4-32
October 2012
4.7
Dipper Wells
Equation 4-13. Water Savings From Dipper Well Retrofit or Replacement (gallons
per year)
= Current Water Use of Dipper Well –Water Use After Retrofit or
Replacement
Where:
••
Current Water Use of Dipper Well (gallons per year)
••
Water Use After Retrofit or Replacement (gallons per year)
Payback
To calculate the simple payback from the water savings associated with retrofitting
an existing dipper well, consider the equipment and installation cost of the retro-
fit in-line flow restrictor, the water savings as calculated in Equation 4-13, and the
facility-specific cost of water and wastewater.
After retrofitting an existing dipper well with an in-line flow restrictor, facilities can
save energy from the reduced hot water use. This energy savings will further reduce
the payback period and increase replacement cost-effectiveness.
Dipper Well Replacement With Push-Button, Metered Faucet
Although installing a dipper well retrofit is likely the most cost-effective choice for a
facility, significant water savings can also be achieved by replacing a dipper well with
a push-button, metered faucet.
Current Water Use
To estimate the current water use of an existing dipper well, use Equation 4-12.
Water Use After Replacement With Metered Faucet
To estimate the water use after replacing an existing dipper well with a push-button,
metered faucet, identify the following information and use Equation 4-14:
••
Flow rate of the push-button, metered faucet (in gallons per cycle).
••
Average cycles used per hour.
••
Average daily use time.
••
Days of facility operation per year.
