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3Ts Flushing Best Practices
Flushing is a too! schools can use as a general best practice to improve overall
water quality and during flush sampling (i.e., samples targeting the plumbing inside
of the wall).
LEAD IN DRINKING WATER IN SCHOOLS
The potential for lead to leach into water can
increase the longer the water remains in contact
with lead in plumbing. As a result, facilities with
intermittent water use patterns, such as schools,
may have elevated lead concentrations.
Testing helps evaluate plumbing systems and
materials so that targeted remediation efforts can
be taken. It is a key step in understanding the
problem, if there is one, and designing an
appropriate response.
EPA developed the 3Ts for Reducing Lead in
Drinking Water to assist schools and child care
facilities with their drinking water testing
program. The 3Ts applies a Training, Testing,
and Taking Action approach.
WHAT IS FLUSHING?
"Flushing" involves opening taps and letting the
water run to remove water that has been
standing in the interior pipes and/or the outlets.
The flushing time can vary by the type of outlet
being cleared.
The degree to which flushing helps reduce lead
levels can also vary depending upon the age and
condition of the plumbing and the corrosiveness
of the water.
Flushing is a tool, but only when used
appropriately. This fact sheet helps you
understand when flushing should be used, when
it shouldn't, the pros and cons, and how to
conduct flushing in your facility.
FLUSHING TO IMPROVE WATER QUALITY
In schools and child care facilities, establishing an
ongoing flushing program is one of the quickest
and easiest solution to ensure the water quality is
preserved by decreasing water age.
In addition, flushing does not require installation
or maintenance of water treatment equipment or
complex instructions. Flushing can be used as a
regular practice to ensure the water is regularly
moving.
*4
OFFICE OF GROUND WATER
AND DRINKING WATER
Office of Water
EPA 815-F-18-027
October 2018

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EPA OGWDW | 3Ts Flushing Best Practices
FLUSHING AND SAMPLING FOR LEAD
When sampling for lead, it is important that the
sample represents what is being consumed. For
this reason, EPA typically encourages schools not
to collect samples in the morning after vacations,
weekends, or holidays because the water will
have remained stagnant for too long and would
not represent the water used for drinking during
typical school days. It is recommended to flush
after these breaks to maintain water quality.
EPA does not recommend flushing for the sole
purpose of sampling but rather as a regular
practice to ensure the water is regularly moving.
Flushing right before sampling may cause results
showing lower than representative lead levels in
the water. Flushing is only appropriate during
sampling when conducting follow-up flush
sampling or sequential sampling to identify
potential lead concerns in the interior plumbing.
"Flushing can be used as a
regular practice to ensure the
water is regularly moving."
FLUSHING AND REMEDIATION FOR LEAD
Flushing can be a quick and easy solution to high
lead levels, especially when contamination is
localized in a small area or in a smail building. It
can be used as a short-term solution as more
permanent solutions are being implemented.
Automatically flushing individual problem outlets
or all outlets may also represent an albeit
ongoing, solution. This would involve the use of
time-operated solenoid valves that can be
installed and set to automatically flush the main
pipes (headers) of the system. It is important to
note that solenoid valves are not practical for
flushing water coolers.
EPA 815-F-18-027 October 2018
An important consideration when utilizing flushing
for remediation is how often flushing should
occur throughout the week and possibly
throughout the day, and whether it is feasible for
your facility. Depending upon the age and
condition of the plumbing and the corrosiveness
of the water elevated lead levels can return
relatively quickly following flushing.
Unless you can ensure lead levels remain low
throughout the day, it is not recommended to
flush only once a day or once a week as a
solution to high lead levels. Flushing immediately
prior to use may be a short-term solution, in
conjunction with signage and schedules.
Make sure to conduct samples after implementing
flushing for remediation so you can ensure the
water being provided does not contain elevated
lead levels.
THE DOS AND DONTS OF FLUSHING
The Dos
	Utilize flushing as a routine practice to
improve overall water quality;
	Flush when it is included in a sample
instruction (i.e., taking a follow-up flush
sample);
	Flush after remediation. In addition to
replacing or removing lead containing
plumbing or fixtures. Flushing can help
clear out debris or lead particulates that
may be released when remediation occurs.
For more information, visit: epa.gov/safewater/3Ts

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EPA OGWDW | 3Ts Flushing Best Practices
EPA 815-F-18-027 October 2018
The Don'ts
	Flush right before sampling. Flushing prior
to sampling may cause samples to not be
representative of daily consumption.
	Flush to reduce lead levels in coolers.
Flushing is not recommended as a practical
remedy for water coolers.
	Flush as a sole effort after finding
unacceptable lead levels in your school,
without ensuring lead levels will remain low
throughout the day.
	Flushing as a long-term remediation effort
alone. Flushing can be a measure that
could be paired with permanent
remediation like replacement and/or
removal.
TIPS FOR DEVELOPING A FLUSHING PLAN
When using flushing as a regular practice or as a
short-term remediation effort:
	Determine how water enters and flows
through your facility by developing a
plumbing profile;
	Locate all water outlets that are used for
consumption;
	Utilize signage to indicate when and for
how long flushing needs to occur at each
outlet;
	Identify options for collection and
nonpotable re-use of flushed water (e.g.,
plant watering); and
	Develop a system for accountability,
including identifying one person who is in
charge and record keeping.
ADDITIONAL RESOURCES
	3Ts for Reducing Lead in Drinking
Water (PDF)(2018). Link:
https://www.epa.gov/dwreqinfo/3ts-
reducinq-lead-drinkinq-water-schools-and-
child-ca re-facilities
	3Ts Full Toolkit (Website)(2018). Link:
https://nepis.epa .qov/safewater/3T s
Exhibit 1: 3Ts Flushing Instructions
Remember that each drinking water outlet should be flushed individually; flushing a toilet will not flush your water
fountains. All flushing should be recorded in a log submitted daily to the office, or person, in charge of this program.
	Locate the faucet furthest away from the service line on each wing and floor of the building, open the faucets
wide, and let the water run for 10 minutes. For best results, calculate the volume of the plumbing and the
flow rate at the tap and adjust the flushing time accordingly. This 10-minute time frame is considered
adequate for most buildings.
	Open valves at all drinking water fountains without refrigeration units and let the water run for roughly 30
seconds to one minute, or until cold.
	Let the water run on all refrigerated water fountains for 15 minutes. Because of the long time period
required, routinely flushing refrigerated fountains may not be feasible. It may therefore be necessary, and
more economical, to replace these outlets with lead-free, NSF-approved devices.
	Open all kitchen faucets (and other faucets where water will be used for drinking and/or cooking) and let the
water run for 30 seconds to one minute, or until cold.
For more information, visit: epa.gov/safewater/3Ts

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