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Quantifying Lead-Leaching Potential From Plumbing
Exposed to Aggressive Waters
KELSEY J. PIEPER,1 LEIGH-ANNE KROMETIS,2 AND MARC EDWARDS1
1Department
2Department
of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Va.
of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Va.
Section 9 of NSF International/American National Standards
Institute (NSF/ANSI) Standard 61 evaluates lead-leaching
potential from end-point devices to protect consumer health.
However, because the NSF/ANSI protocol stipulates a high
pH and alkalinity characteristic of municipal waters, it is not
likely generalizable to the aggressive water chemistries more
consistent with water quality observed in private systems. To
assess lead release from components installed in private
systems, this study exposed brass and galvanized steel that
meet lead-free requirements to more aggressive waters. As
expected, lead leaching from C36000 brass increased with
decreasing pH and alkalinity, but post-2014 lead-free brass
released nondetectable concentrations when exposed to
aggressive conditions. However, post-2014 lead-free
galvanized steel may still release significant lead in aggressive
waters as a result of the sorption of lead to plumbing.
Although new lead-free brass products are more protective of
communities dependent on private systems, elevated lead from
both legacy materials and galvanized steel remains an issue
for systems without corrosion control.
Keywords: corrosion, lead, NSF/ANSI 61, private systems
Despite the well-known adverse health effects associated with
human exposure, lead remained a common additive to potable
water plumbing components through at least January 2014.
Following the enactment of the Lead Ban provisions in Section
1417 of the Safe Drinking Water Act (SDWA) Amendments of
1986, the US Environmental Protection Agency (USEPA)
required the use of “lead-free” plumbing components in the
installation and repair of drinking water infrastructure and onsite plumbing (USEPA 1989). At the time, “lead-free” was
defined as solder and flux that contained less than 0.2% lead
and piping and fittings that contained less than 8% lead by
weight. With the 2011 Reduction of Lead in Drinking Water Act
(RLDWA), the allowable lead content in piping and fittings was
reduced to a weighted average of less than 0.25% lead with respect
to wetted surfaces, effective January 2014 (111th Congress 2011).
It is important to note that the RLDWA overwrote some important safeguards such as prohibiting plumbing components that
exceed 8% lead by weight and no longer mandating third-party
certification to the NSF International/American National
Standards Institute (NSF/ANSI) (NSF International 2013).
However, state-level plumbing codes may still require compliance with NSF/ANSI standards (VDHCD 2012).
NSF/ANSI 61 examines lead leaching from products that come
into contact with water intended for human consumption (NSF
International 2013). However, there has been considerable debate
regarding the protectiveness of the standard (Purkiss et al. 2011,
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2005), and recent studies identified lead-free plumbing (pre-2014
definition) as the likely source of elevated waterborne lead observed
at the tap in new schools and buildings (Elfland et al. 2010, Boyd
et al. 2008). In response to these problems, sections of the NSF/
ANSI testing protocols were updated, and allowable lead-leaching
thresholds were reduced (Sandvig et al. 2012, Triantafyllidou et al.
2012). Despite improvements, there is still concern regarding characteristics of synthetic waters outlined in NSF/ANSI 61, which are
inherently nonaggressive (Triantafyllidou & Edwards 2007).
Triantafyllidou and Edwards (2007) examined lead release from
brass exposed to more aggressive water (pH = 7.4, alkalinity of
10 mg/L as calcium carbonate [CaCO3]) and observed that lead
concentrations were 10 times higher than from brass exposed to
the Section 9 (of NSF/ANSI 61) test water. These findings are consistent with an NSF/ANSI 61 benchmarking study, which documented that brass exposed to the most aggressive water collected
from a municipality (pH of 4.9, alkalinity of <5 mg/L as CaCO3)
released lead concentrations nine times higher than the NSF/ANSI
test water (Sandvig et al. 2012). This municipality supplied water
from an untreated groundwater source and did not use corrosioncontrol chemicals such as orthophosphate. Although this water
chemistry would be considered unlikely for municipal water systems, untreated, aggressive groundwater supplies are common
sources for private systems.
Approximately 15% of US residents rely on private water
systems (i.e., systems with <15 service connections and serving
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an average of <25 individuals for at least 60 days/year), which
are not regulated by USEPA and not subject to the standards
outlined in the SDWA (USEPA 2013). State surveys report that
18–44% of private systems have a pH below the USEPA recommended 6.5 with measurements as low as 4.8 (Pieper et al. 2015,
Swistock et al. 2013, New Jersey Department of Environmental
Protection 2008), and a survey of homeowners in Virginia
observed that only 5% of systems had acid neutralizers installed
(Pieper et al. 2015). Not surprisingly, given such aggressive
waters, 12–19% of private systems exceed the USEPA lead action
level of 15 µg/L with concentrations as high as 24,740 µg/L
(Pieper et al. 2015; Swistock et al. 2013, 1993).
The goal of this research was to evaluate the protection offered
by the NSF/ANSI 61 Section 9 testing protocol to consumers
reliant on private systems, because the synthetic water used in
Section 9 to evaluate end-point devices (i.e., components installed
within the last 1 L of a system) has a pH of 8.0 and alkalinity of
500 mg/L as CaCO3 (NSF International 2013). The specific objective of the study was to quantify lead-leaching potential from
brass and galvanized steel meeting the lead-free requirements,
following exposure to aggressive water conditions that are more
consistent with water quality observed in private water systems.
Information developed from this effort will define risks related
to waterborne lead in private systems and provide insights into
the protection offered to private system homeowners.
METHODS
Water quality conditions. The Virginia Household Water Quality
Program is a Virginia Cooperative Extension drinking water
outreach program (www.wellwater.bse.vt.edu; Pieper et al. 2015)
that has offered private system homeowners low-cost water quality testing for contaminants for more than two decades. Relative
to the current NSF/ANSI test water of pH 8.0 and alkalinity
500 mg/L as CaCO3, 94% of private systems water samples had
a pH below 8.0, and 99.4% had an alkalinity below 500 mg/L
as CaCO3. To evaluate lead release from plumbing components
under conditions more representative of private water quality,
testing conditions were developed on the basis of this historical
extension data (Table 1). Population percentiles were used to
determine water quality conditions as alkalinity and pH were
highly correlated (Spearman’s rank test, r = 0.69, p < 0.05). Hardness was set at a constant level of 100 mg/L as CaCO3 (added as
calcium chloride) in keeping with the NSF/ANSI protocol. A
chlorine residual was not included in any water conditions,
including the NSF/ANSI synthetic water, because continuous
disinfection treatment devices are rarely installed in private systems (Pieper et al. 2015, Swistock et al. 2013).
Pre-2014 lead-free brass coupons. As of January 2014, C36000
brass is no longer permitted in new construction or repairs of
drinking water infrastructure because this brass alloy contains
2.5–3.7% lead, which exceeds the RLDWA threshold. However,
as components composed of this brass are still present in households constructed before January 2014, it is important to evaluate lead leaching from C36000 brass to fully understand waterborne exposure. Brass coupons (3.5% lead [Pb]) of 12.7 mm
(0.50 in.) diameter and 12.2 mm (0.48 in.) height were epoxied
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to the bottom of 125-mL glass vials (Figure 1, part A), which
maintained the ratio of brass surface area to water observed in
faucets (Triantafyllidou & Edwards 2007). Because C36000 brass
was expected to have the highest lead release, brass coupons were
exposed to all eight water conditions (A–H).
Post-2014 lead-free brass coupons. The RLDWA reduced the
allowable lead content in plumbing components from no more
than 8% by weight to less than 0.25% lead for a component
composed of a single material. To evaluate lead release from leadfree brass alloys manufactured after 2014, C87850 brass coupons
(<0.09% Pb) were epoxied to the bottom of 125-mL glass vials
(Figure 1, part B). Since C87850 brass contains low levels of lead,
these coupons were exposed only to the three most aggressive test
water conditions (F–H). In addition, these coupons had double
the exposed surface area compared with C36000 brass coupons
as a result of their shape.
Post-2014 lead-free faucet connectors. For multi-component
fittings and fixtures, the RLDWA requires a weighted average of
less than 0.25% lead with respect to the wetted surfaces. Therefore, components within a fitting/fixture can contain lead, but
their wetted surface area must be relatively small. To illustrate,
lead-free faucet connectors can comply with this new regulation
while containing C36000 brass ferrules with 3% lead as long as
the wetted surface area is less than 8.3% of the total, as this
allows the weighted average to be less than the 0.25% criteria.
To evaluate lead release from brass ferrules (1% Pb) within leadfree faucet connectors, 12.7 mm × 50.8 cm (0.5 in. × 20 in.)
braided stainless steel faucet connectors (Figure 1, part C) were
exposed to the three most aggressive test water conditions (F–H).
Each faucet connector was sealed at the bottom with a threaded
polyvinyl chloride cap, and a threaded polyvinyl chloride male
adapter was added to the top. The male adapter was covered with
parafilm for each period of stagnation.
Post-2014 lead-free galvanized steel nipples. Although galvanized steel is not typically installed in premise plumbing (e.g.,
components within the home), it is used for well components such
TABLE 1
Test water conditions developed on the basis of the
extension data set (1989–2009; n = 12,766)
Condition
Population
Percentile
pH
Alkalinitya
mg/L as CaCO3
Hardness
mg/L as CaCO3
A
94b (99.4c)
8.0
500
100
B
75
7.5
175
100
C
50
7.0
80
100
D
25
6.4
30
100
E
10
6.0
15
100
F
5
5.7
10
100
G
1
5.2
5
100
H
0.01
4.0
0
100
CaCO3—calcium carbonate
aThe
precision of the alkalinity measurements was ±5 mg/L (Standard Methods 1998), which
may have influenced the accuracy of more aggressive water conditions (E–H).
bPercent of private system water samples with a pH <8.0.
cPercent of private system water samples with an alkalinity <500 mg/L as CaCO .
3
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as drop pipes and well casings. Such well components would
typically be certified under NSF/ANSI 61, Section 4 (evaluation
of pipes and related products), but galvanized steel was included
in this experiment because of the aggressive water and lack of
corrosion control observed in private well systems. To quantify
lead release from the zinc–lead galvanized coating of galvanized
steel, 12.7-mm- (0.50-in.-) diameter, schedule 40 galvanized steel
nipples were evaluated (Figure 1, part D). Because these lead-free
components were manufactured after 2014, nipples (0.1% Pb)
were exposed to the three most aggressive test water conditions
(F–H) as well as the NSF/ANSI test water condition (A) to serve
as a control. Each nipple was sealed at both ends with a threaded
polyvinyl chloride cap.
NSF/ANSI 61 Section 9 testing protocol. To evaluate lead-leaching
potentials, each test apparatus was exposed to its water quality
conditions using a static dump-and-fill method, and all testing
was done in triplicate. In accordance with the NSF/ANSI protocol, each apparatus was subjected to varying periods of stagnation
(2–64 h) for 19 days with lead quantified on days 3, 4, 5, 10, 11,
12, 17, 18, and 19. All test containers were filled completely with
water to exclude air. For quality assurance/quality control purposes, an epoxy control test bottle was exposed to the NSF/ANSI
water (A) without any brass. Lead samples were analyzed via
inductively coupled plasma–mass spectrometry per Method 200.8
(Standard Methods 1998).
Spike and recovery to examine sorption. To understand potential
lead leaching from the galvanized coating, the galvanized steel
nipples were exposed to their water quality according to the NSF/
ANSI 61 Section 9 protocol, but lead was quantified only on day
FIGURE 1
A
19. Since observed lead release was lower than expected on the
basis of observed zinc concentrations and lead content, additional
testing was conducted to determine whether the galvanized coating could adsorb lead released by corrosion and accumulate the
lead in scale. Each water condition (A, F–H) was spiked with an
initial concentration of 100 µg/L soluble lead. Any decrease in
lead from this initial value demonstrated uptake of lead in water
by the plumbing material and accumulation in the scale. As
before, each test nipple was exposed to its water quality condition
using a static dump-and-fill method, and lead was quantified
following 16-h overnight stagnation (day 20).
NSF/ANSI 61 Section 9 Q statistic. NSF/ANSI 61 Section 9 certifies lead-leaching potentials from endpoint devices using an
evaluation criterion known as the Q statistic (NSF International
2013). The Q statistic is a calculation of the upper 90% confidence interval of the 75th percentile, which is used to determine
a component’s lead contribution to a 1-L sample and acceptability of the product line:
–
Q = eY ek1S(1)
–
where Y is the log-dosage mean of the normalized lead concentrations (i.e., observed concentrations normalized to 1 L), S is
the log-dosage standard deviation of the normalized lead concentrations, and k1 is an NSF/ANSI coefficient determined by
the number of replicates. As of July 2012, the Q statistic was
lowered to a threshold of 3 µg/L for supply stop, flexible plumbing connectors, and miscellaneous components, and 5 µg/L for
all other endpoint devices, except commercial kitchen devices.
NSF-certified lead-free testing apparatuses
B
C
D
Pb—lead
A
B
C
D
3.5% Pb C36000 brass coupon epoxied in a 125-mL glass vial
<0.25% Pb C87850 brass coupon epoxied in a 125-mL glass vial
<0.25% Pb faucet connector sealed at the bottom with a threaded polyvinyl chloride cap and a threaded polyvinyl chloride male adapter added to the top
<0.25% Pb galvanized steel nipple sealed at both ends with threaded polyvinyl chloride caps
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With a Q statistic threshold of 3 or 5 µg/L, endpoint devices can
contribute 3 or 5 µg lead to a 1-L first-draw sample.
RESULTS
Effect of pH and alkalinity on leaching. C36000 brass coupons
were exposed to the eight water conditions with pH and alkalinity ranging from 4.0 to 8.0 and 0 to 500 mg/L as CaCO3.
In keeping with previous observations (Sandvig et al. 2012,
Triantafyllidou & Edwards 2007), lead leaching from C36000
brass increased following exposure to more aggressive water
(Figure 2). Brass coupons exposed to water conditions E–H
released lead concentrations that exceeded the USEPA action
level of 15 µg/L in the 125-mL samples throughout the 19-day
experiment, while lead concentrations in samples exposed to
conditions A–D decreased below 15 µg/L during the last week
of the experiment. On days 17–19, mean lead release was four
to 17 times higher from brass exposed to conditions E–H
compared with condition A (Figure 3).
As the NSF/ANSI testing protocol evaluates a component’s
contribution to a 1-L sample, results were normalized to a 1-L
volume (i.e., multiplied by a correction factor of 0.125), and Q
statistics were calculated via Eq 1. All normalized lead measurements were below 15 µg/L during the last week of the experiment,
with concentrations ranging from <1 to 13.1 µg/L. On the basis
FIGURE 2
Mean Lead Concentration in 125 mL—µg/L
1,000
of the lead leaching observed during the 19-day experiment and
the variation between the triplicates, brass coupons exposed to
the NSF/ANSI test water (condition A) had a Q statistic of 2.3,
which was less than the Q threshold of 5 for NSF/ANSI 61 certification. While conditions B–D also had Q statistics less than 5,
conditions E–H did not (Q = 5.1–28.9; Table 2). Therefore, brass
exposed to water with a pH less than 6 and alkalinity less than
15 mg/L as CaCO3 (conditions E–H) would be expected to release
lead concentrations above 5 µg in the 1-L first draw of water.
Effect of reducing allowable lead content on single-material components. C87850 brass coupons were exposed to the three most
aggressive water conditions (F–H) with pH and alkalinity ranging
from 4.0 to 5.7 and 0 to 10 mg/L as CaCO3. For the most aggressive condition (H), brass coupons only leached detectable lead
concentrations for the first two sampling days (days 3 and 4), and
mean concentrations never exceeded 15 µg/L in the 125-mL samples (maximum of 2.5 µg/L); nondetectable concentrations were
observed for remaining days (5 through 19). Nondetectable mean
lead concentrations were observed in all 125-mL samples collected
from conditions C and D. Not surprisingly, Q statistics were less than
5 for all conditions (Table 2). Therefore, when exposed to even the
most aggressive water quality observed in private systems, lead-free
brass fittings manufactured after 2014 would not be expected to
release lead concentrations above 5 µg in the 1-L first draw of water.
Mean lead released from C36000 brass coupons exposed to water conditions with varying pH and alkalinity
Condition pH Alkalinity—mg/L
A
8.0
500
B
7.5
175
80
C
7.0
30
D
6.4
15
E
6.0
10
F
5.7
5
G
5.2
0
H
4.0
USEPA action level
100
10
1
3
4
5
10
11
Sampling Day
12
17
18
19
USEPA—US Environmental Protection Agency
Error bars denote 95% confidence intervals.
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FIGURE 3
Effect of reducing allowable lead content on multi-component
fittings. To evaluate potential lead leaching from multi-component
fittings, faucet connectors with C36000 brass ferrules (1% Pb)
were exposed to the three most aggressive conditions (F–H). In
the 30-mL water samples collected, the brass ferrules exposed to
conditions G and H leached lead above the action level throughout the experiment, with mean concentrations ranging from 28
to 673 µg/L (Figure 4). Mean lead results from brass exposed to
condition F were above the USEPA action level in all samples
except on day 19, which measured 13.9 µg/L. When normalized
to a 1-L sample, lead concentrations were below 15 µg/L for all
samples exposed to conditions F and G (maximum normalized
mean lead was 3.5 µg/L), and Q statistics were less than 3 µg/L
(Table 2), with mean lead leaching on a downward trend. However, this was not observed for condition H, which had a Q statistic of 24.6 µg/L because the normalized lead results were still
elevated with concentrations as high as 20.2 µg/L. Condition H
(pH 4.0, alkalinity of 0 mg/L) represents the most aggressive
water documented in the historical extension data set and is
considered the worst-case scenario (i.e., cistern water).
Adsorption of lead to iron scale. Galvanized steel nipples were
exposed to the three most aggressive conditions (F–H) and the
NSF/ANSI test water (A), with lead concentrations only quantified on day 19. Despite having 0.1% lead in the galvanized coating, galvanized nipples exposed to conditions F–H released lead
concentrations ranging from 4.2 to 14.4 µg/L in the 30-mL
samples, and nipples exposed to NSF/ANSI test water (A) released
nondetectable lead concentrations (<1 µg/L; Figure 5). The galvanized nipples tested had Q statistics less than 5 µg/L for all
conditions (Table 2). Although lead release from C36000 brass
coupons was highest when exposed to condition H (pH 4.0,
alkalinity of 0 mg/L), lead release from galvanized nipples was
highest when exposed to condition F (pH 5.7, alkalinity of 10 mg/L).
Furthermore, this finding was not consistent with zinc leaching
Mean lead released on days 17–19 from C36000
brass coupons under each water condition
Condition
A
B
C
D
E
F
G
H
pH
8.0
7.5
7.0
6.4
6.0
5.7
5.2
4.0
Alkalinity—mg/L
500
175
80
30
15
10
5
0
Mean Lead on Days 17–19 in 125 mL—µg/L
140
120
100
17
80
60
40
6
4
20
2
0
A
2
B
4
2
C
D
E
F
G
H
Condition
More Aggressive Water
NSF/ANSI—NSF International/American National Standards Institute
Increases in release relative to the standard NSF/ANSI test water are
shown at the left of each column.
Error bars denote 95% confidence intervals.
TABLE 2
Observed lead concentrations on day 19 and calculated Q statistics for NSF/ANSI lead-free certification
3.5% Pb
C36000 Brass Coupon
<0.25% Pb
C87850 Brass Coupon
<0.25% Pb
Faucet Connector
<0.25% Pb
Galvanized Steel Nipple
Test
Water
Day 19a
Pb—µg/L
Q statistic
µg/L
Day 19a
Pb—µg/L
Q statistic
µg/L
Day 19b
Pb—µg/L
Q statistic
µg/L
Day 19b
Pb—µg/L
Q statistic
µg/L
NSF
4.4
2.3
—
—
—
—
BDLc
<0.1
B
10.0
4.1
—
—
—
—
—
—
C
7.4
2.2
—
—
—
—
—
—
D
11.0
3.0
—
—
—
—
—
—
E
20.7
5.1
—
—
—
—
—
—
F
18.2
7.3
BDLc
0.2
13.9
1.3
14.4
1.7
G
32.2
13.9
BDLc
<0.1
27.8
1.2
8.2
3.1
H
70.1
28.9
BDLc
<0.1
540.4
24.6
4.2
1.1
BDL—below detection limit, NSF/ANSI—NSF International/American National Standards Institute, Pb—lead
aSample
volume of 125 mL (before being normalized to 1 L)
volume of 30 mL (before being normalized to 1 L)
of 1 µg/L
bSample
cBDL
A dash indicates that the condition was not tested.
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FIGURE 4
Mean lead released from lead-free faucet connectors
Condition
pH
Alkalinity—mg/L
F
5.7
10
5
G
5.2
H
4.0
0
USEPA action level
Mean Lead Concentration in 30 mL—µg/L
1,000
100
10
from the galvanized coating as zinc concentrations increased as
the pH decreased and the conditions became more aggressive. It
was hypothesized that these inconsistent observations were due
to the adsorption of lead to the iron pipe and/or scale, which has
been documented in previous literature (De Rosa & Williams
1992). Therefore, to assess this theory, the galvanized nipples
were exposed to their corresponding water conditions for an
additional day (day 20), but in this case, each condition was
spiked with a concentration of approximately 100 µg/L lead to
quantify lead recovery and evaluate adsorption (Figure 6).
A surprising degree of lead “removal” was actually adsorption
by the plumbing materials, and the extent of this observed uptake
was a function of the pH, which is in keeping with the strong
sorption of lead to iron rust in the 4.0–8.0 pH range (Figure 7;
Masters & Edwards 2015, Snoeyink & Wagner 1996). For example, the highest mean lead concentrations were observed in condition F samples (40% average recovery; Figure 6) and lowest mean
concentrations in condition H samples (17% average recovery).
When exposed to the NSF/ANSI test water (A), only 6% of the
lead was recovered. This highlights the potential limitations of a
short-term, 19-day NSF/ANSI experiment in evaluating long-term
health risks to consumers as lead sorbed to iron scale is likely to
later release. While there are no data describing the extent of
1
4
5
10
11
12
Sampling Day
17
18
19
FIGURE 6
Mean lead recovery and zinc leaching from
galvanized steel nipplesa
USEPA—US Environmental Protection Agency
Initial Pb spike
Lead recovered
Zinc
Error bars denote 95% confidence intervals.
FIGURE 5
Mean lead and zinc released from galvanized steel
nipples on day 19
Condition
A
F
G
H
pH
8.0
5.7
5.2
4.0
Alkalinity—mg/L
500
10
5
0
300
30
250
25
200
20
150
15
100
10
50
5
0
A
F
G
Condition
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H
0
Mean Zinc Concentration in 30 mL—mg/L
Mean Lead Concentration in 30 mL—µg/L
35
Mean Lead Concentration in 30 mL—µg/L
120
Lead
Zinc
Condition
A
F
G
H
pH
8.0
5.7
5.2
4.0
Alkalinity—mg/L
500
10
5
0
350
300
100
250
80
200
60
150
40
100
20
0
50
A
F
G
H
Mean Zinc Concentration in 30 mL—mg/L
3
0
Condition
Pb—lead
aOn
day 20 after being spiked with 100 µg/L of soluble lead
Error bars denote 95% confidence intervals.
The recovery indicates the lead in water that is released from galvanized
steel to the water, as well as the fraction of the lead spike that was not
removed from water.
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FIGURE 7
A
NSF-certified lead-free galvanized steel nipples
exposed to water conditions A and F–H for 19 days
F
G
H
Condition
Red-orange scale is starting to form on nipples exposed to condition
G and is visible on nipples exposed to condition H.
galvanized pipe used in private systems, anecdotally, wells greater
than 180 m (600 ft.) in depth require a stronger drop pipe material and often rely on galvanized steel. Depending on the geology
and/or well driller’s preference, the well casing pipe can also be
galvanized steel. Present understanding of the impact of galvanized steel on lead concentrations at the point of homeowner use,
particularly over time, is not understood.
DISCUSSION
Potential underestimation of lead leaching via NSF/ANSI
certification. The high levels of lead observed in the 30-mL samples
collected from faucet connectors illustrate potential issues associated with the normalization factor currently used for the NSF/
ANSI 61 Section 9 certification. The maximum mean lead released
from faucet connectors exposed to condition G was 3.5 µg/L when
normalized to a 1-L volume, but was 13.9 µg/L when normalized
to a 250-mL volume (i.e., four times higher because of ¼ volume).
The Q statistics for condition G when normalized to a 250-mL and
1-L volume were 5.8 and 1.45, respectively. Therefore, there is a
potential for exposure to elevated waterborne lead concentrations
(i.e., ≥3 µg/L for a faucet connector) if smaller volumes are ingested,
despite components satisfying the Q statistic. This is important
because the USEPA recommends 250-mL first-draw samples in the
3Ts for Reducing Lead in Drinking Water in Schools sampling
protocol, since this volume is more representative of a serving
consumed by a child (USEPA 2006). Furthermore, the NSF/ANSI
protocol only considers a single component’s contribution to the
1-L sample. If several lead-free components are in series and are
releasing low levels of lead (i.e., 1–5 µg/L), there is potential for
elevated waterborne lead concentrations at the tap. Further evaluation should be conducted to understand the potential cumulative
effect of lead-free components that are in series and lead concentrations at the tap when smaller sample volumes are collected. In
addition, allowable Q statistic thresholds should be reevaluated to
be consistent with current knowledge regarding adverse health
effects of lead in water at low concentrations (Lanphear et al. 2005,
Canfield et al. 2003).
Private system homeowners potentially at risk in Virginia. Roughly
10% of the private systems in Virginia are supplied by water with
a pH less than 6.0 and alkalinity less than 15 mg/L as CaCO3,
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which means that one in 10 homes may potentially be at risk for
exposure to elevated lead release (≥5 µg/L) from C36000 brass
in their drinking water, assuming they have yet to upgrade to the
post-2014 “lead-free” components. With integration of new leadfree brass components manufactured after 2014, all homeowners
reliant on private systems should be sufficiently protected; i.e.,
fittings and fixtures manufactured after 2014 are sufficiently
protective for approximately 99% of private system homeowners.
However, caution should be taken with systems having a pH of
4, alkalinity of 0 mg/L (i.e., cistern water). Lastly, the risks of
waterborne lead exposure from galvanized steel requires further
evaluation because there is concern with the sorption of lead to
iron scale and potential for remobilization.
Plumbing regulations for private water systems. Although this
paper focuses on the potential issues associated with third-party
certification to NSF/ANSI 61, it is important to discuss the ambiguity associated with codes and regulations that prevent waterborne lead exposure for private system users. Although the 1986
Lead Ban required the use of lead-free plumbing, this regulation
specifically stated “any plumbing . . . which is connected to a
public water system” (USEPA 1989). As a result, it appears that
the use of leaded and pure-lead well components was discontinued around 1995 because of concerns regarding lead leaching
from submersible pumps (Minnesota Department of Health 2014,
CDC 2010, Maas et al. 1998, USEPA 1994). This phrase has since
been removed, and Section 1417 of the SDWA (i.e., the Lead Ban
and RLDWA) mandates the use of lead-free plumbing in installation or repair of “any plumbing in a residential . . . facility
providing water for human consumption” (USEPA 2002). However, it is at the discretion of the state to define the bounds of a
“residential facility” and enforce this regulation. Multiple state
agencies are therefore responsible for the oversight of private well
water distribution systems (Figure 8), which may be problematic
if there is insufficient coordination.
The Virginia Department of Housing and Community
Development oversees the Virginia Uniform Statewide Building
Code, which requires lead-free components in the premise plumbing (VDHCD 2012). The Virginia Department of Health enforces
the Virginia private well regulations that delineate well construction standards (e.g., depth of casing and grouting) and setback
minimums relative to sources of contamination, which aim to
minimize surface water and bacterial contamination (Virginia
Department of Health 1992). The Virginia Department of
Professions and Occupations Regulation requires licensing and
vocational training to become a certified Water Well Systems
Provider for water well and pump contracting (VDPOR 2016).
Unfortunately, these agencies do not regulate or enforce the installation of lead-free plumbing within the well (e.g., drop pipe, pump).
However, the Virginia Well Water Association, a nonprofit organization consisting of local well drillers across the state, promotes
best drilling practices in Virginia and voluntarily complies with the
RLDWA. It is important to emphasize that this collaborative situation may not be present in all states, as some states still do not
have statewide private well regulations (Department of
Environmental Conservation 2016; Swistock et al. 2013). Therefore, further examination is needed to understand the regulatory
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Regulatory oversight of private wells in Virginia
Private
well
Premise
plumbing
FIGURE 8
Building and plumbing
codes (DHCD)
Lead banc,d/RLDWAd
NSF/ANSI 61f
Best drilling practices (VWWA)a
State well regulations (VDH)b
Contractor license (DPOR)e
DHCD—Department of Housing and Community Development,
DPOR—Department of Professional and Occupational Regulation,
NSF/ANSI—NSF International/American National Standards Institute,
RLDWA—Reduction of Lead in Drinking Water Act, VDH—Virginia
Department of Health, VWWA—Virginia Water Well Association
a 1949: The VWWA
was established.
enacted regulations that addressed siting and
construction of private wells but did not regulate the plumbing
components in the well.
c 2002: Section 1417 of the Safe Drinking Water Act was updated and the
phrase “which is connected to a public water system” was removed.
d The definition of “residential facility” was left to the discretion of the
state agency regulating the plumbing network.
e 2007: The DPOR required licensing and training for a Water Well
Systems Provider for water well and pump contracting.
f 2014: The RLDWA no longer required lead leaching certification to
NSF/ANSI 61.
b 1990: The VDH
framework addressing waterborne lead exposure in private
systems and the challenges and barriers associated with protecting this population.
CONCLUSION
Lead leaching from plumbing components meeting the lead-free
requirements was evaluated following exposure to waters representative of water quality observed in private systems. Results
indicate the following:
•• C36000 brass coupons exposed to more aggressive water
(i.e., lower pH and alkalinity) present in private systems
leached higher lead concentrations than those commonly
used in public water systems. Unless homeowners construct
or repair their plumbing networks, older lead-free fittings
(i.e., <8% lead) can serve as sources of waterborne lead.
Therefore, further outreach efforts should focus on communicating the importance of water quality testing for waterborne metals to all homeowners with systems constructed
before 2014.
•• The RLDWA reduced the allowable lead content in leadfree components, which appears to improve protection
for private system homeowners. Even when exposed to
extremely aggressive conditions, nondetectable concentrations were released from lead-free brass coupons.
Although lead-free, multi-component fittings and fixtures
may still contain leaded materials if the wetted surface
area is relatively small, these fittings are expected to keep
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lead in water concentrations at <3 µg/L in systems with
a pH greater than 5.2.
•• Despite the reduction in allowable lead content as of 2014,
there is still a potential for elevated waterborne lead concentrations at the tap if smaller volumes are collected, and/or
several lead-free components in series are releasing low levels
of lead (i.e., 1–5 µg/L).
•• Lead appeared to adsorb to the iron pipe and/or scale when
galvanized nipples were exposed to aggressive water conditions. When water conditions were spiked with 100 µg/L
soluble lead, only an average of 6–40% initial lead was
recovered. While the short-term NSF/ANSI 61 testing did not
indicate an issue with lead release from these components, it
is expected that there would eventually be mobilization of
particulate lead. Additional testing of galvanized materials
used in private wells is recommended under NSF/ANSI 61
Section 4 and Section 8 (evaluation of in-line devices), which
stimulates different sampling protocols and synthetic water
chemistries. However, as before with Section 9, the Sections
4 and 8 test water conditions should be modified to represent
actual conditions observed in private systems (e.g., no use of
corrosion inhibitors).
ACKNOWLEDGMENT
This research was supported through a Virginia Tech Graduate
Research Development Program grant. The authors would like
to thank Jordan Wetzig and Matt Razaire for their assistance with
sampling, and the Virginia Household Water Quality Program
for providing data for the setup of this study. The authors thank
Virginia Department of Health, the Virginia Department of
Housing and Community Development, and the Virginia Well
Water Association for their assistance with regulatory standards.
Lastly, the authors would like thank the Journal AWWA reviewers for their time and feedback.
ABOUT THE AUTHORS
Kelsey J. Pieper is a postdoctoral fellow in
the Civil and Environmental Engineering
Department at Virginia Polytechnic
Institute and State University (Virginia
Tech), 481 Durham Hall, 1145 Perry St.,
Blacksburg, VA 24061 USA; kpieper@vt.
edu. She received her BS degree in
mechanical engineering at Binghamton
University, Binghamton, N.Y. She received her MS degree in
civil engineering and PhD degree in biological systems
engineering at Virginia Tech. Leigh-Anne Krometis is an
assistant professor in the Department of Biological Systems
Engineering at Virginia Tech. Marc Edwards is the Charles
P. Lundford Professor in the Department of Civil and
Environmental Engineering at Virginia Tech.
PEER REVIEW
Date of submission: 01/07/2016
Date of acceptance: 04/19/2016
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Peer-Reviewed
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