Construction of Water Supply and Sanitation Facilities: Borehole Drilling, Collection, Transmission and Distribution Mains, Concrete Water Reservoir, Water Points and Community Latrines in IDPs Qoloji Camp; Somali Region, Ethiopia

Reference: ITB/2021/25257

Description:

UNOPS intends to construct WASH infrastructure facilities with an objective of improving access to water supply and sanitation to Qoloji IDPs located 65 Km to the East of Jigjiga town, Somali Region, Ethiopia. The scope of works will include:

Drilling two boreholes at designated locations on drawings to a depth of 70.0m;

Supply and installation of submersible pump in the boreholes;

PV Solar power system that include solar panels, inverter, switch board and cabling works;

Construction of four 100m3 capacity ground water reservoir at elevated location;

Collection and Transmission Piping works for ensuring proper water supply from the two boreholes and feed to the water reservoirs located about 2.0Km from the boreholes;

Distribution piping works from the water reservoirs to the water points located within the settlement of the IDPs;

Water points for supply of water for IDPs and host communities;

Construction of VIP latrines within the settlement of the IDPs.

The construction of the WASH facilities will include the following works:

a) Mobilization

Site preparations, sign board, site safety and security works;

b) Civil, Mechanical, Electrical and Plumbing (MEP) Works

Earthwork: Setting out of the facilities, site clearing, trench excavation for piling works, backfill with selected material (95% Proctor) and cart away as directed by the site supervisor;

Borehole Drilling Work:

Drilling of standard boreholes of 17" diameter from 0 meter up to 6 meters and 14” up to 70m;

Supply and install 16" diameter standard ASTM steel surface casing, 8" diameter standard PVC Blind casing, and 8" diameter PVC Well Screen;

Provision and installation of electric submersible pump sets complete with motor, starter, sensor, water level sensors and controllers;

Pump Tests and commissioning;

Fencing the borehole area with galvanized wire mesh as detailed including all intermediate straining, concrete posts and struts and all associated works.

PV Solar Power Supply System

Supply and Install SPV modules: GF 270, 144 pcs or equivalent; Solar array power- 38.88 kW; polyCrystalline silicon cell, terrestrial; IEC 61215, IEC 61646 standards;

Supply, install and commission Set Wire kit array to array;

Supply and install Grid tied Hybrid Inverter: RSI 3x380-440V IP66 30kW 61A or equivalent;

Supply install and test and commission: SPV module main Junction boxes, (PV circuit combiner) Made of FRP or cast Aluminum/copper;

Supply install and test and commission Mounting racks for PV module array; solar panel support structure made of Aluminum or approved system;

Supply, install and test and commission Main distribution panel board; Surface mounted MDB with lockable door;

Construction of switch board house of size 2000mm x 2200 made of concrete base, steel structure and steel grating wall covered with iron sheet;

Installation of Earth System and Manholes;

Basic operation and maintenance training to staff.

Collector and Transmission Main

Supply and Installation of PN-16 HDPE pipes and fittings from the respective boreholes to water junction and water reservoirs;

Supply and installation of various fittings such as water meter, valves, check valve, air release, washouts, reducers, Tee joints, etc.

Construction 1.20mx1.20m masonry wall valve chamber with 10cm thick c-20 RC concrete manhole cover;

Construction of trust blocks for bends and tees in C-25 reinforced concrete;

Construction of grade C-20 reinforced concrete for pipe encasements at road crossings;

Pipeline testing and commissioning for the whole work;

Water Reservoir

Earthwork: Setting out of the structures, site clearing and excavation, backfill with selected material (95% Proctor) and cart away as directed by the site supervisor;

Concrete Foundation: Reinforced concrete bottom slab for the water reservoirs on top of well compacted fill material and crushed stone hardcore as detailed on the drawings;

Concrete Wall and top slab: Reinforced concrete for vertical circular wall, and top slab of C-30 concrete grade and high strength reinforcement bars;

Finishing: Cement plastering and waterproofing paint internally and rendering for external surface wall;

Supply and installation of fittings and piping works in and out of the water reservoir;

Installation of Manhole cover 800 x 800 mm made of chrome plated nickel steel with ventilation and safety lock;

Provide a ladder made of steel as per the drawing. Both internal and external;

Fencing the water reservoir area with galvanized wire mesh as detailed including all intermediate straining, concrete posts and struts and all associated works.

Distribution Main

Supply and Installation of PN-16 HDPE pipes and fittings from the water reservoir to IDPs and community water points;

Supply and installation of various fittings such as, valves, reducers, Tee joints, etc.

Construction of trust blocks for bends and tees in C-25 reinforced concrete;

Construction of grade C-20 reinforced concrete for pipe encasements at road crossings;

Pipeline testing and commissioning for the whole work;

Disinfection of pipelines: Flushing with clear water, filling with water containing 0.15g/l calcium hypochlorite, left for 24hours.

Community Water Points

10cm thick C-20 mass concrete in water point base and on the surface of the hard core;

Hard trachytic or equivalent stone masonry water point wall grouted and filled with 1:3 mortar;

Finishing Works: Pointing stone masonry wall of water point with rich (1:3) mortar and 100mm cement screed on top of the water point and make a platform;

Piping and accessories including the supply and installation of individual faucets;

Community Latrines

Earthwork: Setting out of the building structures, site clearing and excavation, backfill with selected material (95% Proctor) and cart away as directed by the site supervisor;

Foundation work: Strip masonry foundation for the latrine buildings;

Concrete Ground Floor: Reinforced concrete floor for the buildings on top of well compacted fill material and crushed stone hardcore as detailed on the drawings;

Concrete structural Frame: Reinforced concrete for ground beams, vertical columns, and top tie beams of C-25 concrete grade and high strength reinforcement bars;

Walls made of Hollow Concrete Block around the perimeter and partition of the buildings;

Steel Roof Structure: Supply and fix steel truss and purlins;

Roof Sheeting: CIS sheet roofing cover all as per the drawings;

Construction Duration: 180 Calendar Days (6 months) for the Whole Works