Plan International Zambia
Plan International Zambia Tel: 260-1-260074/5
Plot No. 87A Kabulonga Road F ax: 260-1-260093
Lusaka P/Bag 518X RW
INVITATION FOR BIDS
TENDER FOR DRILLING OF 04 x BOREHOLE AND INSTALLATION OF AFRIDEV HAND PUMP AT MUSHINGWA PRIMARY, TWAMPANE PRIMARY, LUPILI PRIMARY AND LUWO PRIMARY SCHOOLS IN CHEMBE DISTRICT, LUAPULA PROVINCE.
Plan International Zambia has funding Support to Rural Water Supply and Sanitation for in MUSHINGWA PRIMARY, TWAMPANE PRIMARY, LUPILI PRIMARY AND LUWO PRIMARY SCHOOLS Chembe District, Luapula Province.
Plan International Zambia now invites sealed bids from eligible bidders to bid for:
Drilling of 04 x borehole and installation of AFRIDEV pumps at Mushingwa Primary, Twampane Primary, Lupili Primary and Luwo Primary Schools in Chembe District, Luapula Province.
Bidding will be conducted through the selective bidding procedure consistent with plan international procurement regulations
Interested and eligible bidders may obtain further information through [email protected] and [email protected] on 0763 882568 & 0977417676 respectively at Plan International Zambia, kabulonga Road, plot 87A Lusaka Zambia, strictly between 10:00hours and 12:30 before the deadline of submission on 10th October, 2020. The bidders who may need some further clarification on the tendering procedures and technical information of the aforementioned works may contact the Logistics and Procurement Department and Water and Sanitation Manager, respectively.
Bidders are also requested to provider the following information in the narrative/technical proposal:
1. Company registration certificate
2. National council for construction Registration Certificate in category C Grade 5 or better
3. Valid practicing certificates from engineering institution of Zambia and engineer s registration board
4. VAT registration/clearance
5. WARMA registration and approval for drilling boreholes
6. Completeness scope of tender /works
7. Power of attorney
8. Bid form complete and signed
9. No pending litigation status that would negatively affect this contract
10. Detailed list of equipment, vehicles and staff members. If a bidder intends to subcontract the job , full details of the sub-contractor should also be provided
You are requested to consider the requirements as expressed in the bidding document and allowed to bid for ALL four (4) boreholes in sites. Bids should be entered in the bids register and deposited in the tender box at plan international Zambia, Plot 87A Kabulonga Road, kabulonga. Lusaka Zambia and Plot 1030 Chitimukulu Road, Mansa Zambia on or before 9th October 2020 by 12:30hours local Time.
The bid validity shall be 30 days
The Bidder shall seal the original and a copy of the Bid in two inner envelopes and one outer envelope, duly marking the inner envelopes as “ORIGINAL” and “COPY”.
The inner and outer envelopes shall
(a) Be addressed to Plan International
(b) Provide a warning not to open before the 12:00hrs on the 09th October, 2020.
In addition to the identification required above, the inner envelopes shall indicate the name and address of the Bidder to enable the Plan International Zambia to contact bidder and inform them of the late submission.
If the outer envelope is not sealed and marked as above, Plan International will assume no responsibility for the misplacement or premature opening of the Bid.
SEALED BIDS CLEARLY MARKED “TENDER FOR THE MUSHINGWA PRIMARY, TWAMPANE PRIMARY, LUPILI PRIMARY AND LUWO PRIMARY SCHOOLS BOREHOLE CONSTRUCTION” MUST BE DEPOSITED IN THE TENDER BOX SITUATED AT THE RECEPTION, PLAN INTERNATIONAL ZAMBIA, PLOT NO. 87A KABULONGA ROAD, KABULONGA AND PLOT 1030 CHITIMUKULU ROAD, MANSA ON OR BEFORE 9TH OCTOBER, 2020 AT 12:30 HOURS LOCAL TIME.
Prior to depositing the bids in the Tender box, all Bidders must sign in the Tender Deposit Register to be found at the reception.
1. HOWEVER, BIDS SUBMITTED VIA FACSMILE WILL NOT BE ACCEPTED
2. The closing date for the receipt of bids is 9TH OCTOBER, 2012 at 12:30 hour’s local time and any bids received after the time and date stipulated above will not be accepted. There will be no public tender opening.
LATE, EMAILED OR FAXED BIDS WILL BE REJECTED.
The Country Director
Plan International Zambia
Please quote your lowest prices for the borehole drilling, supply, installation and commissioning of the following items.
Item DESCRIPTION OF SERVICES
A Drilling of 04 x borehole and installation of AFRIDEV pumps at MUSHINGWA PRIMARY, TWAMPANE PRIMARY, LUPILI PRIMARY AND LUWO PRIMARY SCHOOLS in Chembe District.
The evaluation criteria for this contract consist of the following three parts;
PART ONE : QUALIFICATION INFORMATION FOR BIDDERS
To qualify for award of the Contract, bidders shall meet the following minimum qualifying criteria:
a) Work performed as prime Contractor on works of a similar nature and volume over the last two years. The values should be indicated in Zambian Kwacha. Also list details of work under way or committed, including expected completion date.
Project name and within Zambia Name of client and contact person Type of work performed and year of completion Value of contract Client’s contact/ details
b) Bidders should submit proposed Program (work method and schedule). Descriptions, drawings, and charts, as necessary, to comply with the requirements of the bidding documents.
c) The minimum required annual volume of construction works within Zambia for the successful bidder in any of the last two years shall be ZMW50,000.00.
d) The minimum amount of liquid assets and/or credit facilities net of other contractual commitments of the successful Bidder shall be: ZMW100,000.00.
e) The essential machinery to be made available for the Contract by the successful Bidder shall be a minimum of one DTH drilling rig. The bidder should provide proof of ownership of the essential machinery.
f) Qualifications and experience of key personnel proposed for administration and execution of the Contract.
Position Name Years of experience (general) Years of experience in proposed position
(a) Drilling Engineer
(b)Foreman of drilling works
PART TWO – WEIGHTING FACTORS FOR THE TECHNICAL EVALUATION
The following weighting factors shall be used for the Technical Evaluation;
Weighting (% of total score)
a. Quality of vehicles, plant, equipment and materials; 50%
b. Quality of personnel; 20%
c. Relevant experience; 20%
d. Completeness of Tender;
All tenders achieving a score of 80% or higher will proceed to Part 2.
PART 3- TENDER PRICE AND VERIFICATION
The lowest bidder passing PART 2 will be visited to verify sub-clauses (a) and (b) of Part 2. if the verification is confirmed the contract shall be awarded to that bidder. If not the second lowest bidder will be visited and so on.
Plan international reserves the right to:
- Contact any or all references supplied by the Bidder
- Request additional supporting or supplementary data (from the Bidder).
- Accept any bids in whole or in part to accept or reject any Bid, and to cancel the bidding process and reject all bids, at any time prior to the award of Contract, without thereby incurring any liability to the affected Bidder or bidders or any obligation to inform the affected Bidder or bidders of the grounds for Plan’s action.
- Negotiate with the most favorable Bidders
- Award contracts to more than one Bidder for portions of the statement of work defined herein.
- Plan International Zambia shall pay the contractor 45% of the contract value before commencement of works.
- Plan International Zambia shall pay the contractor 45% of the contract value upon satisfactorily executed, completed works and certified by the PLAN Authorized Representative.
- Plan international Zambia shall pay the final 10% upon the expiry of the retention period; where no damages have occurred on the said boreholes caused by poor workmanship or poor quality of materials.
DEFECT LIABILITY PERIOD.
The Defects Liability Period is 3 Months; however any damage to the works caused thereby arising from faulty materials or workmanship occurring within the agreed Defects, Liability Period (whichever period is the greater) shall be made good by the Contractor at his own cost.
A retention fee of 10% of the contract value shall be allowed for the Defect Liability Period. The successful bidder shall secure a maintenance bond in the equivalent sum of the retention amount upon completion of the works and then Plan shall release the retention money.
The contractor is to pay liquidated damages to Plan International Zambia at the rate of ZMW 500.00 per calendar day for each day past the completion date of the works.
FORM OF TENDER
Contract Title.: LOT _______________________
Date of Tender: ________________________
Description Work: ____________________________________
Contracting Agency: Plan International Zambia
Private Bag 58RW
Name of contractors/ company: _____________________________________
Address of Company: ______________________________________
Telephone Number: _____________________
Fax Number: ___________________________
Having read, understood and given due consideration of the set terms and conditions; we offer to undertake the drilling and construction of borehole in ………………….at the scheduled of rates given in attached form. The proposed work plan is detailed below:
DISTRICT NO. Of boreholes
Type and make of rig that will be used
Number of weeks
To be Drilled and works to be done.
A. Detailed list of technical staff who will be actually in field to execute this works:
B The resident representative responsible for this works:
Contact Phone and email:
C. Details of the subcontractor to be engaged for hydro geological siting/survey:______________________________
SPECIFICATIONS FOR DRILLING AND CONSTRUCTION OF BOREHOLE FITTED WITH HANDPUMPS FOR RURAL WATER SUPPLIES IN CHEMBE
1. The Bill of Quantities for drilling of Boreholes and Superstructure Construction
2. The Bill of Quantities do not generally give a full description of the plant and equipment to be supplied and the services to be performed under each item. Bidders shall be deemed to have read the Technical Specifications and other sections of the tender documents and reviewed the Drawings to ascertain the full scope of the requirements included in each item prior to filling in the rates and prices.
Rates and prices inserted in the Schedules shall be deemed to cover the work, finished and complete in all respects. The Bidders shall take full account in his rates and prices of all requirements and obligations, expressed or implied in all parts of the Contract, together with all incidental and contingent expenses, and risks of every kind involved in the proper construction of the Works. No claim for additional payment will be allowed for any error or misunderstanding in this respect.
The entered rates and prices shall be deemed to include for the full scope as aforesaid, including overheads and profit.
3. If Bidders are unclear or uncertain as to the scope of any item, they shall seek clarification in accordance with the Instructions to Bidders in the tender documents prior to submitting their tender.
4. The permanent Works shall be measured net notwithstanding any general or local customs except where otherwise specifically described or prescribed in the Contract and no allowance shall be made for waste, tolerance, prevention, working space or over break.
5. The method of measurement of the completed work for payment shall be in accordance with “Civil Engineering Standard method of measurement” CESMM3 third edition, 1995, published by the Institution of Civil Engineers of United Kingdom.
6. Prices shall be filled in indelible ink, and any alterations necessary due to errors, etc., shall be initialed by the Bidder.
Prices shall be fixed and firm for the duration of the Contract.
7. Prices shall be quoted in the manner indicated and in the currencies specified in the ITT in the tender documents.
For each item, Bidders shall complete each appropriate column in the respective Bills, giving the price breakdown as indicated in the Bills.
Prices given in the Bills against each item shall be for the scope covered by that item as detailed in the Technical Specifications, Drawings or elsewhere in the tender documents.
8. Where there are errors between the total of the amounts given under the column for the unit rates and the amount given under the Total, the former shall prevail and the latter will be corrected accordingly.
Where there are errors between the total of the amounts of Bill, the former shall prevail and the latter will be corrected accordingly.
Where there are discrepancies between amounts stated in figures and amounts stated in words, the amounts stated in words shall prevail.
9. Payments will be made to the Contractor in Zambian kwacha.
10. Items left blank will be deemed to have been included in other items. The TOTAL for each Schedule and the TOTAL of the Grand Summary shall be deemed to be the total price for executing the Facilities and sections thereof in complete accordance with the Contract, whether or not each individual item has been priced.
11. When requested by the Contracting Agency for the purposes of making payments or part payments, valuing variations or evaluating claims, or for such other purposes as the Contracting Agency may reasonably require, the Contractor shall provide the Contracting Agency with a breakdown of any composite or lump sum items included in the Schedules.
12. The Bidder shall be deemed to have taken into account all of the following in his tender prices and his construction programme:
(a) All recognized holidays, festivals, religious and other customs.
(b) Normal weather conditions.
13. No claim will be considered for further payment in respect of any work or method of execution which may be described in the Contract or is inherent in the construction of the Work as detailed on the drawings on account of:
(a) items having been omitted from the Bill of Quantities;
(b) any omission from the wording of the items or from clauses in the Preamble;
(c) no mention or such work or method of execution having been made in the Preamble.
14. The accuracy of the quantities given in the Schedules is not guaranteed and quantities given should not be taken as a guide for ordering materials. All quantities given in the Schedules may be subject to re-measurement, to the unit of measurement shown and at the rate inserted against each item and payment made of the re-measured items.
15. The Contractor shall execute all works in good weather conditions, and the whole cost thereof will be deemed to be included in the rates and prices.
16. Unless expressly stated otherwise, all rates and prices entered in the Bill of Quantities will be deemed to have included the following:
(a) Labour and all costs in connection with the execution of the Works and the correction of defects until the expiry of the defects liability period.
(b) Construction plant, equipment and all costs in connection therewith.
(c) Sampling and testing materials and goods, testing workmanship, providing, storing, packing and transporting samples to and from the place of testing in accordance with the Specifications.
(d) Fixing, erecting, installing or placing of materials and goods in position.
(e) Disposing of surplus and unsuitable materials and goods and excavated materials, including stacking, storing, loading, transporting and unloading.
(f) All general obligations, liabilities and risks involved in the execution and maintenance of the Works set forth or reasonably implied in the documents on which the Tender is based.
(g) Establishment charges, overheads and profit.
(h) Complying with all the requirements of the Contract Documents.
17. The rates and prices inserted by the Tenderer shall apply throughout the Contract to any location within the Contract and to any additional work ordered by the Employer.
18. The total quantity included in the final measurement of each item shall be measured to the [nearest integer relative to that item, or to one decimal place if so indicated in the Bills of Quantities.
19. The sums inserted in the Bills of Quantities shall include for leveling; removing surplus material; providing and maintaining signaling, fencing and removal on completion, and access and drainage and de-watering where specified; and for reinstating the Works Areas to their original condition upon completion.
20. The Tenderer is deemed to have included in his price personnel to help the on-site Employer’s representative (the supervising engineer) to fulfill his duties like level checking, checking quantities etc.
He shall also provide to the on-site Employer’s representative all equipment necessary, like measuring tape and leveling instrument. The equipment shall be returned to the Contractor after termination of the Contract.
21. The Tenderer shall include in his rates the preparation of as-built drawings for the works carried out based on the design drawings.
22 Abbreviations used herein shall have the following meanings:
mm = millimeter
cm = centimeter
m = metre
km = kilometre
m2 = square metre
m3 = cubic metre
kg = kilogram
t = tonne (1000 kilograms)
l = litre
h = hour
no. = Number
LS = lump sum
LM = linear meter
1. Borehole Sites and Identification (before drilling)
The on-site Employer’s representative shall provide the Contractor with a list of sites where the boreholes will be constructed and the Contractor shall construct the boreholes at these sites as specified. The exact location of each drilling point is the responsibility of the Employer and his representative in consultation with the communities. The Contractor is not allowed to start drilling unless the On-Site Employer’s representative has confirmed that the drilling site is located correctly. Drilling sites will be identified with clear markers labeled with a position reference from the geophysical survey. Boreholes shall not be drilled more than 1m from the marker, except where this has been approved by the on-site Employer’s representative.
The on-site Employer’s representative shall allocate a temporary number to each borehole.
2. Contract on Site
Whenever the Contractor is undertaking work in relation to drilling, installation of casing or screen, development, pumping test or water sampling on a site, the Contractors staff shall keep a full copy of the Contract on site. The Contractor, at his own cost, shall prepare a sufficient number of copies of the Contract. The Contractor shall make the Contract available for inspection by the on-site Employer’s representative on request.
3. Borehole Drilling
3.1. Drilling Methods
It is expected that the most appropriate method of drilling in the project area will be Mud-Rotary to stabilize the unconsolidated formations. In some places Down the Hole Hammer techniques may be employed to improve penetration rates.
The tenderer should clearly indicate what method/s are intended and ensure that the equipment, materials and personnel experience are clearly indicated including a detailed description of the methods offered. Details of logistical support such as spare parts carried, office equipment to be provided, communications equipment so be used etc. must be provided.
The rig must have the necessary accessories including sufficient working casings and drill bits to drill through the various formations. If direct circulation rotary is used, the flushing medium should be air, water or stable foam. If, at any stage the use of mud is considered necessary either as a primary fluid or as an additive to create “stiff foam”, only degradable high quality polymer will be acceptable.
In zones of sandy formations such as the Kalahari Sand the diameter of the hole in the screened zone and down to the bottom of the borehole should be minimum 200mm in order to make sufficient annular space for gravel pack in the annulus between the hole and the screen (112 mm).
In areas with unconsolidated overburden followed by hard basement rock the drilling must be carried through the overburden and highly weathered rock using a bit with diameter between 200mm to 250mm and then through the moderately weathered rock and the fresh rock using a bit with diameter of 165/176mm.
3.2. Verticality and Alignment
In a completed and developed borehole, the casing must allow the installation of the pump without difficulty at any depth. Thus, the borehole must be both straight and vertical. If so required by the on-site Employer’s representative, the Contractor shall demonstrate the verticality and alignment of any borehole by lowering a cylindrical dummy 3 m in length and with a diameter of not less than 15 mm smaller than that of the borehole or casing, throughout the whole length of the section being tested. Should the dummy fail to move freely throughout this section, or should the deviation from the vertical exceed two thirds of the minimum diameter of the section, the Contractor shall be obliged to correct the verticality and straightness of the borehole at his own expense. If this is not possible he shall drill a replacement borehole nearby at his own expense.
3.3. Protection Casings
Protection casing made of steel shall be installed in unstable overburden before drilling the basement. Protection steel casing shall normally have an outside diameter of 200 mm and shall have screwed flush joints. The Contractor shall ensure that it is of sufficient diameter to enable drilling of the complete well, together with installation of the permanent well casing, screen, and for placing the gravel pack.
For successful boreholes, the protection casings in the soft formations shall be removed from the hole, as soon as the borehole has been completed, unless the on-site Employer’s representative instructs the Contractor to do otherwise, based on the nature of the geological formation.
In case of unsuccessful boreholes, the protection casings shall be removed unless the on-site Employer’s representative instructs the Contractor not to remove them, see 2.3.11.
During drilling, samples of unwashed drill cuttings shall be collected at 1m interval and at every change of rock type or colour. The sample shall be logged by the driller and the record kept on a daily log sheet. The record shall indicate:
a) The lithology
b) The degree of consolidation or hardness
c) If unconsolidated, nature of the material, i.e. subjective description of grain sizes, degree of rounding, clay content, and colour.
A representative sample of every distinct horizon or change of rock type as directed by the on-site Employer’s representative, packed and stored in solid polythene bags and accurately labelled with the name of the community, borehole number, date and depth of sampling.
3.5. Rate of Drilling
Accurate records of penetration rate per metre shall be maintained and included on the daily log sheet, see attached sample form (Attachment 1).
3.6. Interim Yield Tests
Interim yield tests shall be carried out at the first struck of water and at each stage during drilling when the flow of water increases (when down the hole hammer method is applied interim tests are possible, if mud drilling is applied interim yield tests are not possible). The depths of measurement and the yield of water shall be recorded on the daily log sheet. Interim yield tests shall be carried out for at least 30 minutes to establish the optimum yield at the final depth of drilling.
3.7. Final Drilling Depth
The on-site Employer’s representative has the responsibility for determining the final drilling depth according to indications provided by the hydrogeological and geophysical survey and analysis of drill cuttings on site.
3.8. Identification of the Drilled Boreholes
The Contractor shall mark the Identification Number given by the on-site Employer’s representative on the borehole casing, using a permanent water-proof marker.
Dry and abandoned boreholes shall also be numbered on the daily log sheet.
4. Borehole Construction
Generally the design elaborated in drawings no. 1 and 2 (refer Vol. III.ii) will be used. The detailed design including positions of screens and type of gravel pack for the boreholes will be determined on site by the on-site Employer’s representative together with the Contractor’s Hydrogeologist/Drilling Superintendent.
4.2. Borehole Lining
Lined boreholes shall use high impact-resistant Poly Vinyl Chloride (UPVC) plastic casings and screens specifically manufactured for boreholes.
The PVC shall have a uniform colour and should not have been directly exposed to the sun for longer periods. There shall be no damage of the PVC of any kind. The PVC shall be free from cracks and the surface shall be smooth without impurities or grains.
The PVC casing and screens shall be in accordance with the specification in the table below.
Characteristics of PVC casing and screen
REFERENCE CHARACTERISTICS STANDARD
Material UPVC of quality without lead stabiliser, masse additives maximum 3 %, elasticity module 3,000 N/mm2, tensile strength 45-55 N/mm2. DIN 8061
Inner/outer diameter 112/125 mm DIN 8062
Wall thickness 5.04 mm (minimum) DIN 8062
Screen Screw flush joints, traction resistance 2,000 kg DIN 4925
Screen slots 0,25, 0,5 and 1 mm openings, open area minimum 9% DIN 4925
Compressive strength Minimum 17 bars DIN 19532
4.3. Plain Casings
The casings shall have an inner diameter of 112 mm and a wall thickness of 5.04 mm, i.e. 112/125 mm (Standard DIN 4925).
The inner diameter and wall thickness shall be the same as for the plain casings above. The screen shall have a slot size of 0.25 mm, 0.5mm or 1 mm depending on the aquifer material (Standard DIN 4925). The screen slots of 1mm is normally applied for hard basement rocks and slots of 0.5 mm is applied in loose sedimentary formations. However in very fine grained formations (Kalahari Sand for example) screens with slot size 0.25 mm shall be available. The type of screen shall be decided by the on-site Employer’s representative.
All casings and screens shall have screwed flush joints. The threads must be sturdy, either curved or angular with no eccentricity to allow for easy handling.
Centralizers of suitable size (certified by the on-site Employer’s representative) shall be fitted to casings at 6m intervals.
4.7. Bottom Plugs
A bottom plug shall be fitted on the lower end of the screen or casing as designed in drawings No. 1 and 2.
4.8. Gravel Pack
Boreholes shall be gravel-packed as in designs given in drawings No. 1 and 2, with clean, well-rounded quartz gravel of 1-2 mm grading for sedimentary formation and 2-4 mm grading for basement aquifers. In very fine grained formations such as or similar to the Kalahari Sand 0.4 – 0.8 mm gravel pack should be available and installed.
The gravel shall be installed within the annulus between the borehole wall and the screen using methods approved by the on-site Employer’s representative and the level measured accurately before grouting. The gravel pack shall be topped up as necessary to maintain the prescribed level also after development, in accordance with the instructions from the on-site Employer’s representative.
4.9. Sanitary Seal
The sanitary seal shall be made with cement-bentonite grout. Quick-hardening cement is NOT allowed for sanitary seal of the PVC casing since the heat production is increased and may cause damage on PVC.
Bentonite shall comprise 4 % by weight of the cement. First, bentonite shall be mixed with water, then cement shall be added and the grout mixed thoroughly until it forms thick slurry free of lumps. The grout shall be placed outside the casing, using a grout pump and pipe, in one continuous operation, from the bottom and upwards. If necessary, the Contractor shall ensure that the casing is filled with water, to prevent collapsing.
A sample shall be taken to check the hardening of the grout, and no activity that can affect the grouting shall take place until the sample is hardened.
A layer of fine sand shall be placed on top of the gravel pack before placement of the grout.
Grout shall be allowed to set for 24 hours. No work shall be carried out on the borehole during this time.
Grout seals shall be placed with 1m grout seal above the gravel pack, and a 4 m thick grout seal above the back filled material. These columns shall be separated by backfilling material.
The annulus between two grout seals of successful boreholes shall be filled with drill cuttings or other suitable material approved by the on-site Employer’s representative.
4.11. Abandoned Boreholes
(1) Unsuccessful boreholes due to non-compliance with the Technical Specifications, loss of tools, accidents or any other cause, which is the responsibility of the Contractor, shall be entirely at his expense.
(2) If a borehole which has been sited by the on-site Employer’s representative, has been properly constructed and developed by the Contractor, but has insufficient yield, the Contractor may, with the written agreement of the on-site Employer’s representative, abandon it after recovering all linings, screens and other equipment that can be reasonably salvaged and after restoration of the site to its original condition receive full payment for all works completed at the unit rates applicable.
(3) If, during the drilling of a borehole, the on-site Employer’s representative judges the lithology or hydrogeological conditions unfavourable for obtaining adequate groundwater, he may give the order to abandon the drilling. In this case, the work carried out will be paid in full at the unit rates applicable.
(4) Site preparation, dismantling and restoration will be settled according to the Bills of Quantities.
Taking into consideration the geological log of the borehole, the on-site Employer’s representative will instruct the Contractor to remove the protection casings from unsuccessful boreholes.
4.12. Borehole Capping
All permanent borehole linings should be completed 0.5m above ground surface and be temporarily capped and locked if necessary with a suitable capping device approved by the on-site Employer’s representative.
4.13. Borehole Development
Borehole development shall be limited to jetting, surging airlifting and over-pumping methods only. Any damage caused by development procedures shall be rectified by the Contractor to the on-site Employer’s representative satisfaction.
All airlifting will be carried out using suitably sized eductor and inductor pipes (2 pipe system). The bottom of the inductor pipe to have a perforated pipe with the bottom closed. The top of the eductor pipe to have a “Tee” piece with a gland for the introduction of the inductor pipe and a discharge pipe to deliver the water away from the well head and facilitate yield measurement.
The pipes for airlifting shall be installed initially at different depths ensuring development at the top of the screen section and working downward through the screen and below the screen section. Development shall be continued until the discharged water is free of sand and micaceous material, and the on-site Employer’s representative decides that further development will result in no significant improvement in the yield or quality.
The minimum development time shall be two hours. Sediments and other materials falling to the bottom of the borehole during the development shall be removed by airlifting or bailing after the completion of the development. Development shall be considered complete when the water is clean i.e. produces a sand and/or silt spot less than 3 mm in diameter in a 10 litre sample of water.
See Borehole Development Form (Attachment 2)
4.14. Pumping Test
A six (6)-hour uninterrupted constant yield test shall be carried out with a suitable submersible pump approved by the on-site Employer’s representative at a discharge rate between 50% and 90% of the estimated air lift yield of the borehole. The exact discharge rate shall be determined by the on-site Employer’s representative. The 6-hour pumping shall be followed by a three (3)-hour recovery test. The pump rate shall not fluctuate more than +/- 10% during pumping. In case of a breakdown of the equipment during the pumping test the borehole shall be allowed to recover to its static water level and for at least 6 hours and the test repeated at no additional cost to the Employer.
During the pumping test the contractor shall make arrangements for disposal of all water arising from tested borehole by means of an impermeable pipe, flume or lined trench, to a point at least 50 meters downstream from the tested borehole in order to minimize the risk of recharging the well. The Contractor shall complete the appropriate pumping test and recovery, see Pumping Test Form (Attachment 3).
5. Water Quality Test
The Contractor shall provide a portable pH meter, conductivity meter and test strips for Total Iron and Nitrate for on-site water quality measurements at the end of each drilling phase. Water samples for laboratory analysis and on site tests shall be taken immediately before the end of the 6 hours of pumping test. One sample shall be used for on-site analysis for pH, conductivity, total iron and nitrate.
Two other samples shall be taken in volume of 1litre in bottles recommended by a certified laboratory. The samples for laboratory tests shall be analyzed for the parameters indicated in the Laboratory Report Form attached (attachment 4). The sample for Ca, Mg, Fe and Mn shall be conserved with HNO3 to pH <2. The pH shall be checked without contaminating the sample.
The samples shall all be kept in a cold place such as a cool box or refrigerator at approximately 5 degrees Celsius until they are delivered at the laboratory. The Contractor can deliver the water samples taken in one week to the laboratory Monday the following week, provided that the sampling procedure is followed strictly. All sample bottles shall be filled completely and closed tightly and marked with the name of the site. The contractor shall arrange with a certified laboratory agreed by the Plan to undertake the analysis within 24 hours after samples are delivered to the laboratory. A qualified Chemist must certify the results of the analysis.
The contractor shall disinfect the borehole as the last exercise before pump installation. During the disinfection process it must be ensured that the concentration of available chlorine in the well and filter pack is at least 50 mg/l and that it remains for 2 hours. Borehole surfaces that are above the static water level in the well must be completely flushed with the solution.
7. Borehole Completion
After completion of each borehole, the Contractor shall submit to the on-site Employer’s representative a report (in three copies) summarizing the data from the daily drilling records and including a borehole sketch and lithological log.
8. Work-on-site Journal
The Contractor shall maintain a “work-on-site journal” in which all the information concerning the works would be recorded. The information to be recorded shall include:
• Site name (name of the village)
• Borehole number
• Time and date of arrival and departure of the rig
• Number of kilometers indicated on the rig truck when leaving
• Compressor time counter at the beginning and the end of drilling, and similarly for development and pump testing.
• Time at which the rig was set up and the start of the drilling
• Drilling time for each rod sections
• Diameter and technique used with each rod
• Depth reached with each rod
• Description of drilled formation indicating as well whether it is soft, hard…etc.
• Shut down period due to breakdown
• Length of casings, screens, gravel pack
• Duration of development, yield and state of water.
• On site water quality test
• Any other information considered technically necessary
LIST OF DRAWINGS
Drawing No. 1 General Well Design in Consolidated formations
Drawing No. 2 General Well Design in Unconsolidated formations
PENETRATION RATE FORM Attachment No. 1
PENETRATION RATE AND YIELD LOG
Depth (m) Time (min) Yield (mm) Marsh Funnel (seconds) Mud Mixing Comment Depth (m) Time (min) Yield (mm) Marsh Funnel (seconds) Mud Mixing Comment
FW = 1st Strike SW = 2nd Strike MS = Main Strike
Community BH Code
Lithological Log Borehole Design 80m
BOREHOLE DEVELOPMENT Attachment 2
District: Borehole Number:
Depth at start of Development: m Static Water Level: m
Depth at end of Development: m Date:
Screen One: Casing Stick Up:
Screen Two: Mud Additive:
Cycle Start time End time Cycle time (min) BH depth (m) Observations
Total cycle time (min)
Cycle Start time End time Cycle time (min) Observations
Total cycle time (min)
Contractor Representative District Representative
Price A1 Preliminary Mobilisation
The lump sum covers the mobilisation to the drilling area including transport of the drilling unit and all other equipment, plant and materials from the point of origin to the base camp area and setting up the base camp. The necessary insurances of the whole equipment, plant and materials are included in the lump sum.
Price A1 Demobilisation from the drilling area to the place of origin
The lump sum covers demobilization including striking the base camp, cleaning the site of the base camp and transport of the drilling unit and all other equipment, plant and materials from the base camp to the next base camp or to the place of origin. The necessary insurances of the whole equipment, plant and materials are included in the lump sum.
Price B.1 Drilling 212-250 mm borehole in overburden
The price covers the drilling per meter of 212 -250 mm in overburden which is unconsolidated formations of clay, silt, sand, gravel and stones.
Price B.2 Drilling 165-176 mm in basement rocks
The price covers the drilling per meter in the basement rocks using down the hole hammer.
Price B.3 Mud drilling in unconsolidated formations
The price covers the drilling per meter in unconsolidated formations using biodegradable mud. Any type of bentonite mud is not allowed.
Borehole lining and installation
Price C.1 Supply and install 112/125 mm PVC casing
The price covers supply and installation per meter of 112/125 mm PVC casing with flush threaded joints respecting DIN 4925.
Price C.2 Supply and install 112/125 mm PVC screens slot 0,25, 0.5 mm and 1 mm
The price covers supply and installation per meter of 112/125 mm PVC screens, slots 0,25 mm, 0.5 mm and 1 mm with flush threaded joints respecting DIN 4925.
Price C.3 Supply and install centralizers for 125 mm casing and 125 mm screens
The price covers supply and installation of non-corrosive centralizers suitable for 112/125 mm casing and 112/125 mm screens. Centralizers shall be installed for every 6 meters in the sections with casing and screens. The price is per unit.
Price C.4 Supply and install bail plug
The price covers supply and installations of bottom plugs of PVC at the bottom of the borehole.
Price C.5 Supply and install gravel pack with grain size 2-4 mm
The price covers supply and installation of well calibrated, well washed gravel with grain size 2-4 mm. The price is per linear meter (LM).
Price C.6 Supply and install gravel pack with grain size 1-2 mm
The price covers the supply of well calibrated, well washed gravel with grain size 1-2 mm. The price is per linear meter (LM).
Price C.7 Supply and install gravel pack with grain size 0.4-0.8 mm
The price covers the supply of well calibrated, well washed gravel with grain size 0.4-0.8 mm. The price is per linear meter (LM).
Price C.8 Back filling between the two seal grouts
The price covers supply and installation of cuttings or other suitable material approved by the consultant in the annulus between the two seal grouts (Drawing No. 1 and 2).The price is per linear meter (LM).
Price C.9 Supply and install grout seal
The price covers supply, preparation and installation of cement bentonite grout. In each successful borehole a 1 m grout seal shall be installed above the gravel pack and a 4 m grout seal shall be installed above the back filled material. The price is per linear meter (LM) (Drawing No. 1 and 2).
Cleaning, Development and Testing
Price D.1 Cleaning and development by air lift
The price covers development of the borehole by air-lift until water is clear and free of sand silt or clay or other material, after installation of casing, screens and gravel pack. The air-lift shall cover a compressor capable of delivering 17 bars. The price comprises measurements of yield and measurements of dynamic water level every 15 minutes. The air-lift shall not be less than two hours. The price is per hour running time of the compressor.
Price D.2 Pumping tests, draw down, pump in use
The price covers installation of submersible pump capable of pumping with a discharge of 50-90 % of the airlift yield and performance of a 6 hours constant yield pumping test according to specifications in the technical specifications. The pumping test has to be documented (i.e. as per developed pump test form). The price is per hour of pumping.
Price D.3 Pumping test, recovery, pump stopped
The price covers measurement of water table during a recovery period of at least 3 hours after the pump has been stopped according to technical specifications. The price is per hour of recovery.
Price D.4 Installation and removal of pump test unit at site
The price covers installation and removal of the pump test unit at site and the transport of the unit from one site to another in the drilling area.
Price D.5 Water quality analysis
The price covers the taking of water samples at the end of pumping test, transport of samples to a licensed laboratory or an otherwise agreed laboratory and analysis of the water samples in the laboratory of the parameters according to technical specification (inclusive Laboratory Report Form). The price is per analysis of all the parameters specified in the specifications
BOQ for 06 Boreholes
Description of activity unit Qty. Rate Amount in ZK
A Mobilization / Demobilization:
A.1 Mobilization of sites
(includes moving, setting up, maintaining and dismantling the drilling unit and equipment and cleaning the site)
B Borehole drilling :
B.1 Drilling 212-300mm through overburden M 84
B.2 Drilling 165-176mm in basement rock M 600
B.3 Drilling 200 mm in unconsolidated sedimentary formations M 84
C Borehole lining and installation:
C.1 Supply and Installation of 112/125 mm PVC casings with flush threaded joints. M 540
Supply and Installation of 165 mm PVC screen. Slot 0,25 mm, 0.5mm or 1mm with flush threaded joints
C.3 Supply and Installation of Centralizers for 165 mm casing and 165 mm screen M 120
C.4 Supply and Install Bottom plug Nr 6
C.5 Supply and installation of 2-4mm of gravel pack M 180
C.6 Supply and installation of 1-2mm of gravel pack M 156
C.7 Supply and installation of 0.4-0.8 mm of gravel pack M 0
C.8 Backfilling annulus M 144
C.9 Supply bentonite cement, mix and place grout seal above gravel as per Drg. 1 and 2 (5 M) M 120
D Cleaning, Development and Testing
D.1 Cleaning and development by airlift Hrs 12
D.2 Pumping test, draw down Pump in use Hrs 24
D.3 Pumping test, recovery Pump stopped Hrs 12
D.4 Installation and removal of pump test unit at site Nr 6
D.5 Water quality analysis Nr 6
E Equipping of the Borehole
E.1 Supply and install Afridev hand pumps Nr. 6
SUMMARY OF WORKS
Item Description Amount
A Drilling of 06 x borehole and installation of an India Mark II pump at Chembe Secondary, Chipete Primary, Lukola Primary, Lumbu Primary, Milima Primary and Malenge Primary Schools in Chembe District.
Schedule of major equipment the Contractor intends to use for carrying out the Contract
Item Nos. Make Year Capacity Present Condition Country of origin Present location
1.1 Drilling rigs (at least two nos.)
1.3 Mud pump unit and accessories (state if separate or mounted on drilling rig)
1.4 Well flushing and pumping units
1.5 Support trucks and vehicles
Requirements as to Contractor’s Organization and Key Personnel
The Contractor shall furnish with his tender a description on how he will organise the Work and the Key Personnel he will assign to the tasks of the Work.
The Contractor shall carry out the following and submit as part of the tender:
1) Give a full description and overview of the company (text and organogramme)
2) Describe in detail the Site organization which will be responsible for carrying out the Work.
From the description and the organization chart it must clearly be stated and/or appear who is to be the in-charge at the Site.
3) For the key site personnel the Contractor shall submit short CV’s (World Bank format) outlining in detail educational background, language skills and practical experiences in the last 10 years.
KEY PERSONNEL ON SITE
1) Drilling Engineer
2) Foreman for the Drilling Crew
Request for Contractor’s preliminary overall work plan
The Contractor shall furnish with his tender a preliminary overall work plan on how he will carry out the Work.
The Work Plan shall in overall give information on major activities and when (in place and time) the Contractor intents to carry out the activities.
It has to be so detailed that it is possible to follow how the Contractor intents to carry out the work for the water points.
How the Contractor intents to organise the work involved with a single water point – drilling, well development, pump tests and finalisation, construction of superstructure and installation of pump etc.).
How the Contractor moves between the various water points, the various teams he applies (i.e. drilling crew, masonry team, pump installation team) the logistical support he provides, base camp(s), stores etc.
The presentation can make use of the Gant chart or Pert chart method or any other method for work plan presentation.
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