Toilets comprise the largest category of indoor water use, averaging from over one-third to almost one-half of total indoor use. Replacing older high-volume toilets (those manufactured prior to 1994) with more efficient toilets can significantly reduce your water usage.
In 1992 federal law (Energy Policy Act of 1992) mandated that all toilets sold in the United States use an average of 1.6 gallons per flush (gpf) or less.
Toilets made during the period 1980 to 1992 use 3.5 gpf or more. Toilets made prior to 1980 use 5 to 7 gpf or more. The oldest toilets can use more than 8 gpf.
The date of manufacture is often imprinted under the tank lid. If your toilet was manufactured after 1994, the flush rate would be 1.6 gpf or less.
Reduced Water Use
Reduced water use translates into increased savings on your water bill for both water and sewer. Long-term effects include a reduction in the cost of water and wastewater treatment and increased effective capacity for treatment facilities.
WaterSense
Many different manufacturers produce toilets that have been tested under the Environmental Protection Agency’s (EPA) criteria for WaterSense toilets. High efficiency toilets (HET) that have met the WaterSense requirements are listed on the EPA’s website. WaterSense toilets have a rated 20 percent decrease in flush rate than the federal standard.