Consultancy Services for Feasibility Studies, Detailed Engineering Design, Procurement Support, Construction Supervision and Defects Liability Support
World Bank Financed Assignment — Official Use Only
This Terms of Reference is issued under the Gambia Water and Sanitation Project (WASAP — P513113), financed by the World Bank/IDA. The assignment shall comply with the World Bank Environmental and Social Framework, applicable Procurement Regulations for IPF Borrowers, and all applicable laws and standards of The Gambia. Selection is by Quality and Cost Based Selection (QCBS).
Background & Context
The Greater Banjul Area is The Gambia’s principal urban and economic centre. Urban water services face production constraints, intermittent supply, low pressure, aging infrastructure, limited storage, and high non-revenue water. Sanitation services in Banjul and Kotu are constrained by deteriorated sewerage assets, underperforming treatment systems, and inadequate fecal sludge management.
WASAP is the first standalone Water Supply and Sanitation Project in The Gambia with Performance-Based Conditions in the sector. The project will finance priority infrastructure to reduce service gaps in the Greater Banjul Area — including new boreholes, treatment and storage facilities, expansion of distribution networks, household connections, and measures to reduce non-revenue water. It will also strengthen sanitation service delivery through investments in a fecal sludge treatment plant and flood-resilient sanitation systems.
The assignment will prepare and supervise investments in two closely linked components: urban water supply in Kombo East/Brikama East, and urban sanitation in Kotu and Banjul.
Investment Components
| Component | Core Investment Scope |
|---|---|
| Urban Water Supply | Brikama East water treatment facilities; four boreholes; raw-water and treated-water mains; ground and elevated storage; clear-water pumping; medium-voltage power and backup supply; SCADA; approximately 50 km of distribution network; and approximately 6,000 new household connections. |
| Urban Sanitation | Kotu fecal sludge treatment plant; Kotu wastewater treatment plant rehabilitation/expansion; priority sewer rehabilitation in Kotu and Banjul; Banjul sea outfall condition assessment and works as justified; and maintenance equipment. |
Assignment Objectives
To prepare technically sound, climate-resilient, environmentally and socially compliant, economically justified, and procurement-ready urban water and sanitation investments — and to support their implementation through procurement, construction supervision, commissioning, and the defects liability period.
- Validate demand, service areas, beneficiaries, design criteria, and priority investment needs
- Assess existing systems and identify least-cost, lifecycle-efficient solutions
- Prepare feasibility studies, detailed designs, BOQs, and complete procurement packages
- Integrate climate resilience, energy efficiency, environmental and social requirements
- Provide technical support throughout bidding and contract award
- Administer and supervise works through testing, commissioning, handover, and defects correction
- Build NAWEC capacity through structured training and O&M documentation
Five-Phase Scope of Work
Firm Qualifications & Experience Required
- At least 15 years of experience in water supply and sanitation engineering
- At least 10 years in detailed design and construction supervision of WSS infrastructure
- Demonstrated experience with urban water treatment, transmission, storage, distribution, SCADA, wastewater, sewerage, pumping stations, and fecal sludge treatment
- At least two comparable assignments financed by multilateral development partners within the last seven years
- Demonstrated experience in Africa and with international conditions of contract including FIDIC or equivalent
- Established QA, environmental and social, OHS, and design management systems
- Contract type: Lump-sum for feasibility, design and procurement support; time-based for construction supervision and DLP support
- Payment: Linked to approved deliverables (lump-sum) and verified personnel inputs and reimbursables (time-based)
- Duration: 46.5 months with overlapping phases as approved in the work program
- Proposals: Technical and financial proposals shall address all tasks, personnel, reimbursables, and deliverables required by this TOR
- Selection method: Quality and Cost Based Selection (QCBS)
Indicative Key Expert Positions (19 Roles)
| # | Position | Primary Role |
|---|---|---|
| 1 | Team Leader / Senior Water and Sanitation Engineer | Overall leadership; design integration; contract administration; client coordination |
| 2 | Deputy Team Leader / Resident Engineer | Day-to-day coordination and supervision; site leadership |
| 3 | Water Supply / Hydraulic Engineer | Water demand, modelling, treatment, transmission, storage, distribution, and connections |
| 4 | Wastewater and Fecal Sludge Process Engineer | FSTP/WWTP process assessment, technology selection, detailed design, commissioning |
| 5 | Sewerage and Drainage Engineer | Sewer assessment, hydraulic design, rehabilitation, pumping, outfall interfaces |
| 6 | Electro-Mechanical Engineer | Pumps, treatment equipment, power, controls, standby systems, testing |
| 7 | SCADA / Instrumentation Specialist | Automation architecture, telemetry, instrumentation, functional specifications, commissioning |
| 8 | Structural Engineer | Reservoirs, treatment structures, buildings, stations, and rehabilitation |
| 9 | Geotechnical Engineer | Investigations, foundations, earthworks, pipeline geotechnics, constructability |
| 10 | Quantity Surveyor / Cost and Contract Specialist | BOQs, cost estimates, payment certification, variations, claims, final accounts |
| 11 | Quality Assurance / Materials Engineer | QA/QC systems, materials, laboratory and field testing, source inspection |
| 12 | Environmental Specialist | E&S assessment, ESMP integration, monitoring, pollution prevention, reporting |
| 13 | Social Specialist | Stakeholder engagement, land and livelihood impacts, GRM, social monitoring |
| 14 | OHS Specialist | Worker and community health and safety, contractor systems, incident prevention and monitoring |
| 15 | Climate Resilience / Energy Specialist | Climate risk, resilience measures, energy efficiency, and GHG considerations |
| 16 | Surveyor / GIS Specialist | Topographic and route surveys, setting-out, GIS database, asset mapping |
| 17 | Socio-Economist | Surveys, demand, affordability, beneficiary and service-level analysis |
| 18 | Financial / Economic Analyst | Lifecycle costing, economic and financial analysis, sensitivity assessment |
| 19 | CAD/BIM Technicians and Site Inspectors | Drawings, document control, daily inspections, records, measurements |
Indicative Deliverable Schedule (20 Outputs)
| # | Deliverable | Component | Indicative Timing |
|---|---|---|---|
| 1 | Draft Inception Report | All | Month 1 |
| 2 | Final Inception Report | All | Month 1.5 |
| 3 | Urban Water Feasibility Study | Water | Month 3 |
| 4 | Urban Water Preliminary Design | Water | Month 4 |
| 5 | Urban Water Detailed Design | Water | Draft Month 6; Final Month 6.5 |
| 6 | Urban Water E&S Instruments / Updates | Water | Month 7 |
| 7 | Urban Water Procurement Package | Water | Month 7 |
| 8 | Urban Sanitation Feasibility Study | Sanitation | Month 5.5 |
| 9 | Urban Sanitation Preliminary Design | Sanitation | Month 7.5 |
| 10 | Urban Sanitation Detailed Design | Sanitation | Draft Month 9.5; Final Month 10 |
| 11 | Urban Sanitation E&S Instruments / Updates | Sanitation | Month 10.5 |
| 12 | Urban Sanitation Procurement Package | Sanitation | Month 10.5 |
| 13 | Procurement Support Report — Water | Water | By Month 13 or upon completion |
| 14 | Procurement Support Report — Sanitation | Sanitation | By Month 16.5 or upon completion |
| 15 | Monthly Progress Summary | Applicable phase | Within 7 days after month-end |
| 16 | Quarterly Progress Report | Applicable phase | Within 7 days after quarter-end |
| 17 | Construction Completion / Close-out Report | Each works contract | Within 2 months of substantial completion |
| 18 | Quarterly DLP Report | Each works contract | Quarterly during DLP |
| 19 | Final Consultancy Report | All | One month before service completion |
| 20 | Final As-Built and Handover Review | Each works contract | Before final completion |
“The overall objective is to prepare technically sound, climate-resilient, environmentally and socially compliant, economically justified, and procurement-ready urban water and sanitation investments — and to support their implementation through procurement, construction supervision, commissioning, and the defects liability period.”