Central Ground Water Board Tender

Enlargement of hole by reaming to accommodate well assembly of recommended size and gravel envelop of minimum 100 mm thickness

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

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

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

Using 349.255mm (13-3/4") RR Bit for 125mm (5") assembly pipe

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

Supply and installation of ERW casing pipe conforming to Table 3 of latest version of IS: 4270-2001

200 mm (8”) Nominal Bore

150 mm (6”) Nominal Bore

100 mm (4”) Nominal Bore

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

150mm (6") Nominal size Slot opening 1.0 mm

100mm (4") Nominal size Slot opening 1.0 mm

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

Particle size range 3.35mm to 4.75mm for 1.0 mm slot opening

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 one water samples from observation well adopting standard procedure in 1 litre HDPE bottle, along with video recordings of compressor hour meter, discharge etc.

Development unit till water become sand/slit free and pumping test (minimum 20 hours) SDT, APT and collection of 6 water samples in teflone coated/HDPE Bottle per site and submission of data in prescribed performa and analysis report.

Construction of cement concrete platform of dimension 0.70x0.70x0.60m (0.30m 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 for EW as per drawing with Allen Keys . MS plate size 5mm imbossed and welded with permanent marking of "CGWB, EW" should be carved with welding on outer surface of casing pipe.

Supply and installation of protection box made of 3.15mm G.I Sheet of size 550mm x450mmx530mm along with bruss lock (7 lever hardened ) and 3 keys for each lock as per drawing.

Preparation and submission of basic data report along with analysis sheet, graph sheet, datas etc. chemical analysis report. Ground Water sample will be collected by the Vendor from each site for which sample bottles/acids will be supplied by CGWB, NER. After sample collection, sample bottles need to be submitted to the CGWB, NER, Chemical Lab for analysis. Chemical findings will be shared with the Vendor by CGWB, NER for due incorporation in the BDR. Site location map and approachability with landmarks, photographs and video and activities of drilling assembly lowering, gravel measurement and gravel packing, well development using air compressor and well water discharge, well site with display board, protection box for each site etc. The soft copy as well as hard copy should be submitted. Summery of EW & OW details in excel format (as per proforma given by CGWB) including detatails of dia and depth of assembly pipes, screen pipe, static water level, gravel packing depth and thickness, Litholog etc. should be also submitted.