What is the maximum number of gallons per flush cycle allowed for water closets other than blowouts?

The maximum number of gallons per flush cycle allowed for water closets, excluding blowout types, is 1.6 gallons. This standard is established to promote water efficiency and reduce water waste in plumbing systems. Many jurisdictions, including those governed by plumbing codes, have adopted this figure as a way to support sustainability efforts and lower water consumption.

Water closets designed to use no more than 1.6 gallons per flush are recognized for their effectiveness in flushing solid waste while minimizing water usage. This standard was established by various building codes and standards, including the EPA's WaterSense program, which encourages the use of water-efficient fixtures.

While some facilities might utilize fixtures with lower flush volumes, such as 1.28 gallons, the established maximum for many traditional water closets remains at 1.6 gallons. The option indicating 1.0 gallons is not widely implemented in standard plumbing practices, as it may not provide adequate performance, especially for solid waste removal. The option for 2.0 gallons exceeds the current efficiency standards set in many plumbing codes. Therefore, 1.6 gallons is the correct maximum flush volume allowed for non-blowout water closets.