WaterSense
at Work

Sanitary Fixtures and Equipment

3.4 Showerheads and Bath
and Shower Diverters

Best Management Practices for
Commercial and Institutional Facilities

*

EPA

WaterSense

May 2023


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WaterSenseฎ is a voluntary partnership program sponsored by the U.S. Environmental
Protection Agency (EPA) that seeks to protect the nation's water supply by transforming
the market for water-efficient products, services, and practices.

WaterSense at Work is a compilation of water efficiency best management practices
intended to help commercial and institutional facility owners and managers from multiple
sectors understand and better manage their water use. It provides guidance to help
establish an effective facility water management program and identify projects and
practices that can reduce facility water use.

An overview of the sections in WaterSense at Work is below. This document, covering
water efficiency for showerheads and bath and shower diverters, is part of Section 3:
Sanitary Fixtures and Equipment. The complete list of best management practices is
available at www.epa.gov/watersense/best-management-practices. WaterSense has also
developed worksheets to assist with water management planning and case studies that
highlight successful water efficiency efforts of building owners and facility managers
throughout the country, available at www.epa.gov/watersense/commercial-buildings.

•	Section 1. Getting Started With Water Management

•	Section 2. Water Use Monitoring

•	Section 3. Sanitary Fixtures and Equipment

•	Section 4. Commercial Kitchen Equipment

•	Section 5. Outdoor Water Use

•	Section 6. Mechanical Systems

•	Section 7. Laboratory and Medical Equipment

•	Section 8. Onsite Alternative Water Sources

EPA 832-F-23-003
Office of Water

U.S. Environmental Protection Agency
May 2023

This document is one section from WaterSense at Work: Best Management Practices for Commercial and
Institutional Facilities (EPA-832-F-23-003). Other sections can be downloaded from

www.epa.gov/watersense/hest-management-practices. Sections will be reviewed and periodically updated
to reflect new information. The work was supported under contract 68HERC20D0026 with Eastern Research
Group, Inc. (ERG).

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Sanitary Fixtures and Equipment

4

Showerheads and Bath and Shower Diverters

EPA

WaterSense

Overview

Showerheads can be found in shower stalls in a variety of commercial and institutional
facilities. Bath and shower diverters are installed in shower stalls combined with a
bathtub, which may occur within hotels, hospitals, multifamily properties, or other
commercial and institutional facilities that serve more of a permanent or temporary
residential function. Ensuring water (and energy) efficiency from both of these products
can be fairly simple and cost effective.

Showerheads

Showerheads come in a variety of shapes, sizes, and
configurations, including fixed showerheads and rain
showers, which are affixed overhead and permanently
attached to the wall or ceiling, and handheld
showerheads, which have a flexible hose that enables
the showerhead to be detached from the wall and
moved freely by the user. Other devices used for
showering, such as body sprays (also referred to as
body jets), spray water onto the user from a direction
other than overhead, usually from a vertical column on
the shower wall.

In order to reduce overall water use, the Energy Policy
Act of 1992 (EPAct 1992) established the maximum
allowable flow rate for all showerheads sold in the
United States as 2.5 gallons per minute (gpm) (9.5 liters
per minute [Ipm]), Older showerheads may flow as high
as 3.0 to 5.0 gpm (11.4 to 18.9 Ipm). While body sprays
are not regulated under EPAct 1992, the American
Society of Mechanical Engineers (ASME)

A112.18.1/Canadian Standards Association (CSA)

B125.1 Standard for Plumbing Supply Fittings addresses performance criteria and test
methods for these products and establishes a maximum allowable flow rate of 2.5 gpm
(9.5 Ipm).

Since EPAct 1992 was enacted, many showerheads have been designed to use even less
water. To evaluate whether reduced flow rate would result in reduced performance, the
U.S. Environmental Protection Agency (EPA) supported consumer market research, which
identified three key performance attributes that are necessary to ensure user satisfaction
under a variety of household conditions: flow rate across a range of pressures; spray

Handheld showerhead

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force; and spray coverage. Each of these criteria can be tested using a specific protocol
that measures accuracy and reliability. All three criteria must be met to produce a
satisfactory shower without using more water.

To address efficiency and advances in showerhead technology, EPA's WaterSense3
program published the 1/VaferSense Specification for Showerheads.1 WaterSense labeled
showerheads are independently certified to flow at a rate of 2.0 gpm (7.6 Ipm) or less,
while also meeting or exceeding EPA's performance criteria for spray force and coverage.

While EPAct 1992 established the maximum allowable flow rate for showerheads at the
national level, some states and municipalities have adopted regulations mandating that
showerheads have a flow rate of 2.0 gpm (7.6 Ipm) or less, consistent with the
WaterSense specification. A few states, including California, Hawaii, and Washington,
require showerheads to have a flow rate of 1.8 gpm (6.8 Ipm) or less.2 It is important to
note that, while some of these regulations establish flow rate criteria consistent with or
more stringent than the WaterSense specification, they may not require products to be
WaterSense labeled or to meet WaterSense's performance criteria. Looking for the
WaterSense label when purchasing showerheads will ensure that the product meets both
efficiency and performance criteria.

Bath and Shower Diverters

Bath and shower diverters (also known as tub spout
diverters) are devices installed in tub-shower
combinations, common in hotels and residences. They
are used to divert the flow of water either toward the
tub spout (i.e., to the bathtub) or toward a secondary
outlet (i.e., the showerhead). An often-overlooked
source of wasted water, many bath and shower
diverters continuously leak a small amount of water
from the tub spout while they are engaged and water is
being diverted from the bathtub to the showerhead.

Over time, the magnitude of these diverter leaks can
increase, sometimes substantially, resulting in
significant water wasted down the drain with every
shower. In addition, because this water is typically
heated, leaking bath and shower diverters can also
result in hot water losses, meaning energy is wasted as

well.	Bath and shower diverter

1	U.S. Environmental Protection Agency's (EPA's) WaterSense program. Showerheads.

vwvw.epa.gov/watersense/showerheads.

2	Appliance Standards Awareness Project. State Standards, https://appliance-standards.org/states.

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The ASME A112.18.1/CSA B125.1 standard allows bath and shower diverters to have an
initial leak rate up to 0.1 gpm (0.4 Ipm). Some states have adopted more stringent
efficiency regulations, allowing bath and shower diverters to leak no more than 0.01 gpm
(0.04 Ipm) initially, and there are models available that allow zero leakage. However, when
installed beyond their useful life or when corrosion and scaling have impacted diverter
performance, water waste from leaky diverters can grow over time. One study found that
34 percent of bath and shower diverters assessed had leaks exceeding 0.1 gpm (0.4 Ipm),
with an average leak rate of 0.8 gpm (3.0 Ipm) and some leak rates as high as 3.0 gpm
(11.4 Ipm).3

Operation, Maintenance, and User Education

For optimum showerhead efficiency, the system pressure should be tested to make sure
that it is between 20 and 80 pounds per square inch (psi) (138 and 552 kiloPascals [kPa]).
This will ensure that the showerhead delivers the expected flow and performance. In
addition, consider the following:

• Verify that the hot and cold water plumbing
lines to the showerhead are routed through a
shower valve that meets the temperature
control performance requirements of the
ASSE 1016/ASME A112.1016/CSA B125.16
standard when tested at the flow rate of the
showerhead installed. This valve will prevent
significant fluctuations in water pressure and
temperature at the outlet and can thereby
reduce risks of thermal shock and scalding. A
plumber can check the compatibility of the
showerhead and shower valve and, if
necessary, install a valve that meets the
recommended standard for the flow rate of
the showerhead.

Don't Forget Routine
Maintenance

Scale build-up in showerheads
and bath and shower diverters may
restrict flow, cause leaks, and
impact product performance. Add
routine maintenance procedures
to the facility's operation and
maintenance plans to include
periodically inspecting
showerheads and bath and shower
diverters for scale buildup and
using cleaning products or white
vinegar to remove scale when
necessary.

•	Periodically inspect showerheads for scale buildup to ensure flow is not being
restricted. Certain cleaning products or white vinegar can dissolve scale from
showerheads with buildup. Do not attempt to bore holes in the showerhead or
manually remove scale buildup, as this may lead to increased water use or cause
performance problems.

•	Similarly, periodically inspect bath and shower diverters when the shower is turned
on to determine whether a significant volume of water (i.e., greater than 0.2 gpm or
0.8 Ipm) is leaking from the diverter. If large leaks are present, remove the diverter

3 Taitem Engineering, PC. 2011. Tech Tip. New York State Homes & Community Renewal, Weatherization
Assistance Program, "Leaking Shower Diverters." www.taitem.com/wp-content/upLoarts/Diverter-VaLve-
Tech-Tip-2011.7.20.pdf.

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and use cleaning products or white vinegar to remove scale buildup, which may
reduce or eliminate the leak. If cleaning does not minimize the leak, replace it with
a new diverter.

Periodically inspect showerheads and/or measure the flow rate to make sure
integral flow restrictors have not been removed. An easy way to confirm the flow
rate of the showerhead is to use a timer and collect water in a flow bag or container
of known volume.

Provide a way for users to track showering time and encourage users to take
shorter showers by placing clocks or timers in or near the showers.

Post signage and train users to report leaking or malfunctioning showerheads to
the appropriate personnel.

Retrofit Options

Because showerheads are relatively inexpensive, replacement is often more economical
and practical than a retrofit. In general, to reduce the flow rate and save water, avoid
retrofitting existing inefficient showerheads with flow control inserts (which restrict water
flow). These devices may not provide adequate performance in some facilities and can
lead to user dissatisfaction. However, there are some viable retrofit options to consider,
including installing thermostatic shutoff valves or installing shower valves for shower
stalls with multiple showerheads.

Thermostatic Shutoff Valves

Shower users frequently will turn on a shower
before entering the stall or tub to allow water
to heat up. There are two types of water waste
associated with this activity: structural waste,
which represents the tepid water that often
must be cleared (and drained) from the hot
water supply line that connects the water
heater to the showerhead; and behavioral
waste, which constitutes water that has
reached the desired temperature, but that

runs down the drain before the occupant

_	Showerhead using hot water

starts their shower. Bathers could walk away

from the shower or tub while the water heats up, performing other tasks prior to entering
the shower. Thermostatic shutoff valves can be installed to eliminate behavioral waste
from showering events. Thermostatic shutoff valves greatly reduce the flow of water to the
tub spout or showerhead once the water reaches the desired temperature for bathing.
When the user is ready to enter the shower, the thermostatic shutoff valve can be
reopened to allow the flow of water.

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Shower Stalls With Multiple Shower Outlets

In certain circumstances, single shower stalls may be outfitted with multiple showerheads
that can be activated simultaneously or individually by the user. In some cases, when
these showerheads are turned on simultaneously, they use more water than the federal
maximum flow rate of 2.5 gpm (9.5 1pm) for an individual showerhead (e.g., two 2.5 gpm
showerheads can use 5.0 gpm or 18.9 Ipm). In these instances, stalls can be retrofitted
with a shower valve so that the showerheads can only be operated separately rather than
simultaneously, or so the total volume of water flowing from all showerheads is equal to
or less than 2.0 or 2.5 gpm (7.6 or 9.5 Ipm). This may require replacing the existing
showerheads with more efficient ones. For shower stalls designed for two persons in
residences and private bathrooms in lodging facilities, EPA recommends that a second
shower valve be installed not less than 96 inches (244 cm) from the first valve.4

The retrofit suggestions for single shower stalls provided here do not apply to communal
showers used in prisons, locker rooms, and barracks. Communal showers may have
multiple showerheads that each flow at a rate equal to or less than 2.0 gpm (7.6 Ipm),
since the showerheads are designed to be used by multiple users at once.

Replacement Options

When installing new showerheads or replacing
older, inefficient showerheads, choose
WaterSense labeled models. WaterSense
labeled showerheads5 are independently
certified to use 2.0 gpm (7.6 Ipm) or less and
thus are 20 percent more water-efficient than
standard showerheads on the market. In
addition, WaterSense labeled showerheads
are independently certified to meet or exceed
minimum performance requirements for spray
coverage and force.

Except for communal settings in prisons,
locker rooms, and barracks, avoid installing
multiple showerheads or body sprays when
remodeling, particularly if they can be
operated simultaneously or so that the total
volume of water flowing from all showerheads

4	Recommendations are consistent with the Plumbing Manufacturers International and Alliance for Water
Efficiency Memorandum of Understanding. November 7, 2019.

www.allianceforwaterefficiency.org/sites/default/files/assets/AWE PMI MOU Multi-
Showerhead Signed.pdf.

5	EPA's WaterSense program, op. cit.

Look for WaterSense
Labeled Showerheads

look for

When replacing old,
inefficient showerheads or
purchasing new
showerheads look for the
WaterSense label. A product
with the label uses at least
20 percent less water than
standard models and is independently
certified for performance. Looking for the
label is a simple way to quickly identify
showerheads that save water and perform
well. Facilities can also use WaterSense's
Product Search Tool to find labeled
showerheads. Go to

www.epa.gov/watersense/product search
to get started.

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is greater than the 2.0 gpm (7.6 1pm) WaterSense specification maximum. These multiple
showerhead systems can waste a significant amount of water and energy.

For showerheads installed at locations with frequent use by transient individuals (e.g.,
locker rooms, beach access locations), consider installing shower systems with
automatic shut-off capabilities. Once activated, these systems allow showers to operate
for a fixed amount of time before shutting off, ensuring water is never left running. The run
time is often adjustable, so facilities should adjust timers to align with intended use
patterns.

When installing new or replacing older bath and shower diverters, install models that
minimize leakage. Look for products tested to achieve a 0.00 gpm leak rate in pre-life
cycle and post-life cycle testing. Use the California Energy Commission's Modernized
Appliance Efficiency Database System (MAEDbS) to help identify models.6

Savings Potential

Water savings can be achieved by replacing
existing showerheads and bath and shower
diverters.

Showerheads

Replacing existing showerheads with WaterSense
labeled models can achieve significant water and
energy savings in frequently used shower
facilities. To estimate facility-specific water and
energy savings and payback, use the following
information:

Current Water Use

To estimate the current water use of an existing
showerhead, identify the following information
and use Equation 1 on the next page:

•	Flow rate of the existing showerhead: Showerheads installed in 1994 or later may
have a flow rate of 2.5 gpm (9.5 Ipm) or less. Older showerheads may flow at a rate
as high as 3.0 to 5.0 gpm (11.4 to 18.9 Ipm).

•	Average duration of each shower: The average shower duration is approximately
eight minutes.7

6	The California Energy Commission's Modernized Appliance Efficiency Database System can be accessed

at https://cacertappliances.energy.ca.gov/Pages/Appl.ianceSearch.aspx.

7	Water Research Foundation (WRF). 2016. Residential End Uses of Water, Version 2. Table 6.9.

WaterSense labeled showerhead

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•	Average use rate of showers in terms of number of showers each person takes per
day: In buildings that serve a residential function (e.g., hotel, dorm, multifamily
building), it can be assumed that occupants shower approximately 0.7 times per
day.8

•	Number of building occupants.

•	Days of facility operation per year.

Equation 1. Water Use of Showerhead (gallons or liters per year)

= Showerhead Flow Rate x Duration of Use x Use Rate x Number of Building
Occupants x Days of Facility Operation

Where:

•	Showerhead Flow Rate: Gallons or liters per minute

•	Duration of Use: Minutes per shower

•	Use Rate: Showers per person per day

•	Number of Building Occupants: Persons

•	Days of Facility Operation: Days per year

Water Use After Replacement

To estimate the water use of a replacement WaterSense labeled showerhead, use
Equation 1 above, substituting the flow rate of the replacement showerhead. WaterSense
labeled showerheads use no more than 2.0 gpm (7.6 Ipm).

Water Savings

To calculate water savings that can be achieved from replacing an existing showerhead,
identify the following information and use Equation 2 on the next page:

•	Current water use as calculated using Equation 1.

•	Water use after replacement as calculated using Equation 1.

8 Ibid.

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Equation 2. Water Savings From Showerhead Replacement (gallons or liters per

year)

= Current Water Use of Showerhead - Water Use of Showerhead After

Replacement

Where:

•	Current Water Use of Showerhead: Gallons or liters per year

•	Water Use of Showerhead After Replacement: Gallons or liters
per year

Energy Savings

Because showerheads use hot water, a reduction in water use will also result in energy
savings. The energy required to heat water can be dependent on: the fuel used for water
heating (e.g., electricity, natural gas); the efficiency of the water heater; and water heater
temperature set points. Since this information is not always readily available, energy
savings that can be achieved from replacing an existing showerhead can be estimated
using the water savings calculated in Equation 2 for showerheads, and the assumptions
presented in Equation 3 below:

Equation 3. Energy Savings From Showerhead or Bath and Shower Diverter
Replacement (kWh of electricity or Mcf of natural gas per year)

= Water Savings x Average Percent of Shower Water That Is Hot x (Energy per
Gallon or Liter Heated t Water Heater Efficiency)

Where:

•	Water Savings: Gallons or liters per year

•	Average Percent of Shower Water That Is Hot: 67.8%

•	Energy per Gallon or Liter Heated (assuming 75ฐF water
temperature increase):

o 0.183 kilowatt hours (kWh) of electricity per gallon

(0.048 kWh per liter); or
o 0.0006 thousand cubic feet (Mcf) of natural gas per
gallon (0.00016 Mcf per liter)

•	Water Heater Efficiency (unless otherwise known by the
facility):

o 1.00 for an electric hot water heater; or
o 0.75 for a natural gas hot water heater

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More detailed information to assist in calculating energy savings that result from saving
water can be found on WaterSense's Data and Information web page at
www.epa.gov/watersense/data-and-information-used-watersense.

Payback

To calculate the simple payback from the savings associated with replacing an existing
showerhead, consider: the equipment and installation cost of the replacement; the water
and energy savings as calculated respectively in Equation 2 and Equation 3; and the
facility-specific cost of water, wastewater, and water heating fuel (e.g., electricity, natural
gas). Showerheads are available across a range of prices, so use the price of the models
you intend to purchase to calculate cost savings and payback.

Bath and Shower Diverters

Replacing leaking bath and shower diverters with models that do not leak can help save
water and energy. To estimate facility-specific water and energy savings and payback, use
the following information:

Current Water Use

To estimate the current water use of a leaking bath and shower diverter, identify the
following information and use Equation 4 on the next page:

•	Leak rate of the existing diverter: Use a bucket or bag to manually collect water
under the tub spout while the water is running and measure the water collected
over a one-minute period.

•	Average duration of each shower: The average shower duration is approximately
eight minutes.9

•	Average use rate of showers in terms of number of showers each person takes per
day: In buildings that serve a residential function (e.g., hotel, dorm, multifamily
building), it can be assumed that occupants shower approximately 0.7 times per
day.10

•	Number of building occupants.

•	Days of facility operation per year.

9	WRF, op. cit.

10	Ibid.

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Equation 4. Water Use of Leaking Bath and Shower Diverter (gallons or liters per

year)

= Diverter Leak Rate x Duration of Use x Use Rate x Number of Building
Occupants x Days of Facility Operation

Where:

•	Diverter Leak Rate: Gallons or liters per minute

•	Duration of Use: Minutes per shower

•	Use Rate: Showers per person per day

•	Number of Building Occupants: Persons

•	Days of Facility Operation: Days per year

Water Savings

Replacing a leaking bath and shower diverter with a new model tested to have no leaks
should eliminate that water use entirely. Therefore, savings should be approximately
equal to the water use identified in Equation 4.

Energy Savings

Because bath and shower diverters leak hot water, a reduction in water use will also result
in energy savings. The energy required to heat water can be dependent on: the fuel used
for water heating (e.g., electricity, natural gas); the efficiency of the water heater; and
water heater temperature set points. Since this information is not always readily available,
energy savings that can be achieved from replacing a leaky diverter can be estimated
using the water savings calculated in Equation 4 and the assumptions presented in
Equation 3.

Payback

To calculate the simple payback from the savings associated with replacing a leaking bath
and shower diverter, consider: the equipment and installation cost of the replacement;
the water and energy savings as calculated respectively in Equation 4 and Equation 3; and
the facility-specific cost of water, wastewater, and water heating fuel (e.g., electricity,
natural gas).

Additional Resources

EPA's WaterSense program. Bath and Shower Diverters. www.epa.gov/watersense/bath-
and-shower-diverters.

EPA's WaterSense program. Showerheads. www.epa.gov/watersense/showerheads.

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Texas Water Development Board. May 2018. Best Management Practices for Commercial
and Institutional Water Users. www.twdb.texas.gov/conservation/BMPs/CI/index.asp.

U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Federal
Energy Management Program. Best Management Practice #7: Faucets and Showerheads.
www.energy.gov/eere/femp/best-management-practice-7-faucets-and-showerheads.

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Disclaimer

This document was prepared as an account of work sponsored by the United States Government.
While this document is believed to contain correct information, neither the United States
Government nor any agency thereof, nor any of their employees, makes any warranty, express or
implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any
information, apparatus, product, or process disclosed, or represents that its use would not
infringe privately owned rights. EPA hereby disclaims any liability for damages arising from the use
of the document, including, without limitation, direct, indirect, or consequential damages
including personal injury, property loss, loss of revenue, loss of profit, loss of opportunity, or other
loss. Reference herein to any specific commercial product, process, or service by its trade name,
trademark, manufacturer, or otherwise does not necessarily constitute nor imply its endorsement,
recommendation, or favoring by the United States Government nor any agency thereof. The views
and opinions of authors expressed herein do not necessarily state or reflect those of the United
States Government nor any agency thereof.

v>EPA

United States Environmental Protection Agency
(4204M)

EPA 832-F-23-003
May 2023
www.epa.gov/watersense
(866) WTR-SENS (987-7367)


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