at Work

Water Use Monitoring

2.2 Leak Detection and Repair

Best Management Practices for
Commercial and Institutional Facilities




November 2023

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 leak
detection and repair, is part of Section 2: Water Use Monitoring. 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

•	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
November 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).

November 2023

Water Use Monitoring


Leak Detection and Repair


Water Sense


Identifying and repairing leaks and other water use anomalies within a facility's water
distribution system, processes, or equipment can keep a facility from wasting significant
quantities of water. As described in Table 1, water leaks and costs from wasted water can
add up over time.12

Table 1. Potential Losses From Water Leaks


Leaking Flow
Rate (gallons per
minute [gpm])3

Water Loss3

Cost of
Water Loss4

Leaking Toilet

•	Small (e.g., worn flapper)

•	Medium (e.g.,
misaligned flapper)

•	Large (e.g., stuck fill

0.02 gpm
0.2 gpm

3.0 gpm

860 gallons per month
8,600 gallons per month

4,300 gallons per day

Up to
$1,400 per

Drip Irrigation Malfunction

1.0 gpm

43,200 gallons per

$5,700 per

Unattended Water Hose at Night

10.0 gpm

5,400 gallons per day

$22,000 per

Broken Distribution Line for:

•	One day

•	One week

•	One month

15.0 gpm
15.0 gpm
15.0 gpm

21,600 gallons
151,200 gallons
648,000 gallons

Up to
$86,000 per

Tempering Water Line on a
Steam Sterilizer Stuck in the
"On" Position

2.0 gpm

86,400 gallons per

$11,500 per

Stuck Float Valve in a Cooling

5.0 gpm

216,000 gallons per

$29,000 per

1	New York City Department of Environmental Protection. Repair Your Leaking Toilets: Save Water and Stop
Flushing Away Your Water Bill, www.nyc.gov/assets/rtep/rtownloarts/prtf/water/rtrinking-water/toilet-rtetect-

2	City of Poway, California. How to Detect a Water Leak. https://poway.org/183/How-to-Detect-a-Water-

3	To convert from gallons to liters, multiply by 3.79.

4	Based on an average commercial rate of $11.09 per 1,000 gallons for water and wastewater determined
from data in: American Waterworks Association (Raftelis Financial Consulting). 2020. Water and
Wastewater Rate Survey.

November 2023


WaterSense at Work

Leak Detection and Repair

An effective leak detection and repair program can help facility managers better
understand building water use and save money by avoiding water waste. Leak reporting
and education of building occupants can also be effective in reducing water waste from
leaks, as long as reported leaks are promptly addressed. Refer to WaterSense at Work
Section 1.3: Education and Outreach at www.epa.gov/watersense/best-management-
practices for more information, and to the WaterSense Fix a Leak Week webpage at
www.epa.gov/watersense/fix-leak-week. which includes resources to post in commercial
and institutional restrooms to encourage leak reporting in the workplace.5 While Fix a Leak
Week occurs in March, educating employees on finding and fixing leaks can happen all
year long.

Best Practices

Reading water meters regularly, installing leak detection and flow monitoring devices, and
conducting visual and auditory inspections are important best practices to detect leaks.
To reduce unnecessary water loss, all detected leaks should be repaired quickly.

Reading Meters and Installing Leak Detection and Flow Monitoring Devices

To reduce water loss, consider the following metering and leak detection methods:

•	Read the facility water meter during off-peak
hours when all water-using equipment can be
turned off and building occupants, employees,
and visitors are not using sanitary fixtures.

After all water uses have been shut off, read
the meter, then read it again an hour later. If
the water meter reading significantly changed,
this indicates there may be a leak somewhere
within the distribution system or within the
facility. Alternatively, many meters include a
leak indicator (e.g., a flashing dot or animated
symbol on electronic meters, a spinning
triangle or dial on mechanical meters). When
all water uses have been shut off, observe if the leak indicator is spinning or
activated, which could mean there is a leak.

•	Contact the water utility to understand whether the facility has advanced metering
infrastructure (AMI). Advanced meters may be capable of recording and
transmitting water consumption data daily, hourly, or in shorter time intervals.

Work with the water utility to obtain access to their customer portal that would
allow more frequent observation of facility water use data. At the same time,
investigate whether the utility offers high water use or leak notifications. For more

5 U.S. Environmental Protection Agency's WaterSense program. Fix a Leak Week: In the Workplace.


Example leak indicator dial

November 2023


WaterSense at Work

Leak Detection and Repair

information about using AMI, see WaterSense's AMI guide, Improving Water
Management Using Advanced Metering Infrastructure Data: A Guide for Facility
Managers at www.epa.gov/watersense/advanced-metering-infrastructure.

Devices to Assist With Leak Detection

There are a variety of devices that can help
detect leaks and assist facility managers in
preventing costly water damage and waste.
There are two main types intended for
commercial and institutional facilities.

Leak sensors (also called flood sensors) are
small sensors, typically in the form of a small
disk or probe, that are placed in areas prone
to leaks or flooding (e.g., under sinks, near
hot water heaters, near other end uses such
as toilets, dishwashers, and ice machines).
When the sensor comes in contact with
water, it activates an alarm response or a
shut-off valve to prevent major damage.

Flow monitoring devices act similar to water
meters to measure water flowing through a
pipe. These devices can be installed
externally or in-line to a water pipe and
communicate water usage. When abnormal
water use behavior is detected, the device
transmits an alert or activates a shut-off valve
on the water line.

• If AMI data is not available to the
facility, read water meters and
water bills monthly. Pay close
attention to water meter readings to
ensure they make sense and are
consistent with expected water use
trends. Compare monthly water
bills to the previous month and to
the same month of the previous
year, keeping in mind expected
seasonal water use increases (e.g.,
more water in the summer months
for building cooling and landscape
irrigation). If water use is
unexpectedly high, a significant leak
might be present in the distribution
lines or within the facility.

• Install leak detection and/or flow
monitoring devices that will send
an alert upon detection of a leak.

Flow monitoring devices

installed inline or attached to

Reading facility submeters

pipe can sense if equipment is

malfunctioning or identify leaks by detecting abnormal increases in water flow over
extended periods of time. Leak detection sensors can be placed on the ground in

• Install submeters on major water-
using equipment (e.g., cooling tower
make-up water lines, reverse
osmosis system supply lines,
irrigation systems). Refer to
WaterSense at Work Section 2.1:
Metering and Submetering at
management-practices for more
information. Monitor and record
the submeter readings to identify
unexpectedly high water uses,
which may indicate that
equipment is malfunctioning or
that a leak is present.

November 2023


WaterSense at Work

Leak Detection and Repair

areas where water might collect in the event of a leak or flood (e.g., near a hot
water heater or clothes washer). An alert is sent when water comes in contact with
the sensor. Flow monitoring and leak detection devices can alert a user if an issue
is detected via alarm, flashing light, text message, building automation system, or
other method. Some can even automatically turn off the water supply to the
equipment when connected to, or integrated with, a shut-off valve.

•	Incorporate multiple flow monitoring devices, surface leak sensors, and sensor-
activated shut-off valves to create a dynamic leak detection system. Linking these
devices to a building automation system or other system connected to the internet
can allow for early detection of leaks and immediate shut-off to prevent significant
water loss and damage. Some companies package these features together as a
service to provide leak detection, water monitoring, and other recommendations
on efficient water use. These companies can monitor real-time data and send
alerts if they notice a potential leak.

Visual arid Auditory Inspection

In addition to meters, conduct visual and auditory inspections as described in the
following best practices:

•	Perform daily tours of the building wherever
water use occurs, including: restrooms;
kitchens; irrigation systems; interior
mechanical spaces with water-using systems
(e.g., boilers, water purification systems,
vacuum systems); cooling towers; and
laboratory spaces. Building maintenance staff
can usually complete these walkthroughs
without much extra effort. Pay close attention
to all water-using equipment indoors and
outdoors by listening and looking for
unexpected water use, such as:

o Sanitary fixtures or water-using kitchen
equipment continuously flushing, leaking,
dripping, or left running.

o Unanticipated discharge to floor drains in mechanical spaces.

o Wet spots on sidewalks, in parking lots, and in grassy areas surrounding the
facility. If soggy ground is unexpected, contact the water utility to determine if
there is a leak in the distribution line.

o Water flowing to an overflow drain(s) within a cooling tower basin.

o For tips on finding more water waste, see the 1/1/aferSense Operations and
Maintenance Water Waste Checklist for Commercial and Institutional Facilities

at www.epa.gov/watersense/tools-ci-facilities.

Example water leak identified through
site walks

November 2023


WaterSense at Work

Leak Detection and Repair

•	Perform a water assessment of the facility once every four years as outlined in
WaterSense at Work Section 1.2: Water Management Planning at
www.epa.gov/watersense/best-management-practices. During a water
assessment, all major water uses will be identified and estimated to establish a
facility water balance. If more than 10 percent of water use cannot be accounted
for, the facility may have leaks in the distribution lines or from equipment and
further investigation is warranted.

•	Use WaterSense's Find a Pro tool at www.epa.gov/watersense/find-pro to select an
irrigation professional certified through a program that has earned the WaterSense
label6 to audit the landscape irrigation system for outdoor water leaks. All audits
should be conducted according to the Irrigation Association's recommended audit

• Educate building occupants,
employees, and visitors to
immediately report to facility
maintenance staff any leaks that
they detect in restrooms, kitchen
areas, or any other part of the
facility. Immediate leak detection
is vital to avoid water and
monetary losses from
unnecessary water waste. To
encourage this feedback and build
a culture of reporting leaks, be
sure to repair leaks in a timely
manner. Contact the facility's
water utility to see if any special
resources, free water audits, or
programs directed at leak

Finding and Fixing Leaks

EPA's WaterSense program sponsors Fix a Leak
Week annually the third week of March to
remind Americans to find and fix leaks. This
week is the perfect time to educate employees
about finding and fixing leaks at home, as well
as in the workplace.

WaterSense has several leak detection and
repair videos and employee education
materials available on its website at
Consider using these videos and other
resources to further educate facility staff about
identifying leaks and posting signs in restrooms
or other locations to encourage employees and
visitors to report leaks.

detection are being offered. See

the WaterSense website at www.epa.gov/watersense/fix-leak-week for tools that
can be used by staff to identify leaks8 and WaterSense at Work Section 1.3:
Education and Outreach at www.epa.gov/watersense/best-management-practices
for more information on ways to encourage leak reporting.

Leak Repair

If a plumbing fixture or other piece of water-using equipment is leaking, repair it according
to manufacturer specifications. If necessary, replace it with new, properly functioning

6	EPA's WaterSense program. Irrigation with a Pro. www.epa.gov/watersense/irrigation-pro.

7	Irrigation Association. Technical Resources: Irrigation Audit Guidelines.

8	EPA's WaterSense program. Fix a Leak Week, www.epa.gov/watersense/fix-leak-week.

November 2023


WaterSense at Work

Leak Detection and Repair

equipment; look for WaterSense labeled or ENERGY STARฎ certified models where

For specific information on operation and maintenance, retrofit options, or replacement
options, see the relevant sections for technologies and systems covered by WaterSense at
Work at www.epa.gov/watersense/best-management-practices.

Additional Resources

City Energy. May 2019. Water Audit Guidance for Commercial Buildings.

content/uploads/2019/05/City Energy Project Resource Library Water Audit Guidance
For Commercial Buildings.pdf.

EPA's WaterSense program. "Fight Leaks and Water Waste in your Facility with
WaterSense." www.epa.gov/sites/default/files/2Q19-Q2/documents/ws-falw-commercial-

EPA's WaterSense program. Fix a Leak Week, www.epa.gov/watersense/fix-leak-week.

EPA's WaterSense program. Improving Water Management Using Advanced Metering
Infrastructure: A Guide for Facility Managers.


EPA's WaterSense program. Tools for CI Facilities, www.epa.gov/watersense/tools-ci-

Irrigation Association. Technical Resources: Irrigation Audit Guidelines.

North Carolina Department of Environment and Natural Resources, et al. May 2009. Water
Efficiency Manual for Commercial, Industrial and Institutional Facilities.

U.S. Department of Energy (DOE), Federal Energy Management Program (FEMP). Best
Management Practice #3: Distribution System Audits, Leak Detection, and Repair.

November 2023


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This document was prepared as an account of work sponsored by the United States Government.
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States Government nor any agency thereof.


United States Environmental Protection Agency

EPA 832-F-23-003
November 2023
(866) WTR-SENS (987-7367)