3Ts: TRAINING, TESTING, TAKING ACTION

¦
Module 5: Conducting Sampling and Interpreting Results
2-Step Sampling at the Tap
Communication Plan: Don't forget to communicate your plans to test your
^Fa facility, and to prepare for communicating results. Results should be shared
regardless of the lead level detected.
2-Step Sampling at the Tap
EPA recommends that schools and child care facilities conduct a 2-step sampling
procedure to identify if there is lead in the outlet (e.g., faucet, fixture, or water fountain)
or behind the wall (e.g., in the interior plumbing). These samples should be taken after an
8 to 18-hour stagnation period.
Please note that this section contains recommendations that are generalized for typical
plumbing configurations. The Detailed Fixture Evaluation contains details on types of
fixtures and targeted sampling.
250-mL First Draw Sample
Take a 250mL first draw sample at
all taps used for consumption to
identify potential lead in the
fixture.
250-mL Flush Sample
If the result of Step 1 is high, take
a 30-second flush sample to
identify lead in the plumbing
behind the fixture.
These samples can be taken in the same
sampling event, which can reduce cost, and
provide you with more information on lead
levels. If not taking these samples at the same
time, and elevated lead levels have been found
in Step 1, the water should not be consumed
while preparing to take the follow-up flush
sample. More information on immediate steps
is in Module 6.
&EPA
OFFICE OF GROUND WATER
AND DRINKING WATER
Ak
Helpful Tip...
For further potential cost savings, you or the lab can
collect, preserve, and hold (but not analyze) the second
sample at the same time the first sample is collected,
then analyze only selected Step 2 samples based on
review of the Step 1 results. Most commercial labs will
"Hold" samples until the client advises to dispose (at
nominal cost) or analyze those samples.
Office of Water
EPA 815-F-18-022
October 2018

-------
TESTING
3Ts: TRAINING, TESTING, TAKING ACTION
Step 1: Initial First Draw Samples
Take first draw samples from fixtures throughout the building that are used for human consumption. EPA
strongly recommends that you collect these samples from all outlets used for drinking or cooking, prioritizing
the high-risk outlets (i.e., fixtures that are known to or potentially contain lead and fixtures that are used most
frequently). The plumbing profile will help pinpoint those high-risk fixtures and to prioritize sample collection.
important: schools and child care facilities should not use sample results from one outlet to characterize
potential lead exposure from all other outlets in their facility. This approach could miss
localized lead problems that would not be identified.
The first draw sample identified in Step 1 is representative of the water that may be
consumed at the beginning of the day or after infrequent use. This protocol maximizes the
likelihood that the highest concentrations of lead will be found because the first 250-mL
sample is collected after overnight stagnation (the water sat in the pipes for at least 8 hours).
Procedures for initial outlet samples are shown below:
•	All samples should be collected before the facility opens and before the fixtures have been used (EPA
recommends an 8 to 18-hour stagnation period).
•	One 250-mL sample should be taken at each fixture. Note this is a first-draw sample. Therefore, collect
the sample immediately after opening the faucet or valve.
•	Compare all sample results to prioritize follow-up
sampling and remediation. Outlets with elevated lead
levels should not be made available for consumption.
250-mL First Draw Sample
Take a 250mL first draw sample
at all taps used for
consumption to identify
potential lead in the fixture.

-------
' o o" ' ' " • C * -

3Ts: TRAINING, TESTING, TAKING ACTION
^ "err
V- . .... iM'. -' ' * ' Ivi _ _
TESTING
High Results Due to Particulate Lead
If initial first draw sampling results reveal high lead levels in the 250-mL sample for a
given outlet, a contributing source of the elevated lead levels could be the debris in
the aerator or screen of the outlet. By cleaning the aerator or screen and retesting
the water following the initial first draw sampling procedures, you can identify
whether or not the debris is contributing to elevated lead levels.
Determining aerator/screen debris contribution:
Scenario 1: The initial sample result is 19 ppb; you decide to see if the aerator is
contributing to lead in the water. After cleaning out the aerator, you take another first-
draw sample. The results come back less than or close to the detection level (e.g., 1
ppb). This result indicates that the debris in the aerator was likely contributing to
elevated levels in the fixture. Continue to clean the aerator on a regular basis;
continued use of the outlet should be acceptable. However, please note that without
regular maintenance, this outlet may serve water with elevated lead levels.
Scenario 2: The initial sample result is 22 ppb; you decide to see if the aerator is
contributing to lead in the water. After cleaning out the aerator, you take another first-
draw sample. The second sample result is very close or equivalent to the 22-ppb
sample. Since the initial sample and post-cleaning first-draw sample results are similar,
the problem is likely not the aerator.
Scenario 3: The initial first draw sample result is 60 ppb; you decide to see if the aerator
is contributing to lead in the water. After cleaning the aerator, you take another first-
draw sample. The post-cleaning sample result is 25 ppb. Although the results are lower,
they are still high; this indicates that the aerator is likely a contributing source and that
the outlet itself and/or the plumbing upstream of the aerator are contributing as well.
If this situation occurs, the school should take this fixture offline, and continue with 2-
step sampling, or consider the
Detailed Fixture Evaluation in
Appendix D to target the
additional contributing sources.
* When taking a second first-draw
sample, please remember to follow
the same sampling procedure as the
initial first-draw sample. Ensure that
fixtures and outlets have been out of
use for 8-18 hours, sampling before
students arrive at the facility.
Picture of an aerator with particulate

-------
TESTING
3Ts: TRAINING, TESTING, TAKING ACTION
•irw
* _ ...	J •	1..# _
Step 2: Follow-Up Flush Samples
If initial test results reveal elevated lead, follow-up flush testing described in Step 2 is recommended
to determine if the lead contamination results are from the fixture or from interior plumbing components.
Follow-up flush samples generally involve the collection of water from an outlet where the water has run for
30 seconds.
The purpose of Step 2 is to pinpoint where lead is getting into drinking water (i.e., fixtures versus interior
plumbing) so that appropriate corrective measures can be taken.
Procedures for initial outlet samples are shown below:
•	As with initial first draw samples, follow-up flush samples are to be taken before a facility opens and
before any water is used. For best results, flush samples from different outlets that are in close
proximity should be collected on different days. For drinking fountains or other fixtures that are
manifolded closely together, a single flush sample may be representative of the shared interior
plumbing.
•	The sampler should be careful to maintain a
consistent rate of flow when collecting flush
samples.
•	Open up the tap and let the water run for 30
seconds. Then, take a 250mL sample. Make sure
to label this sample bottle as the flush sample.
1
r ^
250-mL Flush Sample

If the result of Step 1 is high,

take a 30-second flush sample

to identify lead in the
i
plumbing behind the fixture.
L. .J

-------
TESTING
3Ts: TRAINING, TESTING, TAKING ACTION
v	err*
Sampling Dos arid Don'ts
Do:
•	Follow the instructions provided by the laboratory for handling sample
containers to ensure accurate results.
•	Assign a unique sample identification number to each sample
collected. Use a coding scheme to help differentiate samples, and
don't forget to label each sample bottle.
•	Collect all water samples before the facility opens and before any
water is used. The water should sit in the pipes unused for at least 8
hours but not more than 18 hours before a sample is taken.
•	Learn how water flows in your facility. If there are multiple floors, it is
typically recommended to sample from the bottom floor and continue
up. Start sampling closest to the main and work away.
Don't:
•	Remove aerators prior to sampling. Potential sources of lead may be
missed if aerators are removed, since debris could be contributing to
the lead in drinking water if particles containing lead are trapped
behind aerator screens.
•	Flush water prior to sampling, unless instructed to do so. Flushing can
be a tool to improve water quality, especially after long holidays or
weekends. However, flushing prior to sampling may cause results
showing lower-than representative lead levels in the water. See
Flushing Best Practices Factsheet for more information.
•	Close the shut-off valves to prevent their use prior to sample
collection. Minute amounts of scrapings from the valves can produce
results showing higher-than-representative lead levels in the water.
Don't forget to maintain a record!
Recording sample information is critical to tracking and managing
water quality year-over-year.

-------