Cleaning of 03 Sedimentation water tanks incl replacement of sand filter media of 33 AR

Amount

Schedule - 'A' Part- I: Schedule 'A' Part-I (Maint of Slow sand filter):

Cleaning of under ground sump, Sedimentation water tanks, Over Head R.C.C. Tank (independent staging) including disposal of slit and rubbish, all as per direction of Engineer-in-Charge. The cleaning shall consist following operations:- (i) Tank shall be emptied of water by pumping & bottom shall be cleaned of silt and other deposits. (ii) Entire surface area of the sump shall then scrubbed thoroughly with wire brush etc. and pressure washed with water. (iii) Chlorination of RCC internal surface by liquid chlorine. (iv) The treated surface shall be dried using air jetting and all loose particles shall be removal from the surface. (v) Finally the surface shall be treated with ultraviolet radiation etc. as per direction of Engineer-in-Charge.

Dismantling old plaster or skirting raking out joints and cleaning the surface for plaster including disposal of rubbish to the dumping ground within 50 metres lead.

15 mm cement plaster on rough side of single or half brick wall finished with a floating coat of neat cement of mix : 1:3 (1 cement: 3 fine sand)

Extra for providing and mixing water proofing material in cement concrete work in doses by weight of cement as per manufacturer's specification

Providing and laying 20 cm thick brick (local best quality) 1st class in two layers one on edge and one on plain for under layer drainage system @ 70 bricks/Sqm for filter media of slow sand filter.

P/L of 30 cm thick gravel stone in three layers of 10 cm each having effective size of 2.00mm – 10.0mm for top layer, 15.00mm – 25.0mm for middle layer and 30.0mm –45.0mm for bottom layer.

P/L of 0.45 cm thick sand for filter media having the following properties: (a) Sand should be hard & resistant, quartz orquartzite, free from clay and dirt of any description etc. (b) Effective size shall be 0.30 mm (c ) Uniformity co-efficient should be 2.00 to 3.00 (d) Silicon content should be less than 99.80% (e) Wearing less/shall not exceed 3%

Schedule 'A' Part-II (Schedule of Credit):

Creadit of Amount: Old Gravel stone removed from sand filtration tank are the property of contractor and reuse the same matterial duly cleaning and quality insure by Engr-in- Charge (net quantity of stacks of cleaned materials will be measured).

M/s Ravina Enterprise (BID ID -3110949)