Page 140 - WaterSense at Work

October 2012
Food Disposals
Conventional Garbage Disposal Replacement—Food Strainer
Conventional garbage disposals can be replaced with a food strainer. Because a food
strainer does not use water for the grinding/food disposal process, installing a food
strainer to replace an existing garbage disposal can eliminate this water use.
Current Water Use
To estimate the current water use of an existing garbage disposal, use Equation 4-20.
Water Use After Replacement
A food strainer can completely eliminate the use of water for the grinding/food dis-
posal process.
Water Savings
To calculate the water savings that can be achieved from replacing an existing con-
ventional garbage disposal with a food strainer, use Equation 4-21. In this case, water
savings will be exactly equal to the current water use because the replacement food
strainer uses no water.
To calculate the simple payback from the water savings associated with replacing a
garbage disposal with a food strainer, consider the equipment and installation cost
of the food strainer, the water savings as calculated in Equation 4-21, and the facility-
specific cost of water and wastewater.
Because garbage disposals can use hot water, a reduction in water use could also
result in energy savings. Eliminating the use of the garbage disposal may also save
energy. The potential energy savings could further reduce the payback period and
increase the cost-effectiveness.
Additional Resources
East Bay Municipal Utility District. 2008.
WaterSmart Guidebook—A Water-Use
Efficiency Plan Review Guide for New Businesses
Pages FOOD9-11.
Koeller and Company and H.W. (Bill) Hoffman & Associates, LLC. June 2010.
A Report
on Potential Best Management Practices–Commercial Dishwashers
Prepared for the
California Urban Water Conservation Council. Pages 5-7.