Ian gave a great response ...

Ian gave a great response and I'd like to add a couple of comments.

1 ) You stated the pump power consumption. Where did this number come from and is it actually the power consumption of the pump? If you know how much power the pump is consuming then you can calculate pump efficiency directly from the power equation.

2 ) How long does the pump run per day? Given the data presented, the cost is Power x Run Hours x CostElectricity/Hour = Cost/Day. Of course this is assuming that the power consumption is the actual consumption of motor (see 3 below).

3 ) A typical electrical motor in the US is about 94.5% efficient in converting electrical power to shaft horsepower (SHP). If you divide 3-phase power by 0.746 this will give you the equivalent horsepower. As the motor is not 100% efficient, you will have to multiply the equivalent horsepower by 0.945 to get the actual horsepower applied to the pump shaft.

4 ) Assuming the power consumption stated is actual as read by a power meter then the simple answer is Operating Cost = Power x Hours x CostPerKw. You don't need anything else to determine cost, however to do this correctly you should evaluate the actual performance of the pump to see if it needs to be replaced/rehabilitated.