Water, Sanitation and Hygiene Programme
GOAL
Technical Specification and Drawings
For
Siting, Drilling, Pump Installation and Associated Works
For
Construction of 59 Nr Boreholes in Communities and Institutions in Bugiri and
Namayingo Districts
Nov 2015 – July 2016
1.0 Scope of works
The scope of the works require that contractors furnish only successful boreholes to the
client. A successful borehole is defined as one conforming to all the requirements for the
siting, drilling, pumping testing, yield and water quality requirements. The well delivers more
than 450l/hr and passes the minimum acceptable potable water quality standards
(Government of Uganda acceptable water quality standards). By this definition, the bidder
MUST include costs of replacement of unsuccessful boreholes (poor water quality and dry
boreholes) in their BoQ.
Dry wells or wells with poor water quality according to GOU standards will be replaced by the
contractor at no further cost to GOAL. The drilling records for all unsuccessful wells must be
provided to GOAL including for poor quality wells the water quality test certificates.
All the wells successfully drilled and tested will be installed with U2 hand pumps with
stainless steel (G316 steel) pipes and rods or depending on the depth of the well, PPR pipes
and stainless steel rods. As a general rule, all wells with hand pumps deeper than 39 meters
will be installed with Stainless steel pipes and rods (G316 steel) as described in the
specification. All wells with hand pumps shallower than 39m will be installed with PPR pipes
and stainless steel rods. The contractor is required to price these separate items in the BoQs.
The depths of installation of hand pumps must be approved by GOAL
The successful contractor will carry out the siting/hydrogeological survey for the borehole locations,
carrying out the drilling works, pumping tests, water quality tests and the installation of the pumps and
aprons ready for use.
1.1
Location of the works
The works are located in communities and institutions in Bugiri (Bulidha and Muterere sub-counties)
and Namayingo (Banda, Mutumba, Buyinja and Buhemba sub-counties) districts.
1.2
Borehole siting
The contractor is to carry out detailed geophysical analysis in the communities and institutions in the
named sub-counties. A method of geophysical survey best suited to the geography/geology of the
area is to be employed
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The geophysical analysis will include the desk study, the hydro census and the geophysical survey.
The reports of the surveys will be included as part of the final reports submitted for the whole works.
The desk study will include a review of existing reports, borehole logs, topographical, geological and
hydro geological maps, previous geophysical surveys and the evaluation of aerial photographs if any.
The contractor’s hydro-geologist should carry out a hydro census in the vicinity of the target areas.
This will include a detailed inventory of all existing water supplies to ensure that the current site does
not influence nearby wells and to be able to make decisions that could affect the success of the new
boreholes.
The contractor should ensure that the siting/Geophysics work is to be carried out by suitably qualified
and experienced person(s). The nominated person(s) shall be available for the specified contract
period. Proposed changes to the hydro-geologist should be agreed with the supervising
engineer/GOAL.
During the siting, the hydro-geologist should ensure that representatives of the local
community/institution shall be involved. GOAL will assist with community liaison activities.
2.0 Drilling site
Borehole locations shall be identified in agreement with the local communities and in consultation with
the Client. Sites selected for the hand pump should preferably be within the communities and not
further away than 0.5km from 80% of people of the village. Boreholes should not be sited in or near to
places that get flooded during rains. Flood plains should be avoided. Additional measures should be
taken to ensure that sites are located outside the minimum distances prescribed from sanitation
installations, sources of pollution, landfills, grave yards and animal kraals.
It is advisable that the hydrologist uses their experience to determine alternative suitable sites for
borehole construction for each village so that these can be developed if initial sites are abandoned for
any reasons including dry wells or unsuitable water quality wells.
The contractor shall drill the well(s) at location(s) as determined by their hydrogeological surveys.
Access to the site shall be the responsibility of the Contractor. Tracks required for access of drilling
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plant, gear, camp and accessories to the well site shall be made by the contractor, and shall minimize
as much as possible interference with existing fences and cultivated land.
3.0 Hydrogeology
While deep wells have been constructed in these areas before, there is inadequate information
regarding success rates and soil profiles. The conditions of drilling cannot therefore be precisely
described and the precise or proximate locations of aquifer(s) cannot be described. Previous
borehole logs and drilling records have not been found. While drilling conditions are not expected to
be difficult, the driller should be prepared to deal with dry wells and wells whose water quality
is unsuitable for portable water supply as recommended by the GOU water quality standards.
4.0 Environmental protection of the site
Care must be taken in the handling and storage of drilling fluids, oils, greases and fuel to avoid
introducing environmental contaminants and pollutants. The Contractor shall dispose of any toxic
materials including drilling fluids, cuttings and discharged waters in a manner approved by the Client
and so as not to contaminate/pollute public and private property. The contractor shall adhere to
relevant National regulations and guidelines on Environmental protection that apply to drilling. The
Contractor shall ensure that all their personnel are aware of Environmental protection requirements.
5.0 Materials for the works and Workmanship
Materials that will form part of the complete works must be supplied new and never used. Materials
must comply with the minimum specifications in the relevant codes. Materials not specified here must
comply with the minimum specifications in the relevant codes of practice. Where a national standard
does not exist for the material, the relevant British Standard shall apply.
The Contractor is expected to carry out all works as specified and in a professional manner. The
Contractor shall carry out operations in accordance with the terms of the contract and to the
satisfaction of the Client. The Contractor shall use suitable equipment, and supply efficient and
experienced staff.
a) The Contractor will provide an experienced project Coordinator to oversee the drilling and testing
to be carried out under this Contract.
b) The Contractor will maintain a full crew on each drilling unit and pump test unit. If a member of
crew quits for personal reasons or must leave because of illness or injury, the Contractor will replace
him as soon as possible with a worker of similar experience.
c) If the Client is dissatisfied with the performance of members of the crew, such members shall be
informed of their shortcomings and warned by the contractor. If no change results within a reasonable
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period, the Contractor will be notified and requested to take necessary measures on the
unsatisfactory crewmember.
d) If the Client wishes to operate drilling equipment more than one shift per day, the Contractor shall
increase the size of the drilling crew as required. However, in the percussion drilling, the rig will be
operated for a maximum of 20 hours a day.
e) In the case of absence of one or more members of the drilling crew the decision of whether to
proceed with drilling operations will be at the discretion of the Client
6.0 Contractor to provide all equipment for the works
All necessary machinery, equipment and materials to carry out the drilling, test pumping, headwork
construction shall be provided by the contractor. Test pumping equipment shall be independent from
the drilling rig(s). Prior to mobilization the Client shall verify the specifications and state of repair of all
major items of plant and transport, and shall have the right to order the removal and/or replacement
of any items which in his opinion are insufficient or in unsatisfactory condition. Acceptance by the
Client of the Contractor’s proposed plant and transport does not relieve the contractor of his
obligations under this contract, in cases where such plant and transport accepted by the Client fails to
successfully complete the required works.
7.0 Drilling method
The Contractor should make exclusive use of direct or reverse circulation rotary and down-the-hole
hammer drilling techniques, using an appropriate (biodegradable) drilling fluid. Bentonite is not to be
used as a drilling fluid.
The Contractor may use any motorized drilling technique that will achieve the depth and diameter
required of the well, provided that the techniques used are those specified in his proposal and
approved by the Client. The rig to be deployed must be capable of drilling to at least a depth of 25%
beyond the anticipated final depth at the required diameter. Temporary casing may be installed in the
borehole to prevent formation heave or collapse.
The average anticipated borehole depth will be in the region 60m. Shallower or deeper boreholes
may be encountered.
During rotary drilling using air as the circulating fluid, approved surfactants and artificial foam
stiffening additives may be used if ground conditions warrant their use. Fluid additives of bentonite
will not be accepted. Cellulose based reconstitution powder, or liquid polymeric additives may be
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required for viscosity enhancement. The contractor will be required to state the type of polymer to be
used, and describe the means by which the selected fluid additive will be mixed.
8.0 Strata sampling and borehole geo data
While the drilling operation progresses, representative samples (min. 100 grams) of strata penetrated
shall be collected at every Two (2) meters intervals or according to standard requirements of the
Ministry of Water and Environment (MWE) where applicable. Strata samples will also be taken at
every change in the profile and where water or an aquifer is struck
At completion of drilling, the contractor will be required to complete the borehole geo-log with all
information describing the properties of the samples, appearances of water and aquifers, rock types
and sampling details.
The contractor will then complete the borehole log reports forms and supply them together with the
borehole completion records including water quality test certificates to the client. Incomplete records
or un-obtained samples are a reasonable ground for rejection of a borehole (conditions of contract
Clause 10).
The contractor will be required to hand to the client at the end of the drilling operation
borehole logs and pumping test data including information from dry boreholes and boreholes
considered unsuccessful as a result of poor water quality.
9.0 Borehole depth and diameter
The Contractor shall drill to the total appropriate depth depending on the geological formation and to
a diameter that shall allow minimum borehole nominal diameter bore of 4 inches (103mm) at the
completion of the borehole, including casing installation. Expected borehole depths are an average
60 meters depth. The contractor will be required to drill a minimum of 60m deep.
The minimum acceptable stable yield at test pumping shall be 450 ltrs/hr.
Drilling diameter should be a minimum of 6.5” (165mm) through unconsolidated formations such as
sands, gravels, clays and silts using mud rotary methods (or similar approved methods)
Drilling diameter should be a minimum of 5.875” (150mm) through consolidated rock utilizing downthe-hole hammer and compressed air supply – augmented as required by water foam injection
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The Contractor shall however drill to the total depth and at such diameter as will be instructed by the
Supervising Engineer. No borehole will be accepted if drilled to such depth and diameter other than
agreed by the Supervising Engineer.
In collapsing formations, the borehole drilling will be telescopic. In this case 200mm (8 inch) or of
appropriate diameter drilling (approved by the Engineer) is required to allow installation of temporary
casing. This temporary casing must enable further drilling of 200mm (8 inch) boreholes for the
installation of 100mm (4 inch) nominal internal diameter PVC casing and screen.
When rotary-drilling method is used, either a water meter or a 90-degree V-notch flow measurement
device or a drainpipe shall be permanently set up in an approved manner and level, so that
continuous monitoring of airlift yields can be obtained. Average yields shall be read every 3 meters of
penetration and recorded in the driller’s log. Care should be taken to ensure that the flow of water
through the meter, over the V-notch or through the drainpipe is not impeded by debris.
Boreholes shall be drilled to such depths as to penetrate below the shallow water table aquifers and
tap the first potential deeper aquifer in confined/semi confined conditions with a discharge above
450l/hr to sustain a continuous and reliable operation of hand pumps fitted on them, subject to water
quality considerations. The depth to be drilled should be at least 5 to 10 meters below the main
aquifer to provide proper installation of a hand pump and to provide a sand trap of at least 1 – 2
meters. If the discharge is less than 450l/hr a decision to abandon the borehole or continue to drill
deeper will be at the discretion of the Contractor.
10. Temporary casing
In order to prevent the collapse of unstable strata, the contractor may use temporary casings. These
temporary casings will be provided by the contractor and removed after use. Installation and diameter
(which should not be less than 8 inches) of any temporary casing required for the construction of the
borehole will be at the discretion of the Contractor provided that the finished product meets the
specifications and is approved by the Supervising Engineer. Cost for supply, installation and removal
of temporary casing shall be borne entirely by the Contractor. Casings left in the borehole, which is
not retrievable, cannot be claimed by the Contractor from the Employer.
The uPVC casings and screens to be supplied by the Contractor shall have a minimum wall thickness
of 6mm and nominal length of sections approximately 3 meters they should have a diameter of 4
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inches. The Supervising Engineer reserves the right to vary these specifications and to reject
materials if found substandard.
The casings and screens must be centralized in the borehole so that a minimum 2" (50.8 mm)
annular space exists between the borehole wall and the casing.
Filter pipes (screens) shall be 4” slotted uPVC, with minimum wall thickness of 6mm and slot size
depending on aquifer material and thickness but generally 1mm. The screen open area shall not be
less than 1.5%, while the slots shall be uniform, and not wider than 3 mm.
The screen shall be joined water tight in an approved manner by either flush threaded connections or
by an appropriate method. Screened sections shall be attached to the plain casing using the
manufacturer’s standard connections.
The casing should extend 0.3 metres above the ground surface.
The contractor will transport and store the casing pipe at the drilling site, to prevent distortion and
bending of the pipe.
Installation and diameter of any temporary casing required for the successful construction of the
boreholes will be at the discretion of the Contractor provided that the completed borehole meets the
specifications and design required under this Contract and is approved by the Supervisor. The cost
for supply, installation and removal of temporary casing shall be entirely borne by the Contractor.
11 Casing and screens
Aquifer zones shall be completely or partly lined with UPVC screens supplied by the contractor and
shall have a minimum wall thickness of 3.3mm for 110mm ND casing. The Client however reserves
the right to vary these specifications if deemed necessary. The collapse resistance of the casings
shall normally be a minimum of 6.5kg/cm2, while that for screens shall be a minimum of 50% of that of
the casing. The screen open area shall not be less than 4% and shall have a uniform slot size of
between 0.3-1mm. Screen length should not be compromised to save cost as this can result in a dry
borehole.
Sections of the screen shall be provided in maximum 3m lengths and joined water tight by either flush
threaded connections, or by an appropriate method recommended by the screen manufacturer or an
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equivalent standard, so that the resulting joint shall be strong and have the same structural integrity
as the casing and the screen themselves. In particular cases the lower end of the screen shall be
completed with a sump of minimum 0.5m and maximum 2m length. The bottom end shall be sealed
with a suitable bottom cap.
The casing and screens must be centralized in the well so that an annular space of at least 25mm
exists between the well wall and the casing. Suitable centralizers shall be provided to allow the casing
screen to be set correctly in the center of the well. A centralizer shall be used every 3m.
12. Verticality and Alignment
All wells shall be vertical, shall be drilled and cased straight, and all casings/screens shall be set
round, plumb and true to line. If required by the Client, the Contractor shall make a verticality test
during and after drilling by approved methods and at his own expense to demonstrate that the
departure from the vertical does not exceed 0.1% between ground level and the bottom of the well. If
this departure is exceeded, the Contractor shall make the necessary corrections to the approval of
the Client, without additional payment. If the error cannot be corrected, then drilling shall cease, and a
new well shall be drilled. The abandoned well shall be backfilled and /or capped. No payment shall be
made for re-drilling, the sealing/backfilling of the abandoned well, or for moving to a new site. Any
materials (i.e. casing, screens, gravel pack, cement, etc) lost in the abandoned well shall be at the
contractor’s cost.
13. Loss of equipment
Any equipment lost down a well must be removed by the Contractor or the well shall be considered a
lost bore. A replacement well shall have to be constructed at the Contractor’s expense. The
contractor shall not be entitled to further payments for such a well.
14. Lost bore
If completion of the well is prevented by any of incident to the plant, behavior of the ground, jamming
of the tools, or casing or any other cause, the well shall be deemed to be lost and no payment shall
be made for that bore or for any materials not recovered there from, nor for any time spent during
drilling or while attempting to overcome problems.
In the event of a lost bore, the Contractor shall construct a new well. The option of declaring any bore
lost shall rest with the Contractor, subject to the approval of the Client.
A lost bore shall be treated as follows:
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a) The Contractor may salvage as much casing and screen from the lost well as possible, and
may use it if not damaged in a replacement well, with the approval of the Client.
b) Any material supplied by the Employer and salvaged damaged shall become the property of
the Contractor, and the Contractor shall compensate the Employer accordingly.
c) The lost bore shall be sealed by concrete or cement grout, which shall be placed from the
bok6ttom upward by methods approved by the Client.
d) The upper 2 meters of the lost bore shall be backfilled with native top soil. Sealing of such
abandoned wells shall be done in such a manner as to avoid accidents or subsidence, and to
prevent it from acting as a vertical conduit for transmitting contaminated surface or subsurface
waters into the water bearing formations.
15. Water supply for drilling
The contractor shall make his own arrangement for obtaining, transporting and pumping of water
required for drilling purposes and for use by the drilling crew at their camp site.
16. Well design
The final design of the borehole shall be confirmed by the Client in consultation with the Contractor
during the drilling process, or immediately after drilling is completed using the tabulated borehole
strata data log. Typical standard borehole designs are described below:
•
Design A - Drilled at 10 5/8" through soft collapsible overburden until firm rock is encountered.
Drilled further with 8" or 6" bit for 3m or more through non-collapsing formation. Cased with 5"
ND uPVC Class D casing, 6mm wall thickness. Drilling to continue with 4 1/2" bit to final depth.
Bottom annular space between uPVC casing and borehole to be grouted with cement slurry of
1.67-2.08 Kg cement/litre (24-30 litres of water per 50 Kg bag of cement). Grout is to be
injected into the annulus using tremie pipes, or a method approved by the Client, in a
continuous operation so that a complete and continuous seal is achieved.
•
Design B - Drilled with 10 5/8" bit to final depth where necessary finished with 8" bit to final
depth. Cased with 5" ND uPVC Class D casing, 6mm wall thickness. Screened sections
adjacent to aquifer zones at depths as instructed by the Client. The screened sections are to
be gravel packed.
(Example borehole designs drawings are included towards the end of this document.
Alternative Ministry of Water and Environment drawings are attached as Annex A)
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17. Gravel pack
The Contractor shall supply suitable gravel pack. Prior to delivery, samples of the gravel pack shall be
subjected to a grain size analysis at the Contractors expense and the Client must approve the results
before the gravel pack is used. Gravel pack shall consist of washed, well-rounded particles of a
uniform grading of between 2.5 and 4.0mm, shall comprise at least 95% siliceous material and must
contain no clay, shale, silt, fines, excessive amounts of calcareous material or crushed rock. The
gravel pack needs to be installed slowly and carefully, preferably with a tremie pipe and a funnel
18. Sanitary seal
To provide an effective seal to the entry of contaminants, the upper 5 meters of the annular space
between the casing and the well wall shall be grouted using suitable prepared cement slurry. Grout is
to be injected into the annulus in a single operation so that a complete and continuous seal is
achieved.
19. Development and cleaning of wells
Well development must be undertaken before the contractor moves to the next site. Development and
cleaning of the wells, in order to remove native silts, clay and drilling fluid residues deposited on the
well wall during the drilling process, shall be carried out by the Contractor upon completion of the
drilling and installation of casings. The borehole should be flushed until it is free of fines and turbidity
for a continuous period of not less than 30 minutes or until the water has fully cleared.
Whenever possible, natural well development must be used. If organic drilling fluids are used, they
shall be broken down chemically according to manufacturer’s recommendations before or during
development. Cleaning may be carried out by airlift pumping, surging, backwashing or jetting, to the
approval of the Client. Clay de-segregation by means of Sodium Hexametaphosphate (“Calgon”)
treatment may, in some cases, also be called for by the Client.
The method proposed by the contractor for development of wells shall be submitted to the Client in
writing for his approval. Development of wells shall be effective from the depth at which water is
encountered to the bottom of each well. Development shall continue for such time as directed by the
Client and until the Client is satisfied that the water is as free from fine particles as possible. Upon
completion of development, any accumulation of material shall be removed from the bottom of the
well by airlifting.
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20. Pumping Tests
Pumping test will take place for 6-hours, of which the first 2 hours is step drawdown test (each step
running for 40 minutes) and 4 hours of continuous test and a minimum of 4-hour recovery test or until
the water level returns to 80% of the static water level.
Pumping rates for the step drawdown test will commence at 0.3l/s for the initial 40 minutes. The next
steps will be pumped at 0.6 l/s and 1.5 l/s.
Constant rate pumping test pumping rates will normally range between 0.5l/s and 2.5l/s but may not
fall below 450l/hr. If the pumping rate is below 450l/hr then the borehole will be regarded as dry. Once
the flow rate has been determined and preliminary adjustments made, the measured discharge rate
shall be maintained within 15% of the required rate for the duration of the test. Persistent fluctuations
beyond this tolerance will require abortion of the test.
Failure of the operation to produce the desired minimum pumping rate for a period greater than one
percent of the elapsed pumping time shall also require abortion of the test.
Any test, which is aborted due to the reasons above, shall be repeated after recovery of the water
level. The contractor will not claim stand by time for aborted tests or for standing time during water
level recovery after aborted tests.
Discharge measurements shall be made by using a flow meter or other measuring device approved
by the supervising engineer. During pumping tests, the discharge water will be diverted in an
appropriate manner over a distance of at least 50 m downslope from the wellhead. Water discharge
measurements shall be taken at appropriate time intervals as instructed by the Supervising Engineer,
while at the same time Electrical Conductivity readings are to be taken.
After completion of the test the contractor shall remove by bailing and pump or other methods any
sands, stone or other foreign materials that may have become deposited in the borehole and with
consent of the Engineer, the borehole shall be chlorinated.
Pumping test data shall be supplied to the Supervising Engineer from all pumping tests conducted at
the borehole. These will show dates, water levels, discharge rates, electrical conductivity values,
times of starting and stopping the pump, changes in discharge, weather, and other conditions that
could affect the test data.
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The Contractor shall supply appropriate electric contact water level gauges for measuring water
levels in the borehole to the nearest 10 mm at pre-determined intervals. The minimum length of the
electrical dipper shall be 250 metres. Wellhead arrangements shall permit these gauges to be
inserted and passed freely. Hereto the Contractor shall be required to install a dipping tube, minimum
3/4" inner diameter, lowered to approximately 2 metres above the pump intake or the anticipated
maximum drawdown level.
Other methods of measuring water levels are subject to approval by the Supervising Engineer.
The method for varying the discharge rate of the pumps shall depend on the type of pump used. The
Contractor shall ensure the provision of a suitable means of achieving the range of constant flow
rates specified.
21. Water level observation
The contractor shall apply appropriate electronic contact water level gauges for measuring water level
in the wells. Measurements shall be made at predetermined intervals, depending on the nature of the
test. Well head arrangement shall permit these gauges to be inserted.
Water level shall be measured to 10mm accuracy during test pumping by the Contractor by means of
an electronic contact gauge (dipper). The frequency of measurement shall be as specified on the
agreed test pumping data form, or one otherwise determined by the Client.
Discharge shall be measured by volumetric methods, or means of approved measuring device.
During test pumping, discharged water shall be disposed-off sufficiently far from the well to prevent
recharge.
22. Water Quality Testing
Water samples for testing the biological, physical and chemical properties shall be taken at the end of
the test pumping. The contractor shall collect and store samples in approved containers. The
Contractor shall be responsible for testing of the water quality in approved water testing laboratories
and as specified, furnish the client with the test certificate.
The following parameters should be tested on site using portable water quality testing meters.
The results of these tests shall be included as part of the final borehole records for each well.
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
Electrical conductivity

Temperature

PH

Turbidity
After completion of test pumping the borehole, the contractor will take two (2) liter samples in clean,
properly sealable, sterilized plastic bottles for laboratory analysis. The samples will be used for
physical and chemical analysis. The samples should reach the laboratory within 6 hours from the time
of collection. Specific parameters to be measured include

Physical Parameters – Colour apparent (PtCo), Turbidity (NTU), Electrical Conductivity
(µS/cm), TSS (mg/L)

Chemical Parameters – Nitrate(mg/L N), Total Hardness (mg/L), Fluoride (mg/L F), Chloride
(mg/L Cl-), Sulphate (mg/LSO42-), Total Iron (mg/L Fe) Manganese (mg/L Mn), TDS (mg/L),
Calcium (mg/L Ca2+), Magnesium (Mg/L Mg2+), Bicarbonate (mg/L CaCO3), Alkalinity (total
mg/L CaCO3)
23. Capping of well
During well construction, installation, development and test pumping, the Contractor shall use all
reasonable measures to prevent entrance of foreign matter into the well. Well caps should be used at
all times. Wooden logs shall not be used to replace well caps. The Contractor shall be responsible for
any objectionable materials that may fall into the well and any effect it may have on water quality or
quantity until completion of the Works and acceptance by the Client.
24 Acceptance of well
The Client shall accept the well upon satisfactory completion of all drilling operations,
installation of casings and screens, development works, pumping tests, presentation and
approval of complete drilling reports and logs and provided the well yield is above minimum
recommended values and water quality tests are suitable for potable water according to the
GOU standards.
25. Standby time
In the event of delays occurring as a result of the action or inaction of the Client, for which the
Contractor would be entitled to claim Standby Time, the Contractor shall notify the Client immediately
in writing. A claim for Standby Time is only effective if all the Contractor’s plant, equipment and
personnel are on site, available for work and in a serviceable condition. Standby Time shall not
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exceed the standard working day as defined in the Contract Data, and any claim shall only be
deemed to start at the date and time of a notice in writing to the Client.
26. Concrete apron/platform casting and hand pump installation.
Upon receipt of satisfactory water quality results and after being verified by the Client, the contractor
shall cast a concrete slab on the wells according to these specifications
The Contractor shall construct concrete platform for each successful borehole carrying out the following
activities in order:
Excavate square pit 760x760x400mm deep around casing pipe.
a) Place stand assembly (pedestal) over casing pipe, ensuring third leg (corresponding to the water
tank spout pipe position) faces the proposed direction of the drain.
b) Making sure the pedestal is vertical, construct concrete in layers of 100mm up to top of legs.
c) Cover stand assembly with a cover plate and, level the ground around the pump pedestal.
d) Lay the mild steel shuttering (moulds) and cast platform in mass concrete (mix 1:2:4/20mm agg.)
conforming to the dimensions and other specifications shown in drawings.
e) Cure concrete for 3 days and protect it from excessive sunshine (using gunny bags and thorny
bushes, etc).
f)
Plaster platform and drain in cement screed to a smooth finish, then engrave the borehole details
provided by the Client on the platform
27. Hand pump equipment and installation
The Contractor shall supply pipes and pump parts, to cast and install India Mark II Deep well Hand
pump as per Bureau of Indian Standard Specifications IS-13056: 1991, Bureau of Indian Standard
Specifications IS-13056: 1991 – Amendment 6, with 50mm dia. cast iron brass sleeved open top
cylinder assembly with extractable plunger and foot valves assemblies or a similar specification
according to Uganda standards. Note that all pipes and rods are replaced with stainless steel G316.
The Contractor shall supply Either Grade 316 Stainless steel pipes , 1¼” Nominal pipe diameter, 3m
long with average weight of 2.73 Kg/m and Stainless steel rods of grade 316, not less than 17mm
diameter together with two rod centralizers for pump installation greater than 36m deep or Poly
Propylene Random (PPR) pipe 32mm or 1¼” Nominal pipe diameter with stainless steel wire locking
coupler design with square threads and rubber rings pipes thicker in the threaded portions with safe
allowable hydrostatic pressure of 26 kg/cm2 and stainless steel rods of G316 and not less than 17mm
diameter for pump installations not greater than 36m.
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28. Pump cylinders
All hand pumps to be installed deeper than 40m are to be installed with heavy duty extra deep well
cylinders with 3 washer cups or valves. The Client must confirm the cylinder before installation.
29. Clearing the site
Upon completion of works on a well site, the site must be left free from debris, hydrocarbons and waste,
and all pits must be filled up. A site not delivered clean may render the well unacceptable.
30 Records and reporting (See Annexes 1 -5)
The Contractor shall keep daily activity records for each borehole. The records shall contain the
information as specified below. In addition separate records should be supplied for each borehole
upon completion.
i) Daily Record
_ Site name
_ Reference number of borehole
_ GPS Co-ordinates of borehole (latitude / longitude)
_ Date of reporting
_ Names of foreman and drillers
_ Method of drilling
_ Make, model, type and size of drilling rig
_ Diameter of hole, and depth of changes in diameter
_ Depth of hole at start and end of shift or working day
_ Depth and size of casing at start and end of shift or working day
_ Description of strata drilled with depth of transitions encountered
_ Depth at which water is struck
_ Yield of air lifted water, when drilling or developing with air in litres per second.
_ Time log showing rate of penetration in minutes per metre, type of bit, standby time due to
breakdown.
_ Depth intervals at which formation samples are taken
_ Records of components and quantities used or added to the drilling fluid or air.
_ Water level at the start of each working day
_ Electrical conductivity measurements during test pumping
_ Problems encountered during drilling
_ Details of installations in the borehole (if any)
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_ Depth, size and description of well casing
_ Depth, size and description of well screens
_ Aquifer depth and SWL after completion of well
A copy of the Daily Record shall be made available daily to the Supervisor, and should include
Borehole drilling technical specification & Guidelines Page 7 of 11 any other pertinent data as may be
requested by the Supervisor.
ii) Borehole Completion Record
_ As per standard Borehole Completion Form.
_ Detailed drillers geological log.
_ Borehole design and installation details (as-built drawing)
ii) Monthly Contract progress report
The contractor shall submit a monthly progress report detailing progress on the contract. The month
report shall include the progress of projects successfully completed, problems encountered that are
hindering progress and remedial recommendations to accelerate contract progress.
iii) End of Contract Report.
The Contractor shall prepare an end of Contract report, which should address at the minimum the
following issues;
1. The selected sites
(Suitability, accessibility)
2. The drilling /test pumping methodologies
(Type of drilling, designs used, test-pumping methods)
3. Contract schedules and duration
(Summarised diary of events and actual durations)
4. Summary of results and analysis
(Table showing locations, well numbers, depths, casing type and depths, driller’s and test pumping
yields, water quality and any other information necessary)
5. Casing /screens received and used on the Contract (if any)
(Table showing casings received, used, damaged and balances)
6. Problems encountered
(With accessibility, formations, equipment and community, etc)
7. Suggestion for improvement
(On supervision, documentation, durations, etc)
8. Borehole Completion Records,
(Original Drilling and test pumping logs bound separately from the report)
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9. Any other information that the Contractor may deem important or necessary. Two copies of the
End of Contract Report (one without the Borehole Completion Records) shall be submitted to the
Supervisor.
31. Typical Schematic Drawing of Well Designs
Borehole design 1: Unconsolidated formations
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Borehole design 2: consolidated formations
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Borehole design 3: Consolidated formation
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Alternative drawings: Ministry of Water and Environment (See attached DWD drawings)
Schematic Drawing of Hand pump platform designs
2.00m
Soak away
10.00m
Platform
3.00m
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Annex 1 Test Pumping: Step Draw Down (Typical format)
PUMP TEST - STEP DRAW DOWN TEST REPORT
Village;
GPS Co-ords N…………….…… E……………….…
STEP 1 :
Discharge set at ( Liters/Second):
TIME ELAPSED (In
DEPTH TO WATER LEVEL
DRAWDOWN
Minutes)
(Meters)
(In meters)
0
1
2
3
4
5
6
7
8
9
10
15
20
STEP 2:
Discharge set at ( Liters/Second):
TIME ELAPSED (In
DEPTH TO WATER LEVEL
DRAWDOWN
Minutes)
(Meters)
(In meters)
0
1
2
3
4
5
6
7
8
9
10
15
20
STEP 3 :
Discharge set at ( Liters/Second):
TIME ELAPSED (In
DEPTH TO WATER LEVEL
DRAWDOWN
Minutes)
(Meters)
(In meters)
( 20 MINUTES)
0.25
REMARKS
REMARKS
REMARKS
0
1
2
3
4
5
6
7
8
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9
10
15
20
Pump Supervisor
Sign
Drilling Manager
Sign
Drilling Supervisor Sign
Annex 2 Test Pumping: Constant Discharge
PUMP TEST - 4 HOURS AQUIFER TEST
Village:___________________________
Start Time…………….
Date:___________
GPS Coords N……………… E …………….
Time elapsed in
S.no
Drawdown (meters)
minutes
1
0
2
1
3
2
4
3
5
4
6
5
7
6
8
7
9
8
10
9
11
10
12
15
13
20
14
25
15
30
16
35
17
40
18
50
19
60
20
70
21
80
22
90
23
105
24
120
25
135
26
150
27
165
28
180
End Time……………
Yield ( ltr / sec)
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Remarks
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29
195
30
210
31
225
32
240
33
260
34
280
35
300
Pump Supervisor Sign
Drilling Supervisor Sign
Drilling Manager Sign
Annex 3 Recovery Measurements
BORE HOLE - RECOVERY TEST
Village:……………………………
GPS Co-ords N……………………
E ……………………
S.N TIME ELAPSED DRAWDOWN
O
IN MINUTES
(METERS)
1
0
2
1
3
2
4
3
5
4
6
5
7
6
8
7
9
8
10
9
11
10
12
15
13
20
14
25
15
30
16
35
17
40
Date:……………………
Start Time……………………….
End Time……………………..…
YIELD ( LTR
/ SEC)
GOAL Uganda – Borehole Technical Specification reviewed November 2015
REMARKS
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18
45
19
50
20
55
21
60
22
23
24
25
26
27
28
29
30
Pump Supervisor
Drilling
Supervisor
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Drilling Manager
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Annex 4: Borehole log sheet (Typical)
Bore Hole Litho log and drill time log with water strike zones
Borehole Number
Dates Started:
Date Ended :
Drill Time Log
Minutes / per meter drilled
BORE
HOLE
Drilling Company:
Village
N_______________________________
GPS Cood
E________________________________
Water strikes
Litho-logical Log
Depth in
Ground
Meters
Surface
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Annex 5 Bore Hole Completion Record (Typical)
Bore Hole No……………………………………………………..
Bore Hole Name………………………………………………….
_______________________________________________________________________
1. Village………………… Parish ……………………..District………………………..
Coordinates; N ………………E………………… Elevation …………………..ASL
3. Contactor/Driller………………………………………… Address…………………….
…………………………………………………………………………………………
4. Type of Bore Hole; Drilled; Driven; Bored; Jetted; Other………………………………
…………………………………………………………………………………………..
Type & Make of the drilling Rig………………………………………………………...
5. Bore Hole Design & Construction (Sketch to accompany)
Drilling Started………………………… Drilling Completed………………………….
All work completed………………………………………………………………………
Total Depth: Reported………m;
Measured…….m; Final (Backfilled) Depth;……..m
Hole Diameter………………mm.
……………….mm
……………….mm
……………….mm
From ……….m to……………….m
From ……….m to……………….m
From ……….m to……………….m
From ……….m to……………….m
Permanent Casing:
Plain:
Type………..; Dia……..mm; Length………m; From………m to……….m
Type………..; Dia……..mm; Length………m; From………m to……….m
Type………..; Dia……..mm; Length………m; From………m to……….m
Type………..; Dia……..mm; Length………m; From………m to……….m
Screen:
Type & Make………………………………………………………………………………
Diameter………mm; Length……….m Set from…….m to……………m
Gravel Pack:
Size of grains…………mm, Roundness (Good, Fair, Poor)………………………..
Volume inserted to the annular space………cu.m, from………….m to…………..m
6. Aquifer: 1st Water Struck at ……………….m.; Water rest level………………………….m
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Main Aquifer struck at …………...m. ; Water rest level…………………………m
Water bearing material…………………………, from……..m to………………..m
Other Aquifers, Remark etc……………………………………………………………………...
…………………………………………………………………………………………………….
………………………………………………………………………………………………
7. Yield: SWL………m.; DWL……….m. below GL; Discharge………………….Ltrs/min
after pumping ……………..Hrs; Recovered to SWL in …………….Minutes;
Recommended production discharge………….Ltrs/Hr, with pump set at …………..m below GL
8. Bore Hole Development Start……………. Finish …………… Hrs…………………
9. Pumping Test Record in summary (Attach detailed test records – Test pumping & BH
tests) – All depth measurements to be in Metres below GL
recovery
Description
Date of Test (Day, Month, Year)
Depth of BH at time of test (m)
Static Water Level (SWL) before test (m)
Type of Pump used
Depth of Pump Intake (m)
Discharge (Ltrs/Minute)
Dynamic/Pumping water level (m)
After Pumping continuously for (Hrs)
Time of recovery to original SWL (Minutes)
Rate of Recovery – WL after 5 Minutes (m)
WL after 20 Minutes (m)
WL after 60 Minutes (m)
WL after 180 Minutes (m)
WL after 360 Minutes (m)
Additional pumping tests to be mentioned in Remarks
10. Quality of Water: (Water Quality Test Certificates to accompany)
Sample (Yes/No) collected at …………………………. Hour on …………………….. (Date)
Sediment………………………….., Taste ……………………….., Odour…………………….
Colour………………………………; Specific conductivity……………….μmho/cu. m;
Temperature……...oC
11. Remarks: (Drilling difficulties, gravel pack details, all pertinent information about drilling and
completion of the Bore Hole)
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
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……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
………………………………………………………………………………………………………….
12. Sketch of Bore Hole Construction
( Sketch to include depth, & changes of hole diameter; casing positions, manner of casings (if
different diameters), connections, and casing connection to the screen; depths of screen, how casing is
closed at the bottom, formation caving zones and any other pertinent information)
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