High efficiency toilet (HET)
A toilet with an average water consumption of 1.28 gallons per flush or 4.8 liters per flush, when tested in accordance with a standard or product specification, such as the United States Environmental Protection Agency's WaterSense program. HETs use 20 percent less water than mandated by the Energy Policy Act of 1992, which lowers utility bills and reduces the strain on septic systems. HETs are eligible for special rebates in many drought-prone areas. They are available as single flush gravity toilets, dual-flush gravity toilets or pressure-assisted toilets.