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ToR - Geophysical Surveys for Water Borehole Siting & Installation on Mango and Macadamia Farms (Malawi)

  • On-site
    • Lilongwe, Central Region, Malawi
  • Project Positions

Job description

Project Background

The Foreign, Commonwealth and Development Office (FCDO) has established a Matching Grant Fund (MGF) to catalyse enhanced productivity and exports of macadamia and mango in terms of volume and value. The MGF is under the Malawi Trade and Investment Programme (MTIP), a five-year FCDO-funded initiative which aims to break Malawi’s cycle of low growth through driving exports. Specifically, the fund is targeted at; i) macadamia and mango mid-sized farms (MSF) with landholding from 3 to 40 ha with existing or planned export partnerships through off-takers; and ii) smallholder farmer (SHF) cooperative organisations involved in macadamia and mango production, with existing or planned export partnerships through off-takers.

Assignment

  • The MGF is in the process of shortlisting applicants. The final shortlist includes farms under 10 ha which require boreholes to access water for irrigation. The MGF is therefore seeking a service provider of geophysical surveys to enable shortlisted MGF applicants to effectively site boreholes as well as carry out the drilling and installation of boreholes.

  • These surveys will provide critical data on subsurface conditions to optimise borehole placement, ensuring sustainable water supply for the agricultural operations. The subsequent drilling operations will establish functional water extraction points to support the irrigation systems that will be installed by another provider.

  • The assignment is split into two phases (geophysical surveys and borehole siting/installation). The first phase will be followed by irrigation design work delivered by a separate Irrigation Expert, which will inform the final list of farms for which borehole siting/installation will be carried out. The latter list therefore remains to be determined at the time of procurement and will be confirmed following completion of the irrigation designs.

  • The geophysical surveys must be completed by 31st May with no flexibility to extend the timeline.

  • The Contractor will carry out geophysical surveys for the following farms:

Objectives

The primary objectives are to:

  1. Identify and map potential groundwater-bearing zones (aquifers) beneath the target farms

  2. Determine optimal locations for drilling boreholes based on groundwater potential

  3. Estimate the depth to water-bearing formations

  4. Identify geological structures that may influence groundwater occurrence and movement

  5. Drill and install functional boreholes at the identified optimal locations

  6. Conduct yield testing to confirm water availability and extraction rates

  7. Install appropriate borehole equipment for sustainable water extraction

  8. Provide documentation and recommendations for ongoing borehole maintenance and operation

Scope of Work

The Contractor will undertake the following tasks:

Phase 1: Geophysical Surveys

Pre-survey Activities

  • Review existing available data relevant to the survey areas

  • Conduct a preliminary site visit to assess site conditions and identify potential constraints

  • Develop a detailed survey methodology and plan tailored for each farm site

  • Consult with the farm owners/manager, MGF team and other involved consultants to understand specific water requirements and constraints

Field Survey Activities

  • Conduct appropriate geophysical surveys across the designated farms using a combination of appropriate methods (to be agreed), which may include: Electrical resistivity tomography (ERT), electromagnetic (EM) conductivity surveys, vertical electrical soundings (VES), ground penetrating radar (GPR) where appropriate, magnetic surveys as required to identify geological structures

  • Ensure sufficient survey coverage across each farm to adequately assess groundwater potential

  • Collect GPS coordinates of all survey lines and points

  • Document site conditions, including surface features that may influence groundwater occurrence

Data Processing and Interpretation

  • Process all geophysical data using industry-standard software

  • Interpret results to identify aquifer characteristics including:

    1. Depth to water-bearing formations

    2. Estimated thickness of aquifers

    3. Relative water quality indicators where possible

    4. Geological structures (fractures, faults, etc.) that may influence groundwater flow

  • Generate subsurface cross-sections and maps illustrating the findings

Reporting

  • Prepare comprehensive reports for each farm surveyed

  • Identify and prioritise optimal locations for borehole drilling

  • Provide recommendations for borehole design specifications including:

    1. Suggested drilling depths

    2. Expected water strike zones

    3. Recommended casing and screen intervals

    4. Estimated sustainable yield where possible

  • Prepare GIS maps showing recommended drilling locations with coordinates

 

Phase 1 to be followed by development of irrigation designs, which will be carried out by Irrigation Expert contracted separate to this assignment.

 

Phase 2: Borehole Drilling and Installation

Pre-Drilling Preparations

  • Obtain any necessary permits and authorisations for borehole drilling

  • Develop a detailed drilling programme based on geophysical survey results

  • Conduct site preparation and ensure access for drilling equipment

  • Implement appropriate environmental management measures

  • Notify relevant authorities and stakeholders before drilling commences

Drilling Operations

  • Mobilise appropriate drilling equipment to each site

  • Drill boreholes at locations identified by the geophysical surveys

  • Maintain detailed drilling logs documenting:

    1. Lithology/geology encountered

    2. Drilling rate and penetration

    3. Water strikes and yield estimates

    4. Samples of geological formations

  • Conduct geological logging of drill cuttings

  • Install appropriate casings and screens according to design specifications

  • Construct sanitary seals and surface completion according to industry standards

  • Develop boreholes using appropriate techniques to optimise yield

 

Borehole Testing and Commissioning

  • Conduct pumping tests to determine:

    1. Safe and sustainable yield

    2. Aquifer parameters

    3. Drawdown characteristics

    4. Recovery rates

  • Install appropriate pumping equipment sized for the determined yield

  • Test pumping equipment and measure actual delivery rates

  • Install water level monitoring equipment where specified

Borehole Documentation and Reporting

  • Prepare detailed borehole completion reports including:

    1. As-built diagrams of each borehole

    2. Geological and technical logs

    3. Pump test results and analysis

    4. Recommended sustainable extraction rates

    5. Recommended maintenance schedule

  • Provide operation and maintenance manuals for installed equipment

Deliverables

The Contractor will provide the following deliverables:

Geophysical Survey Deliverables

  1. Overview of survey methodology and workplan (prior to fieldwork commencement)

  2. Weekly field progress verbal reports during the surveying campaign

  3. For each farm site:

    • Technical report including methodology, data acquisition, processing procedures, results, interpretation, and recommendations

    • Digital data files of all geophysical readings in standard formats

    • GIS-compatible maps (QGIS/ARCview) showing:

                                               i.     Survey line locations

                                              ii.     Interpreted subsurface conditions

                                             iii.     Recommended borehole drilling locations with GPS coordinates

                                             iv.     Estimated depths to groundwater

  • Cross-sectional diagrams showing subsurface geological interpretation

Borehole Drilling Deliverables

  1. Drilling methodology statement and work plan

  2. Weekly drilling progress reports by site

  3. Borehole completion reports for each site including:       

    • Geological logs and lithological descriptions

    • Construction details (depth, diameter, casing details, screen positions)

    • Development and testing procedures employed

    • Pumping test results and analysis

    • Recommended sustainable extraction rates

    • GPS coordinates and site photographs

  4. As-built drawings for each completed borehole

  5. Operation and maintenance guidance for all installed equipment

Please note that, in accordance with best practice in Malawi, payment will be contingent upon successful borehole drilling and the presence of water. Costs associated with any dry boreholes will not be covered. Therefore, the service provider is expected to conduct a thorough and accurate geophysical survey to maximise the likelihood of successful water extraction.

Project Deliverables

  1. Final project completion report summarising:

    • Geophysical survey findings across all farms

    • All drilling activities and outcomes

Timing and Duration

The assignment should commence as soon as possible with geophysical surveys to be completed no later than 31st May 2025. The timeline for the borehole work is to be determined, taking into consideration the findings of the geophysical surveys and irrigation designs.

The work should be completed according to the following timeline:

Job requirements

Qualifications

The selected contractor will require the following expertise:

  1. Minimum 7 years of experience providing integrated groundwater exploration and borehole drilling services

  2. Valid registration/licensing for both geophysical surveys and water borehole drilling

  3. Proven track record of at least 5 similar projects combining geophysical surveys and borehole drilling

  4. Adequate equipment ownership or rental arrangements for both survey and drilling operations

  5. Valid insurance coverage for all field operations

  6. Quality management system certification

  7. Environmental management certification preferred

Ready to Apply?

Interested parties should submit a comprehensive proposal inclusive of:

  1. Technical proposal detailing approach, methodology and equipment to be used

  2. Team composition and qualifications

  3. Detailed timeline for survey completion

  4. Cost proposal with detailed breakdown of expenses

  5. References from similar previous projects

The deadline for applications is Tuesday, 20 May 2025 with geophysical survey work to commence immediately to be completed by 31st May 2025.

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