Computing water usage costs - march 2011

Here is how to compute the cost per hour of water usage

First determine the local pressure/flow. Turn the hose on and determine the

time (in minutes or fraction thereof) it takes to fill a one gallon pail. Divide that

number into 60. This produces gallons per hour. This number then has to be

converted to cubic feet per hour. (100 cubic feet = 748 gallons) (100/748=.134

which means one gallon = .134 cubic foot)

Multiply the number of gallons per hour times .134 to determine how many

cubic feet per hour used.

In the city of Newton (MA) the water rates are:

Water and Sewer Rates effective as of 07/01/2010

Water Sewer Combined

to 20 hcf $5.14 $7.28 $12.42

to 70 hcf $6.17 $8.74 $ 14.91

> 70 hcf $7.40 $10.49 $17.89

Using the $12.42 amount multiply cubic feet per hour times $.1242 to get the

dollar per hour cost of outside watering (the 12.42 is for a hundred cubic

feet/hr).

Example:If the usage is 300 gallons per hour 300 times .134 = 40.2 cubic feet/hr.

If the price of water/sewer is $12.42 per hundred cubic feet (hcf)

that is $.124 per cubic foot.

40.2 cubic feet times .124 equals $4.98 per

hour cost of outside watering.