WaterSense

WaterSense® Notice of Intent to Revise
the Specification for Tank-Type Toilets

WaterSense® Notice of Intent to Revise the Specification for Tank-

Type Toilets

I.	Introduction and Background

WaterSense is a voluntary partnership program sponsored by the U.S. Environmental
Protection Agency (EPA). The program's foundation is the WaterSense label, which identifies
products that have been independently certified to be at least 20 percent more water-efficient
and perform as well as or better than standard models. EPA released the WaterSense
Specification for Tank-Type Toilets in 2007. EPA has since completed two minor revisions to the
specification, releasing the latest version (Version 1.2) in June 2014. To date, dozens of
manufacturer partners have produced more than 5,200 WaterSense labeled tank-type toilet
models.

In accordance with the America's Water Infrastructure Act of 2018, EPA published its Notice of
Specification Review for tank-type toilets, lavatory faucets and faucet accessories,
showerheads, flushing urinals, and weather-based irrigation controllers in December 2018. The
specification review considered changes to the water efficiency and performance criteria for
each product category. Following completion of the review, EPA announced that no changes
would be made to the specifications at that time.

EPA intends to revisit the WaterSense Specification for Tank-Type Toilets as the agency
recognizes opportunities to make improvements to the specification criteria. EPA is reevaluating
the effective flush volume requirements, including potentially the criteria for dual-flush toilets,
due to changes in the marketplace resulting from state and local requirements, opportunities to
further transform the marketplace, and potential additional water savings that could be
achieved. EPA is also soliciting input on other items from the Notice of Specification Review or
otherwise related to the current specification for tank-type toilets. Because modifications to the
specification would likely impact the certification status of currently labeled tank-type toilet
models, EPA considers the intended revisions to constitute a major revision and is therefore
initiating, through this NOI, a formal specification revision process to engage with stakeholders
and the public.

To establish and better define the criteria to incorporate into a revised specification, EPA is
seeking feedback on the existing WaterSense Tank-Type Toilet Specification and WaterSense's
initial thoughts and potential approaches for revising the specification, including—but not limited
to—the topics and discussions identified in the following sections. All interested parties are
encouraged to submit written information and comments regarding any of the concepts or
issues presented in this notice of intent (NOI) to watersense-products@erg.com. Comments
and information on the issues presented in this NOI are welcome and will be taken into
consideration as EPA develops a revised WaterSense specification for tank-type toilets.

II.	Scope

The current WaterSense Specification for Tank-Type Toilets establishes the criteria for a high-
efficiency tank-type toilet under the WaterSense program. It is applicable to:

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WaterSense® Notice of Intent to Revise
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•	Single-flush, tank-type gravity toilets

•	Dual-flush, tank-type gravity toilets

•	Dual-flush, tank-type flushometer tank (pressure-assist) toilets

•	Tank-type, flushometer tank (pressure-assist) toilets

•	Tank-type electrohydraulic toilets

•	Any other tank-type technologies that meet these performance specifications

The specification is designed to ensure both sustainable, efficient water use and a high level of
user satisfaction with flushing performance.

Tanks or bowls intended for tank-type toilets are not independently eligible to earn the
WaterSense label under the specification. EPA intends to keep the scope of the
specification the same.

III.	General Requirements

The current specification requires a toilet to conform to applicable water closet requirements in
American Society of Mechanical Engineers (ASME) A112.19.2/Canadian Standards Association
(CSA) B45.1 Ceramic Plumbing Fixtures, except as otherwise indicated in this specification. If
the toilet has dual-flush capabilities, the current specification requires it to conform to
requirements in ASME A112.19.14 Six-Liter Water Closets Equipped with a Dual Flushing
Device.

There is an ongoing effort by the ASME/CSA Technical Committee for Plumbing Fixtures to
incorporate the applicable requirements of ASME A112.19.14 into ASME A112.19.2/CSA B45.1.
These changes are anticipated to be published in the 2024 edition of the ASME A112.19.2/CSA
B45.1 standard. Therefore, within a revised specification, EPA no longer intends to explicitly
reference ASM E A112.19.14.

Aside from the removal of explicit reference to ASME A112.19.14, EPA intends to keep
the General Requirements section of the specification the same.

IV.	Water Efficiency Criteria

The current water efficiency criteria requirements in the WaterSense Specification for Tank-
Type Toilets are as follows:

For single-flush toilets, the effective flush volume shall not exceed 1.28 gallons (4.8 liters) when
evaluated in accordance with the sampling plan contained in 10 CFR 429.30. For single-flush
toilets, the effective flush volume is the average flush volume when tested in accordance with
ASME A112.19.2/CSA B45.1.

For dual-flush toilets, the effective flush volume shall not exceed 1.28 gallons (4.8 liters) when
evaluated in accordance with the sampling plan contained in 10 CFR 429.30. For dual-flush
toilets, the effective flush volume is the average flush volume of two reduced flushes and one
full flush. Flush volumes shall be tested in accordance with ASME A112.19.2/CSA B45.1 and
ASME A112.19.14.

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EPA also establishes criteria to limit the adjustability of the flush volume. Samples with an
average flush volume in excess of 0.1 gallon (0.4 liter) greater than their rated flush volume are
deemed to fail testing requirements due to excessive flush volume. Samples with average flush
volumes less than or equal to 0.1 gallon (0.4 liter) greater than their rated flush volume are
adjusted, if possible, to their rated flush volume prior to performance testing. Samples with
average flush volumes less than their rated flush volume are tested at measured volume, and
this volume are recorded on the test report.

The number and percentage of WaterSense labeled tank-type toilets by effective flush volume
in gallons per flush (gpf) are presented in Table 1 below.

Table 1. Number and Percentage of WaterSense Labeled Tank-Type Toilets1

Effective Flush
Volume

<1.28 and
>1.1 gpf

<1.1 gpf and
>1.0 gpf

<1.0 gpf

Total

Percentage
of Total

Single-Flush
Models

2,752

49

455

3,256

62.4%

Dual-Flush
Models

1,051

573

335

1,959

37.6%

Total

3,803

622

790

5,215



Percentage of
Total

72.9%

11.9%

15.2%





Modification of Dual-Flush Toilet Flush Volume Requirements

Dual-flush toilets are designed with two flushing modes: a "reduced flush" mode that uses a
smaller volume of water to remove liquid wastes; and a "full flush" mode for removing solid
wastes. Many dual-flush tank-type toilets are operated by two-button systems, though some
models use bidirectional handles or levers where the user pushes the handle in one direction
(i.e., up or down, forward or back) for the reduced flush and in the opposite direction for the full
flush. The specific flush volumes of the two flush modes vary by make and model and range
from 0.5 to 1.1 gpf (1.9 to 4.2 liters per flush [Ipf]) in the reduced flush mode and up to 1.6 gpf
(6.1 Ipf) for the full flush mode.2

Wthin the current specification, the effective flush volume of dual-flush toilets is established by
averaging the flush volumes of two reduced flushes and one full flush. Therefore, dual-flush
toilets may have full-flush volumes of up to 1.6 gpf (commensurate with a toilet meeting the
federal standard established by the Energy Policy Act of 1992) and still meet the effective flush
volume requirement of the specification.

1	Data collected from the WaterSense Product Listing as of March 24, 2023.
www.epa.gov/watersense/product-search.

2	Ibid.

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The number and percentage of WaterSense labeled dual-flush tank-type toilets by full-flush
volume in gpf are presented in Table 2 below.

Table 2. Number and Percentage of WaterSense Labeled Dual-Flush Tank-Type Toilets3

Full-Flush
Volume

<1.6 and >1.3

gpf

<1.3 gpf and
>1.1 gpf

<1.1 gpf

Total

Dual-Flush
Models

1,453

419

87

1,959

Percentage of
Total

74.2%

21.4%

4.4%



From the initial development of the WaterSense Specification for Tank-Type Toilets and more
recently in comments received on the Notice of Specification Review, EPA has received
feedback from some stakeholders indicating that dual-flush toilets with a full flush of 1.6 gpf may
not realize the 20 percent water savings when employed in real-world applications due to user
confusion, user preference, or other factors. In effect, users may be using the full-flush mode of
a dual-flush toilet more regularly than once every three flushes. Therefore, states and
municipalities establishing criteria to require WaterSense labeled toilets or utilities offering
rebates on WaterSense labeled toilets may not be realizing the full 20 percent water savings.

In 2012, the U.S. Department of Energy (DOE) considered allowing manufacturers to calculate
the average representative water use (i.e., the effective flush volume) using the composite
average of two reduced flushes and one full flush. Ultimately, the DOE determined that there
was not sufficient evidence to base a test procedure for the average representative water use
for dual-flush water closets because the ratio required further evaluation to confirm its
representativeness.4 Because DOE decided not to adopt such a test procedure, manufacturers,
distributors, retailers, and private labelers are not permitted to make any representations of
water use that reflects an average of the full- and reduced-flush modes for dual-flush water
closets. Essentially, DOE is prohibiting the use of an effective flush volume to market dual-flush
water closets.

In addition, several green building standards and other specifications have begun to abandon
the 2:1 flush volume ratio used to calculate the effective flush volume. Beginning with its 2017
version, ASHRAE 189.1 Standard for the Design of High-Performance Green Buildings, for
example, establishes a maximum flush volume of 1.28 gpf for the full flush of both tank-type and
flushometer-valve dual-flush toilets. The International Green Construction Code (IgCC) adopted
the same requirements as of the 2018 version. MaP PREMIUM, an independent, voluntary
testing program that evaluates performance of toilets beyond the WaterSense criteria, sets a 1:1
ratio for the effective flush calculation and requires the volume of the full-flush mode to be 1.28
gpf or less. As of 2019, the City of Vancouver, British Columbia, requires all dual-flush toilets

3	Ibid.

4	U.S. Department of Energy. Energy Conservation Program for Consumer Products and Certain
Commercial and Industrial Equipment: Test Procedures for Showerheads, Faucets, Water Closets,
Urinals, and Commercial Prerinse Spray Valves. Docket No. EERE-2011-BT-TP-0061. Federal Register,
Volume 78, No. 205. October 23, 2013. www.regulations.gov/document/EERE-2011 -BT-TP-0061 -0039

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sold to achieve a maximum flush volume of 1.28 gpf, regardless of whether the toilet has dual-
flush capabilities.

EPA compiled the following studies evaluating dual-flush tank-type toilets in Table 3. As shown,
dual-flush toilets are rarely shown to achieve the 2:1 ratio that is assumed when calculating the
effective flush volume.

Table 3. Existing Dual-Flush Tank-Type Toilet Studies

Report

Authors

Reduced : Full Ratio

Seattle Home Water Conservation
Study (2000)

Peter Mayer et al.
(Aquacraft, Inc.)

0.77:1

Canada Mortgage and Housing

Corporation Dual-

Flush Toilet Project (2002)

Veritec Consulting

1.6:1 (single-family)
1.1:1 (office male)
2.7:1 (office female)
1.7:1 (office overall)
1.3:1 (coffee shop)

Residential Ultra-Low-Flush Toilet
Replacement Program (2003)

Paula Mohadjer, Jordan
Valley Water Conservation
District

1.48:1

Resident Indoor Water
Conservation Study: Evaluation of
High Efficiency Indoor Plumbing
Fixture Retrofits in Single-Family
Homes in the East Bay Municipal
Utility District Service Area (2003)

Peter Mayer et al.
(Aquacraft, Inc.)

0.48:1

Yarra Valley Water Residential
End Use Measurement Study
(2004)

Peter Roberts (Yarra Valley
Water)

0.75:1

South East Queensland
Residential End Use Study: Final
Report (2011)

Cara Beal and Rodney A.
Stewart (Urban Water
Security Research Alliance)

1.16:1 (Gold Coast)
1.16:1 (Brisbane)
1.72:1 (Ipswich)
1.37:1 (Sunshine Coast)

Melbourne Residential Water Use
Studies (2013)

Kein Gan and Michael
Redhead

1.50:1 (Summer)
1.08:1 (Winter)

In the United Kingdom, where dual flush toilets are prevalent, several studies have attempted to
assess whether users are confused about how to activate the reduced-flush mode compared to
the full-flush mode, which is a commonly cited reason that dual-flush toilets may not achieve
their intended water savings. Thames Water conducted a study that indicated more than 75
percent of people identified the incorrect flush mode.5 SES Water found that only 28 percent of
the 1,200 customers surveyed said they knew which button on their own toilet produced a

5 Thames Water. "Big flush or little flush?" November 19, 2019. www.thameswater.co.uk/about-
us/newsroom/latest-news/2019/nov/biq-flush-or-little-flush

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reduced flush.6 A study on dual-flush button designs conducted by the Water Regulations
Approval Scheme (WRAS) found that out of 2,000 people surveyed and asked to identify the
button for a reduced flush:

•	No dual-flush button designs out of 18 dual-flush button designs tested achieved 100
percent recognition.

•	The most recognized dual-flush button designs only achieved 92 percent recognition.

•	One dual-flush button design only had 19.5 percent recognition.7

In summary, even well-intentioned individuals may not be using the correct flush mode when
using a dual-flush toilet, thereby potentially negating water savings.

As a result of stakeholder feedback, an evaluation of user behavior pattern studies, and shifting
efficiency requirements for dual-flush toilets, EPA has decided to reevaluate the effective flush
volume calculation and maximum flush volume requirements for dual-flush toilets to earn the
WaterSense label. EPA is considering establishing a singular maximum flush volume
requirement (i.e., a maximum flush of 1.28 gpf, or a lower flush volume as determined during
the specification revision process) for both single-flush toilets and the full-flush of dual-flush
toilets, which would provide assurance of water savings irrespective of user behavior. This
alleviates an arbitrary flush ratio that relies on user behavior to achieve water savings. It would
also align tank-type dual-flush toilet requirements with those of the WaterSense Specification for
Flushometer-Valve Water Closets, which does not distinguish the maximum flush volume
between single- and dual-flush models. EPA is seeking feedback on its intention to
eliminate the effective flush calculation and establish a maximum flush volume criteria
for both single-flush toilets and the full-flush mode of dual-flush toilets.

EPA is also aware of concerns with leaks from dual-flush toilets in the United Kingdom. Thames
Water reported that water loss from leaks and continuously flowing toilets is exceeding the
amount of water the dual-flush toilet design should be saving. The Bathroom Manufacturers
Association, a United Kingdom-based trade group, acknowledged that drop valve systems,
frequently used within dual-flush toilets, are more prone to leakage.8 EPA requests feedback
on whether there are design and/or leakage concerns specific to dual-flush toilets in the
United States, similar to those reported in the United Kingdom.

Wthin the WaterSense Specification for Flushometer-Valve Water Closets, EPA references the
test protocol within ASME A112.19.2 for evaluating the flush volume for single-flush toilets, as
well as the full- and reduced-flush modes of dual-flush toilets. Consistent with EPA's intended
changes to remove the reference to ASME A112.19.14 discussed in Section III: General
Requirements, EPA intents to similarly no longer reference ASME A112.19.14 for the test
protocol to evaluate the reduced-flush mode flush volume. This change will not impact the
testing procedures used for dual-flush toilets, since ASME A112.19.14 already references the
ASME A112.19.2/CSA B45.1 procedure when evaluating the volume of the reduced-flush mode.
Further, as discussed previously, the requirements of ASME A112.19.14 are in the process of

6	Waterwise. "Why plumbers should be key partners in raising awareness of dual flush buttons"
www.waterwise.orq.uk/2022/11/16/whv-plumbers-should-be-kev-partners-in-raisinq-awareness-of-
dualbrflush-buttons/

7	Ibid.

8	The Guardian. Dual-flush toilets "wasting more water than they save." September 29, 2020.
www.thequardian.com/environment/2020/sep/29/dual-flush-toilets-wastinq-more-water-than-thev-save

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being incorporated into ASME A112.19.2/CSA B45.1. EPA requests feedback on its intent to
remove the reference to ASME A112.19.14 within the water efficiency section of its
specification and otherwise align the requirements of the specification, to the extent
practicable, with the WaterSense Specification for Flushometer-Valve Water Closets.

Flush Volume for Labeled Toilets

There are currently many models of tank-type toilets that operate at an effective flush volume of
less than 1.28 gpf. At least 12 states and Washington D.C. (representing approximately 43
percent of the U.S. population),9 as well as multiple other municipalities, have implemented
regulations requiring tank-type toilets operate at an effective flush volume of 1.28 gpf or less,
consistent with the WaterSense specification.10 Because 1.28 gpf toilets are required in multiple
states, many utility conservation programs now only rebate toilets operating at a lower flush
volume. For example, there are multiple utility conservation programs (e.g., Metropolitan Water
District of Southern California, the Saving Water Partnership, Metropolitan North Georgia Water
Planning District) that rebate or otherwise incentivize toilets operating at 1.1 gpf or less, which
would represent a 14 percent water savings compared to the current 1.28 gpf threshold.
Similarly, MaP PREMIUM, which multiple WaterSense utility partners depend on to guide their
rebate programs, requires an effective flush volume of 1.1 gpf or less.11 Further, at least one
municipality (West Hollywood, California) mandates that new toilets have an effective flush
volume of 1.1 gpf or less.

While many jurisdictions now require 1.28 gpf toilets, there are a limited number that mandate
toilets to flush below 1.28 gpf. Therefore, the market has not shifted below the WaterSense
water efficiency threshold, as EPA has observed with other plumbing products (e.g., lavatory
faucets, showerheads). As shown in Table 1 and Table 2, approximately 15 percent of
WaterSense labeled single-flush tank-type toilet models and approximately 4 percent of dual-
flush tank-type toilet models have a maximum flush volume of 1.1 gpf or less.

EPA acknowledges the success of high-efficiency toilets operating at 1.28 gpf or less in the
marketplace; however, there remains significant water savings potential from replacing existing
models of toilets, particularly those flushing at greater than 1.6 gpf. A 2019 study by GMP
Research on behalf of Plumbing Manufacturers International (PMI) found that only 16.8 percent
of tank-type toilets installed throughout the United States were WaterSense labeled.12 A
subsequent study by GMP Research on behalf of PMI focused on California found only 23
percent operated at 1.28 gpf or less.13 Toilets have a relatively long useful life, sometimes
exceeding 30 years, so full replacement of existing toilets can take time. Further, as a result of
feedback obtained from stakeholders during EPA's WaterSense specification review, many
raised concerns regarding whether higher-efficiency toilets, such as those operating a 1.0 gpf or

9	Based on 2020 Population and Housing State Data from the U.S. Census Bureau.
www.census.gov/library/visualizations/interactive/2020-population-and-housing-state-data.html

10	Appliance Standards Awareness Project. States, https://appliance-standards.org/states. Accessed May
25, 2023.

11	MaP Testing. "MaP PREMIUM." https://map-testinq.com/map-premium/. Accessed May 25, 2023

12	GMP Research Inc, 2019. 2019 U.S. WaterSense Market Penetration.

www.safeplumbina.ora/files/safeplumbina.ora/docu me nts/misc/7-1 -19-WaterSense-2019-Report.pdf

13	Obtained from public comments submitted by PMI on the California Energy Commission's rulemaking
for Appliance Efficiency Regulations for Water Closets, Docket Number 22-AAER-05.
https://efilinq. energy. ca.qov/Lists/DocketLoq.aspx?docketnumber=22-AAER-05

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less, could offer the same level of performance and maintain the efficacy of the sewer drainline
system in residential and commercial buildings.

EPA is again interested in feedback on whether it should consider reducing the
maximum allowable effective flush volume criteria to improve water efficiency beyond
the current WaterSense specification and potentially further transform the market. If so,
what threshold should EPA consider? To the extent possible, EPA requests supporting
data to inform that decision.

V. Performance and Product Testing

Table 4 summarizes the performance requirements included in the WaterSense Specification
for Tank-Type Toilets, either directly or by reference to the applicable national standard, ASME
A112.19.2/CSA B45.1. Table 4 also describes the purpose of each performance requirement.

Table 4. Specification Performance Requirements

Performance Requirement

Purpose

Granule and Ball

Assesses a toilet's ability to flush media of different sizes and
density (i.e., floating versus sinking media).

Surface Wash

Evaluates a toilet's ability to clean the surface of the bowl.

Drainline Transport
Characterization

Assesses a toilet's ability to transport waste media through a
drainline.

Overflow

Ensures toilet tank does not leak or permit water to otherwise
escape.

Waste Extraction

Determines a toilet's ability to clear soybean paste test media
(meant to be representative of human waste) and toilet paper
from the bowl.

Adjustability Tests

Limits the allowed adjustability of features in the toilet tank that
might increase the flush volume.

The test that primarily addresses toilet performance that is included in the specification is the
waste extraction test. The waste extraction test requires a toilet to fully flush 350 grams of miso
paste, a test media having similar physical properties to human waste, along with four loosely
crumpled balls of toilet paper. Toilets are required to clear the test media on at least four out of
five attempts.

EPA does not intend to revise the specification's performance criteria; however, it is
seeking feedback on whether there are necessary or recommended modifications to the
performance criteria and requirements that would result in improved performance of
WaterSense labeled tank-type toilets.

VI. Marking and Product Documentation

Within the current WaterSense specification, toilet fixtures shall be marked in accordance with
requirements in ASME A112.19.2/CSA B45.1 with the exception identified in the following
statement: Toilet bowls intended to be used with tanks of varying consumption levels (e.g., 1.6

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and 1.28 gpf) can be marked with a dual consumption marking or a consumption range, as
indicated in ASME A112.19.2/CSA B45.1; however, toilet bowls shall not be marked with the
words "or less" to indicate compatibility with tanks of varying consumption levels.

As of the 2018 publication of ASME A112.19.2/CSA B45.1, the use of "or less" is no longer
permitted in toilet bowl markings. Therefore, EPA intends to remove the clarifying language from
its specification.

Within the current WaterSense specification, toilet tanks shall not be packaged, marked, nor
provided with instructions directing the user to an alternative water use setting that would
override the rated flush volume, as established by this specification. Any instruction related to
the maintenance of the product shall direct the user how to return the product to its rated flush
volume.

Aside from the removal of the clarifying language prohibiting the use of "or less," EPA
intends to keep the Product Marking section of the specification the same.

VII. Appendix A: Requirements for WaterSense Labeling

Periodically, EPA issues technical clarifications to a product specification intended to clarify
unclear or vague requirements based upon frequent questions or input received from
manufacturers or licensed certifying bodies. As outlined in the WaterSense Product Certification
System, manufacturers and licensed certifying bodies must adhere to these clarifications, as
applicable, when certifying products to meet WaterSense specifications.

EPA intends to modify the WaterSense Specification for Tank-Type Toilets to incorporate three
clarifications that EPA has made since the publication of Version 1.2 of the specification. EPA
intends to incorporate the following clarifications into Appendix A, Section 3 of the WaterSense
Specification for Tank-Type Toilets-.

•	TT-1216-1: Certification of Tank-Type Toilets With Components Made by Different
Manufacturers. As part of this clarification, EPA is only requiring one of the component
manufacturers (of the tank or the bowl) to submit a toilet combination for testing and
certification and maintaining the affiliated certification listing. The manufacturer that
maintains a certification listing will be authorized to use the WaterSense label in
association with its component product as described in the WaterSense Program Mark
Guidelines and further clarified in Appendix A, Section 3.3 of the WaterSense
Specification for Tank-Type Toilets, and the combination in the WaterSense Product
Search Tool will also only be searchable under the brand name of the manufacturer that
maintains the certification listing.

•	TT-0617-1: Marking and Labeling Requirements for Tank-Type Toilets With Components
Made by Different Manufacturers. As part of this clarification, EPA only allows the
manufacturer partner that maintains the toilet tank and bowl combination's certification
listing to use the WaterSense label on product packaging and product specification
sheets. The manufacturer that maintains the listing must indicate on product
specification sheets or other product documentation the specific brand names, model
names, and model numbers, as applicable, of the counterpart products (i.e., the bowl or
tank) that the product can be used with to form a WaterSense labeled tank-type toilet.

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The manufacturer of the component that is included in the combination, but that does not
maintain the certification listing, is not permitted to use the WaterSense label and does
not need to meet the product packaging marking and labeling criteria specified in
Appendix A, Section 3.3 of the WaterSense Specification for Tank-Type Toilets.

• TT-0617-2: Bowl Packaging Requirements for Tank-Type Toilets Made by Different
Manufacturers. Toilet bowls can be matched with many different toilet tanks from various
manufacturers to form a WaterSense labeled combination. EPA has clarified that bowl
manufacturers that have chosen to certify a tank-type toilet combination with
components from different manufacturers are not required to list all the specific brand
names, model names, and model numbers that are compatible to form a WaterSense
labeled toilet. Product specification sheets or other product documentation for the toilet
bowl must still indicate all of the specific brand names, model names, and model
numbers, as applicable, of the counterpart tank that the product can be used with to form
a WaterSense labeled tank-type toilet.

EPA is seeking feedback on the intended inclusion of these clarifications into Appendix
A of the specification.

VIII. Transition Timing

The current certification status of some toilet models may be affected by EPA's intended
revision; therefore, decertification or recertification may be required. EPA intends to provide an
appropriate transition time prior to the applicable effective date of any specification revision.
Upon release of the draft specification, EPA will discuss with industry which products the
transition process will apply to and the associated transition period such that, at the time the
final specification is released, EPA has established clear requirements for WaterSense
manufacturer partners and licensed certifying bodies regarding product certification and labeling
during the transition period between specification versions. If the changes to specification
criteria under Version 2 do not affect a certain subset of products (e.g., single-flush toilets), EPA
does not intend to require retesting or recertification of those products.

As part of the transition period, EPA anticipates the following activities being required from
licensed certifying bodies and WaterSense partners, including manufacturers, private labelers,
retailers, and distributors. Based on the criteria of the Version 2 specification, licensed certifying
bodies will need to review their certification listings to determine which products must be
removed or retested. Prior to or upon the effective date of the Version 2 specification, licensed
certifying bodies will need to submit updated Product Notification Templates communicating the
resulting list of labeled models for upload into the WaterSense Product Search Tool.
Manufacturer partners and private labelers will be responsible for updating product packaging,
documentation (e.g., specification sheets), marketing material, web pages, and online materials
to remove the WaterSense label from any models that are no longer certified.

EPA is considering establishing a transition period of six to 12 months before Version 2 of the
specification will become effective. This timeline is in alignment with other EPA and U.S.
Department of Energy product certification programs and would permit the sale of current
inventories of labeled models. EPA does not intend to require manufacturers to destroy existing
products, product packaging, or other printed materials that bear the WaterSense label and will

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consider a pause on brand monitoring activities during and immediately following the transition
period.

EPA requests feedback on an appropriate transition period before Version 2 of the
specification takes effect. What factors should EPA consider in setting an appropriate
transition time? What, if any, transition guidance should EPA develop for retailers and
distributors?

IX.	Summary of Information Requests

Water Efficiency

•	EPA is seeking feedback on its intention to eliminate the 2:1 effective flush calculation
and establish a maximum flush volume criteria for both single-flush toilets and the full-
flush mode of dual-flush toilets.

•	EPA is requesting feedback on whether leakage concerns such as those identified in the
United Kingdom exist for dual flush toilets in the United States.

•	EPA is requesting feedback on its intent to remove the reference to ASME A112.19.14
within the water efficiency section of its specification and otherwise align the
requirements of the specification, to the extent practicable, with the WaterSense
Specification for Flushometer-Valve Water Closets.

•	EPA is seeking feedback on whether to reduce the maximum allowable effective flush
volume criteria below 1.28 gpf to improve water efficiency beyond the current
WaterSense specification criteria and further transform the market. If so, EPA is seeking
feedback on what flush volume threshold it should consider.

Performance Criteria

•	EPA is seeking feedback on whether there are necessary or recommended
modifications to the performance criteria in the specification and requirements that would
result in improved performance of WaterSense labeled tank-type toilets.

Appendix A: Requirements for WaterSense Labeling

•	EPA is seeking feedback on the intended inclusion of three existing clarifications related
to the certification, marking, labeling, and packaging of toilet components made by
different manufacturers within Appendix A of the specification.

Transition Timing

•	EPA requests feedback on an appropriate transition period before Version 2 of the
specification takes effect. What factors should EPA consider in setting an appropriate
transition time? What, if any, transition guidance should EPA develop for retailers and
distributors?

X.	Schedule and Next Steps

EPA is requesting input, supporting information, and data from all interested parties on topics
discussed in this NOI and otherwise related to the WaterSense Specification for Tank-Type
Toilets. Interested parties can provide input to WaterSense regarding any of the issues
presented in this notice by submitting written comments to watersense-products@erg.com. The
deadline to submit comments is August 14, 2023. Comments and information on the issues

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June 2023


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WaterSense

WaterSense® Notice of Intent to Revise
the Specification for Tank-Type Toilets

presented in this NOI are welcome and will be taken into consideration as EPA revises the
WaterSense tank-type toilet specification.

EPA will hold a public meeting to discuss the information presented in this NOI.

12

June 2023


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