Terms of Reference for a firm to conduct Inspection and Assessment of Elevated Water Storage Tanks, and Analysis of Water Treatment Plant Operations

Gambia Energy Restoration and Modernization Project (GERMP) – Additional Financing

Terms of Reference for a firm to conduct Inspection and Assessment of Elevated Water Storage Tanks, and Analysis of Water Treatment Plant Operations

Context

1. The GERMP additional financing, in the amount of USD 43 million, was approved by the World Bank Board of Directors on 29 June 2020. This project, which expands the scope of the parent GERMP, aims to improve the operational performance of the National Water and Electricity Company (NAWEC), which provides electricity and water services throughout most of the country.

 

2. NAWEC provides water and sewerage services to urban areas and provinces with more than 100,000 residents. However, it faces many challenges in service provision. In urban areas, about 69 per cent of the population has access to safely managed water, but the quality of services is weak due to frequent service outages, with some neighbourhoods not receiving water for days, weeks or even months at a time. Investments in service expansion are not enough to meet growing demand and water and sewerage assets are in need of rehabilitation and upgrades. In addition, water quality is a challenge in terms of high levels of nitrates, iron and salinity in drinking water.
3. Dilapidated sewerage infrastructure and poor sanitation across the board are a looming health and environmental crisis. There is only one wastewater treatment plant in Greater Banjul, located in Kotu and serving mostly tourists. While there are stabilization ponds, they are overloaded, resulting in the regular discharge of inadequately treated sewage into natural receiving bodies. The second challenge is poor faecal sludge management. Many unconnected residents of GBA resort to poorly constructed septic tanks, or soak-aways constructed in areas with high water tables, with the infrequent or inadequate collection and disposal of faecal sludge, which is often dumped in the open or in waterways that border agricultural zones. Poor faecal sludge management is already undermining water quality, and by extension water availability, mainly through nitrate contamination.
4. The GERMP Additional Financing will provide essential support to NAWEC to address some of these challenges. The project plans to strengthen the utility’s functioning through a service contract covering both electricity and water; the introduction of water drinking modules in the information management system (IMS); training; and strategic studies on sanitation. A separate component will strengthen NAWEC’s planning on non-revenue water reduction; install retail meters and DMAs; introduce energy efficiency measures; rehabilitate storage tanks; finance new water connections, and improve water quality at selected water treatment facilities. Moreover, in light of the current coronavirus pandemic, the project will provide emergency support to NAWEC to purchase IT equipment for staff; supply water to unconnected areas through borehole drilling and tanker trucks; purchase needed inputs to ensure continuity to service provision; provide handwashing and hygiene kits to the population, and implement hygiene campaigns.
5. Description of Project Component 4 activities relevant for the assignment:

(i)    Rehabilitation of water storage tanks: This activity will rehabilitate 3 storage tanks in Greater Banjul in order to improve NAWEC’s water storage capacity. The tanks were built of steel in the 1960s have deteriorated greatly over time, leading to corrosion and leakage of toxins into drinking water. Two of the tanks have been decommissioned. In addition, the poor condition of the tanks forces the pumping systems to work outside of the nominal operating points, thus decreasing the efficiency of pumps and increasing the energy consumption.  Rehabilitation of tanks will consider environmentally friendly methods and civil works will check for the structural integrity and resiliency to sea level rise and floods events due to climate change. Increasing storage will contribute directly to climate change adaptation.

 

(ii)   Improving water quality at NAWEC water treatment plants: The AF will finance measures to remove iron and manganese from selected water treatment facilities (including either Gunjur or Bansang or both) in GBA. The iron levels have reached such high levels of contamination that one of the boreholes at Gunjur had to be decommissioned. The technical options for improving water quality will be explored (aeration, water softeners, iron filters etc.) and the project will finance the needed equipment, technical services and minor civil works that may be needed.  This activity should help restore water services to up to 15,000 people.

 

Scope of work

 

Under the supervision of the PIU Coordinator, the Engineering Firm shall carry out the following tasks:

 

6. Task 1- Analysis of water quality and treatment plant operations

• Provide technical expertise to assess the existing conditions and operational process of the Gunjur Water Treatment Plant (WTP), in an effort to improve efficiency and quality.
• Based on a review of the World Health Organization, US Environmental Protection Agency and other similar industry-specific regulatory agencies’ standards for potable water, develop pertinent water quality goals for the Gunjur WTP.
• Conduct plant walkthroughs, interview plant operations staff, perform condition assessment and hydraulic analysis to identify performance limiting factors (PLFs). Develop recommendations to address PLFs. Recommendations shall cover operational changes and capital improvements to achieve the desired plant capacity and performance reliability.
• Perform alternatives analysis with advantages and disadvantages, benefit-cost analysis for each of major capital improvement identified to address the plant limitations. Summarize the recommendations from the alternatives analysis as part of a Feasibility Study (FS). Include construction cost estimates for the recommended alternatives as part of the FS.
• Provide recommendations for implementation of a Supervisory Control and Data Acquisition (SCADA) system to control the different components of the plant and monitor and control the plant operations remotely.
• Prepare construction plans, specifications, and documents specific to the project’s needs, to include recommendations for improvements, the addition of chemical feeds, changes to chemical treatment, modifications of treatment processes, with and options based on the client’s needs, safety, economics, and life expectancy of the project. These to include:
  • bills of quantities
  • technical specifications
  • technical designs
  • cost estimates
• Develop technical parts, including Employer’s Requirements, for the bidding documents for goods, works and services for the improvements to the Water Treatment Plant under Component 4 (iv) of the project (see annex).
• Incorporate a work plan that stems from successful regional and international experiences on similar projects.
• Participate in the analysis of bids and contract negotiations with bidders and assessment of contractors’ capacities.
• Be available for technical support and to address any questions and prepare a response to bidders’ requests for clarifications during the bidding process.
• Make staff available to participate in meetings, in person or via teleconferences, with the PIU staff and the World Bank Task Team about project status and other project-related matters.

Provide water quality report of the existing condition as a baseline or reference and to justify recommendations of the new treatment process

Task 2- Inspection and Assessment of Elevated Water Storage Tanks

• Provide technical expertise to assess the conditions of existing water storage tanks, both for coatings performance, corrosion conditions, and structural integrity.
• Conduct investigations and assessments of existing conditions by visual inspection, material testing, measurement evaluation of both the structural integrity and coatings performance of water storage tanks and assess serviceability of the tank, in accordance with acceptable industry standards and regulations (minimum compliance with the United States National Association of Corrosion Engineers-NACE and the American Society for Testing Materials-ASTM requirements or equivalent).
• Prepare construction plans, specifications, and documents specific to the project’s needs, to include protective coating recommendations and options based on the client’s needs, safety, economics, and life expectancy of the project. These to include:
  • bills of quantities
  • technical specifications
  • technical designs
  • cost estimates
• Develop technical parts, including Employer’s Requirements, for the bidding documents for goods, works and services for the rehabilitation of water storage tanks related activities under Component 4 (iii) of the project (see annex). The bidding documents shall be based on the World Bank’s Standard Procurement Documents for Design, supply and installation of Plant; and for Supply of Goods.
• Incorporate a work plan that stems from successful regional and international experiences on similar projects.
• Participate in the analysis of bids and contract negotiations with bidders and assessment of contractors’ capacities.
• Be available for technical support and addressing any questions and prepare a response to bidders’ requests for clarifications during the bidding process.
• Make staff available to participate in meetings, in person or via teleconferences, with the PIU staff and the World Bank Task Team about project status and other project-related matters.

 

 

Estimated Level of Effort and Desired Qualifications

7. It is estimated that the required level of effort of key staff will be 8 staff-months

 

• The Qualifications and Experience of Key Experts shall not be included in the shortlisting criteria. Key Experts will not be evaluated at the shortlisting stage.

The following key staff and CV are required: Civil Engineer, Structural Engineer, Design Engineer, Specialist in Water Treatment, Electrical/Electronic Engineer

8. The successful firm is expected to have the following qualifications and profile:

• At least 10 years’ expertise in water storage inspections, structural assessment of tank structures, and evaluation of protective coatings (paint systems), water quality and treatment design and operations. Project capabilities shall include governmental and institutional projects.
• Firms experience shall include the preparation of feasibility studies, detailed design, procurement, tendering, and working with contractors.
• Employ at a minimum one (1) Professional Engineer (or acceptable equivalent certification) each, in the areas of Corrosion/Coatings and Structural Design, and in the areas of Water Quality and Water Treatment, Electrical/Communications, and Facilities Design. These individuals should possess at a minimum, BS degrees in the respective fields, with 15 years of experience in related areas, or MS or PhD degrees with 10 years of experience.
• Employ technical specialists in the areas of testing and evaluating coatings, corrosion assessment, and structural integrity, and employ technical specialists in the areas of operations of water plants and water distribution systems. Specific personnel expertise should also include chemical piping and sand filtration systems, coating, remodelling office, electrical, and knowledge of pumps, valves, actuators, clarifiers, and cathodic protection systems, as well as SCADA and related electrical and communication systems.
• Demonstrated knowledge of the water sector in Gambia or countries with a similar developmental profile.
• Demonstrated ability or capacity to manage multiple projects concurrently is desired.

Contract Type and Duration

9. The contract will be for a Firm, that will report to the PIU Coordinator

 

Selection of the Consultants will be conducted in accordance with the Consultants Qualification Selection (CQS) method of selection, as outlined in the World Bank Procurement Regulations.

 

10. The firm must mobilize staff to be stationed in Banjul, Gambia full time, for the duration of the field assessment and agreed periodic field visits during implementation. Analysis of data, preparation of designs, reports, etc., as well as engineering assistance during bidding process can be a combination of field and home office work.

 

11. The estimated start date is November 2020. The successful candidate will sign a lump-sum contract.

 

Application Process

12. Interested firms should submit their application as follows:

• An updated Statement of Qualifications (SOQ) documenting professional and technical experiences and qualifications of the firm and the relevant personnel that would be assigned to the project, to include at a minimum:
  • A list of relevant projects undertaken by the firm in the past 5 years.
  • A list of certifications for the firm or its personnel that are relevant to the scope of this project.
  • A mobilization plan and proposed schedule of the work to be completed by the firm if selected.
  • A detailed list of equipment necessary to conduct the inspections.
  • A list of references and completion certificates.
  • A sample report format for the deliverable/assessment as it would be issued at the completion of the project.

 

 

Annex 1: Description of relevant activities of Project Component 4

 

1. Component 4: Short-term investments to address the water crisis

 

 

• Rehabilitation of water storage tanks: This activity will rehabilitate 3 storage tanks in Greater Banjul to improve NAWEC’s water storage capacity. The tanks were built of steel in the 1960s have deteriorated greatly over time, leading to corrosion and leakage of toxins into drinking water. Two of the tanks have been decommissioned. In addition, the poor condition of the tanks forces the pumping systems to work outside of the nominal operating points, thus decreasing the efficiency of pumps and increasing the energy consumption.^[1] Rehabilitation of tanks will consider environmentally friendly methods and civil works will check for the structural integrity and resiliency to sea-level rise and floods events due to climate change. Increasing storage will contribute directly to climate change adaptation.

 

• Improving water quality at NAWEC water treatment plants: The AF will finance measures to remove iron and manganese from selected water treatment facilities (including either Gunjur or Bansang or both) in GBA. The iron levels have reached such high levels of contamination that one of the boreholes at Gunjur had to be decommissioned. The technical options for improving water quality will be explored (aeration, water softeners, iron filters etc.) and the project will finance the needed equipment, technical services and minor civil works that may be needed. This activity should help restore water services to up to 15,000 people.