Public Tender for the Rehabilitation of Deep-boreholes in Northern and Southern Liech, South Sudan


Universal Intervention and Development Organization is a South Sudanese National and Christian organization found in 2004, the organization is legally registered by the Relief and Rehabilitation Commission (RRC). UNIDOR has a strong presence in the country and implementing multi-sectorial projects which are designed to alleviate severe suffering of the communities who are affected by the conflict and natural disaster. UNIDOR is also a member of different clusters in the country as well with NGOs forum the country’s humanitarian network body. UNIDOR's main thematic focus includes Health, Nutrition, WASH, Protection, Food Security and livelihood (FSL), Education and Peacebuilding and conflict mitigation.

As a consequence of continued civil war and repeated droughts, 7.2 million people in South Sudan are currently displaced. In the severely affected counties of Northern and Southern Liech, people have no access to clean water. Deep boreholes reaching the second aquifer have been deliberately destroyed.

In view of the precarious situation, returnees and IDPs can only return home once access to safe drinking water is secured. The project seeks to provide 25,000 people with access to safe drinking water by rehabilitating at least four to five deep boreholes (pumping capacity: 10,000 litres/day each) in Northern and Southern Liech.

Universal Development and Intervention Organization (UNIDOR)

Address: Juba  Nabari, Kololo Road. In front of Catholic University

Contact Person:

  1. Malakal Gatluak Logistic and Procurement Manager

Email: [email protected]

Tel:     +211927225420


  1. Jacob Ukumu Logistic and procurement Officer

Email:  [email protected]

General Terms & Conditions

  1. Deadline for submission of Tender/Bids: 30th August 2019 at 2:30 pm
  2. All bids should be placed in the tender box located at the security gate (or the main office entrance) of UNIDOR (or to a specific staff against a receipt according to the practice in SSD).
  3. Address: UNIDOR South Sudan at Juba Nabari Kololo Road. In front of Catholic University.
  4. In case of placing the bid as described in “2.” above, the bids shall be in sealed envelopes marked with the “Rehabilitation of Deep-boreholes in Northern and Southern Liech, South Sudan”. Alternatively bids can be submitted electronically via e-mail to [email protected] (plus with the same reference.
  5. Only offers covering all sites will be considered.
  6. The total bid amount shall be written in numbers and words.
  7. In case of mathematical error or variation in the total bid, the unit price will govern.
  8. Late bids will not be considered.
  9. The contract is technically divided into two phase a) removal of existing pumping means and developing/regenerating the well b) Provision and installation of the solar pumping system. The latter is subject to the water-quality test result and the actual yield of the well. The works shall be terminated if of the water quality does not meet the adopted standards (WHO) or insufficient yield.
  10. The bidder shall prepare and submit a detailed work schedule (per day) taking into considering the two phases of the contract.




  1. Borehole Development/Rehabilitation
  • Preliminary measures and intensive cleansing of the well sump.
  • The bidder will choose a suitable and appropriate borehole development method. The borehole shall be developed for a period of at least three hours in order to obtain a maximum yield of water that is free of suspended matter.
  • Developing shall be carried out by airlift pumping and surging, jetting and block surging, or other techniques the contractor feels is more appropriate and efficient to suit the casing, hydro-geological and drilling conditions prevailing in that borehole.
  • The bidder should provide a detailed implementation work plan in which the steps and activities are described and determined.
  • The bidder shall produce a detailed report stating all information related to the well development e.g. dynamic and static water levels, recommended pumping rate, depth of the well, etc.
  • The bidder shall also assist UNIDOR field staff or their nominated provider in collecting water samples for testing purposes.



  1. Solar Powered Water Supply Scheme Information

It is envisaged that the system is made up of the following components.

  • Solar generator to provide power
  • Pump and pump motor to pump the required water quantity
  • Control equipment for optimization and regulating the system
  • Water storage (already in place)
  • Distribution point (tap stands)



  1. System Design
  • The system must deliver the specified cubic meters per day based on the month with least solar irradiation in the given location.
  • All components of the solar system shall be robust, neatly assembled, firmly fixed supports in the ground and designed to allow easy access using adequate tools.
  • System designs should eliminate the use of components with a short life. Typical component lives should be 20 years solar generator; 7 years pump motors; 10 years pump; 7 years control equipment; 30 years Structures; 30 years mechanical and electrical fittings. All components should be subject to minimal servicing and without expensive parts.
  • The bidder must provide with their offer an economic analysis showing the payback period for the solar system with the expected cost savings over the life cycle of the systems by considering the capital costs and the O&M costs of the system for 25 years from the time of installation.
  • All components and accessories shall be made from corrosion resistant material to be rust-free by galvanizing and or painting of all surfaces that are exposed to the ambient conditions. All materials shall be resistant to the effects of excessive moisture, water, and ambient temperature. Resistance to corrosion shall be according to DIN 8985 standards.
  • All equipment, parts and accessories shall be well designed and fastened against theft, with considerable difficulty to unscrew the solar modules or metal parts from the entire assembly.
  • The system should be of high quality and designed for use in remote locations. The bidder should outline the key design elements that make the solution suitable for the environment it will be installed in.
  • The bidder shall include detailed calculation of system operation based on least solar irradiation in the given location.
  1. Site Details

The locations are in Northern and Southern Liech State:


  1. Rubkona County, Kaljak I Village. The site is easily accessible via the main road during the dry weather periods and may prove difficult in the wet season.
  2. Rubkona County, Kaljak II Village. The site has no marked access and is situated in the dense shrubs and little trees. Accessible during the dry weather periods and may prove difficult in the wet season.
  3. Koch County, Bargok/Koch Town. The water scheme is located off the main market. The site is easily accessible during the dry weather periods and may prove difficult in the wet season.
  4. Koch County, Rier Town. The well is located at the town market and the site is easily accessible during the dry weather periods and may prove difficult in the wet season.
  5. Leer County, Leer Town/Village. The site is easily accessible during the dry weather periods and may prove difficult in the wet season.


The exact location of the sites shall be shown to the bidder by UNIDOR staff on site or by providing an overview containing the exact GPS coordinates. The bidder is free to seek any clarification on the site characteristics from UNIDOR prior to commencement of the works. Bidders are encouraged to visit the site before bidding at their own expense.


When considering the design of the systems the following planning assumptions should be made for each of the respective sites.


Location (Lat., Long.)
Daily Water Demand (m3) From the pumping test report
Ground water temperature (°C) 30
Cable Length (m) As per the bidder installation plan
Borehole Yield (m3/hr) From the pumping test report
Depth of Borehole (m) same as above
Size of Casing (inches) 4”
Static Water Level (m) From the pumping test report
Dynamic Water Level (m) Same as above
Tank Height (m) 6.5
Ground Elevation (m) 2
Delivery pipeline length to tank (m) As per the bidder installation plan
Total Dynamic Head (m) From the pumping test report
Dirt Allowance 5%
Max allowable cable losses 3%
Ambient Temps Max. 45oC
Existing Tank Capacity (m3) 50


  1. Removal of The Old Pumping System

Carefully disassemble and remove the existing items stated in the BoQ (will be made available upon request) such as wellhead, pumps, discharge hose, pipes, fittings, cables, steel structures, corrugated sheets and any other materials or equipment and hand them over officially to the representative of the respective community in the presence of UNIDOR staff. The hand over minute should include a detailed inventory of removed items.


  1. Bidder Qualification
  • The bidder should represent a reputable manufacturer and with experience to meet the requirements of this project. The bidder must provide a letter of authority from the manufacturer stating that this information has been provided with their co-operation and is true and accurate.
  • The bidder must have a minimum of 7 years’ experience of designing, installing and maintaining solar pumping solutions of a similar size, scope and application.
  • The bidder has to submit a reference list of previous projects including the contact details of the client. The reference projects must be of similar scope, size and implemented within South Sudan. UNIDOR reserves the right to contact references at any time without the bidder consent.
  • The bidder must operate a quality management system that is ISO 9001 or equivalent and have recognized third-party verification. Solar modules, pumps, motors, and control equipment must meet the necessary CE/international standards for safety and where applicable functionality.
  • The bidder must have access to the manufacturer’s design support team


  1. Equipment and Material Specification
  • The bidder MUST attach equipment datasheets detailing equipment characteristics and features. Any equipment or supplies that do not meet the specification requirements will not be considered.
  • The bidder MUST submit Test Certificate or Conformance Certificate for all supplied pipes, paints, epoxy, and any other construction material. UNIDOR shall reject materials without official test certificates.
  • Samples of all material and equipment shall be submitted to UNIDOR upon request for approval before installation, otherwise the contractor shall be responsible for costs incurred from the removal and reinstallation.


Solar Generator

The solar generator must be designed to provide adequate power to the system in real world conditions. Pure theoretical models must be avoided and bidders should show what assumptions have been made in calculating the solar generator size and include it in the design

  • Only certified Polycrystalline and Mono-crystalline silicon modules are generally acceptable. The modules should be certified for compliance with IEC/EN 61215 and 61730 or UL 1703 certified and listed
  • All modules must be of a robust design and bidders should provide evidence of successful prior off-grid use
  • Modules shall be guaranteed for 25 years with 10% derating for the first 10 years, and 20% derating within 20 years. The efficiency of solar-PV cells shall be minimum of 16% and solar modules total efficiency of minimum 14%

The PV Modules shall be clearly labelled and permanently marked with a data plate containing the following information: manufacturer’s name and physical address, type/model number, the watt-peak power rating at STC, open circuit voltage and short circuit current, voltage and current at maximum power point, tolerance and temperature coefficient, country of manufacture, certification, e.g: UL listing, IEC 61215,ISO certification, with fool-proof +ve/-ve connectors


Submersible Pump

  • The pump shall be a multistage centrifugal type closely coupled to an AC motor constructed from AISI 304 Stainless steel or higher. All metal material used for pump construction shall be corrosion resistant, permanently lubricated and maintenance free.
  • The motor end shall be constructed with the following features: single phase 200-240V AC motor (50Hz speed controlled, +5hz selectable speed), corrosion-resistant, all stainless-steel exterior construction, stainless steel shaft, ceramic bearings, NEMA mounting dimensions, hermetically-sealed windings, water lubrication, pressure equalizing diaphragm, able to withstand min water temperature 40°C.
  • The pump end of the water pump shall be constructed with the following features: centrifugal multistage direct-coupled pump end, non-return valve, stainless steel (AISI 304 or higher), water lubricated rubber bearings, able to withstand maximum sand content 50g/m3.
  • For solar systems, a water pump equipped with a variable frequency/speed induction motor is highly recommended.
  • The pump motor must have an efficiency of at least 80% and not be limited to less than 20 start/stop cycles in one hour to maximize water output in early morning late afternoon and on cloudy days
  • The pump must meet EN 809 and EN 60034-1 or internationally recognized equivalent standards
  • The pump set must be of a modular design to allow for replacement of individual parts (pump end, pump motor and electronics) if a failure occurs.
  • The system must have dry run protection to protect the system in the event of low water levels.
  • The pump set should be able to fit into the existing [4 inches] borehole casing.



Control Equipment

A power inverter shall be used to convert DC power from solar PV modules to AC power that can be used to power an AC motor-based water pump. The inverter shall act as a pump drive or controller manufactured and supplied to work with the specified pump type, and universally works well with induction motors; suitable for solar water pumping applications. The inverter shall be designed to provide useful information about voltages, switch and sensor status, and overload conditions; and deliver maximum power [maximum power point tracking (MPPT) and current boosting] under varying conditions. It should offer direct solar connection as standard and have the ability to add on an optional power back up if required in the future. The control equipment must meet EN 61800-1, EN 61800-3, EN 60204-1 or internationally recognized equivalent standards


Other desired features include:

  • Controlling the pump system and monitoring of the status of system operation
  • Has two control inputs for well probe (dry running protection), float or pressure switches for remote control, with automatic reset after well probe turns the pump off
  • Protections for over current, under voltage, over speed, over temperature, reverse polarity and dry running.
  • Data logging of operating parameters including running time, starting/stopping time, max power/voltage of day and total energy generated in the day. The data can be recalled for reference
  • Selectable display of operating including input/output amperage, power and voltage, pump speed and temperature.
  • Control equipment must have simple system health indicators that are user-visible for troubleshooting purposes: typically, of pump status, pump speed, well dry, tank full, low source power information
  • Settable minimum and maximum speed to provide continuous water delivery and overload avoidance.
  • Integrated MPPT (Maximum Power Point Tracking)
  • Maximum efficiency 97 %
  • Inverter enclosure: IP 54 or higher (sealed, weatherproof, insect proof, lizards’ proof)
  • Ambient temperature: -10 to +50°C
  • An inbuilt fan which efficiently cools the controller
  • Electrical switchgear (such as switches, sockets, consumer units, fuses etc.) must be high quality certified to the relevant IEC, British (BS) or equivalent standard. Proof of such certification and origin must be submitted. Module Support Structure
  • The solar modules shall be mounted on a structure fabricated using galvanized iron or aluminium, strong enough to withstand windstorms of 100km/hr. and be painted to reduce corrosion. Fasteners and other installation accessories (screws, bolts, etc.) should be galvanized or stainless steel. The structures when mounted shall have the modules tilted at an appropriate angle from the horizontal plane and the space between them and the roof/ground shall be at least 6 inches.
  • The structural steel for the support of the PV module shall be consist of 4'' GI Pipe Class A poles, drilled plates 160*160*8mm, 50x50x3mm rafters, 50x50x3mm SHS struts and ties, 40x40x4mm angle iron to support the panels. All joints to be bolt and nuts with spot welding. The height of the support structure shall be a minimum of 3 metres above ground at the lowest point. A detailed “Solar Panels Mounting Structure Drawing” will be made available upon request.
  • Steel angle section shall be used only to support the PV modules and not anywhere else.
  • The structure shall incorporate a catwalk scaffolding 60 cm wide made of s perforated checker plate along the solar array to facilitate regular maintenance of the solar panels. The catwalk should have a provision for a removable ladder. The ladder is an integral part of the structure.
  • All steel surfaces shall have a red oxide prime coat and two coats of oil-based or latex based paint upon erection.
  • All welding will be continuous and of full penetration on both sides.
  • In case the steelwork is prefabricated away from the site, a final coat of paint shall be applied upon erection of the structure on site.
  • The structure will be joined and fastened using bolts and nut with spot welding for vandal proofing
  • Design simulation and drawing for the structure should be included with the submission showing all loading that has been factored in, including wind loading for the specific location
  • The bidder should calculate and submit the solar array tilt angle that captures maximum irradiation from the sun.







  • The cabling will be as follows: From the PV generator to the controller and switchgear, from the generator to the switchgear, from the switching gear to the borehole head, sensor cable from the control panel to the borehole head, earthing cable.
  • Cable distances should be kept as short as possible to minimize wire size [voltage drop precautions] and installation cost. The appropriate cable size should be selected for use with respect to the distance, voltage and current values involved.
  • All the structural components and electrical enclosures shall be bonded together to a common earth connection.
  • The ground wire of the pump shall be connected to one of the ground connections in the controller, or the controller enclosure. Grounding helps to prevent shock hazard if there is a fault in the motor
  • An effective discharge path for the surge should be created for earth. One or more 8-foot copper-plated ground rods, preferably in moist earth, should be installed
  • Lightening arrestor must be erected such that it will remain the tallest structure on site and grounded with a copper strip of not less than 25mmx4mm. The system shall be provided with lightning & over voltage protection. The main aim in this protection shall be to reduce the over voltage to a tolerable value before it reaches the PV or other sub system components. The source of over voltage can be lightning, atmosphere disturbances etc. Metal oxide varistors shall be provided inside the Array Junction Boxes. In addition suitable MOV‟s (Metal Oxide Varistors) also shall be provided in the Inverter to protect the inverter from over voltage.
  • Proper termination of cables must be used using well crimped cable lugs and cable glands
  • All submersible cable shall be 4-core flat copper strand, 100% water-tight with PVC or rubber insulation suitable for temperatures up to 400 A high quality, waterproof connection between the pump wires and supply cable is very important.
  • All underground cables shall be armoured.
  • Earthing: The array structure of the Photo Voltaic yard shall be grounded using adequate number of earthing kits. All metal casing / shielding shall be thoroughly grounded to ensure safety of the Solar Photovoltaic power system. Earth resistance readings must be measured by a qualified person and submitted. Resistance values shall conform to IEE regulations.


  1. Equipment Spare Parts

Parts should be replaceable at a low level of modularity to reduce replacement costs. The bidder must recommend the items that would be supplied in line with manufacturer’s recommendation. Recommended service intervals for each component should be stated along with parts costs, time and skill level required to service. Spare parts must be readily available on site within 5 days.


Component   Service task and spare Part Frequency of task/ replacement Time of activity Skill level of technician Consumables items and cost
Solar Generator
Pump and motor


Control Equipment




  1. Scope of work

The scope will include but not limited to the following:


  • Transport and delivery of all the equipment and structural parts to the sites
  • Preliminary activities: removal of old pumping system etc. and development/rehabilitation of the respective borehole.
  • Installation of the submersible pump complete with pipes, cables and dry running protection
    • Water testing, analysis of the result and the way forward
      1. The successful bidder should note that upon completion of the pump testing which should not be less than 72 hours, the samples need to be airlifted from the site to a reputable independent laboratories for quality test analysis.
      2. During this period, the work will be disrupted awaiting the test result of which the results will determine whether the project will continue or not. Therefore it is crucial to develop and submit a detailed time-schedule for the respective construction works in order to have an external professional to collect the samples adequately and at the right time.
      3. If the results fail the laid down parameters, the project will be discontinued and the contractor should be paid a certain percentage which will be agreed upon by both parties while drafting the contract.
      4. If the results will be favourable, then the project will continue with (3) and full payment paid as per the contract terms and conditions.


  • Construction of a suitable base of reinforced concrete to support the solar panel support structure.
  • Erection of the solar panel support structure, positioning of the solar modules on the structure, securing with bolts and nuts with vandal proofing such as spot welding.
  • Installation of all the protective and control equipment including a solar controller, change-over switch, cable connections between the pump, controller, solar modules and generator, grounding, earthing and lightning protection
  • Upon completion of the installation, the contractor shall conduct a short-term pumping and equipment test lasting for the duration of 48hrs to monitor both solar and generator.
  • On completion of all works, the contractor shall submit to UNIDOR a hard and soft copy of the test certificate comprising a test sheet of parameters including insulation resistance, tested peak flow in m3/hr and peak frequency in Hz and others.
  • The contractor shall submit to UNIDOR Office, a delivery, installation and commissioning report (both soft and hard copies) of all the works done including an operation manual detailing in an easy to follow manner, the operation and maintenance regime to be employed in managing the newly installed solar pumping facilities.
  • The contract has to arrange a certified technician to facilitate one day training for the water scheme operators and UNIDOR WASH staff in operation and maintenance of the solar system.
  1. Warranty, Defects Liability, Service and Maintenance

The defects liability period (DLP) is an integral part of this contract.  The DLP is one year starts from the date of the official project handover to UNIDOR. During this period the contractor shall be responsible for repair or replacement at their cost any inferior material, poor workmanship defects or broken parts within 30 days from the UNIDOR official notice. Otherwise, UNIDOR can arrange to repair the defects at the contractor cost. Additionally, bidders shall submit with their bid, a priced proposal for a 2-year service agreement after the expiry of the warranty and DLP.