5. Drilling logistics � Access allowed and possible for Driller team, equipment and vehicles

YES / NO

Other comments:

1 As guidelines and checklists for community mobilisation and training, as well as operation and maintenance are developed, these should be harmonised and, if necessary incorporated into the siting checklist so that they reinforce each other.



Checklist 3: Mobilisation

Name of Contractor

Village/Site

District

Name of Supervisor

Date

Activity Checklist

� 1. Contract � Contract Signed

� 2. Programme of work � Programme of work submitted and approved

� 3. Community liaison � Explain details of drilling process.

� Community member roles, contributions and responsibilities

� Exchange details of main contact persons or community representatives.

� Driller’s representative introduced to the Community

� 4. Equipment is appropriate and in working condition

� Drill rods are adequate

� Hammers and bits are of the right diameter (measure).

� Temporary casing diameter is correct.

� 5. Samples of materials meet with technical specifications

� Drilling fluid

� Sample box

� Casing and screen (measure length and diameter)

� Filter pack and gravel materials

� Screen

� 6. Data collection forms � Format of data entry forms agreed (Refer to Borehole Completion Record)

� 7. Project filing system � Driller given Master Project Checklist (Annex B)

� 8. Drill Camp / Satellite Fly Camp layout

� Location of vehicle and rig parking � Maintenance garage � Site office and living accommodation � Fuel storage and spillage control measures � Water supply source � Sanitation facilities � PVC casing and screens protected from direct sunlight

Other comments:



Checklist 4: Drilling

Activity Checklist � 1. Health and Safety � Rig set up away from traffic hazards and power transmission lines � Rig and support vehicle not positioned on a steep slope � Public safety barrier (bright coloured tape). � Drilling team wearing personal protective clothing: boiler suits, hard hats,

boots, eye protection and gloves � Inflammable items such as petrol or chlorine etc should be kept in approved

containers, properly marked and stored away from sources of heat. � Mast not raised during thunderstorm (lightning strike risk) � Lifting of very heavy or bulky loads which could lead to back strain should be

avoided. Lifting should be done using the legs and not with the back. � Equipment should be kept in good working order. � Area around the drilling rig is kept tidy. � Borehole should be securely capped on completion to prevent tools and other

debris falling into the hole and children throwing stones and corn stalks into it which could render it useless.

� On completion, the site should be restored as far as possible to what it was before the drilling, mud pits filled in and compacted.

� Drill crew should drink plenty of fluids regularly to prevent dehydration, which can lead to poor judgement.

� First Aid kit checked � Emergency procedure in case of major injury and need for hospitalisation � 2. Rig position � Rig positioned over pegged site. � Rig drill mast vertical (checked with spirit level). � Check ground stability for softness that could entrap the rig or cause it to tilt

during drilling � 3. Drilling Depth � Depth measurements being conducted and logged properly � 4. Penetration Rate � Penetration rates being measured properly � 5. Drilling Fluid � Type of drilling fluid being used: � Driller using Marsh funnel to measure drilling fluid viscosity � 6. Drill Cutting Samples � For Rotary mud-flush drilling, check that the circulation mud pits (or portable

tanks) have a volume that is at least three times the volume of the borehole – see Annex D.

� Ensure that the Driller prevents sample contamination due to poor circulation, borehole erosion or caving.

� Ensure that mud pits are kept clean to prevent re-circulation of cuttings. � Samples taken at regular intervals and properly washed, bagged, labelled,

logged and stored in sample box. � Photograph samples � 7. Strata Log � Use samples to prepare a Strata Log. � 8. Final borehole depth � Water table depth (m):

� Final borehole depth (m): � 9. Drill Report � Daily drilling log signed by rig operator and Supervisor. � Record necessary data and information required to complete a Casing and

Well Completion Form (Appendix E3, Code of Practice for Cost Effective Boreholes).



Checklist 5: Borehole Design

Design Criteria Value � 1. Borehole Depth (metres): � 2. Aquifer/Rock Type Basement/Consolidated/Unconsolidated � 3. Yield (litres per second) � 4. Drilled borehole diameter (mm) � 5.a Type of borehole casing and screens: PVC / GRP / Steel / Bamboo / Other: � 5.b Wall diameter and thickness (mm)

check diameter and wall thickness with callipers

� 5.c Quantity of borehole casing & screens (m)

� 6. Screen length (m) � 7. Percentage screen open area (>25%) � 8. Installation of casing and screens � Produce sketch of proposed assemblage of casing and screen. � Layout casing and screening on the ground, check against sketch and

photograph. � Check joints between casing pipes. � 9. Gravel Pack � Ensure that gravel pack design is adhered to (formation stabiliser or

filter pack). � Check that formation stabiliser does not contain mica, clay or laterite. � 10. Sanitary Seal � Check sanitary protection design, proper depth and material

composition.



Checklist 6: Borehole development and site completion

Activity Checklist � 1. Development method

used � Filled in Borehole Completion Record Part 4: Borehole Development and Pumping Test Summary with data in Borehole Completion Record Part 7: Pumping Test Details

� 2. Borehole development success

� Duration of development: � Borehole development successful (water runs clear): YES / NO � If NO then should the Driller re-drill the borehole? YES / NO � If YES a re-drill is needed, should it be at the Driller s cost? YES / NO

� 3. Platform casting � Shuttering is properly anchored and layout matches designs. � Correct sand : cement : aggregate ratios (1:2:4) � Correct drainage slope (1:50) � Surface towelled smooth � Borehole number, date of completion, yield and water levels

embedded in the wet concrete � Concrete kept moist for 72 hours to allow proper curing � Is the finished platform acceptable?

YES / NO � 4. Pump Testing � Stopwatch available YES / NO

� Dip meter available YES / NO � Filled in Borehole Completion Record Part 7: Pumping Test details.

� 5. Water Quality Testing � Filled in Borehole Completion Record Part 5: Water Quality Summary. � 6. Borehole Disinfection a. Depth to static water level unacceptable? YES / NO

b. Dry borehole or inadequate yield? YES / NO c. Unacceptable sand content of pumped water? YES / NO d. Unacceptable turbidity of pumped water? YES / NO e. Borehole straight and vertical? YES / NO f. Unacceptable chemical or bacteriological quality of the pumped

water? YES / NO

FINAL DECISION ON BOREHOLE: SUCCESSFUL / ABORTIVE



Checklist 7: Demobilisation

Checklist 8: Development and Site Completion

Activity Checklist � 1. Work complete � All installation work complete and approved by Supervisor

� All testing completed and documentation and data handed over to Supervisor

� 2. Drilling site cleared � All litter, liquid and solid waste disposed of responsibly so as not to cause nuisance

� Circulation pits filled in

� Equipment cleaned and packed away

� Unused materials taken away (check with contract who owns or pays for unused materials, such as casing, filter packs etc.)

� Public barrier taken down.

Activity Checklist � 1. Reporting � Drilling report completed and copies given to Client, the Community and the

Regulator/Government water or geology ministry

� 2. Handover � Agree handover date with Driller, Community and Client. � Organise signed handover of borehole to the Community or Client.

� 3. Defect Liability Period � Agree monitoring schedule. � Undertake site visits to check that pump is still working and that there are no

problems with the borehole performance. � Report any problems found, or reported by the Community to the Client. If necessary, mobilise the Driller to undertake repair work.

� 4. Invoicing and payment � At end of defects liability period, submit supervision invoice to Client and give approval for final payment to Driller (depending on contract).

Other comments:



APPENDIX 7:

Borehole Completion Record

Contents

1. General

2. Drilling Operation

3. Casing and Borehole Completion

4. Borehole Development and Pumping Test Summary

5. Water Quality Summary

6. Lithology

6a Lithological Logging

6b Characteristics to be evaluated and assessed during logging of drilling samples

7. Pumping Test Details

7a Step Drawdown Test

7b Constant Rate Test

7c Recovery Test

8. Water Quality Analysis Parameters



1. General

Water Well/Borehole Reference No: Use: Community Household/Private Compound

Health Facility Education Facility Company Premises Test Well Other Date:

Location: Owner Name:

Owner Address: Coordinates/Grid Ref:

GPS Reference: N: E:

Financing Programme/Project/Private:

Permit No: Date Issued: Issuing Authority:

Name of Drilling Enterprise: Driller’s License No:

Address of Drilling Enterprise:

Sketch Map (Show location, with information that enables you to get there. Include key features in the vicinity such as buildings (e.g. school, clinic, church). Approximate Scale:



2. Drilling Operation

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

Hand Drilled (specify type) __________________

Percussion Mud Rotary Air Rotary DTH

Combination (details):________________________

Rig make: ____________________________________

Compressor make: _____________________________

Main Water Strike: m

Completion Date:

Static Water Level: m

Dynamic Water Level: (when pumping at ____m3/hr)

m

Average Penetration Rate:_____ m/h (at diameter ____mm/inch)




From To Drilling Diameter

inch mm

Drilling Method

Start Time

End Time Time Taken (min)

Time Taken (h)

Penetration Rate (m/h)

m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m



2. Drilling Operation Drill mud viscosity (for mud-rotary drilling)

Time Drilled Depth Drilling mud viscosity (seconds per litre)




Casing Material: _____________________

Casing Joints: Threaded Glue and Socket

Screen Open Area (%) ______

Bottom Plug: Yes No

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 natural artificial

From To Grain Size Volume used

m m

m m

Backfill and Sanitary Seal

From To Diameter

inch mm

Type and details (Backfill/Sanitary Seal)

Alignment and Verticality Test Remarks:

Well head and Platform

Well Cap: Yes No

Apron:

Concrete slab

Drainage

Soak-away Pit

Fence

Pump: Pump Installed: Yes No

Stand

Fitted around casing

Welded on Casing

Pump Type:____________________________________

Comments: _______________________________________________________________________________________



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

Drawdown: _________m

Comments: ___________________________________

______________________________________________

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

Drawdown: _________m

Comments: ___________________________________

______________________________________________

5. Water Quality Summary

Sample taken: � Yes � No

Date____________

Chemical Quality:

pH:_______________

Laboratory: __________

(for more parameters see separate sheet) Field Parameters:

� Clear

� Turbid

Colour_______ Taste_______ Odour ______ Turbidity______NTU Temp. ______ C TDS______m l EC_______µS-cm pH ______

Bacteriological Quality:

Faecal coliform: ____________cfu per 100ml

Laboratory: _______________________________

Comments: _________________________________________________________________________________



6a. L

ithol

ogica

l Log

ging

Wat

er W

ell/

Bore

hole

Ref

eren

ce N

o:

Loca

tion:

Ow

ner N

ame:

Owne

r Add

ress

: Co

ordi

nate

s/

GPS

Refe

renc

e:

Grid

Ref

: Lo

ng. E

Lat.

N Fi

nanc

ing

Prog

ram

me/

Proj

ect/

Priv

ate:

Bore

hole

Per

mit

No.

Date

Issu

ed:

Issui

ng A

utho

rity

Nam

e of

Dril

ling

Ente

rpris

e:

Drill

er’s

Licen

se N

o:

Wel

l Log

ged

by:

Dept

h (m

) De

scrip

tion

Colour*

Grain size*

Texture*

Degree of weathering*

Sorting*

Roundness

Stratigraphic unit (if known)*

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Penetration rate (min/m)

Discharge

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TDS (mg/l)

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6b. Characteristics to be evaluated and assessed during logging of drilling samples

(Source Misstear et al, 2006; MacDonald et al, 2005)

Standard procedures for sample description such as British Standards Institution (1999) or the American Society for Testing and Materials (2000) should be followed.

Colour In order to aid objectivity, a definitive colour chart, e.g. Munsel® Colour Chart may be used for classification. Munsel® colours are referred to by two or three words such as brownish yellow, or light bluish grey and a number.

Grain Size The visible grains can be compared with a comparator diagram such as the one given below, a grain sample card or the naked eye. A hand lens or microscope may be required to see grains which are not visible to the naked eye.

Figure Grain Size, Sorting and Roundness Chart(Source: University of Wisconsin, 2010)

Texture Is the sample compact and dense, or light and friable? Is it granular or plastic? Can it be moulded or rolled? Can the fragment be scratched with a steel blade or fingernail? Moh’s Scale of Hardness is an indicator.

Degree of weathering The extent of weathering of rocks affects the availability of groundwater. Essentially, the weathering profile comprises the three basic units of soil, weathered rock and fresh rock. Rock weathering is described in terms of distribution and relative proportions of fresh and discoloured rock, decomposed and disintegrated rock.

Degree of Sorting Sorting describes the variability of attributes such as rounding and grain size. In well-sorted materials the component grains are mostly of a similar size, shape and roundness. Sorting can be classified as very well sorted, well sorted, moderately sorted, poorly sorted and very poorly sorted as set out in the grain size and sorting chart above.

Roundness Grains are usually classified as angular, sub-angular, sub-rounded, rounded or well rounded as shown in the chart above.

Formation / Stratigraphic unit (if known - add codes based on the local stratigraphic nomenclature) An experienced geologist or driller may be able to identify stratiographic units. However it is important to distinguish between interpretation and observation. Thus the basic raw data (above) as well as his or her interpretation should be recorded.



7. Pumping Test Details

7a. Step Drawdown Test (for mechanised borehole supply) Water Well/Borehole Reference No: Water Well/Borehole Name:

Start Test Date: Time of Day:

Static Water Level before Test: m Pump Intake: m

Datum for measurements

Pumping Well/ Observation Well (Tick Appropriate)

Time Water Level Discharge (Q) Remark

Real Time Hrs Min Depth to Water Drawdown Volumetric

Method Flow Meter TDS, Temperature, pH and any other observation (m) (m) (l/s or

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





Method Flow Meter TDS, Temperature, pH and any other observation

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

(l/s or m3/h)



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

Water Well/Borehole Reference No: Water Well/Borehole Name:

Start Test Date: Time of Day

Static Water Level before the Test: m Data in this table is for:

Pumping/Observation Well or Borehole (Tick Appropriate)

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


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)




Real Time Hrs Min 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)



7c Recovery Test

Water Well/Borehole Reference No: Water Well/Borehole Name:

Start Test Date: Time of Day:

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

Description of pumping test undertaken prior to recovery test:

Datum for measurements: Time Water Level Time Water Level

Real Time Hours Min Depth to Water

Residual Drawdown

Real Time Hours Minute

s Depth of

Water Residual

Drawdown m m m m



8. Water Quality Analysis (Essential, Desirable and Optional tests for Sierra Leone to be determined)*

Water Well/Borehole Reference No: Maximum Permitted Level According to

National Standards/Guidelines or WHO Guidelines (WHO 2008)

Constituents Unit Concentration

PHYSICAL Colour mg/l Pt (TCU) Odour Taste Temperature Celcius Turbidity FTU Electrical Conductivity µS/cm CHEMICAL Chloride (Cl-) mg/l Sulphate (SO4

2-) mg/l Nitrate (No3

-) mg/l Fluoride (F-) mg/l Sodium (Na+) mg/l Potassium (K+) mg/l Calcium (Ca2+) mg/l Magnesium (Mg2+) mg/l Arsenic (As) µg/l Iron (Fe) mg/l Manganese (Mn) mg/l Nitrite (No2-) mg/l pH Total Dissolved Solids mg/l Microbiological Thermo-tolerant Coliform (E. Coli) Count/100ml Faecal Coliform Count/100ml Total Coliform Count Count/100ml

* Refer to National Standards/Guidelines for Drinking Water Quality or WHO Guidelines (WHO 2008) for list of general parameters.

GOVERNMENT OF SIERRA LEONE

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