Background

Samaritan’s Purse Liberia intends to engage a qualified drilling service provider to carry out compressor airlifting (blow-out) and borehole development works on ten (10) completed village-drilled boreholes. The purpose of the exercise is to remove drilling residues, fine sediments, clay particles, and other foreign materials from the boreholes; improve aquifer connectivity; increase borehole yield; and ensure that each borehole produces clear and sustainable water suitable for hand pump installation and community use.

The Contractor shall provide all labor, equipment, compressor units, air hoses, fittings, transportation, fuel, personnel, tools, and incidental services necessary to complete the works in accordance with these specifications.

Please read carefully the Technical Specifications/Scope of Work for compressor airlifting (Blow out) of Boreholes:

1. Objective of the Assignment

The objective of the airlifting exercise is to:

• Remove drilling mud, clay, silt, and fine particles remaining after drilling
• Develop the aquifer and improve water inflow into the borehole
• Increase borehole yield and recovery rate.
• Improve water clarity and quality
• Verify borehole depth and condition before hand pump installation
• Ensure the boreholes are ready for long-term operations.

2. Scope of Work

The contractor shall perform the following activities for each borehole:

• Mobilization

The contractor shall:

• Mobilize compressor, accessories, hoses, tools, and personnel to site.
• Ensure all equipment is in good working condition before commencement
• Provide adequate fuel and lubricants throughout the exercise.
• Coordinate activities with Samaritan’s Purse’s Drilling Coordinator or Technical Officer
• Pre-Development Verification

Before commencing airlifting operations, the Contractor shall:

• Measure and record total borehole
• Measure static water
• Measure casing
• Inspect the borehole
• Confirm that gravel packing and sanitary sealing have been completed where

No airlifting work shall commence without the presence and approval of the Employer’s Drilling Coordinator or Technical Officer.

• Compressor Airlifting and Borehole Development

The Contractor shall carry out borehole development using a high-capacity air compressor capable of delivering sufficient air pressure and volume to effectively clean and develop the borehole.

The development process shall include:

• Lowering airline pipes to appropriate
• Conducting continuous airlifting
• Surging and agitation of water
• Removal of drilling residues and suspended
• Cleaning of borehole screens and intake zones
• Removal of accumulated sand, silt, clay, and cuttings.

Development shall continue until:

• Water is visibly clear.
• Sand content is negligible
• No significant drilling residue is observed
• Water quality shows substantial improvement
• Borehole yield stabilizes

Under no circumstances shall the Contractor stop development solely based on time allocation if the borehole remains inadequately developed.

• Minimum Development Requirements

For each borehole, the Contractor shall:

• Conduct development for a minimum of two (2) continuous
• Continue beyond two hours whenever water remains turbid or sand content remains
• Ensure development is based on borehole performance rather than fixed

The Employer’s Drilling Coordinator or Technical Officer reserves the right to require additional development if results are unsatisfactory.

• Removal of Sediments

The Contractor shall ensure the complete removal of:

• Clay
• Drilling
• Fine
• Silt
• Organic
• Foreign objects introduced during

Any borehole showing continued sediment production shall undergo additional development until acceptable conditions are achieved.

• Yield Observation

During development, the Contractor shall:

• Observe borehole
• Estimate yield where
• Monitor recharge
• Record development

Any abnormal borehole conditions shall be immediately reported to the Employer.

3. Technical Requirements

The Contractor shall provide:

Compressor

• Minimum working pressure of 12 bar (175 psi) or
• Adequate air delivery capacity for borehole
• Reliable and well-maintained

Airlifting Equipment

• High-pressure
• Airlifting
• Connectors and
• Discharge control

Personnel

At minimum:

• One experienced Drilling
• One Compressor
• Supporting Technicians/Laborers

All personnel shall have proven experience in rural water supply borehole development.

4. Quality Control Requirements

The following minimum standards shall apply:

Water Clarity

The Contractor shall continue development until water appears substantially clear and free from visible suspended materials.

Sand Content

Water discharged shall contain minimal sand.

Borehole Recovery

The borehole shall demonstrate adequate recovery after development.

Borehole Integrity

The Contractor shall ensure that development activities do not damage:

• Borehole
• Screen
• Gravel
• Borehole

5. Deliverables

For each borehole, the Contractor shall submit:

Borehole Development Record

Including:

• Borehole
• Community
• GPS coordinates (if available).
• Initial
• Final
• Static water level
• Development start and end times
• Observed yield
• Remarks and recommendations

Photographic Documentation

The Contractor shall provide clear photographs showing:

1. Site before
2. Equipment
3. Airlifting
4. Discharge water during
5. Final clear water
6. Site after

Photographs shall be shared electronically with the Employer’s Technical Officer on the same day of operation.

6. Supervision and Reporting

• All activities shall be carried out under the supervision of the Employer’s Drilling Coordinator or Technical Officer.
• Daily progress updates shall be
• Any unforeseen condition requiring additional work shall be communicated immediately before action is taken.

No variation work shall be undertaken without written approval.

7. Health, Safety and Environmental Requirements

The Contractor shall:

• Provide appropriate Personal Protective Equipment (PPE) to all
• Secure the work area during
• Prevent injury to community members
• Manage wastewater discharge to avoid erosion and flooding
• Prevent environmental contamination
• Maintain good housekeeping at all sites.

8. Acceptance Criteria

A borehole shall only be accepted when:

• Development has been completed to the satisfaction of the
• Water is substantially
• Sand production is
• Borehole depth has been verified and
• Required records and photographs have been
• No damage has occurred to the borehole

9. Payment Conditions

Payment shall be based on successful completion and acceptance of each borehole and shall be subject to:

• Submission of development
• Submission of photographic
• Verification by the Employer’s Drilling coordinator or Technical
• Acceptance of completed

Failure to achieve satisfactory borehole development may result in rejection of the work and withholding of payment until corrective measures are completed.

10. Defects and Liability

The Contractor shall be responsible for any damage caused to the borehole arising from:

• Excessive compressor
• Poor
• Improper handling of

Any such damage shall be repaired by the Contractor at no additional cost to the Employer.

Special Instruction

The Employer’s Drilling Coordinator or Technical Officer must be present during all airlifting activities. No borehole shall be developed, altered, deepened, or subjected to additional works without prior approval from the Employer’s representative. All measurements, observations, and development records shall be jointly verified and signed before site demobilization.

Tender Bid Submission: from September 29, 2026 to October 9, 2026