Supply, Installation and Construction of a Water Distribution Network and Elevated Tank for Al-Nahdeen Area Sanaa, Yemen

New amendment added #4: The purpose of this amendment is:Extended the tender deadlne. Update the LOT 2 - Phase 01 - BoQ as amendment 002Item No. 1.2.1 - Isolation Valves to read as ''A - DN 180, Gate Valve, PN16'' ''B - DN 125, Gate Valve, PN16'' ''C - DN 90, Gate Valve, PN16 '' ''DN 63,   Gate Valve, PN16'' Update the LOT 2 - Phase 02 - BoQ as amendment 002  Item No. 1.2.1 - Isolation Valves to read as'' B - DN 180, Gate Valve, PN16'' '' C - DN 125, Gate Valve, PN16'' '' D - DN 90, Gate Valve, PN16'' '' E - DN 63,   Gate Valve, PN16'' ​Therefore please note the following changes in esourcing tabs:Esourcing General tab amendedThe tender deadline was '' 7 April 2025'' and will now read as '' 10 April 2025'' Esourcing document tab amended to read as Amendment 002 - LOT 2 - Phase 01 - BoQAmendment 002 - LOT 2 - Phase 02 - BoQAll other terms and conditions remain the same.

New clarification added: Q4 - Clarifications 004 Q1 - We would like to bring to your attention several points that require clarification in the tender documents for the Al-Nahdain Water Network Project, which were observed during the review of the drawings and quantities:Drawing No. 7:The details for rooms (control rooms, washing rooms, valves, etc.) are indicated in the drawings. However, upon reviewing the quantity tables, the civil works for these rooms, including covers, are not mentioned in any of the items, except for the "air valves" item, which clearly includes civil works and other related works.Ans  - Please refer to both the Bill of Quantities (BoQ) and the drawings for the installation of the service box. For Hence for example, in Drawing 8, Page 9, the GATE VALVE for DN <63mm HDPE PIPE SURFACE BOX is clearly shown. On the same page, the installation method of the Single Ferrule Outlet on PE Connections is depicted without surface boxes in a spesific drawing . This confirms that there is no discrepancy between the descriptions of the items in the Bill of Quantities and the corresponding drawings.​ Drawing No. 8:It is clearly indicated in the drawing that there is a concrete water tank, but this is not mentioned in the quantities table.We request clarification on the inclusion of this item in the quantities or any additional details regarding it.Ans - This to confirm that the drawing No.8 is slandered drawing for installation the network as basic requirement and including the valves and detailed pipe connections and the chamber and manholes ... etc. no water tank is required .  Drawing No. 7:The drawing includes a schematic for sloping, diversion, and stabilization concrete, but no quantities or items for these works are mentioned in the quantities table. We request clarification on how to include these works in the quantities or the attached documents, as well as how to determine the concrete quantities needed for these works.Ans - As mention in the STD their location depends on specific conditions, It is knowing that the negligible quantity of concrete should included in the cost of pipe installation Discrepancies Between Drawings and Quantities:There is a noticeable discrepancy between the drawings and quantities for some of the pipelines, such as the 250 mm and 180 mm diameter pipes. The drawings indicate larger quantities than those mentioned in the quantities table.We kindly request clarification regarding this discrepancy and the alignment of quantities between the drawings and the actual quantities.Ans -  An Amendment will be issued to update the needed accordingly 150 mm Steel Pipes: The drawings mention steel pipes in certain lines with a 150 mm diameter, but these are not included in the quantities table. We request clarification on how to incorporate these pipes in the quantities or in the attached documents.Ans - Amendment will be issued to update the needed accordingly Best Regards 

New clarification added: Q9: fire hydrant DN100 not available, only DN80 widely available? Ans 9 - Please adhere to specifications in the tender. Q10: In the BoQ there are some gate valves, the work includes the Service Box. There aren't details about the specifications of the service boxes. also, in Lot2 Drawing 7 - STD-3, there is a chamber typical for valves, which one is applicable, the service boxes or the chambers?Ans 10 - Please refer to the standard drawing for each diameter there is a requirement for hence as an example you can find the GATE VALVE FOR DN ,< 63mm HOPE PIPE SURFACE BOX  in drawing 8 page 9. Q3 - Clarifications 003  Q1. Lot 1: The tender specifies medium pressure galvanized iron (GI) pipe with a diameter of 8 inches for the tank inlet, outlet, overflow, and washout connections. We have found that this specific diameter is extremely difficult to source in the local market and is currently subject to import restrictions. Would you consider accepting a diameter of 6 inches for the GI piping, as this is more readily available and compliant with current market conditions?Ans 1 - Please adhere to specifications in the tender. Q2. Lot 1: The tender specifies ductile iron (DI) ventilation pipes with a nominal diameter (DN) of 4 inches. We have encountered significant challenges in sourcing DI pipes of this specification in the local market, and we understand that their import is currently prohibited. Furthermore, it appears that the use of DI ventilation pipes is an over requirement for this application. Would you consider accepting galvanized iron (GI) pipes as an alternative material for the ventilation pipes, given the current market constraints and the fact that GI pipes are sufficient for this application?Ans 2 - Please adhere to specifications in the tender. Q3. Lot 1: The tender specifies aluminum ladders for installation inside the tank. It is widely recognized that aluminum can react with concrete, potentially leading to corrosion and structural damage over time. Would you consider accepting stainless steel ladders as an alternative to aluminum, to ensure the long-term integrity and safety of the tank?Ans 3 - Please adhere to specifications in the tender. Q4. Lot 1: The tender includes site preparation, and our initial assessment indicates that significant removal of existing structures and materials is required for proper site preparation. We understand that the removal of these structures and materials is specified in Lot 2. What are the contingency plans if the contractor for Lot 2 (responsible for removal) is not selected before the contractor for Lot 1 is selected? Ans 4 - As Lot 1 and Lot 2 pertain to different components, the site clearance requirements for each component vary accordingly.For Lot 1, please refer to BoQ Item 2.For Lot 2, please consult BoQ Phase 1, Bill 2, Item 2.2.1.1.

New clarification added: Dear Bidders Please find below answers: Q1 First: Pipe Diameters and Valve DiametersWe have noticed a discrepancy between the diameters of the valves and the dimensions specified for the pipes in the bill of quantities. The specified dimensions are as follows:Pipe Diameters: DN 180, DN 125, DN 90, DN 63.Valve Diameters: DN 200, DN 150, DN 100, DN 75, and DN 50.This difference in diameters between the pipes and valves negatively impacts the installation and efficiency of the system. We request clarification on whether we should price the valves based on the diameters mentioned in the bill of quantities, despite the differences with the pipe diameters. Are there specific guidelines or recommendations, or drawings that illustrate the connection mechanisms and components (fitting) between the valves and pipes to ensure diameter compatibility and achieve optimal system performance?Or, the valve items will be updated to align with the pipe diameters in the bill of quantities to facilitate proper pricing and ensure correct execution?Second: Isolation ValvesItem 1.2.1 in the bill of quantities states: "Supply, install and test isolation valves including spindles and surface boxes for buried valves, and all fittings and accessories as specified and shown in the drawings." It is mentioned that "surface boxes" are required, but upon reviewing the drawings, it has been observed that concrete chambers are required  instead of the “surface boxes"   .The discrepancy between the description of the item in the bill of quantities and the drawings makes it difficult for us to determine the price of this item. We request clarification on whether "surface boxes" as described in the bill of quantities are required, or if "valve chambers" are needed according to the drawings, to facilitate proper pricing and ensure correct execution.Third: Single Ferrule Outlet on PE ConnectionsIn the description of item 1.2.6, it states: "Supply and install Single ferrule on DI mains including all fittings and accessories as specified and shown on drawings." Similarly, in the description of item 1.2.7 in the bill of quantities, it states: "Supply and install Single ferrule on PE pipes including all fittings and accessories as specified and shown on drawings."The execution of "surface boxes" is not mentioned in the descriptions of these two items in the bill of quantities; however, upon reviewing the drawings, there is a plan for the execution of "surface boxes." The discrepancy between the descriptions of the items in the bill of quantities and the drawings makes it challenging for us to price these items. We request clarification on whether "surface boxes" are required for the execution of these items or if they are not necessary according to the descriptions in the bill of quantities, to facilitate proper pricing and ensure correct execution.Ans 1 - Yes, the diameter of HDPE fittings should match the valve diameter to ensure proper connection and functionality. Compatibility between the two components is crucial for maintaining the integrity of the system, preventing leaks, and ensuring smooth operation.an amendment will publish soon. -Please refer to the standard drawing for each diameter there is a requirement for example you can find the GATE VALVE FOR DN ,< 63mm HOPE PIPE SURFACE BOX  in drawing 8 page 9.-Please refer to both the Bill of Quantities (BoQ) and the drawings for the installation of the service box. For example, in Drawing 8, Page 9, the GATE VALVE for DN <63mm HDPE PIPE SURFACE BOX is clearly shown. On the same page, the installation method of the Single Ferrule Outlet on PE Connections is depicted without surface boxes in a specific drawing . This confirms that there is no discrepancy between the descriptions of the items in the Bill of Quantities and the corresponding drawings.Q2 - Clarifications 002 Q1: In Lot 2 - Drawing 4, additional pipe types are present, specifically Φ150/Φ200 Ductile Iron and Φ150 UPVC, which are not included in the Bill of Quantities (BoQ). Ans 1 - Please refer to the Plan drawing Amendment 001 - LOT 2 - 3-5B-Phase Two PROFILES DRAWINGS.pdf Q2: Regarding the HDPE pipe and fitting connections, there are several types available, including Butt-Fusion welding, electrofusion connections, and mechanical/push-fit connections.Ans 2 - As this system involves the rehabilitation and extension of an existing network, each type of connection is specified with its respective diameter and connection type in the corresponding drawings Q3 - Could you please clarify which connection type is required between the pipes themselves and which type is needed for the connections between pipes and fittings? Ans 3 - As this system involves the rehabilitation and extension of an existing network, each type of connection is specified with its respective diameter and connection type in the corresponding drawings Q4: In Lot 2 – Drawing 7, Drawing No. STD-4, which illustrates the Typical Washout Type C with Manhole C1, there are no details provided regarding the thickness of the concrete base and   the precast concrete base, and the walls. Ans 4 - As this system involves the rehabilitation and extension of an existing network, each type of connection is specified with its respective diameter and connection type in the corresponding drawings Q5: The pipe thrust blocks lack details regarding their locations and quantities. Ans 5 - As mention in the STD pages 6 their location depends on specific conditions, such as:Changes in Direction: Thrust blocks are installed at bends (horizontal or vertical) to resist forces caused by changes in the flow direction.Pipe Fittings: They are placed at tees, reducers, and wyes where the pipe diameter or flow path changes.Dead Ends: At the termination points of pipelines, such as caps or valves, to prevent movement.It is knowing that the negligible quantity of concrete is included in the cost of pipe fitting installation Q6: Is a 50 cm wide excavation adequate for small diameter pipes? Could you elaborate on this topic? Ans 6 - Please refer to the STD drawing for the specific LOT  Q7: In the local market, there is a submersible pump model that almost meets the specifications (head 450m and flow 54 m3/hr). The impeller, suction casting, discharge casting, and stage casting are made of alloy cast steel (1.4308), while the bearing brush is made of EPDM, and the shaft is constructed from stainless steel (1.4057). Do these specifications fulfill the requirements? Ans 7 - Please adhere to specifications in the tender. Q8: It’s required to supply and install inverter. Is this a solar inverter which capable of supplying power from both the public grid and solar energy? Ans 8 - Please adhere to specifications in the tender.

New clarification added: Dear Bidder Please find the below clarificiatons as follows: Q1 - بشأن تكلفة الخطة البيئية ESMP والذي تكلفتها 16900$ هل نضيفها فوق الكميات او ماذا يقصد بها Ans 1 - Regarding the ESMP, please refer to the e-sourcing document tab for each LOT; there will be a document titled "ESMP," which pertains to the Social Environmental Management Plan. This document must be signed and stamped to confirm your agreement, For the estimated amount of $16,900, as determined by the World Bank and UNOPS for implementing the plan. The supplier will need to review and take into account the costs associated with the implementation of the ESMP processes in case awarded. Regards 

New clarification added: Dear Bidder Please find the below clarificiatons as follows: Q1 - We kindly request you to reduce the production capacity of the submersible pump slightly, by no more than 15%., since the required pump is not available in the market from all suppliers, This matter is up to you to make the decision, as we have presented our proposal.? Ans 1 -Please share the tenders and item specsRegards  

New amendment added #3: The purpose of this amendment is:Extended the tender deadlne. Extend the tender clarifications​Therefore please note the following changes in esourcing tabs:The Esourcing General tab amendedThe tender deadline was ''24 March 2025'' and will now read as '' 07 April 2025'' Extend the tender clarifications was '' 12 March 2025'' and will now read to read as '' 26 March 2025'' All other terms and conditions remain the same.

New amendment added #2: The purpose of this amendment is:Update the LOT 2 - Phase 01 - BoQ as amendment 001 - Update LOT 2 - Phase 01 - BoQ - Distribution Network tab to read as  '' Item 1.1.1 section A to read as '' DN 180  mm Dia''. Update LOT 2 - Phase 01 - BoQ - Distribution Network tab to read as  '' Item 1.1.2 section A to read as '' DN 125  mm Dia'' Update the LOT 2 - Phase 02 - BoQ as amendment 001 -Amendment 001 - LOT 2 - Phase 02 - BoQ - Distribution Network tab to read as '' Item No. 1.1.1 - A  DN 180 mm Dia.'' Amendment 001 - LOT 2 - Phase 02 - BoQ - Distribution Network tab to read as '' Item No. 1.1.1 - A  DN 300 mm Dia.'' Amendment 001 - LOT 2 - Phase 02 - BoQ - Distribution Network tab to read as '' Item No. 1.1.1 - A  DN 125 mm Dia.'' Update  LOT 2 -  3 - 5B-Phase Two PROFILES DRAWINGS​Therefore please note the following changes :The Esourcing Document tabAdd Amendment 001 - LOT 2 - 3-5B-Phase Two PROFILES DRAWINGSAmendment 001 - LOT 2 - Phase 01 - BoQAmendment 001 - LOT 2 - Phase 02 - BoQAll other terms and conditions remain the same.

New clarification added: Dear Bidder Please find the below clarificiatons as follows: The quantity tables for the HDPE water network do not include the diameter of 125 mm while this diameter is present in the drawings (Plane). - The profiles indicate that the pipes are Ductile Iron with a diameter of 150 mm while in the drawings (Plane) as well as the quantity tables they are made of HDPE material with different diameters.There is a diameter of 400 mm in the quantity table but it is not present in the drawingsThe diameter of 160 mm is mentioned in the quantity tables and this diameter is not present in the drawings.The diameter of 180 mm is mentioned in the drawings and this diameter is not present in the quantity tables.For all the above clarifficiatons , Please refer to Amendment 001 - LOT 2 - 3-5B-Phase Two PROFILES DRAWINGS, Amendment 001 - LOT 2 - Phase 01 - BoQ. and Amendment 001 - LOT 2 - Phase 02 - BoQ.The specifications for the tapping ferule and saddle are to be made of gunmetal and its accessories of nails are stainless steel. These specifications apply if the pipes are ductile iron. Note that the tapping ferule and saddle are very expensive and do not necessarily have to be used with HDPE pipes. The specifications also indicate the type of ferule strap that has a push-fit system. This system is not available in the local market or in the markets of neighboring countries, and importing it from Europe requires a long time.Please refer to item 1.2.6: Supply and install Single Ferrule on DI mains. A small quantity will be utilized to connect with the existing networks. Kindly ensure full compliance with the RFQ specifications and requirements. We hope to agree to extend the deadline for submitting the tender so that we can obtain appropriate prices for the materials, since more than 60% of the project value represents the value of the materialsExtension had already been granted in prevoius amendment. We hope to clarify the pipe pressure, as only limited items were mentioned, which is 16 bar pressure, and the rest of the items did not mention any details about the required pipe pressure. We hope you can clarify for each country.The minimum  system pressure requirement  is PN16 The pipe diameters in the drawings are 300 mm, 180 mm, and 125 mm, but these diameters are not listed in the Bill of Quantities, which specifies the following diameters for the pumping line: 400 mm, 250 mm, and 200 mm, while the diameters for the distribution network are 160 mm and 90 mm."Please refer to Amendment 001 - LOT 2 - 3-5B-Phase Two PROFILES DRAWINGS, Amendment 001 - LOT 2 - Phase 01 - BoQ. and Amendment 001 - LOT 2 - Phase 02 - BoQ.Regards 

New amendment added #1: The purpose of this amendment is:Extended the tender deadlne. Upload pre bid meeting minutes.Therefore please note the following changes :The Esourcing General tab amended:Deadline to read as 24 March 2025 The Esourcing Document tab Add Pre-Bid Meeting -  Prebid Meeting RFQ-2025-56464All other terms and conditions remain the same.