The Federal Regulations on Toilet Gallons
The Energy Policy Act of 1992, which became law in 1994, mandates a maximum flush volume of 1.6 gallons for toilets manufactured and installed after this date. Modern toilets that use even less water than this may be certified by the U.S. Environmental Protection Agency’s WaterSense Program.
Benefitting the Environment
Prior to enactment of the Energy Policy Act, toilets used from 3.5 to 5 gallons per flush. The first toilets that conformed to the new 1.6-gallon-per-flush standard were notoriously poor flushers. Manufacturers continued to make improvements, however, adding larger tank outlet holes to increase water flow and larger internal passageways to prevent clogs. According to the EPA, the water saved through implementation of the act has had a number of positive environmental consequences, including restoration of wetlands and fisheries and savings in the amount of energy needed to pump water.
Saving More Than Water
In addition to ultra-low-flush toilets, which are the successors to the original low-flush models, consumers can now choose high-efficiency ones that use either a gravity- or pressure-fed flushing system; some have a dual-flush function. High-efficiency toilets that use 1.28 gallons per flush or less can be certified under the EPA’s WaterSense program and earn a homeowner who installs one a higher subsidy in some states and municipalities.
Courtesy of homeguides.sfgate.com