Difference Between Standard & Low-Flow Toilets

Standard Toilets

• The amount of water required to efficiently operate a standard toilet depends in part on when it was manufactured. Pre-1980 toilets typically required between five and seven gallons of water per flush, while those manufactured between 1980 and 1992 used approximately 3.5 gallons per flush.

Low-Flow Toilets

• The Energy Policy Act of 1992 mandated all new toilets to use a maximum of 1.6 gallons of water per flush. Early attempts to meet the government mandate resulted in models that sometimes required several flushes to completely clear the bowl. Advances in low-flow technology have contributed to more efficient toilets at even lower water-usage levels than those mandated by the federal government.

High-Efficiency Toilets

• High-efficiency toilets, sometimes referred to as HETs, are designed to produce satisfactory results while using a maximum of 1.3 gallons per flush. There are a number of different types of HETs, including single-flush, dual-flush and pressure-assisted toilets. High-efficiency toilets provide a water savings of approximately 20 percent over low flow-toilets, according to the Marin Municipal Water District.

Considerations

• Toilets account for approximately 30 percent of the water consumption for the average American home, according to the Environmental Protection Agency. A family of four could save up to 16,000 gallons of water per year by replacing one standard 3.5 gallon-per-flush toilet with a low-flow 1.6 gallons-per-flush toilet, according to the Lower My Energy Bill website. The savings for converting to a high-efficiency toilet is even more dramatic.