United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-88/066 Mar. 1989
x°/EPA Project Summary
Proposed Test Protocol to
Determine Toxicant
Leaching into Potable Water
Ronald Rossi, Craig R. Turner, and Dipak K. Basu
A simple apparatus was con-
structed from Teflon* to test
teachability of contaminants. Plates
coated with coal-tar-based mate-
rial were placed In the Teflon test
chamber of the apparatus, and water
of controlled parameters was con-
tinuously passed through the
chamber at a velocity of 2 L/min for a
period of 24 hr.
The test apparatus was unique in
its ability to perform an accelerated
leaching test under flowing water
conditions. These tests showed
migrations of various component
polynuclear aromatic hydrocarbons
(PNA) with no detectable aging effect
in three successive 24-hr leachates
in results that fell in the range of 30
to 400 pg/L.
The possibility of PNA migration
from the coal-tar-based material
lining pipes in the field was tested at
three utilities. No quantitative corre-
lation could be established between
the leaching observed under labora-
tory and field tests. However, the
leaching pattern from the field pipes
can be quantitatively explained from
the results of laboratory leaching
tests.
This Project Summary was devel-
oped by EPA's Risk Reduction Engi-
neering Laboratory, Cincinnati, OH, to
announce key findings of the
research project that Is fully docu-
* Mention of trade names or commercial products
does not constitute endorsement or recom-
mendation for use.
mented In a separate report of the
same title (see Project Report
ordering information at back).
Introduction
Potable water used by large segments
of the U.S. population is exposed to
direct and indirect additives. The direct
additives are chemicals that are
deliberately added during the treatment
of raw water for coagulation, softening,
corrosion control, disinfection, fluorida-
tion, and other purposes. As a result,
finished water may contain both intended
and unintended residuals from direct
additives. Indirect additives are defined
as contaminants that are inadvertently
introduced into the potable water through
paints, coatings, liners, sealants, pumps,
and other items used during storage and
distribution of potable water to con-
sumers. The change in potable water
quality as a result of the presence of
direct and indirect additives necessitates
an evaluation of the possible health
hazards arising from these additives.
Through a memorandum of under-
standing signed by the U.S. Food and
Drug Administration and the U.S.
Environmental Protection Agency (EPA)
in 1979, the responsibility for monitoring
and controlling these additives was
vested in EPA (44FR42775, July 20,
1979). As one of the initial steps towards
meeting this responsibility, EPA, in
cooperation with the National Research
Council, produced a Water Treatment
Chemicals Codex for direct additives
only. The Codex recommends a mini-
mum acceptable purity specification as it
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related to health for about 25 commonly
present additives in potable water.
Indirect additives, on the other hand,
have been monitored through a voluntary
program and through the issuance of
advisory opinions by EPA or its
predecessor agencies. Obstacles to the
development of a safety evaluation
program for indirect additives include a
lack of established maximum contami-
nant levels in several instances, absence
of suitable laboratory simulation data and
field studies, and the lack of a general
consensus regarding the target param-
eters to be monitored as indicators of
indirect additives. The present investi-
gation was undertaken to provide support
for Codex development methodology for
indirect additives. The purpose of this
research was (1) to develop a compre-
hensive and realistic laboratory test
protocol that would simulate contaminant
migration from coal-tar-based mate-
rials similar to those that line potable
water pipes and tanks in the field, and (2)
to correlate the laboratory test results
with actual field studies. Coal-tar-
based materials were used to represent
sources of secondary additives for
developing the test protocol because
leachates from these materials are
known to contain a large number of
compounds, some of which are sus-
pected to be carcinogenic.
Experimental
Laboratory Apparatus
The laboratory leaching apparatus was
fabricated and assembled inhouse. It
consisted of four parts: (1) a leaching
compartment of Teflon having a well
20-1/2 by 1-1/2 by 9/20 in. in the
midsection and a removable Teflon top
plate for the insertion of test plates; (2)
Teflon connecting fittings and tubes; (3)
a variable speed circulating pump with all
Teflon wetable parts; and (4) a flowmeter.
A diagram of the laboratory apparatus is
shown in Figure 1.
Test plates were fabricated from a
stainless steel sheet 0.05 in. thick. Each
plate had a dimension of 20 x 1.5 in.
These plates were sand-blasted before
being coated. Each plate was cleansed
with purified deionized distilled water
(DDW) and acetone and was dried before
the application of the coating material. A
one-coat Bitumastic Super Tank
Solution (Type I) was used in the
experiments as a coating system. The
test plates were coated with the
suction-feed spraying system at a
delivery pressure adjusted to about 60
psi at the gun, as recommended by the
manufacturer of the coating material.
Two coats of the coating material were
evenly applied on both sides of the test
plates. The test plates were air dried for
10 days and those plates with total dry
thickness ranging from 0.040 to 0.060 in.
were selected for further leaching tests.
The leaching test with coated plates
began by pre-exposing the plates in a
solution of sodium hypochlorite con-
taining 50 ppm of free chlorine at a pH of
10.5. The plates were allowed to stand in
this solution overnight and were
subsequently washed with purified DDW.
Two plates were placed inside the
leaching compartment, and it was sealed.
The compartment was filled with test
water of controlled parameters, and the
flow rate of the circulating water was
maintained at the desired value. The
entire leaching apparatus was transferred
to an environmental chamber where the
temperature at which the test was
conducted could be controlled. It was
experimentally determined that for a flow
rate of 2 L/min, the temperature of the
environmental chamber had to be set at
12.8°C for the circulating water to attain
an equilibrium temperature of 21.5°C
and at 25.6 °C to attain a temperature of
28.5°C. The system was allowed to
for the desired length of time.
At the end of the run, all of the w
from the leaching apparatus was drai
into a measuring cylinder. An aliquc
the water ( = 70 mL) was kept sepa
for performing alkalinity, hardness,
and residual chlorine tests. The resii
leachate was solvent extracted \
methylene chloride (6 mL of methyl
chloride for every 100 mL of water).
extract was concentrated to a f
volume of 1 mL using a Kuderna-Dai
apparatus and subsequent blowdi
using prepurified N2 gas at 30 °C.
Field Sampler
The field sampler consisted of
following three main components: (1)
containing a two-stage resin coli
system; (2) variable water pumping
consisting of a Masterflex pump i
appropriate pumpheads and f
controller; and (3) flowmeter. Chroma
extender-type columns of 150 x 25 x
mm were used to hold the resin bed.
resin bed consisted of equal volumes
XAD-2 and XE-348 resins separa
by glass wool. The length of the s<
resin bed was set at 13 cm. The end
the Chromaflex columns were plug
Flowmeter
Pyrex®/Teflon® _ Ajf B,egd
Stopcocks,{.
Teflon®
Tubing
Teflon®
Teflon®
.
Teflon® Male Fitting
Male Fitting Steel Plate Leaching Compartment
Figure 1. Schematic diagram of leaching apparatus (not to scale).
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with clean glass wool and were
connected to two tapered column
adaptors by "0" rings and clamps. Two
such resin columns were connected in
parallel to the water to be sampled
through a Pyrex glass Y-tube. The other
end of the column was connected
individually to a variable Masterflex
pump. The pump units with their flow
controllers allowed water to pass through
the resin bed at the desired rate. The
outlets of the pumps were connected to
calibrated flowmeters to measure the
flow rate that was maintained at 40
mL/min. The effluent water was collected
in calibrated collapsible plastic carboys.
Measurement of the total water collected
in each carboy over a known period of
time permitted the gross water flow rate
through the resin beds to be estimated.
All connections along the different
components were made with the
custom-made 8-mm Pyrex glass tub-
ing of convenient shape and length, and
minimum lengths of Tygon tubing were
used for interconnecting the Pyrex glass
tubing.
Field Sampling Analyses
Potable water samples from three
water supply systems on the West Coast
of the United States were analyzed as
ield samples. The rationale for selecting
these systems was that they represented
three large public water utilities and all
contained transmission pipes lined with
coal-tar-based material. The expected
occurrence of secondary additives in this
water make it well suited to test whether
or not the designed laboratory leaching
apparatus, upon which the proposed test
protocol is based, could be successfully
used.
At each water supply, water samples
were collected at three points. The first
point was the water at the treatment plant
before it was exposed to lined trans-
mission pipes or tanks. The second and
third sampling points were near the
beginning and near the end of a
transmission system that had pipes lined
with coal-tar-based materials.
The sampling unit was transported to
each sampling location by packing the
individual components in suitcases. For
the convenience of transportation, the
Masterflex pumps with the flow-
controllers and pumpheads were carried
in a separate suitcase provided by the
manufacturer. A total of 20 L of water
was collected from each sampling point.
At the end of the sampling, the ends of
'he resin columns were sealed with
.jolyurethane foam plugs, parafilm, and
masking tape. The columns were
wrapped in aluminum foil, cooled with
non-wetable ice packs, and then
transported to the laboratory. In the
laboratory the resin beds were warmed
and separated, and only the XAD-2
portions were spiked with a known
amount of C14-fluorene. Only the
XAD-2 resins were subjected to the
elution method. The XE-348 beds
containing more polar compounds were
not further analyzed.
The XAD-2 resin bed was washed
with about 20 to 25 mL of acetone. The
vacuum from an aspirator removed
excess acetone from the resin bed. The
dry XAD-2 bed was removed to a clean
thimble, and the resin was Soxhlet-
extracted for 24 hr with methylene
chloride. The acetone wash was diluted
with purified DDW and extracted with
methylene chloride. The two methylene
chloride layers were combined and
concentrated to 1 mL for radioactive
counting and analysis using a gas
chromatography-mass spectrometry-
data system combination (GC-MS-
DS). Before the radioactive counting, a
solvent exchange of methylene chloride
to toluene was performed on 500 pL of
the above concentrated extract. The
collection efficiency of seven PNA's with
this sampling apparatus averaged 84% in
the laboratory.
To increase the sensitivity of the GC-
MS-DS analysis, several modifications
were made in the original system. The
injection port of the original packed
column GC was replaced according to
the manufacturer's instructions with an
on-column (capillary) injection system.
The interface of the exit end of the
column with the MS was also altered; the
jet separator and its associated
accessories were completely removed
and the exit end of the capillary column
was introduced directly into the ion
source. The conditions used for the
operation of the GC-MS were as
follows:
Analyzer
temperature:
MS delay:
Scan:
Scan time:
200°C
4 min following
sample injection
50 to up to 500 amn
1.2 sec/scan
Column:
Column
program:
30 m x 0.25 mm
DB-1 fused silica
capillary
50°C for 4 min;
8°C/min to 270°C;
Hold at 270 °C for 20
min
Carrier gas He
linear velocity: 35 to 45 cm/sec
Source
temperature: 170°C
In the specific ion mode, the parent ion
and two other fragment ions with the
highest intensities were monitored for a
period of 150 millisec each.
The performance characteristics of the
MS were verified by frequently injecting
50 ng decafluorotriphenylphosphine
(DFTPP) into the GC-MS system. When
the performance characteristics fell below
the recommended levels, the source of
the unacceptable performance charac-
teristics were corrected either by
cleaning the ion source, plugging pos-
sible leaks, or changing the sorbent traps
for the carrier gas.
The GC-MS system produced a total
ion chromatogram of each sample. Since
the chromatograms contained large
numbers of peaks, the MS data system
was used to identify the peaks and locate
the individual peaks when necessary.
The tentative identification of each peak
was by NBS Spectral Library search. The
final identification of a compound was
made by matching the relative retention
time (with respect to anthracene-d-io)
and the MS fragmentation pattern with an
authentic standard. A peak was quantified
by comparing its area with that of the
anthracene-dio internal standard. This
method of quantification assumes a linear
response of peak area with the
concentration.
Results and Discussion
The 24-hr laboratory leaching
experiments conducted with plates
coated with a coal-tar based material
and water of controlled parameters
(aggressive index, 8.6; free residual
chlorine, 3.3 ± 0.03; and temperature
21.5 ± 0.5°C) showed the migration of
the following components at the specified
concentrations (iig/L); indene, 73;
naphthalene, 36; quinoline, 213; indole,
45; acenaphthalene, 77; fluorene, 79;
phenanthrene/anthracene, 298; carba-
zole, 399; pyrene, 117; and triphenylene/
chrysene, 81. The results of three
consecutive 24-hr washings, each per-
formed to determined the aging effect of
the coated plates, failed to show any
difference in the concentrations of the
individual PNA's in the successive
leachates. The increase of residual
chlorine level in water from 0.93 to 3.3
mg/L, resulted in decreased concen-
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trations of some of the PNA's,
particularly the levels of phenanthrene/
anthracene, purene, and fluorene in the
leachates, possibly because of the
formation of more chlorinated PNA's at
higher chlorine level. No clear trend
resulting from the teachability of PNA's
was observed by changing the water
temperature from 21.5°C to 28.4°C.
Field test results of water collected
from one utility showed that the
concentrations of a few PNA's noticeably
increased as a result of finished water
passing through transmission pipes/tank
lined with coal-tar-based material. For
example, the concentration of indene,
fluoranthene, and pyrene increased from
0.12 pg/L, 0.06 pg/L, and none detected
to 0.17, 0.11, and <0.05 jig/L,
respectively. No noticeable difference in
the level of PNA's in water originating
from pipes lined with coal-tar-based
material was observed, however, when
compared with levels from the other two
utilities. This is probably because the
transmission pipe used for sampling
water in one utility was relatively new
( = 5 yr) and the transmission pipes in the
other two utilities were older ( = 10 years
old). Probably a difference of PNA
concentrations in the two other systems
would have been observed if the
detection limit for the PNA's had been
lower (<0.05 ng/L). No quantitative
correlation could be established between
the leaching observed under laboratory
and field tests. This is not surprising
considering that, among the many
differences between the two cases,
laboratory plates leach at about 4 orders
of magnitude higher than do the field
pipes. However, the leaching pattern
from the field pipes can be qualitatively
explained from the results of laboratory
leaching tests.
Summary and Conclusions
The Laboratory leaching apparatus and
the test protocol developed in the
present study have been successfully
used to determine the teachings of major
individual components from plates lined
with coal-tar-based material. The test
protocol was developed to identify and
quantify the major individual contam-
inants in the leachates. This is an
important improvement over the pre-
viously available protocols because it will
permit the assessment of possible health
hazards arising from the individual
leached components. The developed test
protocol accelerates the leaching of
components from coated surfaces and
permits measurement of the level of
major leachables in short-term leaching
tests.
The leaching study shows that PNA's
are the major contaminants that will leach
into water from surfaces lined with coal-
tar-based material. Evidence is pro-
vided that PNA concentrations in leach-
ates depend on the free residual chlorine
in the water and that an increase in
chlorine level will decrease the level of
some PNA's in the leaching water. The
study also demonstrates that short-term
laboratory leaching tests are not suitable
for studying the aging effect in the field
of pipes lined with coal-tar-based
materials.
Results of a few field tests with potable
water after their passage through pipes
lined with coal-tar-based material
demonstrate that no quantitative corre-
lation can be made between the
laboratory and field leaching tests. The
leaching of components from lined pipes
in the field will be about four orders of
magnitude lower than laboratory leaching
from coated plates. To establish the
possible PNA leaching in the field from
transmission pipes lined with coal-tar-
based material older than 5 yr, therefore,
the detection limit for PNA quantification
should be s50 ng/thousand liters. The
results of laboratory leaching tests are
useful in field tests aimed at predicting
and rationalizing the observed leaching
of contaminants from transmission pipes
lined with coal-tar-based material.
Recommendations
Based on our experience with the
present project, we recommend that the
following ideas be considered for imple-
mentation of further research:
1. Proper interlaboratory verification I
undertaken so that the test apparat
and the test protocol developed in tl
study can be used by EPA as
standard method for the approval
materials intended to be used
contact with drinking water.
2. The verified test protocol be used
identify and quantify the maj
individual components for subseque
toxicological testing to determii
which of those identified are causati
factors in leachates found to be toxic
3. The verified test protocol be used
further establish the effect of wal
quality parameters on the migration
contaminants into the water.
4. A guideline based on the toxicity
the individual contaminants I
established to specify the minimi.
acceptable detection limit of t
contaminants for the verified te
protocol.
5. Further research be conducted
verify the applicability of the prese
test protocol to other materials used
the transmission of potable water.
6. Further research be conducted
establish a possible correlate
between the leaching observed unc
laboratory conditions and those unc
field conditions.
The full report was submitted in f
fillment of Cooperative Agreement f>
CR-811083 by Syracuse Resear
Corporation, Syracuse, NY 13210-40*
under the sponsorship of the U.
Environmental Protection Agency.
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Ronald Rossi, Craig R. Turner, and Dipak K. Basu are with Syra. —
Corporation, Syracuse, NY 13210-4080.
Alan A. Stevens is the EPA Project Officer (see below). —"
The complete report, entitled "Proposed Test Protocol to Dete> I R;'K-J ^ /;'"!">jsi ~ fj 7 C !*
Leaching into Potable Water," (Order No. PB 89-125 9591 AS; "" v /: *' ~" " '"'"
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States Center for Environmental Research BULK RATE
Environmental Protection Information POSTAGE & FEES PAID
Agency Cincinnati OH 45268 EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S2-88/066
0000329 PS
M
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