Tenders Are Invited For Drilling Of New Boreholes

Tenders are invited for Drilling of Two (2)New Boreholes (Indian Mark Ii) in Nuba Mountains 1.1 Mobilization of personnel, equipment and materials lumpsum 1 0 1.2 "Geo physical survey Perform VES ground water survey and determine most potential and appropriate location for high yield borehole. The survey must be conducted by an experienced Hydrogeologist consultant /expert. Including preparation and submission of hydrogeological report " BH 1 0 Subtotal 1. Preliminary and general 0 2. Borehole construction 2.1 "Drilling to a maximal depth of 80m Note: depth depending on geo physical survey (most boreholes in the area are 60-70m deep and the water intake is at around 45m depth)" m of drilling overburden 50 0 m of drilling rock 30 0 2.2 Sampling and storage of drill cuttings at 2m intervals or as instructed by Engineer BH 1 0 2.3 Supply and installation of UPVC casings (5"ND) 3M long x 170mm (5") external diameter with a minimum thickness of 3mm including end cap (average of 80m minus the length of the screen) # pipes 20 0 2.4 Supply and installation of UPVC screens (5"ND ) 3M long x 170mm (5") external diameter with a minimum thickness of 3mm (average of 18m per BH) # pipes 18 0 2.5 Supply and installation of gravel pack with uniform grading between 2.5 and 4.0 mm diameter from clean river gravel (5m3 per BH) m3 5 0 2.6 Well developed during a minimum of 5hours until a stabilized satisfactory yield is reached and the turbidity is less than 5 NTU clear water according to technical specifications hrs 5 0 2.7 Supply and installation of cement grouting of 1m diameter and 4m depth below the ground level, with all required activities, around the casing to act as sanitary seal (1m3 per per BH) m3 4 0 Subtotal 2. Borehole construction 0 3. Test pumping 3.1 Perform a minimum of 5 hours constant rate test and recovery data are to be reported on standard borehole log. At least a yield of 5000ltrs/h is realized as per installation BH 1 0 Subtotal 3. Test pumping 0 4. Water quality analysis 4.1 Water sampling, physical test, bacteriological and chemical test analysis, Original copies of results of the Water quality testing, showing date of sampling and date of analysis must be availed by contractor prior to payment for drilled borehole. The analysis to be checked against GOSS and WHO standards, and levels to be permissible before further construction. BH 1 0 4.2 Clean and disinfect the borehole with B23 50mg/liter with all required related activities. BH 1 0 Subtotal 4. Water quality analysis 0 5. Hand pump installation 5.1 Supply and installation of pedestral, water tank, pump head assembly and cylinder set 1 0 5.2 Supply and installation of India Mark II raiser pipes (UPVC) with sockets and connecting rodes (according to water level and pump test; average of 12 pipes) pipe 36 0 Subtotal 5. Hand pump installation 0 6. Head work 6.1 Reinforced Concrete construction of apron (diameter 2m, raised 30cm to allow proper drainage) and installation of the hand pump pedestal & third plate, to cover the borehole. Construction of a drainage channel (6m long). Keep moist for at least 72 hours. BH 1 0 6.2 Excavation and construction of soak away pit (2m deep) filled up with stones BH 1 0 6.3 Cleaning the working site and removing all of the unnecessary items and submission of completion report BH 1 0 Tender Link : https://comms.southsudanngoforum.org/c/tenders