Construction of 20 Nos Exploratory and 6 Nos Observation WELLS in West Bengal STATE

Amount

Drilling of overburden by rock roller/ drag/ button bit to accommodate casing pipe of 175 mm (7") dia. up to bed rock including formation sample collection at every 3 m interval, preparation and submission of litholog along with video recording

Supply and installation of ERW casing pipe conforming to latest version of IS: 4270-2001

300 mm (12”) Nominal Bore, pipe thickness 7.1 mm

250 mm (10”) Nominal Bore, pipe thickness 7.1 mm

225 mm (9”) Nominal Bore, pipe thickness 6.0 mm

200 mm (8”) Nominal Bore, pipe thickness 5.4 mm

175 mm (7”) Nominal Bore, pipe thickness 5.4 mm

Drilling by DTH method using appropriate sizes of button bits so as to reach targetted depth with diameter of hole not less than 165 mm at 100 m depth and final diameter not less than 152 mm at hole bottom including measurement of discharge through V-notch at various stages (depth) of drilling, collection of water sample for each aquifer formation/fracture zone encountered adopting standard procedure, formation sample collection at every 3 meter intervals, preparation and submission of litholog, discharge measurement etc. with video recordings of discharge and V notch readings, lithlog samples, pull out of rods after completion of target depth of drilling

Electrical logging using 406 mm and 1626 mm (16" and 64") SP resistivity probe and preparation of composite log along with video recordings

Natural gamma logging submission of logging graph, report along with video recordings

Caliper logging to decipher the depth and width of fracture zones, submission of detailed report including logging graph, interpretation of graph, generation of composite log along with video recordings

Pumping Test including pre-pumping for 8 hours and recuperation for 24 hours, SDT (3 steps for total 300 minutes), APT for 1000 minutes (90% or full recovery) and collection of 4 Nos. water samples adopting standard procedure for basic parameter and heavy metals in 1 litre good quality HDPE bottle along with video recordings

Preliminary Yield Test (PYT) including collection of 2 Nos. water samples adopting standard procedure for Basic Parameters and Heavy Metals in 1 litre good quality HDPE bottle and submission of analysis report with data and video recordings

Slug Test and submission of analyis report with data and video recordings

Reaming with rock roller/ drag/ button bit as appropriate to accommodate part assembly as given below

Supply and installation of ERW casing pipe (for part assembly conforming to latest version of IS: 4270-2001. The part assembly pipe should be lowered by using reverse socket through drill string. Video of lowering part assembly should also be submittted.

175 mm (7”) Nominal Bore, pipe thickness 5.4 mm

150 mm (6”) Nominal Bore, pipe thickness 5.4 mm

125 mm (5”) Nominal Bore, pipe thickness 5.4 mm

100 mm (4”) Nominal Bore, pipe thickness 5.4 mm

Supply and installation of MS slotted pipes conforming to sizes and slotting arrangement as per latest version of IS: 8110-2000

300 mm (12”) Nominal Bore, pipe thickness 7.1 mm

250 mm (10”) Nominal Bore, pipe thickness 7.1 mm

225 mm (9”) Nominal Bore, pipe thickness 6.0 mm

200 mm (8”) Nominal Bore, pipe thickness 5.4 mm

175 mm (7”) Nominal Bore, pipe thickness 5.4 mm

150 mm (6”) Nominal Bore, pipe thickness 5.4 mm

125 mm (5”) Nominal Bore, pipe thickness 5.4 mm

100 mm (4”) Nominal Bore, pipe thickness 5.4 mm

Chemical analysis of water samples for 15 parameters (pH, EC, TH, TDS, Ca, Mg, Na, K, CO3, HCO3, SO4, NO3, Cl, F & Fe) in NABL accredited lab and submission of report from NABL lab

Chemical analysis of water samples for Heavy metals (As, Pb, Zn, Cu, Cr, Se, Ni, Mn, U) in NABL accredited lab and submission of report from NABL lab

Construction of cement concrete platform of dimension 0.70 X 0.70 X 0.60 m (0.30 m above ground level) using concrete mix of 1:2:4 around the housing pipe welded with minimum 6 Nos of anchoring plate as per drawing

Supply and fitting of well cap as per drawing with Allen Keys. MS Plate size 5 mm embossed & welded with permanent marking of “ CGWB EW” for Exploratory Wells & "CGWB OW" for Observation Wells should be carved with welding on outer surface of casing pipe 0.5 m

Supply and installation of protection box made of GI sheet of 3.15mm thickness along with Brass lock (7 lever hardened of branded item) and three keys/District wise Master Key for each lock as per drawing

Supply and installation of Display Board as per specification in drawing

Preparation and submission of Basic Data Report per site (including EW and OW) in triplicate along with logging graphs, data sheets, analysis sheet, chemical analysis report from NABL lab, photographs and videos of activities during drilling, assembly lowering, part assmbly lowering, pump lowering, pumping tests, discharge during pumping test, V- notch discharge at various depth of drilling, pumping test with well discharge, compressor development, water sample collection, well site with display board, well cap, protection box etc. Soft copy and hard copy should be submitted. Summary of well details in xls format including details of dia and depth of housing pipe, part assembly pipe if any, screen pipe if any, static water level, aquifer parameters, safe discharge, gravel packing depth and thickness, litholog, depth of fracture zone and respective V-notch discharge, details of chemical analysis (Basic Parameters and Heavy Metals) should be also submitted in the detailed report.

Description of Work / Item(s)

Amount

Drilling of pilot hole using bentonite fluid for EW not larger than 216 mm (8 ½”) by rock roller/ drag bit including formation sample collection at every 3 m and change in formation, preparation and submission of litholog along with video recordings

Electrical logging using 406 mm and 1626 mm (16" and 64"), SP resistivity logging, Natural Gamma logging to target depth of minimum 300 m, submission of report including zone wise water quality and preparation of composite log along with video recordings

Enlargement of hole by reaming in EW to accommodate well assembly of recommended size and gravel envelop of minimum 100 mm thickness as given below

Using 558.8 mm (22”) RR Bit for 300 mm (12”) assembly pipe

Using 508 mm (20”) RR Bit for 250 mm (10”) assembly pipe

Using 444.5 mm (17-1/2”) RR Bit for 200 mm (8”) assembly pipe

Using 406.4 mm (16”) RR Bit for 175 mm (7”) assembly pipe

Using 381 mm (15”) RR Bit for 150 mm (6”) assembly pipe

Using 311.15 mm ( 12-1/4”) RR Bit for 100 mm (4”) assembly pipe

Drilling of Hole for OW by rock roller/ drag bit of size given below to accommodate well assembly of recommended size and gravel envelop of minimum 100 mm thickness, including sample collection and preparation of litholog along with video recordings

Using 508 mm (20”) RR Bit for 250 mm (10”) assembly pipe

Using 444.5 mm (17-1/2”) RR Bit for 200 mm (8”) assembly pipe

Using 406.4 mm (16”) RR Bit for 175 mm (7”) assembly pipe

Using 381 mm ( 15”) RR Bit for 150 mm (6”) assembly pipe

Using 311.15 mm ( 12-1/4”) RR Bit for 100 mm (4”) assembly pipe

Supply and installation of ERW casing pipe conforming to latest version of IS: 4270-2001 of diameter and thickness given below

300 mm (12”) Nominal Bore, pipe thickness 7.1 mm

250 mm (10”) Nominal Bore, pipe thickness 7.1 mm

225 mm (9”) Nominal Bore, pipe thickness 6.0 mm

200 mm (8”) Nominal Bore, pipe thickness 5.4 mm

175 mm (7”) Nominal Bore, pipe thickness 5.4 mm

150 mm (6”) Nominal Bore, pipe thickness 5.4 mm

125 mm (5”) Nominal Bore, pipe thickness 5.4 mm

100 mm (4”) Nominal Bore, pipe thickness 5.4 mm

Supply and installation of MS slotted pipes conforming to sizes as per Table 1 with slotting arrangement shown in Figure 2 of latest version of IS: 8110-2000 of dimensions given below

150 mm (6”) Nominal Size thickness 7 mm with slot opening size 1.5 mm

Supply and shrouding of pea gravel conforming to latest version of IS: 4097-1967

Particle size range 3.35 mm to 4.75 mm for 1.5 mm slot opening

Particle size range 2.00 mm to 3.35 mm for 1.0 mm and 0.75 mm slot opening

Cement sealing using 53 grade cement of 5 m thickness including 1 m thick fine sand/ clay between cement seal and gravel pack

Supply and filling up borehole/ annular space between casing pipe and bore hole wall with local clay, if required

Development by Air Compressor of adequate capacity for minimum 5 to 10 hours in EW and 2-5 hours in OW by over pumping and by other means till discharge water is clear and free of sand including collection of two water samples from EW/OW adopting standard procedure in 1 litre HDPE bottle, along with video recordings of compressor hour meter, discharge etc.

Pumping test (incuding pre pumping for 8 hours and 24 hours recuperation, SDT (for 300 minutes), APT (for 1000 minutes and 90% or full recovery) and collection of 4 Nos. of water samples using standard procedure for basic parametes per EW (in 1 litre HDPE bottle) and for heavy metals and submission of detailed report with data, graph sheet, analysis etc. along with video recordings

Preliminary Yield Test by lowering of pump in wells where SDT & APT is not being carried out - including collection of 2 Nos. water samples adopting standard procedure for basic parameters and heavy metals (in 1 litre good quality HDPE bottle) and submission of analysis report with data with video recordings

Chemical analysis of water samples for 15 parameters (pH, EC, TH, TDS, Ca, Mg, Na, K, CO3, HCO3, SO4, NO3, Cl, F & Fe) in NABL accredited lab and submission of report from NABL lab

Chemical analysis of water samples for Heavy Metals (As, Pb, Zn, Cu, Cr, Se, Ni, Mn, U) in NABL accredited lab and submission of report from NABL lab

Construction of cement concrete platform of dimension 0.70 X 0.70 X 0.60 m (0.30 m above ground level) using concrete mix of 1:2:4 around the housing pipe welded with minimum 6 nos. of anchoring plate as per drawing

Supply and fitting of well cap as per drawing with Allen Keys. MS Plate size 5 mm embossed & welded with permanent marking of “CGWB EW” for Exploratory Wells & "CGWB OW" for Observation Wells should be carved with welding on outer surface of casing pipe

Supply and installation of protection box made of GI sheet of 3.15 mm thickness along with Brass lock (7 lever hardened of branded item) and three keys/District wise Master Key for each lock as per drawing

Supply and installation of Display Board as per drawing

Preparation and submission of basic data report per site (includes EW and OW) in triplicate along with logging graphs, data sheets, analysis sheet, chemical analysis report from NABL lab, site location map and approachability with land marks, photographs and videos of activities of drilling, assembly lowering, gravel measurement and gravel packing, well development using compressor and well water discharge, pump lowering, pumping test (SDT, APT, PYT), water sample collection, well discharge with discharge measurement/orifice with manometer head, well site with display board, well cap, protection box for each EW site etc. The soft copy and hard copy should be submitted. Summary of wells details in xls format including details of dia and depth of housing pipe, assembly pipe, screen pipe, static water level, aquifer parameters, safe discharge, gravel packing depth and thickness, chemical analysis result (basic parameters and heavy metals) etc. should be also submitted as detailed report.

BSR CORPORATION Pvt Ltd

shivdrillers