DRAF
Suggested Sampling Procedures to D«t«rTsin< L«ad
in Drinking Hater in Buildings Oth«r Than Single
Family Homes
PRO
Jun« 1988
Office of Drinking Water
401 K. Street S.W.
Washington, D.C. 20460
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Suggested Sampling Procedures to Determine Lead
in Drinking Water in ba.iildir os )tner rhan Single
Family Homes.
PURPOSE
This guidance is to be used to determine the levels and
sources of lead in drinking water in buildings other than single
family homes. A separate sampling protocol to determine the lead
level in drinking water in single family homes has also been
prepared by the Environmental Protection Agency (EPA), and is
available upon request. The methods outlined in this sampling
protocol are similar to the sampling procedures used by water
suppliers to determine cotrçliance with the requirements of the
Safe Drinkino water Act (SDWA). However, this guidance is not
to be used for the purpose of determining whether a supplier
meets the Federal standards. This sampling protoco) i designed
to identify the sources of lead in drinking water and to assist
in the evaluation of potential remedies.
This protocol has been field tested and found to provide
results whic are generally reliable. Experience in the
laboratory and in the field indicates that lead levels observed
in drinkin: water at a particular sample site may vary over
time. This may affect the repeatibility of the analytical results
of sanpies taken at various times from the same sample site.
However, in instances where lead levels significantly above 20
parts per billion (ppb) are encountered, the results of repeat
analyses indicate that, in general, lead levels will continue to
stay abovi 20 ppb in subsequent samples taken from the same
site. Conversely, similar trends are observed in instances
where lead levels significantly below 20 ppb are encountered.
Therefore, in general, variations of lead levels in the water
are not expected to significantly influence the outcome of the
.conclusions that may be drawn regarding the source of the lead
in the drinking water. EPA requests your comments on this protocol,
particularly if you determine ways to improve it to better detect
or track down sources of high lead levels in drinking water.
EPA recommends that the sampling program be done in two
steps. The first step involves the collection and analysis of
screenino samples from drinking water outlets within the building.
The purpose of this first step is to identify the outlets which
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provide drinking water with lead levels of COncern. The second
step of the process involves the collection and analysis of
follcw—up samples from outlets where lead levels of concern have
ucen identified and, if ne ssarj, ad ti iaj samples from tho
interior plumbing within the building. The purpose of the
follow—up samples is to pinpoint the sources of lead in the
drinkina water. Once the Lources of contamination are known,
appropriate remedial actions toward their elimination may be
taken.
EPA recommer3d.s that estabilishment of sample sites be
prioritized on the basis of likelihood of contamination of the
drinking water by lead and the sensitivity of the consumer
towards lead. In general, the larger the number of samples
collected and analyzed, the better the assessment of the
source and extent of the presence of lead in drinking water.
Sample sites which are most likely to have lead contamination
include 1) areas of low flow and/or infrequent e (where long
contact tir e oetween the water and the plumbing ..._curs); 2) areas
of recent construction and cepa.ir with lead solder or materials
containing lead; 3) areas where the plumbing is used to ground
electrical circuits and; 4) areas where corrosive water having
low p! and alkalinity is distributed. The special sensitivity
of infants, children and pregnant women towards lead means that
samplino for lead in drinking water should be most extensive in
newly constr .3cted scnoo s and child care centers.
If results of analyses of samples taken from the selected
sites indicate extensive contar ination of the drinking water by
lead, additional sarpling from other sites deemed less vulnerable
to lead contarlnation rna be indicated.
INTRODUCTIOK
In general, elevated lead levels do not occur in drinking
water that is delivered from water supplies via distribution
mains to buildings. Lead levels in the drinking water delivered
from the main seldom exceed 5 ppb. The primary source of lead
is the corrosion of service connections and of the pipes, fixtures
and other parts of plumbing systems which distribute the water
within the buildings.
The extent of lead contamination in the water supplied to
a building is affected by a number of factors including: the
corrosivity of the water; the amount of lead contained in the
plumbing, the faucets, or apparatus dispensing the water; the
con€act time of the water with materials containing lead; and
whether or not electrical systems are grounded to the water pipes.
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Because of the variebility of flow rates and materials
used in a building’s plumbing,. lead contamination in the drinking
. ate will not oc.cuz t niforrnly 1.hcougt 1 : t a Zacil ty. Large
variations in lead levels in the drinking water may be observed
among individual outlets in a building where the sources of
contamination differ. In instances where the source of the
contamination is at the beginning of the distribution system,
such as from lead service connections, high lead levels in the
drinking water may be widespread throughout the plumbing of
the building. High lead levels in the drinking water may lao
be found in sections of the distribution system where the
water is infrequently used.
GENERAL CONSIDERATIONS
In order to determine, with a minimum number of samples,
whether water in a particular building contains a high amount
of lead, approach the task systematically. Prior to sampling,
study the layout of the plumbing system of the building.
Locate service intakes, headers, laterals, fixture supply pipes,
drinking water fountains, central chiller units, £tcrige tanks.
riser pipes and different drinking water ioops. Lxam ,les of
various plumbing configurations in buildings are illustrated
in the attached diagrams.
Ultimately the number of samples taken from a building is
dependent upon the size of the ouilding, the number of outlets
used to supply drinking water, and the extent of the contamination.
More outlets with elevated lead levels will require correspondingly
more follow—up samples to pinpoint the source of contamination.
Owners of offices or businesses leasing only part of a
building or shopping center will sample the potable water
outlet. only within the premises they occupy. In that case,
additional sampling may not be necessary if the source of the
contamination is limited to the fixtures and the plumbing
connections to the fixture supply pipes within the rental
unit. However, if the results of the analyses indicate that
the source of the contamination is not limited to the plumbing
within the premises, additional follow-up sampling in the
building may be necessary to pinpoint the locat n of the
sources of lead in the drinking water.
EPA recommends that one collect and analyze samples in
two steps, especially in large buildings where the number of
samples to be taken is large. In the first step, the initial
sampling should be done at the outlets such as faucets and
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fountains used for drinking water. This initial round of
collection and analysis of scree’ing sar’ ples will pinpoint the
location of sites which provide water having lead levels of
concern . EPA recommenas thá 5CL 0fl be taker 1 to .limit exposure
or reouce lead in water supplies in instances where the lead
levels exceed 20 parts per billion (ppb). [ Note: ppb is often
expressed as micrograms per liter (ug/L)). In instances where
the lead levels exceed 50 ppb, EPA recommends that the drinking
water fountain or the tap be taken out of service immediately
until remedial action is taken to remove the contamination.
Such remedial actions may include setting up a program to flush
the water, implementing treatment to reduce the corrosivity of
the water, eliminating the sources of lead from the plumbing
system or reducing other causes of lead contamination such as
eliminating grounding of electrical systems on water pipes.
Lead levels an drinking water at schools and day care centers
should be kept at the minimum since children exposed to lead
are at greater health risk than adults.
In the second step o the sampling program, follow—up
saTnples need only ce taken from sites where the analytical
results indicate levels of concern in the drinkLng water.
The purpose of the follow-up samples is to pinpoint the source
of leao contaffination ar.c tc facilitate plans for appropriate
remedial actior .
Ultimately, the choice to perform the sampling in one or
two steps is up to the personnel performing the sampling. For
small facilities with relatively few sites to be sampled, it
may be feasible to perforr all of the sampling at once. A flow
chart out.linin: the overall general sarnplino strategy is
attache .
LABORATORY ANALYSIS AND HANDLING OF SAMPLE CONTAINERS
The water samples collected should be analyzed by a State—
certified laboratory which uses EPA approved methods. Contact
your local water utility or your State or local health department
for information and assistance. In some instances, these
authorities will test your water samples for you. If not,
they can refer you to a qualified laboratory. Discuss the
proposed sampling procedures with the laboratory .or State
agency who will perform the analyses of the saiples.
The laboratory should provide you with a sufficient number
of appropriate sample containers. Make sure that you follow
the instructions provided for handling the sample containers
carefully. Failure to follow the instructions may result in
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erroneous sample results. Do not rinse the sample containers
before filling. The laboratory has prepared the container to
receive the sar ’ples you bili ‘.aIe an it may contain a chemical
needed to preserve the samples properly until they reach the
laboratory. Avoid any contact with this chemical. Be careful
not to overfill the sampling containers with water.
SUGGESTED SAMPLING PROCEDURES
The sampling procedures outlined here may be used to
determine the source of lead in water obtained from specific
components that are used to distribute, process, store and
provide drinking water in buildings and public facilities.
These include water fountains, faucets, central chiller units,
internal plumbing and service connections. Comparison of the
analytical results of the samples collected will provide
information on the presence and distribution of sources of
lead contamination in a building or a public facility.
Collect the sarrples before the facility is open for business
and before any water is used. Ideally the water should sit in
the pipes unused for at least 8 hours, but not more than 18
hours before the sarple is taken. Make sure that no water is
w.ithdra.m fror. the taps or fountains from which the samples
are to be collected prior to sa’npl.ing. Samples collected from
the designated sites after they have been used will show erroneous
results indicatir lower lead levels in the water than may be
actually encountered. Samples collected in the morning after
vacat1or s, ee’ends or holidays will contain higher lead levels
than the samples collected after allowing water to be in contact
with the plumoin: for 8 to 18 P ours. If the facility is open
continously, collect the samples immediately after the period
during which water consumption is the lowest. Label all of
the sample bottles with the location of the sample site. Also
note the manufacturer’s name and model number of water fountains,
central chillers and any other water dispensing outlets from
which samples are taken.
SECTION I — Drinking fountains
There are four main types of drinking water fountain systems.
They include the following configurations:
1. water is supplied to the drinking fountain directly from
the building plumbing. This type of fountain is often called
a bubbler.
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2. A central chiller unit cools waLer for a number of drinking
four tains (bubblers) in the builthng.
3. The water fountain is equipped with its own cooling system.
This type of water fountain is often called a water cooler.
The water to the cooler is supplied from the building plumbing.
4. Water to the drinking fountain is supplied from bottled
water. This type of water fountain is often called a bottled
water dispenser.
SAMPLING PROCEDURES
Note: Do not close the valves to the water fountains to prevent
their use. Minute amounts of scrapings from the valves
will result in erroneous results indicating higher than
actual lead levels in the water. Take all samples with
the taps fully open.
1. ubblers withott central chiller .
All sai ples should contain 250 mL of water.
Initial screenirg sarrple (nur.ber l ) :
Take t us sample before the facility is open for business
and before any water is used. Collect it immediately after
opening the faucet it’ ut allowing any water to waste
prior to sampling.
This water sample consists of water that has been in contact
with the bubbler valve and fittings and the section of plumbing
closest to the outlet of the unit. It is representative of the
water that may be consumed at the beginning of the day or after
infrequent use.
Follow—up samples should be taken from those water fountains
where the results of analysis indicate elevated lead levels in
excess of 20 ppb.
Follow—up sample (number 2A) :
Let the water run from the fountain for 30 seconds oefore
collecting the water sample. This water sample represents the
water that is in the plumbing upstream from the bubbler.
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Interpretation of the results :
In order to determine the source of lead in the water, compare
the results of the analyses of samples 1A and 2A.
.1. If the comparison of the analytical results indicates that:
— lead levels in sample 1A are higher than in follow—up sample
2A, a portion of lead in the drinking water s from the bubbler.
— the lead level in sample 2A is -identical or close to the
lead level observed in sample IA, the majority or all of the
lead in the drinking water may be from the plumbing upstream
fro n the bubbler. EPA recommends additional sampling from the
distribution system supplying water to the lateral to locate
the source of contamination. Refer to the sections entitled,
interior Plumbing and Service Connections .
— the lead level in sarr’ple 2A is very low (close to 5ppb),
very little lead is picked up from the plumbing upstream from
the outlet. The majority or all of the lead in the water is
fr3m the burnbler.
2. Bubblers supçlied with water frorr central chiller .
All samples should contain 250 ml.. unless otherwise specified.
Initial screening sarrple (numDer 1E) :
Take this sample before the facility is open for buisness
and before any water is used. Collect it immediately after
opening the faucet without allowing any water to waste
prior to sampling.
This sample consists of water that has been in contact with
the bubbler valve, the fittings, and the section of plumbing
attached to the unit. This water sample is representative of
the water that is consumed at the beginning of the day or
after infrequent use.
Follow—up samples should be taken from those bubblers
where the analysis indicates lead levels in excess of 20 ppb.
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Follow—up sample (number 23) :
Let the water run from the fountain for 3D seconds before
collecting the water sample. Tnis water sampLe represents the
water that is in the plumbing supplying the water from the
chiller to the bubbler.
Interpretation of the results :
In order to determine the source of lead in the water.
compare the results of the analyses of samples lB and 28. If
comparison of the analytical results indicates that:
— the lead level in sample lB is higher than in sample 28, a
portion of lead is from the water fountain.
— the lead level in sample lB is identical or :.. se to the
lead level observed in sample 23, the ma)ority C: all of the
lead in the drinKing water.may be contributed from the lateral
plumbing supplyin; the water from the chiller, and from the
plumbing supplyin; water to the chiller. EP recommends
additional sai ;ling (sarnples 33 and 43) from the chiller unit
supplying water to the lateral to locate the source of contami-
nation.
— the lead level in sample 23 is very low (close to 5ppb),
very little lead is picked up from the plumbing upstream from
the outlet. The majorit, or all of the lead in the water is
contributed from the bucbler.
Central Chiller Unit
Follow—up sample (number 3B) :
Take this sample from the plumbing which supplies water to
the chiller. Take the sample from a tap or valve as close to
the inlet of the chiller as possible. Collect this sample
immediately after opening the faucet without allowing any
water to waste. This water sample represents water that has
been in contact with the plumbing upstream from the chiller.
Follow—up sample (number 43) :
Take this sample from as close to the outlet of the chiller
as possible. Collect it immediately after opening the faucet
or valve without allowing any water to waste. This water sample
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consists of water that has been ii tOnta t with the chiller
unit and the plumbing upstream which supplies water to the
chiller. Often, water supplied to the butiblers is recirculated
to the chiller unit. In this instance, sample 4B consists of a
mixture of water from the water supply and recirculated water
from the plumbing supplying water to the bubblers.
Interpretation of the results :
If the comparison of the analytical results indicates that:
— the lead level in sample 2B is higher than in sample 4B, lead
is contributed from the plumbing supplying the water from the
chiller to the water fountain.
— the lead level in sample 4B is greater than the lead level
in sar ple 3E, a portion of the lead in the drinking water may be
coming from the chiller.
(Note: If the lead level in sample 3B taken from the supply
line (which supp1ies water from the interior plumbing to the
chiller) exceeds 20 ppb, EPA recommends additional sampling
from the distribution system supplying water to the chiller to
locate the source of contamination. Refer to the section on
Interior Plumbing and Service Connection. )
— the lead level in sample 3B taken from the supply line is
very low (close to 5ppb), very little lead is picked up from
the plumbing upstream from the chiller. The nia)ority or all
of the lead in the water may be attributed to the chiller unit.
3. Water Coolers
The two most commonly used types of water coolers are the
wall mounted and the free standing. Water in the cooler is
stored in a pipe coil or in a reservoir. Refrigerant coils in
contact with either of these cool the water. Lead in water in
these coolers may come from internal components of the cooler,
the section of the pipe connecting the cooler to the lateral,
and/or from the interior plumbing.
Note: All samples should contain 250 mL unless otherwise specified.
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Initial Screening sample (number IC) :
Take this sample before the facility s open for business
and before any water is used. Collect this sample immediately
after opening the faucet without allowing any water to waste
prior to sampling.
This water sample is representative of water that has been
in contact with the bubbler valve, the fittings, the storage
unit, the section of plumbing attached to the unit and the
Anterior plumbing. This water sample is also representative
of the water that is consumed at the beginning of the day or
after infrequent use. Follow—up samples should be taken from
those water coolers where the results of analysis indicate
lead levels in excess of 20 ppb.
Follow—up sample (nuw.ber 2C) :
Collect this sai ple after the facility closes at the end
of the cay. Let the water run from the fountain for 15 n inutes,
then collect t. e 253 mL sample. This amount of time is needed
to assure that the storage unit of the cooler is thoroughly
flushed and no stagnant water, which may contain lead as a
result of extended contact time witi t e plumbing, is left in
the storaoe unit. Make sure that t o water s taken from the
co’l- r zefcre follow—up sample 3C is collected next morning.
Follow—up sample (number 3C) :
Collect this sample the next morning in the same mi,. er as
you collected sample number 1C . Remember, do not allow any
water to run prior to sampling. This water sample is
representative of the water that was in contact with the cooler
overnight.
Interpretation of results :
1. If the comparison of analytical results indicates that:
— the lead level in sample 3C is higher than in sample 2C,
the water cooler is contributing lead to the water.
— the lead level in sample 3C is higher than in sample 2C,
and the lead level in sample 1C is higher than in sample 3C,
both the plumbing upstream from the cooler and the cooler are
contributing lead to the water.
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2. I the compartson of analytical resn.lts indicates that:
— tI e lead levels in samples 2C and 3C are identical and
close to 5 ppb, the water cooler is not a source of lead.
— the lead levels in samples 2C and 3C are identical, close
to 5 ppb, and in sample 1C is higher than in sample 3C, the
plumbing upstream from the cooler and/or the plumbing connection
leading to the cooler are/is contributing lead to the water.
3. If the lead level in sample 2C is in excess of 10 ppb
and is equal to or greater than the lead levels observed in
samples IC and 3C, the source of the lead may be sediments
contained in the cooler storage tank or in the plumbing
upstream from the cooler. To verify the source of lead, take
the followin; steps. First, take a flushed sample from a tap
upstream from the cooler or compare sample 2C with the results
obtained from follow—up sampl:s taken from outlets upstream from
the cooler. If low lead levels are found in these samples (close
to Sppb), the source of lead may be the sediments in the cooler
or the plumbing connecting the cooler to the lateral. Second,
take follow—up sample 4C, which is outlined below. If the flushed
samples from the upstream outlets have lead levels in excess of
Sppo, then the cooler and the upstream plumbing may both
contribute lead to the water. To confirm whether the cooler
is a source of lead, take and analyze sar ple 4C.
Follow—up sample (number 4C) :
Turn off the valve leading into the cooler. Disconnect the cooler
from the plumbing and look for a screen at the inlet. Remove
the screen. If there is debris present, check for the presence
of lead solder in the debris by forwarding a sample to the
laboratory for analysis. Some coolers also have a screen
installed at their bubbler outlet. Carefully remove the bubbler
outlet by unscrewing it and check for the presence of a screen
and for debris. If there is debris present, forward a sample
to the laboratory for analysis. Collect sample 4C from the
disconnected plumbing outlet in the same manner as you collected
sample number IC . Compare the analytical results obtained from
this sample (number 4C) with the result.s obtained from the other
samples. Some coolers are equipped with a drain valve at the
bottom of the water reservoir. In this case, a sample from
the bottom of the water reservoir should also be taken and
analysed for the presence of lead. Check for the presence of
debris in this water.
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Interpretation of Results
— If the lead level in sample 4C is close to 5 ppo, then the lead
is frcm sed ments in the cooler or the screen.
— If the lead level in sample 4C is close to the lead level
£n sample 2C, then the source of lead as from the plumbing or
materials n the distribution system located upstream from the
cooler.
— If the lead level in sample 4C is significantly greater than
5 ppb but less than the lead level in sample 2C, the source of
lead is from the cooler and in the plumbing upstream from
the cooler.
4. Bott1e water Dispensers
All sançleE should conta r 250 mt unless otherwise specified.
Initial screenin sarrple (number 1D) :
Take this sample before the facility is open for business
an before any water is used. Collect it immediately after
opening the faucet without allowing any water to waste prior
to sa plinc. This water sample consists of water that has
been in contact with the dispenser valve and the fittings
incorporatec to the outlet of the unit. It is representative
of tne water that is consumed at the beginning of the day or
after infre uent use.
Follow—up sai’ple (number 2D) :
If analysis indicates that the initial screening sample (number
1D) contains lead levels in excess of 20 ppb, collect a water
sample directly from the bottle supplying the water to -the
unit to determine the source of lead in the water. If the
lead level in sample 1D is higher than in sample 2D, contribution
of lead to the water from the dispenser unit may be suspect.
Note: The present regulatory requiremLnts specify 50 ppb as the
maximum contaminant level for lead. Therefore, at the present
time, lead levels in the water of up to 50 ppb are legally
acceptable. However, EPA does not recommend drinking any water
containing lead levels above 20 pub.
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Section II — Ice making machines.
All samples should contain 250 inL ur less otherwise specified.
Initial screening sample (number 1E) :
Fill a suitable container (250 niL or larger, wide mouthed
bottle or Whirl-Pak TM) prepared by the laboratory at least
three quarters full of ice. Do not touch the ice with your
hands. Use the non—metal scoop or disposable plastic gloves
provided by the laboratory.
If the analytical results indicate high lead levels in the
samples taken from the ice making machine, take an additional
sample (number 2E) to ascertain whether the source of the lead
in the water is in the plumbing or in the ice making machine.
Follow—up sample (number 2E) :
Disconnect the icemaker from the plumbing and look for a
screen at the inlet. Remove the screen. If there is debris
present, check for the presence of lead solder in the debris
visually and by forwarding a sample for analysis to the labora-
tory. Collect a sample from tne plumbing as close to the ice
maker as p 3 5 5 1 01 . ?.
Interpretation of results :
If comparison of analytical results indicate that:
— the lead level in sample 2E is close to Sppb, the source
of lead is in the ice making machine.
— the lead level in sample 2E is identical or close to that of
sample 1E, the source of lead is in the plumbing upstream from
the icemaker. If the lead level in sample 2E exceeds 20 ppb,
additional sampling from the distribution system supplying
water to the ice making machine is recommended to locate the
source of contamination. Refer to the section on Interior
Plumbing .
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Section III — Water faucets
All samples should contain 2 0 ITtL unless otherwise specified.
Initial screening sample (number IF) :
Collect this sample immediately after opening the faucet.
Do not allow any water to run into the sink prior to sampling.
This water sample represents the water that has been standing
in the faucet and the plumbing connection to the lateral during
the n ght or during infrequent use.
Follow—up sa’nples should be taken from all water faucets
whose samples contained lead levels in excess of 20 ppb.
Follow—up sarrple (number 2F) :
Let the water run frbm the faucet for 30 seconds before
collecting the water sat ;le. This water sample represents the
water that is in the lateral plumbing.
Interpretation of the resi.lts :
In order to determine the scurde of lead in the water, compare
t results of the analyses of samples IF and 2F.
1. If the compariso’ of the analytical results indicates that:
— t e lead levels in sa rple iF is higher than in sample 2F, the
source of lead is the water faucet and/or the plumbing connection
to the lateral.
— the lead level in sample 2F is identical or close to the
lead level observed in sample iF, the ma)ority or all of the
lead in the drinking water may be attributed to the lateral
plumbing. EPA recommends additional sampling from the distri-
bution system supplying water to the lateral to locate the
source of contamination. Refer to the section entitled
Interior Plumbing and Service Connections .
— the lead level in sample 2F is very low (close to 5 ppb),
very little lead is picked up from the plumbing upstream from
the faucet. The majority or all of the lead in the water is
contributed from the faucet and/or the plumbing connection
to the lateral.
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Section IV — Interior P]umbing
The configuration of the interior plumbing can vary
depending on the layout of the ouilding. See the attached
diagrams for an example. In high—rise buildings, the water is.
elevated to the floors by one or more riser feed pipes. Water
supply distribution from the riser feed pipes is usually achieved
through several different drinking water loops. In addit on,
in some buildings water may be stored in a tank prior to
distribution. In single story buildings, the water goes from
the service connection via main plumbing branches (often called
headers). The headers, in turn, supply water to the laterals.
Water is supplied to the faucets, drinking fountains, and
other outlets through smaller plumbing connections from the
laterals and loops.
In general, if lead levels above 20 ppb are encountered in
the follow—up samples taken from the drinking water outlets,
additional sa’nples from desig.oLed sample sites in the interior
plumbing should be taken. The sampling should proceed systematically
upstream from the initial follow—up sample sites, isolating
se:tions of the interior plurnbinç suspected to be contributors
to lead in drincing water. Comparison of analytical results
obtained from the designated sample sites and the analytical
results already availatle snoi ld provide information about the
sources o lead in from the interior plumbing of the building.
1 . Laterals
All samples should contain 250 mL unless otherwise specified.
Sample number IC - :
Open the tap that has been designated as the sample site
for the collection of the water from the lateral pipe.
Let the water run for 30 seconds before collecting the sample.
The purpose of flushing the water is to clear the plumbing
between the sample site and the lateral pipe. This will assure the
collection of a representative sample.
Note: Sample 1G is identical to follow—up samples taken from other
outlets such as 2A, 2E, and 2F. Results of analysis of follow—up
samples from outlets upstream and downstream from sample site
IG may provide additional information about the source of lead
in the watqr in portions of the lateral which are upstream and
downstream from sample site 1G.
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Interpretation of results :
If lead levels above 20 ppb are encountered, collect
aaditional samples from the plumuing Upstream (the service
line, the riser pipe, the loop or header supplying water to the
lateral). High lead levels may also be caused by recent repairs,
by additions using lead solders, and by particulate matter arid
debris in the pipe (particulate matter will adsorb lead from
the water). Debris in the plumbing is most likely to be found
in areas of infrequent use. A sample of this debris should be
forwarded o the laboratory for analysis of lead content.
If the comparison of analytical results indicates that:
— the lead level in sample IC is equal to the lead level ii a
sample taken do&nstream from sample site IC, the lead is
contributed from the the lateral or from interior plumbing
upstream from the lateral. Possible sources of lead may be
from loop, heacer, riser or service connection.
— the lead level in sample IG is close or equal to 5ppb, neither
the portion of the lateral upstream from sample site l nor the
interior plumoino supplying water to the lateral as coT tributing
lead to the drink.in; water.
— the lead level an sample IC significantly exceeds 5ppb
(for example l0ppb), and is less than the lead level in a
sample taken downstream from sample site 1G . the source of a
portion of the lead is downstream from the sample site.
2. Loops and/or headers
Because of different use patterns in various locations
within a buildino, EPA recommends that water samples from
each individual loop and/or headers be collected. Experience
indicates that construction materials may vary among loops.
This may be especially true in larger facilities and high—rise
buildings where subsequent additions and repairs have been made.
All samples should contain 250 niL unless otherwise specified.
Sample number lH (header) or sample 11 (loop) :
Locate the sampling point which is furthest from the
service connection or a riser pipe on a floor. Open the faucet
and let it run for 30 seconds before collecting this sample.
The purpose of : flg the water i to clear the faucet and
plumbing betwee -. e sample site and the loop and/or header pipe,
thus assuring the collection of a representative sample.
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17
Int ! retatjon of results :
If lead levels above 20 pph re encountered, collect
additional samples from the plumbing upstream that supplies vater
to the loop or header. High lead levels may also be caused by
recent repairs, by additions using lead solders, and by
particulate matter and debris ira the pipe (particulate matter
will adsorb lead from the water). Debris in the plumbing is
most likely to be found in areas of infrequent use. A sample
of this debris should be forwarded to the laboratory for analysis
of lead content.
If the comparison of analytical results indicates that:
— the lead level in sample 1H (or 11) is equal to the lead level
in a sample taken downstream from sample site IH (or 11), the
source of lead is the header (or the loop) or the interior
plumoing upstream from the header (or from the loop). Possible
sources of lead may be the loop, header, riser pipe or service
connection.
— the lead ievel in sample 1 (or II) is close or equal to Sppb,
the portion of the header (or loop) upstream from “;Je site 1H
(or IL) and the interior plur oing supplying water to the loop
or header are not cor tributin; lead to the drinking water.
The source of lead is downstream from the sample site.
— the lead level n sample fl (or II) significantly exceeds
Sppo (for exarrple 1Opp ), and is less than the lead level in a
sample taKe 1 dowr.streari frcc sarrple site 1H (or 11), the source
of a portion of the lead is downstream from the sample site.
1. Riser pipes
All -samples should contain 250 mL unless otherwise specified.
Sample number 13
Open the tap closest to the riser pipe. Let the water
run for 30 seconds before collecting the sample. The purpose
of flushing the water is to clear the faucet an .d moing
between the sample site and the riser pipe. This will assure
the collection of a representative sample.
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18
Interpretation of results :
If lead levels above 20 ppb are encountered, collect
additional samples from the plumbing upstream from the riser pipe.
High lead levels in the riser pipe may also be caused by recent
repairs and by additions usin; lead solder.
If the results indicate that:
— the lead level in sample 13 is equal to the lead level in a
sample taken downstream from sample Bite 1R, the riser pipe
and/or the plumbing and service connection upstream from the
riser pipe are the sources of lead.
— the lead level in sample 13 as close or equal to 5ppb, neither
the portion of the riser pipe and plumbing upstream from sample
site IR nor the service connection is contributing lead to the
drinking water. The source of lead is downstream from the
sample site.
— the lead level in sample 13 significantly exceeds Sppb
(for example lOppo), and is less than tne lead ‘.evcl i’ a
sample taken downstrean from sample site 13, a portion of the
lead is contriouted frorr downstream of the sample site.
Section V — Service Connections
The service connection is the plumbing connection between
the districution main in the street and the plumbing in the
buildinc. In some locations, lead pipes have been used for
service connections. This practice has ended Only recently.
In general, lead pipes up to 2 1/2 inches in diameter have been
used for lead service connectors. Other materials used for
service connectors include copper, galvanized steel, plastic,
and iron. Take the service line sample from the tap closest
to the service line. This is especially important in larger
facilities where more than one service connection is present.
Collection of Samples
All samples should contain 250 mL unless otherwise specified.
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19
S a nip]. elK :
Oper. the ta’ clo=? : t• the service connection. Let the
water run and feel the temperature of the water. As soon as
you feel the water change from warm to cold, collect the sample.
Since water warms slightly after standing in the interior
plumbing, this cold water sample represents the water that had
been standing just outside of the building and in contact with
the service line.
Interpretation of the results :
— If high lead levels are observed in sample 1K, the service
line is most likely made of lead. However, in the absence of a
lead service line, lead goosenecks or other appurtenances
containing leaa in line with the service connection may be the
source of contamination. o significant amount of lead above
5 ppb is expected to be contributed from the distribution main.
To verify this, an additional bample of the water in the distribu-
tion main may be takers b allowing the water to run for three
minutes after the first observed temperature change before
collecting this sample.
— If the lead level in sample IS is very low (close to S ppb),
very little lead is picked up from the service line. The ina ority
or all of the lead levels observed in samples taken from locations
in the uildinc indicate that the source of lead is from the
interior plwnbing and outlets.
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Overall Sampling Strategy
oils c i and analyze
enlng sample from
l$( M Ornlfl 9 FIrS t D(J
4
Lead level In screenIng
Sample Is below 20 ppb
4 No
Lead Iiv i In screening
sample Is below 50 ppb
V..
Outlet ok to us.
I
We Drink water only If lead
levels at. reduced to below
20 ppb
CoII•ct and analyze
follow—up samples (interior
plumbing)
Lead Iev•is hi Ir?terloT
plumbing follow-up samples
are close or equal to 5 ppb
contributed fr ,,
erlor plumbing
servics cormection
Collect and analyze IT
sample
No
Is contributed from
orpumbIngsnde It
V ..
connection sample Is I—
iqual to5 ppb
4 Ne
Lead Is contributed from
Interior plumbing and
service Ins
‘Oi.iVet
- Drinking Fountain
- Bubbler
— Faucet
• line riot Plumbing
— Lat•rals
— l4iaderi
- Loop,
- Plumbing ConnecUoflS
— lser Pipes
I .
I
Lead level In inlerlor
plumbing follow-up samples No I
ars close or equar to lead
levels observed in screening
sample
4 .
4 y..
41
Lead i s contributed
from outlet
4 m l
Lead level service
conrt.ctIOfl sample Is Close
or equal to lead levels
observed In Interior
plumbing foHow-up samples
No
4 ml
Lsad Is contributed from
service Connection
Lead Is contributed
from Interior plumbIng
I
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Water Supply to Water Fountain and Bubblers
from Central Chiller
Morning first aw sample from 000lSr$.
i tOurnainS. (S wung Sampiss
18)
Sampi. from lateial or loop from
2 øS&r a1 o flhs1 (Follow—tç SwT 1S 23)
j Ch llr sampte taken from tap Closut to
%iIlq o .fll•t (Sample 4B)
Interior plumoir g sampte taken lrorn tap
‘ ctosesi 10 uUer tr e1 (Sarnole 3B)
From Supply
Suggested Sample Sites
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Single-Levee ui1ding
Foun Ia
Header
PIP,
Faucet
DrinkIng Water
Treatment Plant
‘lpes
(laterals)
toot ,,
Servic, tins
Suggested Sam Ie Sites
Morning VI si &aw samples from cOóIers,
I tapg Io r,lali etc. (Saeenlng Sati,tes
• IA, 18, Ic. lb. 1E, IF)
• Samples from lateral after 30 second flush
from dnslgna1 j otAtot (Fottow-( Samples
2A, 2E, 2F, 20)
Sample frøm hea j 0 taken *uitn thp
farthesg from service line (Sample I H)
Service Line sample taken from lap
4 closest to service w i. (Sample 1K)
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High Rise..BuiIding
+ Upp.s
Suggested Sample Sites
A Morning first 31w $arr Is from OIVs
LL Sampies
$s r i s from loop — tap $ft r a 30
2 ucon 1lu t from
(FoHow-up Sarrçn.s 2A. 2E. 2F. 2G)
Sarr le from loop taMn from tap
fa.r iest tram risr pips (SampIe 11)
Riser pipe sample tai.n from tap
C1O$ gt 10 flier pipe (Sampi. 1J)
S.rvt , Ur • sample tiken from tap
closisi tc service Ir (Samp:e 1K)
Riser
Pips Loop
Drinking Water
Treatment Punt
0
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