Toilets are by far the main source of water use in the home, accounting for nearly 30 percent of an average home's indoor water consumption. Older, inefficient toilets that use as much as 6 gallons per flush also happen to be a major source of wasted water in many homes.
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Recent advancements have allowed toilets to use 1.28 gallons per flush or less while still providing equal or superior performance. This is 20 percent less water than the current federal standard of 1.6 gallons per flush. The WaterSense label is used on toilets that are independently certified to meet rigorous criteria for both performance and efficiency. Only water-saving toilets that complete the certification process can earn the WaterSense label.Whether remodeling a bathroom, starting construction of a new home, or simply replacing an old, leaky toilet that is wasting money and water, installing a WaterSense labeled toilet is a high-performance, water-efficient option worth considering. WaterSense labeled toilets are available at a wide variety of price points and a broad range of styles and in many areas, utilities offer rebates and vouchers that can lower the price of a WaterSense labeled toilet.
By replacing old, inefficient toilets with WaterSense labeled models, the average family can reduce water used for toilets by 20 to 60 percent—that's nearly 13,000 gallons of water savings for your home every year! They could also save more than $140 per year in water costs, and $2,900 over the lifetime of the toilets.
Nationally, if all old, inefficient toilets in the United States were replaced with WaterSense labeled models, we could save 360 billion gallons of water per year, or the amount of water that flows over Niagara Falls in about 9 days.
Household leaks can waste 180 gallons per week. Toilets are often the culprit. If your toilet has a leak most likely it is due to an old or worn-out toilet flapper (e.g., valve seal) which can cause leaks. Flappers are inexpensive rubber parts that can build up minerals or decay over time. Replacing them is quick and easy. To see how easy it is check out our WaterSense Bath Hack Video.
- WaterSense Bath Hack #3 shows how easy it is to Replace Your Leaky Toilet Flapper.
The former “low-flow” toilets of the 1990s were sometimes associated with performance issues (e.g., double flushing) and poor user satisfaction. However, manufacturers have worked diligently since that time to redesign and reengineer their products to achieve both efficiency and performance. Beginning in early 2006, EPA worked with a variety of stakeholders to develop performance criteria in addition to water efficiency criteria to recognize the advancements in technology and help overcome the perceptions of the past. This included the adoption of a novel test to assess the ability of the toilet to clear waste from the bowl. WaterSense performance criteria have since been adopted into the national plumbing standard, American Society of Mechanical Engineers (ASME) A112.19.2/Canadian Standards Association (CSA) B45.1 Ceramic Plumbing Fixtures.
All WaterSense labeled tank-type toilets must comply with and are independently certified to meet the same rigorous performance requirements as standard toilets, including:
- Mixed testing media flushability: Ability to flush testing media of different sizes and density (i.e., floating versus sinking media).
- Bowl surface cleaning: Ability to clean the surface of the bowl.
- Drainline waste transport: Ability to transport waste media through a drainline.
- Waste extraction: Ability to clear soybean paste test media and toilet paper (meant to be representative of human waste) from the bowl.
For more information on how WaterSense assessed performance when developing the specification:
On June 2, 2014, EPA released a revised version of the WaterSense Specification for Tank–Type Toilets (Version 1.2). The specification changes are minor in nature and are intended to provide clarification of the existing requirements. The changes also align the specification with recent revisions to the ASME A112.19.2/CSA B45.1 Ceramic Plumbing Fixtures standard and ensure that tank-type toilets receiving the WaterSense label are certified and labeled consistently, in accordance with EPA’s intent, and will continue to meet consumer expectations for efficiency and performance.
- Version 1.2 of the WaterSense Specification for Tank-Type Toilets (PDF) (6 pg, 48K, About PDF)
- Summary of Revisions to the WaterSense Specification for Tank-Type Toilets (Version 1.2) (PDF) (5 pg, 52K, About PDF)
For more information about the WaterSense specification development process for toilets, please see the Tank-Type Toilet Specification Background Materials page.
Manufacturers that produce tank-type toilets meeting EPA's efficiency and performance criteria can apply to have their products certified to earn the WaterSense label. Before submitting products for testing, manufacturers must have a partnership agreement with EPA in place. Visit the manufacturer section on the partner page to learn more.
Draft Version 2.0 Specification
In December 2023, EPA released the draft Version 2.0 of the WaterSense Specification for Tank-Type Toilets. Within the draft specification, EPA modified the water efficiency criteria for dual-flush toilets by eliminating the effective flush volume calculation and instead establishing a singular maximum flush volume requirement for both single-flush toilets and the full-flush mode of dual-flush toilets. Additionally, EPA improved the readability throughout the specification by simplifying language, aligning language to maintain consistency with similar WaterSense specifications, and consolidating referenced ASME standards to avoid redundancy. EPA also incorporated clarifications that have been made to the specification since its original publication.
Read the draft specification and the Summary of Revisions to learn more.
- WaterSense Specification for Tank-Type Toilets, Version 2.0 (DRAFT) Cover Letter (pdf)
- Draft Version 2.0 of the WaterSense Specification for Tank-Type Toilets (pdf)
- Draft Version 2.0 of the WaterSense Specification for Tank-Type Toilets – Redline Comparison to Version 1.2 (pdf)
- Draft Summary of Revisions to the WaterSense Specification for Tank-Type Toilets (pdf)
The revisions included in the draft specification constitute a major revision, as they will affect the certification status of some WaterSense labeled dual-flush toilets. Please refer to Section III of the Summary of Revisions (“Timeline for Compliance With Version 2.0 of the Specification”) to learn more about how the revisions will affect certification status and when EPA expects compliance.
EPA is also sharing its draft product notification template associated with the revised specification for tank-type toilets. When EPA releases the final Version 2.0 specification, licensed certifying bodies will be required to submit updated information regarding WaterSense labeled tank-type toilets to EPA using this template:
EPA held a virtual public meeting to discuss the suggested criteria within the draft specification and obtain feedback on January 9, 2024. Information from the public meeting is below.
- Draft Version 2.0 of the Specification for Tank-Type Toilets Public Meeting Presentation (pdf)
- Draft Version 2.0 of the Specification for Tank-Type Toilets Public Meeting Recording
EPA invites interested parties to provide written comments or materials relevant to the draft Version 2.0 of the WaterSense Specification for Tank-Type Toilets. Please send any comments or suggestions to firstname.lastname@example.org no later than February 23, 2024. Please use WaterSense’s Template for Public Comment Submission (doc) to submit feedback.
Notice of Intent to Revise the Specification
In June 2023, EPA issued a Notice of Intent (NOI) to revise the WaterSense Specification for Tank-Type Toilets to make improvements to the specification criteria. EPA is looking to reevaluate the effective flush volume requirements, including the criteria for dual-flush toilets. Read the NOI to learn more.
A compilation of the comments received as of August 2023 is below.
EPA held a virtual public meeting on July 18, 2023 to discuss the NOI and obtain stakeholder feedback. Information from the public meeting is below.
- Tank-Type Toilets NOI Public Meeting Presentation (pdf)
- Tank-Type Toilets NOI Public Meeting Recording
- Tank-Type Toilets NOI Public Meeting Summary (pdf)
Are you interested in finding out more about the revision to the WaterSense specification for tank-type toilets? Please email email@example.com to receive information about this effort.