Water pumps for domestic wells operate off and on throughout the day and night.
To estimate the cost of pumping water, you need to have a rough idea of the amount of water you use. The average household uses about 90 gallons of water per person per day.
A one-horsepower pump uses about 1,000 watts of electricity when it's running. Domestic pumps deliver about 20 gallons of water per minute.
You can use the following formulas to figure your cost of pumping water.
To calculate how long the pump is "on": 90 gallons x number of residents = number of gallons used per day / (divided by) 20 gallons per minute= "on" time
Example: 90 (gallons) x 4 (residents) = 360 (gallons per day) / 20= 18 minutes or .3 hour
To calculate the cost of operating the pump: (Horsepower x 1000 x hours) / 1000 watts= kwh x $.0816 = cost per day
Example: (1 x 1000 x .3) / 1000= .3 kwh x $.0816 = 2.5 cents per day In this instance, the estimated monthly cost for pumping water for a family of four would be 73 cents (2.5 cents per day x 30 days).
If you use the pump to provide water for livestock or to irrigate, you will need to increase the estimated gallons used per day. Use can vary greatly depending upon the type of pump, tank and well.
Rates effective November 1, 2011