RFP ZIMA 2014-0 Borehole Drilling Phase2 Annex17

8/18/2019 RFP ZIMA 2014-0 Borehole Drilling Phase2 Annex17

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Technical Specifications & Procedures for drilling & construction of boreholes for hand pumps

Initials of Contractor and Client Page 2

TABLE OF CONTENTS:

List of Annexes…………………………………………………………………………. 3

1. Nature of contract……………………………………………………………………..4

2. Contractors Dril ling Equipment ……………………………………………………4

3. Site Selection……………………………………………………..……………………4

4. Bore Hole Construction …………………………………………………………….. 6

4.1 Dri ll ing Methods ………………………………….………….…………… 64,2 Borehole Depth ……………………………………………. .…………… 64.3. Bore Hole Diameter …………………………………….………............. .64.4. Screen…………………………………………………….……………….... 74.5. Casing Pipe and Sand trap…………………………………….……….. 74.6. Gravel Packing and grouting……………. …..……………………….. 7

5. Bore Hole Development…………………………………………………………….. 8

6. Pumping and Recovery Test……………………………………….……………… 8

7. Water Quali ty Testing……………………………………………………………… 9

8. Sampl ing and Dri ll Time Logs…………………………………………………….. 9

8. Chlorination after Bore Hole completion………………………………………... 9

9. Straightness and Verticality……………………………………………………….10

10. Protection ………………………………………………………………..…………..10

11. Abandonment……………………………………………………….……………….10

12. “ Lost” (Unsuccessful) Boreholes…………………………………..……………1012.1. “ Dry” Bore Holes ………………………………………………………..1012.2 Uncompleted Bore Holes………………………………………………11

13. Test of Acceptabil ity and Reports………………………………..…………….. 11


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TECHNICAL SPECIFICATIONS AND PROCEDURESFOR DRILLING AND CONSTRUCTION OF BOREHOLES

FOR HANDPUMP PROGRAMME.

1. NATURE OF CONTRACT

1.1 The Specifications are for the drilling of boreholes and equipping them with handpumps (Bush Pump Type B) and completion of all civil works involved.

1.2 Client would like to have a turnkey contract for the construction of Hand pump waterfacilities on drilled boreholes. For this the Contractor shall provide all labor,transport, plant, tools, equipment and materials and appurtenances, and shall

perform all Works necessary to satisfactorily locate sites for drilling, construct andcomplete successfully drilled boreholes including lowering of borehole assemblywith PVC casing and Screen and end cap, gravel pack at appropriate intervals andback fill, close near surface water table aquifer, cleaning and development of saidboreholes, pump test for 7 hours, chlorinate borehole, install hand pump, constructapron with drainage and soak away pit and water quality testing both chemical andbiological in accordance with this specification and to any further details as may beordered by the Client. Contractor shall be provided, by the Client, with completesets of hand pumps that meet SAZS 881:2004 .

1.3 The Contractor shall employ only competent workmen for the execution of the

Works, and all such Works shall be performed under direct supervision of an expertwater well driller/site supervisor.

2 CONTRACTOR'S DRILLING EQUIPMENT:

2.1 The Contractor shall specify in the Schedule of Drilling Equipment, boreholedevelopment and other accessory equipment, its type and capacity that is to beused to undertake this work. Its capacity shall be sufficient to cope with the Worksas stated in the Contract. It shall at all times be kept in full working order and goodrepair.

2.2 If the Client considers that the drilling equipment or any accessories in use on thesite of the Works is in any way unsuitable, inefficient or inadequate in capacity, theClient shall have the right to call upon the Contractor to put such equipment in goodorder within seven days or alternatively to remove such plant and replace it withadditional plant or equipment which the Client considers necessary to meet therequirements of the Contract. In the event that this requirement of the Contract isnot satisfied, the Client reserves the right to terminate the Contract immediately.

2.3 No extra payment shall be made for the Contractor's change of drillingequipment , labor or other equipment required to complete the Works specified, norfor any incidentals thereto, the cost being deemed to be included in the schedule ofrates.


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3 SITE SELECTION:

3.1 The Contractor upon arrival in a District will meet the Designated representativefrom Rural Development Council (RDC) in rural areas or other concernedauthorities (list to be provided by UNICEF) and inform about the drilling plans. The

designated representative in consultation with communities will select sociallyacceptable location for drilling purpose (see 3.2 and 3.3 below) The Contractorshall receive from client the list of locations (annex-1). Contractor upon visitingthese locations will determine the road conditions for accessibility of the drilling rigand other heavy equipment. The Contractor will receive from client a list ofadditional reserve locations by order of priority as replacements for any dry orunsuccessful boreholes. Any changes or alternative s ites wil l be in consultationwith Client and designated representatives.

3.2 Within each of the selected location, the driller in consultations with designatedrepresentative will select 2-3 sites that are socially acceptable to the communities.The Contractor will be responsible for getting these socially selected sites checkedby proper Geophysical / Geological and confirm the technical feasibility of drilling asuccessful borehole(s) for hand pump installation. In case the Contractor selects asite that is not one of those selected by the water committee, then he shoulddiscuss with the designated representative and explain the need for changes. If thewater committee members are not satisfied by the change in location thencontractor should communicate to the Client.

3.3 The technical sitting team should ensure that the sites selected for the hand pumpfacility is preferably within the communities and in no case more than 500 metersfrom where at least 80% of people of that village / community live. The siteshould definitely not be in a place that gets flooded in the rainy season and should

be away from the flood plain area of any streams or rivers in the locality. Specialcare must be taken to ensure that the sites chosen are at least 30 metersaway from toilet pits or any other sources of pollution such as grave yard,stagnant pools of dirty water or animal pens (see figure in annex 3 fordetails).

3.4 The Contractor in a District will technically select all sites, prepare a Drilling WorkPlan and communicate it in writing to the Client with a sketch map as shown in(annex-4) showing the rig movement and their distances between the consecutivedrilling sites and Gantt Chart to show the completion plan for all works(annex-5)and report on the geophysical sitting with the interpretation and

recommendations in a format shown in (annex-6)3.5 Sites selected will consider the rainy season and accessibility to heavy drilling rigs

and support vehicles’. If the Contractor considers improvements are required forany reason to enable him carry out the Works he shall make the improvements athis own expense. In the event that improvement is not feasible, and access isstill not possible, then the contractor should notify in writing to the client andseek permission to replace the location from the reserve list.

3.6 At least three (2-3) sites shall be identified at each location, which shall constituteone single sitting payable under this contract. In case the Contractor fails todrill a successful borehole and moves to a new location, he shall make at least

three (2-3) sittings for this new location before claiming payment as stipulated in theBills of Quantities. The contractor will get paid only for sitting successful boreholes.


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3.7 The Contractor may move to a new location only after two unsuccessful boreholesin one location. Payment for sitting will be made on the basis of clause 3.6 above.

4 BOREHOLE CONSTRUCTION:

A typical borehole section is shown in annex: 7. Basic methods of drilling areindicated below as a basic guide, mostly to maintain a few key dimensionalspecifications.

Drilling Methods:

4.1.1 The preferred method of drilling in consolidated compact formations is rotarypercussion with air and/or foam flush. Boreholes will be drilled with 6½ inch drill bitsand reamed with a minimum diameter of 8 inches for sanitary protection or forlowering temporary casings.

4.1.2 In unconsolidated loose, unstable, collapsing formations, rotary with appropriate

drilling stabilizer will be used. In such a case the drilling diameters will betelescopic starting with diameter large enough to lower temporary casing in uppercollapsing formations and continue drilling with a final minimum diameter of 6½ inch bit. If other chemical fluids or solids are used to arrest collapsing offormations, the Contractor has to use proper borehole development and cleaningmethods to make the use of borehole water is safe for drinking purposes. TheContractor will use such fluids or solids with the agreement of the Client. In no casewill the use of Bentonite mud be allowed. Boreholes will be constructed withUPVC casing, screen and sand trap. The Contractor will decide appropriate lengthsof slotted screen in the aquifer intervals. Al l cost of using proper dr ill ing flu idsand solids is included in the rate per meter quoted. No additional payments will

be made by client.

4.2 Borehole Depth:

4.2.1 Boreholes shall be drilled to such depths as to penetrate below the shallow watertable aquifers and tap the first potential deeper aquifer or aquifers in confined/semi-confined conditions with a minimum discharge of 0.25 liters per second to sustaincontinuous pump testing for 6 hours to ensure reliable operation of hand pumpsfitted on them. The depth to be drilled should be at least 40 metres and at least six(6) meters below the main aquifer to provide proper installation of a hand pump andto provide a sand trap of 3 meters. If the discharge is less than 0.25 liters/sec., adecision to abandon the borehole or continue to drill deeper will be at the discretion

of the Contractor.

4.3 Borehole Diameter:

4.3.1 Boreholes will be drilled with telescopic diameters.

4.3.2 The first 6 meters from the surface will have concrete grouting for sanitaryprotection. For this the borehole will be reamed to a minimum diameter of 8 or 10inches and concrete grouting placed in the annular space between the casing andopen borehole wall.

4.3.3 Borehole will be drilled with 6 1/2 inch bit. The reaming diameter will be based onthe type of temporary casing the contractor will use and not less than 8 inches to

install Class 10 PVC casing of 140mm outside diameter for the total depth of the


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borehole1.

4.3.4 The contractor must take into account the depths he has to drill and lowertemporary casing to complete the drilling. This cost must be built in the quoted unitcost for drilling.

4.3.5 The client will not be responsible for any loss of temporary casing which thecontractor is unable to pull out or lost due to snapping or breaking from thecompleted boreholes.

4.4 Screen:

4.4.1 The Contractor will use proprietary; factory-made Class 10 UPVC slotted screens,the slot size and screen length depending on the aquifer materials and aquiferthickness. The Contractor will take sole responsibility of designing the wellassembly and placing screen and casing at appropriate depths to match thepositioning of the aquifer(s).

4.4.2 Slotted screens should be of DIN 4925/8061 or equivalent approved byinternational standards and have the following dimensional specifications: U-PVCcasing pipe, Class 10, drinking water standards, non toxic and in standard lengthsof three (3) meters, Nominal diameter of 125mm, OD 140mm, flush jointed, malefemale trapezoidal threads, slot width 0,75 mm and not more than 1mm, and openarea as percentage of internal surface area 9.26% per linear meter. Depending onthe aquifer, the Contractor may choose an appropriate slot width other than0.75mm.

4.5 Casing Pipe and Sand Trap:

4.5.1 Casing pipe should be of DIN 4925/8061 or equivalent approved by international

standards, and have the following dimensional specifications: U-PVC Class 10, drinking water standards, non toxic and in standard lengths of three (3) meters inlength, Nominal diameter 125mm, outer diameter 140mm, WT 7.5mm, forinstallation down to 90 meters, flush jointed for internal and external diameter, male/female trapezoidal threads and in lengths of 3 meters.

4.5.2 The boreholes will be fully cased to bottom. The threads both male and female areproperly cleaned with a clean brush and cloth before they are joined. If the pipesused are with bell and socket, these are cleaned using fluids and cemented withrecommended solvent cement by the manufacturers of the casing pipes andscreen. Wait for recommended time for the joint to set firmly before lowering into theborehole.

4.5.3 The Contractor will take all necessary precautions during the transportation andstorage of casing pipes from their warehouse to drilling sites to prevent distortions,ending or deformation of the pipe that could result in eccentricity along the length ofthe pipe.

4.5.4 A maximum of 3 meter length of sand trap will be part of the well design whenboreholes are cased to the bottom. The sand trap will be from UPVC casing pipewith specifications described above, fitted to the end of last screen and bottom endwith an end-cap. The end cap is glued with appropriate solvent cement or solutions

1 Note: Drill bit sizes more than those indicated are also acceptable to accommodate the drill bits which the Contractor's rigis equipped with or of which the Contractor may have stocks.


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as recommended by the UPVC manufacturer. Note that the joint sections areproperly cleaned with cleaning fluids and recommended time given for the joint toset firmly before lowering into the borehole.

4.6 Gravel Packing and Grouting:

4.6.1 The annular space between the casing and borehole wall is filled with filter packingmaterials in the screen intervals and back filling materials. The gravel packingmixture to be used depends on the sieve analysis results and the slot size of thescreen. The contractor will do the sieve analysis and then determine the gravelpack materials. Gravel packing material will be stored in a way so as to avoidcontamination or rain washing finer materials. Iron and Calcareous grains will not beincluded in the gravel pack materials.

4.6.2 Gravel packing is carried out as continuous feed operations done usually by twopeople filling uniformly around the circumference of the pipe. It is advisable to addsome water with a pipe so that the gravel flows down. If the gravel gets inside the

temporary casing, the casing is slowly pulled out and gentle well development isdone to allow gravel to settles properly to a height of 3 meters above the top of thescreen interval or the targeted water bearing formation. More gravel is added withdevelopment if the gravel settles down.

4.6.3 Backfilling and grouting is done when the Minimum acceptable yield of 0.25liters/ second is confirmed by development. The borehole cuttings or clayey soilsare back filled up to 6 meters below the ground surface.

4.6.4 The grouting is done with a concrete mix in the ratio of 1:2:3 of cement sand andgravel respectively. The gravel size should be not more than 6mm. Insert a 3meter Steel casing of 6 inches diameter on to the PVC casing, both protruding

above ground level by at least 60cm to facilitate installation of Bush Pump Type B(see manual for details).

5 BOREHOLE DEVELOPMENT:

5.1 On completion of drilling, the Contractor will choose a suitable and appropriateborehole development method. The borehole shall be developed for a period of atleast three hours in order to obtain a maximum yield of water that is free ofsuspended matter. Developing shall be carried out by airlift pumping and surging, jetting and block surging, or other techniques the contractor feels is moreappropriate and efficient to suit the casing, hydro-geological and drilling conditionsprevailing in that borehole. All boreholes shall be presented for testing free of any

bridging or obstruction to the total depth. The Contractor should provide theequipment required for verticality testing as described in ZINWA regulations.Developing will be for a minimum period of 3 hours.

6 PUMPING AND RECOVERY TEST:

6.1 A pumping test is required on a routine basis for each borehole. The Contractor willestimate the discharge from the air lifting rates or blow test during boreholedevelopment. Based on the estimated discharge, the Contractor will certify theborehole as either "successful" or "lost". For successful boreholes for hand pumps,the Contractor will undertake a seven hour pump testing of which the first one houris a three step draw down test. The discharges for the step drawdown test will be

fixed by the contractor based on the well development results. High yieldingboreholes, with a discharge of more than 1 litre/second may be pump tested for 72


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hours. The 72 hours pump test is conducted if the borehole is intended for amotorised pump. After conducting the step drawdown tests the borehole should beallowed to recover almost to the original static water level (1 hour) before theconstant yield test is undertaken continuously for 4 hours at thechosen/predetermined rate.

6.2 The first step could be minimum acceptable discharge of 0.25 liters / sec. Thesecond step will be at an estimated discharge from blow test (during the welldevelopment) and the third step will be 50 to 75% more than the estimateddischarge from blow test. As a thumb rule the range of the three steps could be 0.5liter/Sec or above depending of development results, 0.75 liters /Sec and 0.25 liters/Sec. and each step for 20 minutes (total 1 Hours) the continuous test of 4 hours willbe carried out at a discharge at which the dynamic water level will stabilize. Annex9 and 10 show the formats for recording pump test data. If the discharge isbelow 0.25 liters/second or dynamic water level is below 45 meters then theborehole will be regarded as "Lost" .

6.3 Recovery test will be for one hour or such time when the there is at least recoveryof 80% of the static water level noted at the start of the pump test. The pump testdata and the results of pump test is presented in the standard form attached(Annex- 8).

6.4 The Contractor shall have on site a 900 V-notch weir, preceded by a tank withbaffles, for the measurement of flows. Small flows (less than 0.25 liters/second) canbe measured by timing the filling of a vessel of known volume. The Contractor shallalso have on site an operating electric dip meter, calibrated in centimeters, and withvisual/audible indicator of when the water level is reached.

6.5 Readings of flow and water level shall be taken at the intervals defined on the testpumping form. For accurate measurement, an electrical/ sonic water level indicatorwith graduated tape for taking water level readings should be utilized. Recoveryreadings shall be taken for a minimum of 1 hour, during which period pumpingequipment shall not be removed from the borehole.

7..0 WATER QUALITY TESTING :

7.1 The contractor shall, make sampling and quality analysis of water from everyborehole.

7.2 The water quality test should be conducted at a competent testing laboratory that isauthorized by the client.

7.3 The parameters to be tested are given in table below and standards will beaccording to WHO guidelines for drinking water quality.

7.4 Water samples for chemical analysis should be collected at the end of the testpumping process and analyzed at the approved laboratory at the earliest possibletime to facilitate timely handing over of the borehole for use by the community.Thus the pump handle should only be fitted after acceptable chemical analysisresults. Samples for biological testing will be collected later in suitable batches soas to meet the time limit of 48 hours between collecting and analysis in thelaboratory

Table 1: showing parameters to be tested


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Biological Physical Chemical

Coliforms Colour Arsenic

E. Coliforms Odour Fluoride

Taste Nitrate

Turbidity ManganesePH value Total Iron

Electric Conductivity Chloride

Total Hardness

Total Dissolved Solids

Sulphate

Copper

8. SAMPLING AND DRILL TIME LOGS:

8.1 Representative samples of the strata intersected shall be collected every one

meter or less depending on the change of geological formation. For collection, theContractor shall cease drilling, circulate all cuttings to the surface, resume drillingand collect the cuttings then brought to the surface. The Contractor shall takeevery possible precaution to guard against sample contamination due to poorcirculation, bore hole erosion, or caving. Cutting samples shall be bagged, labeledwith borehole depth at time of collection, and stored in a position where they willnot be contaminated by site conditions or drilling operations. The Contractor shallsupply strong, transparent sample bags and indelible labels as required. Thedriller in-charge will also record the drill time logs/penetration rate of each rod or atevery three meter interval. A sample of Litho logical log with drill time log is shownin Annex - 8

9. CHLORINATION AFTER BOREHOLE COMPLETION:

Each successful borehole must be chlorinated following completion drillingoperations. The Contractor will decide on the concentration of chlorine based on thevolume of water in the borehole.

11. PROTECTION:

During the contract period, when work is not in progress, the boreholes shall bekept capped in such a manner as to prevent the entrance of foreign materials. The

Contractor shall remove any foreign matter at his own expense. On completion ofeach borehole, the Contractor shall supply and fit an approved permanent lock-upcap. Casing shall terminate not less than 0.5 meters above ground level and arefitted with the approved lock-up cap.

After successful completion of drilling, casing and testing head-works will beconstructed in line with the guidelines given in the Head-work Manual which formspart of the documentation of this contract.

12. ABANDONMENT.12.1 The Client shall have the right at any time during the progress of the Works


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to order the abandonment of the borehole. The Contractor shall thereuponremove the drilling rig, withdraw any casing and screen and salvage all suchmaterials as the Client shall direct, and shall fill and leave the borehole to thesatisfaction of the Client. In such case all works done and materials used willbe paid by client.

13. "LOST" (UNSUCCESSFUL) BOREHOLES:

"Lost" boreholes are either "dry" boreholes or "uncompleted" boreholes.

13.1 DRY BOREHOLES:

Dry boreholes are defined as:

13.1.1 A borehole having no water bearing zones/aquifers.

13.1.2. A Borehole that has insufficient discharge (less than 0.25

liters/second) for 6 hours of continuous pumping test.13.1.3 A borehole with stabilized Dynamic Water Level of more than

45 meters at minimum acceptable discharge of 0.25liters/second.

13.1.4 A borehole that has failed verticality test (see section 8).

13.1.5 Hand pump facility is unable to provide discharge of 0.25 litersper second. The hand pump installed on such borehole isunable to sustain continuous use by the communitiesthroughout the day*.

* This situation may arise with time within the Guarantee period because of one or moreconstructional defects such as ruptured / cracked casing, sections of boreholes collapsed, heavysilting closing the screen, screen chocked; lowering the discharge, or poor sitting of borehole withno potential sustainable aquifers, drilling up to insufficient depths to tap potential sustainableaquifer. In the above case the Contractor shall either improve the discharge by appropriate welldevelopment methods or if the dynamic water level is less than 40m, lower the pump inlet withadditional riser pipes and connecting rods. In the case of any remedial works not being effectivethe Contractor shall drill a new borehole at an alternative site mutually agreed with the WaterCommittee and the Contractor. If, after investigations, the Contractor f eels that there are nopossibil ities of drill ing a successful borehole in the village/ community, then the Contractorcan move to a new location. This should, however, be after two failed attempts to drill theborehole in the same location. If the contractor is unable to remove the defects, abandoned

due to any other reason then the borehole is classified as “Dry” and contractor has to refund thepayment made by the client for that borehole.

13.2 UNCOMPLETED BOREHOLES:

13.2.1 For any reasons, contractor is unable to continue drilling andcomplete the construction of borehole then this borehole is deemed tobe an “uncompleted “borehole.

13.2.2 In case of ‘"uncompleted" boreholes, no payment shall be made for

that borehole either for drilling or materials that cannot be salvaged


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and the rig's unproductive time spent. If the Contractor chooses todeviate from standard procedure and the agreed method of drilling,and wishes to adopt any other procedure or techniques that involvesany additional cost and time required it will be done so entirely at theContractor's own risk and cost.

14. TEST OF ACCEPTABILITY AND REPORTS:

14.1 Subject to meeting the requirements of the maintenance period, the borehole shallbe accepted for payment on presentation of the following reports at schedulesshown in the table below and sample of the formats given in the annexes:

NAME DESCRIPTION FREQUENCY

1. Sketch Mapshowing thedrilling plan.

See annex-1

A table showing the location, name, boreholenumber, and distances in kilometers from thelast drilling location along with a sketch mapshowing the above information and sequencein which the drilling will progress i.e. route ofmovement of the rig. ( see Annex -1).

Once, before thestarting of drillingoperations. .

2. Results ofGeophysicalsurveys

A table showing the location by District andWards, borehole number, GPS co-ordinates,and results of geophysical surveys showinggeology type, type of resistivity sounding curvewith the thickness of interpreted layers andtheir thickness, recommended depth to bedrilled. ( see Annex -2 for sample format)

Once after thecompletion ofgeophysical survey.

Submitted to clientbefore drillingcommences and alsoas part of final report.

Detailed report on resistivity surveys on eachborehole with i)sketch map showing thelocations of three sites investigated , ii)datacollection sheet for Vertical ElectricalSounding(VES); iii) VES curves withinterpretation on a log-log paper showing withthickness and resistivity and recommendationsfor drilling. ( A sample report will be provided )

Once - One report foreach district.

To be submittedalong with theinvoices for finalpayment.

3. Strata log,penetration rateLog and locationof main strikes.

(see Annex-8)

An accurate record of strata passed throughand the depths at which strata wereintercepted; also progressive measured (V-notch) airlifted yields after reaching water.; Anaccurate record of the penetration ratesachieved in minutes for each meter drilled,together with type, size and grade of bit.

Recorded daily asdrilling progress.

Submitted to clientwith invoices forpayment.

An accurate record of time spent each day ondifferent phases of drilling, to include rig downtime, with causes.

A record of depth at which the water zoneswere struck during the drilling. Thisinformation can be combined with strata log

and penetration log.


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4. Pumping Testdata ( seeannex 9) andrecovery testresults.

( See annex 10)

A detail report on the pump test, including thedata of draw down with time and recover test,specific yield and draw down,recommendations on hand pump installation.

Once, recorded duringpump test


5. Constructionlog

(See Annex-7)

An accurate record and a figure showing thedetails of well construction- position of allcasing, slotted casing, sand trap, end capplaced in the borehole, their quantities, handpump installation- position of cylinder, numberof connecting rods and riser pipes.

Recorded for eachborehole aftercompleting boreholeconstruction.


6. Invoices forworks done.

Invoices in same form in which rate schedulewere quoted for each borehole and a summarysheet of all invoices.

Once after completionbathes of 10boreholes.

7. Certificate ofCompletion ion

A certificate of Completion & .acceptance ofhand pump facility constructed from Clientstaff.

Once after theinspection of handpump facility by Clientstaff and Submitted toclient with theinvoices..

14.2 The Contractor is expected to submit four (3) bonded copies of the above reportsfor each district separately and a summary in the beginning for eachinstallment of payment. Client will provide Standard report format to thecontractor.


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ANNEX -1Table showing Locations for dr illing of Boreholes

with Distances Between locations.

1 Xxxxxxxx District

No. Location NAME BH No.Dist. In Kilometers from

last drilling site

1 A LW 2-1 0

2 B LW 2-2 40

3 C LW 2-3 23

4

5

6

7

8

9

10

11

12

2. Xxxxxxxx District

13 A LW 1-100 34

13 B LW 1-101 10

14 C LW 1-102 28

1516

17

18

19

20

21

22

23


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Annex -2

Map Showing the Locations for the Drilling of Boreholes.

JOLLY DISTRICT SKETCH MAP 29/03/2007 Not drawn to scale

Seke Road

ToMasvingo

SimonMazorodzeRoadTo

Highfield

N

● ●

● ● ●

BH


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Annex-3

Figure showing the distances from sources of pollution to be observedfor site selection for constructing a water point.


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Annex-4

o an yre

e c ap s ow ng e rou es or r gs an s ancese ween e consecu ve r ng oca ons.

anzo a

s

-a aame

en aman an o o

ms ms ev

u v

ar

R o u t e 1 f o r

r i g

m o v e m e n t

3


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Annex -5

Annex-5

Table showing the completion of works by the contractor ( separate table for each LOT)

NoDescription ofActivity

2009 January Feb. March April

Weeks 1 2 3 4 5 6 7 8 9 10 11 1213

14 15 1617

18 19 2021

2223

Responsible

1

Initial road surveyfor determining

Mobility of rigs,GPS reading,Distances.

Contractor

2

Technicalverification ofsites(Geophysical

surveys)

3Borehole DrillingWork

4 Pumping Test

5 Pump Installation.

6Apron, spillway andsoak-awayconstruction

7Cleaning the siteand handing over.


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Annex-6

Table showing locations and results of Vertical Electrical Sounding (VES)

Village BH No. GPS Co-ordinates. GeologyCurveType

Resistivity inOhm Meters

Thickness oflayers in ohm

meters

DepthTo drill

(nmeters)No. NAME S Lat. E Long. Type P1 P2 p3 h1 H2 h3

I. XXX .

1 Mbalame (A) LW 2-1 13 49.692 33 17.922 P A 42

2 Kanjanja LW 2-2 13 49.525 33 18.608 P A 39

3 Kanzota LW 2-3 13 48.486 33 17.446 P A 47

4

5

6

7

8

9

10

11

12

Sub-Total in Meters(1) 584

Average Drilling Depth in Meters: 48.67

II-TA KALOLO

13 DzamaLW 1-100 13 51.142 33 16.855 P A 44

14 YotamuLW 1-101 13 51.743 33 17.763 Pg C 38

15 Kanyopola

LW 1-

102 13 51.688 33 17.887 Pg C 44

16

17

18

19

20

21

22

23

24

Sub-Total in Meters(1) 496

Average Drilling Depth in Meters: 41.33


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Annex-7

Sanitary Protection, Dia. 12inches, depth 4 meters, with

steel casing

Steel casing

6inches , 3

meters length.

APRON : Thickness 4 inches, 2

meter dia. Drainage 3 meters

ANNEX -7

End Cap, Glued to sand

trap

Borehole equipped with

bush pump Type B,

Cylinder 600x 750mm

DETAILS OF BOREHOLE CONSTRUCTION

6 meters

45-70 meters

Borehole wall, dia. 8 inch

GI Riser pipe , 2 inches,medium series

PVC Screen, dia 5 inches,

class 10

Sand Trap, PVC casing 5

Inches, class 10, 3 meters

PVC casing , dia 5 inches,

class 10

Note : PVC casing & screen Nominal diameters are 6 inches and not 5 inchesas shown in the figure.


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Annex-8Litho log and drill time log with water strike zones

Drilling Company:

District Borehole Number

Location Date :Waterstrikes

Litho-logicalLog Depth

inMeters

Drill Time Log

GroundSurface

Minutes / per meter drilled

0 2 4 6 8 10 12 14 16

Loose soil

5

WeatheredLime stone

B O R E

H O L E

10

1st Strike

Little water

15

Marls

20

Hard Lime

stone

25

Limestone

30

Fracturedlime stone

2nd Strike 35

CompactLime stones

good waterbearing

3rd Strike Highlyfractured

Limestone

40


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Annex-9 -Continued

Annex-9PUMP TEST - STEP DRAW DOWN TEST REPORT

STEP 1 : Discharge set at ( Liters/Second): 0.25

TIME ELAPSED( In Minutes)

DEPTH TO WATER LEVEL(Meters)

DRAWDOWN(In meters)

REMARKS

0 5.8 0.00

1 6.65 0.85

2 7.25 1.45

3 7.54 1.74 20 L/ 60 SEC

4 8.29 2.495 8.76 2.96

6 8.82 3.02

7 9.08 3.28

8 9.84 4.04 20 L/ 60 SEC

9 10.1 4.30

10 10.5 4.70

15 11.4 5.60

20 11.54 5.74 20 L/ 60 SEC



DRAWDOWN(In meters)

REMARKS

0

1

2

3 20 L/ 50 SEC

4

5

6

7

8 20 L/ 50 SEC

9

10

15

20 20 L/ 50 SEC

STEP 3 : Dischrage set at ( Liters/Second):



DRAWDOWN(In meters)

REMARKS

( 20 MINUTES)

0

1 20 L/ 40 SEC

2

3

4

5

6 20 L/ 40 SEC

7

89

10 20 L/ 40 SEC

15

20

Pump Supervisor Drilling Supervisor Drilling Manager


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PUMP TEST - 4 HOURS AQUIFER TESTName of school: CHAWANTHA Distr ict : LL Date:15.11.2006

S.NOTIME

ELAPSED IN

MINUTES

DRAWDOWN

(METERS)

YIELD ( LTR /

SEC)

REMARKS

1 0

2 1 10 L/ 60 SEC

3 2

4 3

5 4

6 5

7 6 10 L/ 60 SEC

8 7

9 8

10 911 10

12 15

13 20 10 L/ 60 SEC

14 25

15 30

16 35

17 40 10 L/ 60 SEC

18 50

19 60

20 70

21 8022 90

23 105 10 L/ 60 SEC

24 120

25 135

26 150

27 165

28 180 10 L/ 60 SEC

29 195

30 210

31 225

32 240

Pump SupervisorDrilling

SupervisorDrilling Manager


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Annex-9 -Continued

Draw Down Curves

Step Draw downSTEP-DRAWDOWN TEST ; Chawantha

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.0018.00

20.00

22.00

24.00

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60

Time (min)

D r a w d o w n S ( m )

Series 1: 10 ltr/ 60 sec

Draw Down CurvesContinuous At Fixed Discharge

CONTINUOUS TEST ; Chaw antha

0

2

4

6

8

10

12

14

16

18

20

22

24

0 50 100 150 200 250 300

Time (min)

D r a w d o w n S ( m )

Series 1: 0.16 ltr/sec

Annex-10

PUMP TEST - RECOVERY TESTName of school: CHAWANTHA Distr ict : LL Date:10.11.2006


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S.NOTIME ELAPSED

IN MINUTESDRAWDOWN

(METERS)YIELD

( LTR / SEC)REMARKS

1 0 22.34

2 1 20.15

3 2 19.304 3 18.59

5 4 17.97

6 5 17.00

7 6 16.37

8 7 15.99

9 8 15.42

10 9 14.22

11 10 13.29

12 15 13.3413 20 13.15

14 25 10.28

15 30 9.63

16 35 8.48

17 40 7.72

18 45 7.05

19 50 6.61

20 55 6.43

21 60 6.1022

23

24

25

26

27

28

29

30

PumpSupervisor

DrillingSupervisor

Drilling Manager

APRON CONSTRUCTION FOR INSTALLING BUSH HAND PUMP


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Sanitary

Protection

Sand Bed 10 cms

GI casing 6 inches

Foundation

pit 70x70x40

cms

10cms

GI Pipes , 70 cms

welded to Casing pipe

Sand Bed 10 cms

thick

30 cms

cms

40 cms

Welded mesh

Installation of Hand pump will be based on the Manual for Installation of BushPump Type B. Below are some addit ional hints.

1. Level the ground surface.2. Look around the hand pump and find the direction of natural drainage. The

apron drainage should merge with the natural drainage.3. Dig foundation pit for hand pump 70 x70x 40 centimeters around the casing

pipe.4. Cut 3 pieces of reinforcement steel and weld about 30 centimeters below

the ground surface.

5. Mix concrete in ratio 1: 2: 3 (cement: sand: Gravel 20mm) and fill thefoundation pit. Ensure that casing is vertical. Make sure the concrete is wellcompacted and all air bubbles removed.

6. Draw a circle one meter radius or place the mold with the casing pipeslightly off centre on the ground. Dig 10 centimeters below the groundsurface and fill with sand. Compact the sand.

7. Assemble the Apron mold including the drainage mold and foot stand piece. Apply old used oil or diesel to the inner part of the mold. This allows themold to be released easily and not crack the apron casted or getting themold stuck to the apron. Place apron mold and ensure that the drainage forthe mold is along the spout and in the direction of natural drainage. Thedrainage mold with one end closed should be at the end of the drainage

8. Mix concrete Cement: sand: Gravel (20 mm) and pour about 5 cms.Compact the concrete as it is filled. Use a metal rod to ensure that all airbubbles are removed.

9. Make enough open area in the center to place welded mesh through thecasing / Hand pump is already installed. Continue filling the concrete intothe mold.

10. Fill the annular space between the inner and outer mold.11. Similarly fill the drainage mold. Allow the concrete to dry for 3-4 hours

before removing the mold. Gently tap the outer mold to release the mold

from concrete apron.12. Do a rough polishing of the apron surface. Sprinkle some cement and water


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if needed to make the surface little smooth. Work well on the drainagesections and the ridge along the Apron.

13. Make several ridges with sand or soil inside the apron. Fill them with waterfor curing. There should be standing water for 7 days. Apron that is notcured will crack or will soon develop pot holes. In 7-8 days, concrete will get80% of its strength.

14. Install the pump after 7 days.15. Pump several times until the water is clear and there is no fine sand or

materials.16. Properly installed hand pumps should fill a 20 liters bucket in 20- 25 full

strokes. If it takes more than 30 strokes then something is wrong with theinstallation of hand pump. The full stroke of the pump should be ideally 22-23 cms.

Documents

RFP ZIMA 2014-0 Borehole Drilling Phase2 Annex17