Date: 12

th April 2018

TENDER FOR DRILLING OF BORE HOLE & CONSTRUCTION OF WATER TOWER

IN GBARNGA, BONG COUNTY

Mary’s Meals International is a UK based humanitarian organization which responds worldwide

in school feeding. We are feeding over 1.2 million children globally in their places of education.

We have a Country Programme in Liberia with a school feeding program reaching around

114,292 students in 507 schools in Bomi, Cape Mount, Bong and Montserado Counties.

Mary’s Meals Liberia is seeking for contractors to undertake construction works in its warehouse base in

Gbarnga, in Bong County in Liberia.

Contractors are instructed to prepare and submit well costed BoQ’s for the project they are capable of

undertaking in the schedule below.

Submissions should be sent to the emails below or dropped in the tender box at Marys Meals address in

Tubmanburg.

Requirements for submission

The tender should be accompanied by:

1. Annex 1 contains specifications and scope works for the various projects and must be read

carefully

2. Up to date GOL Business Registration Certificate.

3. Valid LRA tax and other relevant statutory tax clearance certificates.

4. Organisation profile (including supplier name, physical address, contact person telephone,

mobile, email, TIN number etc.)

5. Annex 2 cover page MUST be completed and returned with all the documents

Site visit and viewing will be on 17th

and 18th

from 1 pm to 4 pm both days

Please send your proposals to the emails below on or before the 24th

of April 2018.

Amimo.madara@marysmeals.org

Francis.gitau@marysmeals.org

ANNEX 1

CONSTRUCTION OF BOREHOLE AND WATER TOWER

Mary’s Meals Liberia Borehole construction document

1.0 Scope of works

The scope of the works require that contractor furnish successful borehole 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 Liberia acceptable water quality standards). By this

definition, the bidder MUST include costs of replacement of unsuccessful borehole (poor water quality and

dry boreholes) in their BoQ.

The well successfully drilled and tested will be installed with a submersible pump 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 boreholes with submersible pump deeper than 39 meters will be installed with Stainless steel pipes

and rods (G316 steel) as described in the specification.

All wells with submersible pump 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 submersible pump must be approved by Mary’s Meals Liberia.

The successful contractor will carry out the siting/hydrogeological survey for the borehole location, carrying out the

drilling work, pumping test, water quality tests and the installation of the pump ready for use.

1.1 Location of the works

The work is in Mary’s Meals Warehouse compound in Gbanga, Bong County.

1.2 Borehole siting

The contractor is to carry out detailed geophysical analysis in the WAREHOUSE compound in Mary’s Meals

compound in Gbanga. A method of geophysical survey best suited to the geography/geology of the area is to be

employed

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 contractor’s hydro-geologist should carry out a hydro census in the vicinity of the target area. 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/Mary’s Meals Liberia.

During the siting, the hydro-geologist should ensure that representatives of Mary’s Meals shall be involved. Mary’s

Meals will assist with compound accessibility.

2.0 Drilling site

Borehole locations shall be identified in agreement with Mary’s Meals responsible and consultation with the office.

Sites selected for the borehole should preferably be within the WAREHOUSE compound. Borehole 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 site is located outside the minimum distance prescribed from sanitation installations, sources

of pollution, landfills etc

It is advisable that the hydrologist uses their experience to determine alternative suitable sites for borehole

construction so that these can be developed if initial site is abandoned for any reasons including dry well or

unsuitable water quality well.

The contractor shall drill the borehole at location as determined by their hydrogeological survey. Access to the site

shall be the responsibility of the Contractor. Tracks required for access of drilling 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.

3.0 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 the

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.

4.0 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

International 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 the 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 period, the Contractor will be

notified and requested to take necessary measures on the unsatisfactory crewmember.

5.0 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.

6.0 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 or complete PVC casing may be installed in the borehole to prevent formation heave or

collapse.

The average anticipated borehole depth will be in the region 30m. Shallower or deeper boreholes may be

encountered.

7.0 Strata sampling and borehole geo data

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

The contractor will be required to hand to the client at the end of the drilling operation borehole logs and

pumping test data.

8.0 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 30 meters depth. The contractor will be

required to drill a minimum of 30m 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 down-the-hole hammer

and compressed air supply – augmented as required by water foam injection

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.

9.0. Verticality and Alignment

The well 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.

10. 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.

11. 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 WAREHOUSE compound.

12. 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 and refined sand of high grade packed.

(Example borehole designs drawings are included towards the end of this document.)

13. Development and cleaning of wells

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.

14. 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.

15. Capping of well

During well construction, installation, development and test pumping, the Contractor shall use all reasonable

measures to prevent entrance of foreign materials 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.

16. 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 GOL standards. In addition, the contractor will provide a complete detail of

lifespan of the well.

17. Typical Schematic Drawing of Well Designs and Water tower

Borehole design 1: Unconsolidated formations

Borehole design 2: consolidated formations

Borehole design 3: Consolidated formation

Drawing of a water tower

Annex 1 Bore Hole Completion Record (Typical)

Bore Hole No……………………………………………………. Bore Hole Name…………………………………………………. _______________________________________________________________________

1. Location………………… Area ……………………. County………………………. 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. From ……….m to……………….m ……………….mm From ……….m to……………….m ……………….mm From ……….m to……………….m ……………….mm 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 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 recovery tests) – All depth measurements to be in Metres below GL

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) …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

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)

Annex 2 – Cover Page

Contractor Form - Complete and submit with your Bid

Supplier

name:

Contact

person:

Office

address:

Telephone

number:

Email

address:

Supplier declaration: Tick box (√) to

indicate

agreement:

I certify that I am the official representative of the company

named above.

I have given Mary's Meals International Liberia a copy of our

company's updated GOL Business Registration Certificate).

I have given Mary's Meals International Liberia a copy of our

company's valid LRA tax and other relevant statutory tax

clearance certificates

I have given Mary's Meals International Liberia a copy of our

company's/organisation profile (including supplier name,

physical address, contact person telephone, mobile, email,

TIN number etc.

Name Signature Date

Company Stamp