Written by IAPMO 2:10 pm IAPMO R&T - WaterSense, Industry News

U.S. EPA Released a Draft Version 2.0 Specification for Tank-Type Toilets

The U.S. Environmental Protection Agency (EPA) has released a draft Version 2.0 of its Specification for Tank-Type Toilets to earn the WaterSense® label. Tank-type toilets have been eligible to earn the WaterSense label since the release of the WaterSense Specification for Tank-Type Toilets in 2007. During a formal review of the specification, EPA received feedback from stakeholders indicating that dual-flush toilets may not be reaching the expected water savings due to user preference and confusion regarding the different flushing modes of dual-flush toilets.

In June 2023, EPA issued a Notice of Intent (NOI) to revise the WaterSense Specification for Tank-Type Toilets to obtain feedback on potential revisions and has since decided to move forward with the specification revision. Within the revisions to the 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.

The revisions included in the draft specification may affect the certification status of some WaterSense labeled dual-flush toilets. Manufacturers that maintain certification listings of dual-flush toilets should review the revisions and supporting materials to determine if dual-flush toilets will remain in compliance when Version 2.0 of the specification takes effect. EPA does not anticipate that revisions to the specification will impact the labeled status of single-flush toilets or dual-flush toilets that have a full-flush volume of 1.28 gallons per flush or less. On Tuesday, January 9, from 2:00 p.m. to 4:00 p.m. Eastern, EPA will host a virtual public meeting to discuss the suggested criteria within the draft specification revision. Meeting information will be provided upon registration, and materials will be emailed to registered participants prior to the webinar date.

EPA is interested in your input! If you have comments or suggestions on the draft Version 2.0 of WaterSense Specification for Tank-Type Toilets and supporting materials, please email them to watersense-products@erg.com no later than February 23, 2024. Please forward this email to any other stakeholders or customers who might be interested in commenting on the draft specification.


IAPMO develops and publishes the Uniform Plumbing Code®, the most widely recognized code of practice used by the plumbing industry worldwide; Uniform Mechanical Code®; Uniform Swimming Pool, Spa and Hot Tub Code®; and Uniform Solar Energy, Hydronics and Geothermal Code — the only plumbing, mechanical, solar energy and swimming pool codes designated by ANSI as American National Standards — and the Water Efficiency Standard (WE-Stand)™. IAPMO works with government, contractors, labor force, and manufacturers to produce product standards, technical manuals, personnel certification/educational programs and additional resources in order to meet the ever-evolving demands of the industry in protecting public health and safety.

Last modified: January 16, 2024