operation and maintenance of iep at dwarir jangle w-s scheme at sandeshkhali - ii block, north 24 parganas under barasat arsenic division, phe dte.- 1 labour charges for operation & maintenance of iep by engaging 1 no. operator for operating different valves and switches including back washing of filter media to maintain smooth supply of water throughout the day as and when the time will be fixed by the eic all complete as per instruction of eic. 2 sundries & petty repair including periodical charges of engine/gear oil and rubber bag for doser etc. as required as per direction of eic. 3 collecting sample of water for bacteriological and chemical test from any depth at any time during execution of work including hire and labour charges for tools and plants and sterilising the equipments, paying all charges and fees, testing etc. complete in all respect as per direction. 4 supply of d.i.d.f. butterfly valvei) 100 mm dia pn10 5 provision for making payment towards labour wages in case of enhancement within the stipulated period of the said work to be in the following manner{enhancement of wages + 8.33% bonus + 10% contractors profit + 5% overhead expenses + esi + epf}. 6 riverine @22.5% on all the above items. (except item no. 1 & 5) 7 gst @18% on all the above items. (except item no. 5) 8 labour welfare cess @1% on all the above items.