Toilets (also known as water closets) include tank-type toilets that are either gravity or pressure assist and either single- or dual-flush. 


The current national standards for toilets took effect in 1994 and set a maximum water use of 1.6 gallons per flush (gpf). In 2010, DOE officially waived federal preemption of the national toilet standard. This waiver of federal preemption allows states to set standards provided they are more stringent than the national standard.

Since 2007, 12 states have adopted standards for toilets at 1.28 gpf, which is equivalent to EPA’s WaterSense level.


Toilets are one of the primary users of water in the home, accounting for 26% of an average home's indoor water usage, according to a 2016 Water Research Foundation study. In the U.S., there are an average of two toilets per home.


Federal Date States
2024 MD Standard Effective
2023 ME Standard Effective
2023 RI Standard Effective
2022 MD Standard Adopted
2022 DC Standard Effective
2022 NY Standard Effective
2022 MA Standard Effective
2022 NJ Standard Effective
2021 ME Standard Adopted
2021 RI Standard Adopted
2021 MA Standard Adopted
2021 NJ Standard Adopted
2021 WA Standard Effective
2020 DC Standard Adopted
2020 NV Standard Effective
2019 NY Standard Adopted
2019 NV Standard Adopted
2019 WA Standard Adopted
2016 CO Standard Effective
2016 CA Standard Effective
2015 CA Standard Adopted
2014 CO Standard Adopted
2014 CA Standard Effective
2014 TX Standard Effective
2012 GA Standard Effective
2010 GA Standard Adopted
2009 TX Standard Adopted
2007 CA Standard Adopted
1st Federal Standard Effective 1994
EPACT Initial Federal Legislation Enacted 1992
1st Federal Standard Adopted (Congress) 1992

Timeline reflects state standards from 2001 to present; federal standards from inception to present.