Call for Tenders for Wastewater Treatment Project in Communauté de Communes des Vallées de l'Ubaye et du Sérépon, France

Tender Reference: 26-11790

Tender Type: Works

Project Name: Wastewater Treatment Works for the Villages of Larche and Maison-Méane

Procurement Procedure: Adapted Open Procedure

Divided into Lots: Yes (3 Lots in total)

Lot Description:

Lot 1: Larche Village Treatment Plant - Network - Stormwater Retention Basin Civil Works

This lot involves comprehensive civil and environmental engineering works, with the core objective of achieving effective wastewater collection, preliminary treatment, and stormwater management.

Detailed Scope of Implementation and Construction:

Wastewater Treatment Plant:

Preliminary Treatment: Construction or upgrading of screen chambers and grit removal tanks, using concrete structures, equipped with manual or mechanical cleaning facilities.

Biological Treatment: May involve civil foundations and tank construction for compact biological reactors (e.g., SBR Sequencing Batch Reactors, MBBR Moving Bed Biofilm Reactors). Tanks require waterproof concrete and leak testing.

Sludge-Water Separation: Construction of secondary clarifiers, including concrete structures with central inlet and peripheral outlet, equipped with embedded rails for sludge scrapers.

Disinfection and Discharge: Construction of ultraviolet or chlorination contact tanks, and a final clean water discharge chamber connecting to the receiving water body.

Sludge Treatment: May include civil works for small sludge thickeners or sludge drying beds.

Sewer Network Supporting Works:

Pipeline System: Laying of DN 200 to DN 400 HDPE or PVC-U main sewer pipes, required to comply with NF EN 1401 or NF EN 13476 standards. Includes fittings such as elbows, tees, and reducers.

Manholes: Use of precast concrete or brick circular manholes with a minimum diameter of 1000mm, equipped with cast iron or composite covers, and internal ladders. Must ensure one manhole per 40-50 meters of pipeline.

Connection Works: Completion of connection chamber construction linking the new network to existing main pipes or treatment facilities, including pipe cutting, sealing, and joining.

Stormwater Retention Basin Civil Works:

Structural Works: Construction of an underground or semi-underground reinforced concrete retention basin, with volume determined by hydrological calculations (likely between 100-500 cubic meters). Structural design must consider groundwater pressure and earth pressure.

Hydraulic Components: Include inlet (with energy dissipation facilities), outlet (equipped with flow control valves, such as vortex valves), and overflow outlet.

Internal Facilities: Installation of embedded pipes for a flushing system at the basin bottom; diversion walls may be required inside the basin. Ventilation and access for hazardous gas monitoring must be considered.

Safety and Maintenance: Installation of guardrails, access manholes, and safety warning signs.

Service Details:

Preliminary Works: Detailed site surveying, underground utility detection, and development of temporary traffic management plans.

Construction Management: Submission of method statements, construction schedules, and compliance with French Labor Code for site safety.

Quality Control: Provision of conformity certificates for all materials, compressive strength testing for concrete, pressure testing and CCTV inspection for pipelines.

Completion and Handover: Provision of as-built drawings, organization of on-site training, and assumption of warranty obligations during the defects liability period (typically 12 months).

Lot 2: Maison-Méane Village Collection Network

This lot involves linear network works, with the core objective of constructing an efficient, leak-proof domestic wastewater collection network.

Detailed Scope of Implementation and Construction:

Network Layout and Materials:

Main Network: Laying of gravity flow networks following the terrain gradient. In flat or low-lying areas, design of vacuum drainage systems or small pressure networks may be required, including installation of interface valve chambers.

Pipe Specifications: Domestic connection pipes (DN 100), street collection pipes (DN 150-200). Priority given to corrosion-resistant PVC-U SN4 or polypropylene pipes.

Special Crossings: Use of trenchless technology (e.g., micro-tunneling) or protective casings when crossing roads. Use of weighted concrete pipes or directional drilling when crossing rivers.

Node Structures:

Domestic Connection Chambers: Installed in front of each household for future maintenance and metering. Equipped with sealed connectors.

Cleaning Access Chambers: Installed at points where pipe direction or gradient changes to facilitate cleaning by high-pressure water jetting.

Ventilation Shafts: Installed at network ends or high points to prevent airlocks and vent odors.

Earthworks and Reinstatement Works:

Excavation: Use of narrow trenching techniques in residential areas to minimize disturbance to residents. In stable ground, trench sides may be vertical but require a shoring system.

Backfilling: Use of graded backfilling, with granular material for the pipe bedding, and selected fine material within 30cm on the sides and above the pipe to avoid damage from stones.

Road Reinstatement: Restoration of asphalt pavement, curbs, sidewalk paving, and landscaping to original standards. Submission of municipal road occupancy permit is required.

Service Details:

Resident Coordination: Development and implementation of a detailed resident notification and communication plan, specifying work hours, temporary access arrangements, and emergency contacts.

Environmental Management: Implementation of a site environmental management plan to control dust, noise, vibration, and proper handling of excavated contaminated soil.

Testing and Acceptance: Conducting leak tightness tests and flow capacity tests on all pipeline sections. Provision of complete test reports.

Asset Management: Establishment of asset codes for the new network and entry into the municipal asset management GIS system.

Lot 3: Larche Village Pumping Station: Electromechanical Equipment, Automation System, Remote Monitoring

This lot is a high-tech integration project, with the core objective of constructing a reliable, efficient, and intelligent wastewater lifting hub.

Detailed Scope of Implementation and Construction:

Electromechanical Equipment Package:

Pump Units: Provision of a dual-pump alternating operation system (one duty, one standby), each pump capable of independently handling the maximum design flow. Pump types are non-clog vortex pumps or chopper centrifugal pumps, with motor protection class IP68 and insulation class F. Equipped with baseplates, flexible couplings, check valves, and isolation valves.

Electrical System: Design and installation of a waterproof and explosion-proof electrical room compliant with NF C 15-100 standards. Includes main distribution board, motor control center, soft starters or variable frequency drives (for energy saving and soft starting), and uninterruptible power supply for the control system.

Auxiliary Systems: Mechanical screens, screw conveyors; emergency ventilation system; heating and dehumidifier; overhead crane for equipment maintenance.

Automation and Control System:

Control Logic: PLC programming for multi-level control (start, stop, alarm, standby pump start), pump alternation to equalize wear, dry-run protection, and electrical fault diagnostics.

Human-Machine Interface: 10-inch color touchscreen displaying real-time process flow diagrams, equipment status, alarm lists, and historical trend curves. Supports multi-level password protection for operation rights.

Remote Monitoring and Data Acquisition System:

On-site Data Acquisition: Collection of all instrument data via the PLC's communication modules (supporting Modbus TCP/IP, OPC UA).

Communication Network: Use of dual communication redundancy, primary being municipal fiber optic private network, backup being 4G LTE network (equipped with SIM card and data plan).

Central Monitoring Software: Web-based SCADA platform, allowing authorized personnel to log in from any location via a browser.

Features include:

Real-time monitoring of all sites.

Automatic generation of daily/weekly operational reports (energy consumption, runtime, pumping volume).

Advanced alarm management (alarm prioritization, acknowledgment, escalation notification).

Maintenance planning and work order management module.

Data Security: The system must comply with basic security requirements from the French National Agency for the Security of Information Systems for critical infrastructure, such as firewalls, VPN access, and user activity logs.

Service Details:

Design Coordination: Close coordination with the civil works contractor of Lot 1 to ensure complete accuracy of equipment foundation dimensions, embedded parts, and wall penetration sleeve locations.

Factory Acceptance Testing: For major equipment (e.g., PLC cabinets, pumps), invitation of the contracting authority's representative to the manufacturer's factory for testing prior to shipment.

On-site Installation and Commissioning: Supervision of installation, execution of individual equipment commissioning, integrated commissioning, and 72-hour continuous operation testing. Training of the contracting authority's operation and maintenance personnel.

Documentation and Spare Parts: Delivery of complete technical documentation (schematics, program source code, operation and maintenance manuals), and provision of a recommended two-year spare parts list.

Remote Support: Provision of at least 36 months of remote technical support service, including software updates and troubleshooting assistance.

Contract Duration: 6 months

Place of Performance: Vallée de l'Ubaye, France

Main CPV Code: 45232423 (Wastewater treatment plant construction work)

Additional CPV Code: 45232410 (Sewage system construction work)

Qualification Requirements: Submission of economic and financial capacity proof (DC1 and DC2 forms) required

Mandatory Site Visit: Yes

Visit Requirement: Bidders must conduct a site visit to assess construction difficulties and submit an honor statement with the visit date included in their bid.