United States
Environmental Protection
Agency
Municipal Environmental Research ^
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-054 Apr. 1984
&ER& Project Summary
Acid Precipitation and Drinking
Water Quality in the Eastern
United States
Floyd Taylor, Judith A. Taylor, George E. Symons, John J. Collins, and
Michael Schock
Research was conducted to provide
accurate, modern, and historical data
on drinking water quality and the
possible effects of acid precipitation on
water samples. Samples of raw source
and finished water were collected from
more than 270 surface water and
groundwater supplies in the New
England states. New York, New Jersey,
Pennsylvania, West Virginia, Virginia,
and North Carolina. The samples were
analyzed at U.S. Environmental
Protection Agency (EPA) laboratories.
The study used historical records dating
back to 1886.
Acid rain may dissolve harmful
elements from soils and, indirectly,
from water supply distibution systems.
Causal relationships are difficult to
identify, however, because soils can
alter the character of acid rain through
buffering. A helpful approach to this
problem is the use of indices of water
supply sensitivity and corrosiveness.
Reliable chemical data were used to
compare the water supply characteris-
tics with these indices and with drinking
water standards.
Although solution products of acid
rain do not exceed EPA primary
Drinking Water Regulations, in the
water supply sources studied, many
tests for aluminum showed levels that
could be of concern to patients using
kidney dialysis. Because of the low
alkalinity and pH observed at numerous
water sources, it is possible that future
acid deposition could have a
detrimental effect on water quality.
Quantification remains a problem,
however.
This Project Summary was developed
by EPA's Municipal Environmental
Research Laboratory. Cincinnati, OH,
to announce key findings of the
research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
From 1981 to 1983, the New England
Water Works Association undertook this
study with a three part program of water
sampling and analysis to learn about the
quality of drinking water in states
receiving acid precipitation. States
included in the first and second parts of
the study (Rounds 1 and 2) were Maine,
New Hampshire, Vermont, Massachu-
setts, Rhode Island, Connecticut, and
New York (Adirondack Mountain region
only). States included in the third part
(Round 3) were Massachusetts, New
Jersey, Pennsylvania, West Virginia,
Virginia, and North Carolina.
In addition to the data gathered on
present-day water quality, the study also
included historical waterqualitydata kept
by water utilities, state agencies, and
water utility laboratories. Historical data
were used to search for water quality
changes over time. Present water quality
data were compared with water quality
standards and were used to calculate
water quality indices based on CaCO3
solubility, including the Langelier Index,
Ryznar's Stability Index, the Aggressive
Index, and the Calcite Saturation Index.
Many of the waters examined were
deficient in alkalinity and calcium.
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making it impossible to assign values for
pH's, the Langelier Index, and the
Stability Index. Nevertheless, these
parameters were determined by the
Larson Method for pH's so that some
approximation might be had of the
relative corrosivity of the various supplies
with respect to each other and for
comparison with the EPA values for
corrosivity characteristics as addressed
by indices (FR August 27,1980, p57341).
In that document, no exception was made
for waters of low alkalinity.
Study Methods
Field activities were conducted by staff
members selected for that purpose.
Generally one person was responsible for
an entire state. Field staff visited water
utilities, gathering data, collecting water
samples, analyzing for pH, and preparing
water samples for shipment to the
Drinking Water Research Division of the
U.S. Environmental Protection Agency
(EPA) in Cincinnati, where analyses were
performed for chloride, sulfate, nitrate,
alkalinity, copper, iron, manganese, lead,
cadmium, zinc, mercury, calcium,
magnesium, aluminum, and other
constituents. Samples with and without
acid preservation were sent to the EPA
laboratory.
Water samples collected included raw
source water, finished water at water
treatment plants, and household water.
The household water samples were
collected in the morning before any other
use of water. The three household
samples were collected to obtain (1)
water that had been held in household
plumbing overnight, (2) water that had
been held in the service line overnight,
and (3) water from the water main.
The first two rounds of field activities
were conducted in 1981 and 1982,
respectively, and included the New
England states and New York. Round 3
(1982-83) included Massachusetts
(Martha's Vineyard only), the New Jersey
Pine Barrens and coastal areas, and the
Appalachian Mountain regions of
Pennsylvania, West Virginia, Virginia,
and North Carolina.
Analytical methods used by the EPA
laboratory are described in the full report.
They were generally in accordance with
Standard Methods. Field measurements
of pH were made with portable, electronic
pH meters and combination electrodes
standardized in the field before data were
collected. Quality assurance and quality
control are described in the full report.
Basis for Assessing
Water Quality
The quality of water sampled and
analyzed in this study was compared with
that specified by EPA's National Interim
Primary Drinking Water Regulations
(NIPDWR). The regulations have
maximum contaminant levels (MCL's) for
health-related substances, including lead
(0.05 mg/L), cadmium (0.010 mg/L), and
mercury (0.002 mg/L). Secondary
maximum contaminant levels (SGML's)
exist for pH (range 6.5 to 8.5), copper (1
mg/L), zinc (5 mg/L), and other
substances. EPA has noMCLorSCMLfor
aluminum. Concentrations of aluminum
measured in this study were compared
with the American National Standards
Institute limit for aluminum in kidney
dialysis water (0.01 mg/L). Water quality
indices based on CaCO3 solubility,
particularly the Langelier Index and the
Stability Index, have been and are being
used by utility personnel to estimate
whether water would deposit or dissolve
CaC03 and cause corrosion. The ability of
these indices to predict corrosion is
limited, however. The Calcite Saturation
Index has been used by acid precipitation
researchers to assess the susceptibility of
surface waters to acidification.
Results
Table 1 lists the number of raw and
treated water samples analyzed for
cadmium, lead, and mercury, and the
number of samples equal to or exceeding
the MCL's. The MCL was exceeded by
cadmium in 1 of 484 samples, by lead in 5
of 483 samples, and by mercury in 2 of
484 samples.
The pH of both raw and treated waters
often fell outside the 6.5 to 8.5 given as
the SMCL. One fifth or more of the raw
and finished waters from surface and
ground sources fell outside this range in
Round 1. About half of the raw waters
sampled in Round 2 had pH values below
6.5. Fewer than half of the treated waters
in Round 2 fell outside the SMCL range
for pH. In Round 3, 79 percent of the
groundwater samples from New Jersey
and Martha's Vineyard, Massachusetts,
had pH values below 6.0. In contrast, only
19 percent of the samples collected in the
Appalachian region in Round 3 had pH
values below 6.0.
The 0.01 mg/L limit for aluminum in
kidney dialysis water was often exceeded
in raw waters. More than 40 percent of
the raw surface waters from Rounds 1
and 2 had aluminum concentrations of
0.1 mg/L or higher, and about 15 percent
of the raw groundwaters sampled in
Rounds 1, 2, and 3 reached or exceeded
this level. Only kidney dialysis patients
need to be concerned about the health
aspects of ingested aluminum at these
levels.
Forty-three sets of three household
samples were collected. Analysis of
household water samples showed that
copper equalled or exceeded the 1 mg/L
SMCL in 42 percent of the water samples
held overnight in household plumbing, in
Table 1. Cadmium, Lead, and Mercury in Waters Sampled
Cadmium
(O 010 mg/L MCL)
Lead
(O.05 mg/L MCL)
Mercury
Type of Sample
No
>MCL
No.
Samples
No.
> MCL
No
Samples
No.
>MCL
No.
Samples
Raw Surface Water:
Round 1
Round 2
Total
Raw Groundwater:
Round 1
Round 2
Round 3
Total
Treated Surface Water:
Round 1
Round 2
Total
0
0
0
0
0
0
0
0
1
1
120
42
162
12
83
71
166
101
33
134
0
0
0
0
1
1
2
119
42
161
12
83
71
166
101
33
134
0
0
0
0
0
0
0
120
42
162
12
83
71
166
101
33
134
Treated Groundwater.
Round 1
Round 2
Total
0
0
0
10
12
22
0
1
1
10
12
22
0
0
0
10
12
22
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21 percent of the water samples held
overnight in service lines, and in only 5
percent (2 of 43) of the samples flowing
directly to the tap from the distribution
system. Likely sources of copper are
copper service lines and household
plumbing.
Lead equalled or exceeded the 0.05
mg/L MCL in 8 percent (7 of 86) of the
household plumbing or service line
samples but did not exceed the MCL in
water samples flowing directly to the
household tap. Sources of lead could
include lead service lines,lead plumbing,
and lead-tin solder used to join copper
pipes and fittings.
Cadmium in the household water
samples never exceeded the 0.010 mg/L
MCL, and zinc never exceeded the 5
mg/LSMCL.
The water quality indices calculated for
the waters sampled indicate that the raw
waters in Rounds 1 and 2 tend to dissolve
CaC03. The Langelier Index was less than
-2 for 85 percent of Round 1 raw waters
and less than -2 for more than 90 percent
of Round 2 raw waters. Values of
Ryznar's Stability Index exceeded 8 for 97
percent of Round 1 waters and 96 percent
of Round 2 waters. These stability index
values have been associated with water
main corrosion and rusty water problems
by Ryznar. More than 60 percent of the
raw waters from Round 1 and more than
70 percent of the raw waters from Round
2 had Calcite Saturation Index values
greater than 3, indicating susceptibility to
change.
Alkalinity data for raw waters in
Massachusetts were analyzed for trends
over time. Data for four or five decades
were available for most of the water
sources in this analysis. Of the 34
sources, 20 had slopes statistically differ-
ent from zero (0.05 level). Alkalinity in 18
of the 20 sources has declined over the
time for which data are available,
whereas alkalinity has increased in two
water sources. Both in alkalinity and pH
of Scituate Reservoir (in Rhode Island)
have shown declining trends that are
statistically significant at the 0.05 level.
Conclusions
1. Raw water concentrations of
cadmium, lead, and mercury very
seldom exceeded the MCL's (1 in
484 samples for Cd, 5 in 483 smples
for Pb, and 2 in 484 samples for Hg).
2. Raw water pH was frequently below
pH 6.5, the lower limit of the pH
range in the SMCL
3. Stability Index values for many of
the waters sampled indicate that the
waters are corrosive to iron pipe.
4. Household waters were found to be
corrosive. About 40 percent of the
overnight samples from household
piping met or exceeded the 1 mg/L
SMCL for copper. Eight percent (7 of
86) of household and service line
samples had lead concentrations at
or above the 0.05 mg/L MCL,
whereas none of the ' samples
flowing directly from the
distribution main to the tap
exceeded this level.
5. Alkalinity data recorded in the past
four to five decades showed that
alkalinity had declined in 18 of 34
raw water sources in Massachusetts
and increased in two sources. The
slope of the least squares fit of
alkalinity versus time was not statis-
tically different from zero (0.05 level)
for the other 14 raw water sources.
6. No direct relationship was found
between acid precipitation and the
decline in alkalinity in the 18 raw
water sources, nor was any rela-
tionship found between acid
precipitation and the unstable and
potentially corrosive nature of these
sources. The potentially detrimental
effects of acid precipitation should
not be discounted, however, given
the limited buffering capacity in
these supplies, the historical down-
ward trend in alkalinity, and the low
pH of the rainfall in the study area.
More study should be undertaken
on this issue.
The full report was submitted in fulfill-
ment of Cooperative Agreement CR-
807808010 by the New England Water
Works Association under the sponsor-
ship of the U.S. Environmental Protection
Agency.
Floyd Taylor and Judith A. Taylor are with the New England Water Works Associa-
tion, Dedham, MA 02026; George E. Symons and John J. Collins, Consultants.
are retired; Michael Schock is with the Illinois State Water Survey, Champaign,
IL 61820.
Gary S. Logsdon is the EPA Project Officer (see below).
The complete report, entitled "Acid Precipitation and Drinking Water Quality in
the Eastern United States," (Order No. PB 84-157932; Cost: $17.50, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Municipal Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
if U.S. GOVERNMENT PRINTING OFFICE; 1984 — 759-015/7643
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United States
Environmental Protection
Agency
Official Business
Penalty for Private Use $300
Center for Environmental Research
Information
Cincinnati OH 45268
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