CONSTRUCTION OF 41 NOS EXPLORATORY AND 10 NOS OBSERVATION WELLS IN BIHAR STATE

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 3m 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 probe , Natural gamma logging , to target depth of minimum 300m 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 ,thickness 7.1mm

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

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

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

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

150 mm (6”) Nominal Bo,re thickness 5.4mm

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

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

Supply and installation of LCG V- wire screen conforming to latest version of IS: 8110-2000 of dimensions given below

150 mm (6”) Nominal Size thicnkness 7mm with slot opening size 1.0 mm

Supply and shrouding of pea gravel confirming 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 5m thickness including 1m 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 10 hours, over pumping and by other means till discharge water is clear and free of sand including collection of two water samples from OW adopting standard procedure in 1 litre HDPE bottle, along with video recordings of compressor hour meter, discharge etc.

Pumping test (incudes pre pumping for 8 hours and 24 hours recuperaton, SDT, 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 report with data, graph sheet , analysis etc. along 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 labs

chemical analysis of water samples for Heavy metals Arsenic, Cadmium, Mercury, Lead in NABL accredited labs

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 withminimum 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 carved with welding on outer surface of casing pipe 0.5mtrs

Supply and installation of protection box along with Brass lock (7 lever hardened) and three keys 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,logging graphs ,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 activity for each EW site, etc.The soft copy should be submitted.Summary of wells details in xls format (as per proforma given by CGWB) including details of dia and depth housing pipe, assembly pipe, screen pipe, static water level, TDS, aquifer parameters, safe discharge,gravel packing depth and thickness, Litholog etc should be also submitted.

shri ganesh construction company

BSR CORPORATION Pvt Ltd