EPA-670/4-74-008
November 1974
Environmental Monitoring Series
THE OCCURRENCE OF ORGANOHALIDES IN
CHLORINATED DRINKING WATERS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-670/4-74-008
November 1974
THE OCCURRENCE OF ORGANOHALIDES IN
CHLORINATED DRINKING WATERS
By
Thomas A. Bellar, James J. Lichtenberg,
and Robert C. Kroner
Methods Development and Quality
Assurance Research Laboratory
Program Element No. 1BA027
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI. OHIO 45268
For aele by the Superintendent of Document!, U.S. Government
Printing Office, Washington, D.C. 20402
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REVIEW NOTICE
The National Environmental Research Center—Cincinnati has reviewed
this report and approved its publication. Mention of trade names or com-
mercial products does not constitute endorsement or recommendation for use.
11
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FOREWORD
Man and his environment must be protected from the adverse effects
of pesticides, radiation, noise and other forms of pollution, and the
unwise management of solid waste. Efforts to protect the environment
require a focus that recognizes the interplay between the components of
our physical environment--air, water, and land. The National Environ-
mental Research Centers provide this multidisciplinary focus through
programs engaged in
• studies on the effects of environmental contaminants on man and
the biosphere, and
• a search for ways to prevent contamination and to recycle
valuable resources.
The investigation reported herein was made possible by the develop-
ment of a new technique for concentration and determination of volatile
organic compounds in water. This technique is the subject of an Environ-
mental Protection Agency Research Report (EPA 670/4-74-009). Using this
technique it was possible to quantitate and to identify the source of
chloroform and other trihalogenated methanes occurring in chlorinated
drinking waters. As a result of this report and the potential chronic
toxic or carcinogenic nature of these and other volatile organics, our
Water Supply Research Laboratory is conducting intensive studies of the
occurrence of these and other organic compounds in water supplies.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
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ABSTRACT
During the course of the development of an analytical method for the
determination of volatile organic solvents in water, it was observed that
chloroform and other trihalogenated methanes, consistently occur in drink-
ing waters. Water supplies originating from both surface and ground water
sources contain these compounds. Investigations reported here show that
these compounds result from the water treatment practice of chlorination.
i
They further show that drinking waters having surface water as their source
contained higher concentrations of these compounds than those having ground
water as their source. The maximum concentrations found were: chloroform -
150 yg/1, bromodichloromethane - 20 yg/1, and dibromochloromethane - 2 yg/1.
Application of the method to a sewage treatment plant influent and
effluent showed the presence of several other chlorinated aliphatic and
aromatic compounds.
iv
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ACKNOWLEDGMENT
The authors wish to thank J. W. Eichelberger and L. E. Harris for
providing the GC-MS analyses and F. K. Kawahara for consultation regarding
possible reaction mechanisms for the formation of the trihalogenated
methanes.
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CONCLUSIONS
Chloroform and other trihalogenated methanes have been detected in
several municipal water supplies. The highest concentrations (37 to 150
yg/1) of these compounds were found in finished waters having surface waters
as their source. These compounds form as a result of chlorination processes
during water treatment. The repeated addition of chlorine at various stages
of the treatment process plays an important role in determining .the ultimate
concentrations of organohalogens that occur, since a primary limiting factor
is the presence of free chlorine in the water.
Although the trihalogenated compounds resulting from chlorination are
not an acute hazard to man at the levels detected [oral lethal dose of
chloroform to mice is 120 mg/Kg (1)], their presence suggests the need to
monitor finished waters for these and other organohalogens and to determine
whether there may be chronic effects. There is a need to develop analytical
methodology so that the chemistry of the chlorination process can be fully
studied and understood.
In addition to chloroform, several other halogenated aliphatic and
aromatic compounds were detected in a sewage treatment plant influent and
effluent waters.
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INTRODUCTION
In recent years there has been great speculation and concern about the
effect of chlorination upon organic materials contained in natural and waste
waters. Considering the widespread use of chlorine in water and sewage
treatment processes, household and commercial laundering, paper pulp bleach-
ing, and related processes, it is easy to postulate the possible inadvertent
widespread production of chlorinated organic materials. There are an in-
finite number of organic materials commonly contained in natural and waste
waters that may react with free chlorine. For the most part, mechanisms for
these reactions have not been studied because rapid and precise analytical
methods capable of monitoring the reaction products have not been available.
Many researchers have reported the presence of organohalides in finished
waters (2-7), but due to the nature of the studies made and/or the methods
used, no conclusions could be drawn as to their source.
Recently, the Methods Development and Quality Assurance Laboratory of
the National Environmental Research Center-Cincinnati has developed and re-
ported on a procedure for isolating and measuring nanogram quantities of
volatile and semi-volatile organic materials in waste water (8). Preliminary
observations, made while developing this technique, showed the presence of
organochlorine compounds in laboratory distilled and tap water. Further
observations also indicated the presence of some brominated hydrocarbons in
the tap waters. Raw river water, the source of the tap water, contained none
or much lower concentrations of the organohalides. Since their presence in
water may represent a possible health hazard and reflect a background level
for industrial effluents, it was decided to quantitate and to attempt to
identify the source of these compounds.
x
EXPERIMENTAL
Apparatus
_/^^^^^™"™™""^"^"™™—
A Perkin-Elmer 900 Gas Chromatograph was equipped with a dual-flame
ionization detector and a microcoulometric detector (halide mode). Dual,
stainless steel columns, 180 cm (6 ft) long X 2.67 mm (0.105 in) ID were
packed with Chromosorb-101 (60/80 mesh). The oven temperature was isothermal
at 190°C or programmed from 150°C to 270°C at 6.5°C/min. Nitrogen, at 50
ml/min, was employed as the carrier gas.
A Varian Aerograph 1400 gas chromatograph with a Finnigan 1015C Quad-
rupole Mass Spectrometer controlled by a Systems Industries 150 Data Ac-
quisition System was employed. The glass column, 240 cm (8 ft) long X 2 mm
(0.078 in) ID, was packed with Chromosorb-101 (50/60 mesh). Helium, at
30 ml/min, was employed as the carrier gas. The initial oven temperature of
125°C, was held for 3 min, and then programmed to 220°C at 4°C/min.
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The purging device, trap, and desorption system used for this work have
been described previously (8).
Reagents
Water free of interfering organics ^was prepared by passing distilled
water through a Millipore Super-Q water treatment system.
Standard stock solutions were prepared by injecting 1 to 5 yl of the
compound to be determined into a 1-liter volumetric flask partially filled
with organic-free water. The mixture was then diluted to volume with
organic-free water to give concentrations between 1 and 7 mg/1. Dilutions
were then made from the stock solution by pipetting a known quantity of
stock solution into a partially filled volumetric flask and diluting to vol-
ume with organic-free water. [For low level work (1 to 10 yg/1), a 1:10
dilution of the stock solution was prepared and secondary dilutions were
prepared from this solution as required.]
Procedure
Water samples were collected in 125- or 500-ml, ground-glass, stoppered
bottles. The bottles were carefully filled; no bubbles were allowed to pass
through the samples as the bottle filled. Care was taken to eliminate the
air space above the sample by over filling the bottle, then displacing part
of the sample with the glass stopper. Analyses were performed as soon as
possible after the sample collection. Time lapsed between collection and
analyses was noted.
The water samples were analyzed for volatile components by the following
procedure. Nitrogen (200 ml at 10 to 15 ml/min) was bubbled through 5.0 ml
of sample to transfer the volatiles from the aqueous phase to the gaseous
phase. The organic materials contained in the gaseous phase were con-
centrated by using a noncryogenic trapping technique (9-10) followed by a
gas chromatographic analysis. This procedure (8) provides a method capable
of analyzing for organic materials that are less than 2% soluble in water and
that boil below 150°C. An average detection limit of 1 yg/1 was achieved.
Tentative qualitative identifications were made by microcoulometric gas
chromatography (MCT) and then confirmed by gas chromatography -- mass spect-
rographic (GC-MS) techniques. Structure determinations were verified with
the use of a conversational mass spectral retrieval system (11). Quantita-
tive data were generated with the use of the flame ionization (FID) and MCT
detectors.
Standard solutions of chloroform were prepared in "organic free" dis-
tilled water at concentrations similar to those found in the unknowns. The
standards and unknowns were analyzed in an identical manner, and peak areas
were measured and compared for quantitative determination. At the time of
analysis, reagent grade bromodichloromethane and dibromochloromethane were
not available in the laboratory. Since the FID and the MCT should respond,
quantatively, in an identical manner to all of these trihalogenated methane
compounds (12,13) quantitative values were generated using the peak area
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response of chloroform.
Samples were collected from several sources for this study. A major
surface stream, a municipal water treatment plant, finished tap water from
widespread locations, and a sewage treatment plant.
RESULTS AND DISCUSSION
Initial gas chromatographic analyses were performed upon the laboratory
tap water with the use of the FID and MCT. Subsequently, the samples were
analyzed by GC-MS to verify the identity of the compounds detected in the
finished waters. The GC-MS reconstructed chromatogram and the identified
components are shown in Figure 1. Unequivocal qualitative identifications
of ethyl alcohol, chloroform, bromodichloromethane, and dibromochloromethane
were made with the use of this instrumentation. The FID-GC was calibrated
for the trihalogenated methane compounds. Although the presence of ethyl
alcohol was verified by the mass spectrometer, no quantitative data was
obtained.
As a matter of interest, analyses were performed upon other finished
waters. Table I lists the organohalide content found in chlorinated drinking
waters from several raw water sources. Where the water source was low in
total organics, such as well water (approximately 0.5 mg/1 of total organic
carbon), the resulting concentrations of halogenated products were low.
Where the water source was high in total organics, such as surface waters
(5 to 10 mg/1 of total organic carbon), the resulting concentrations of
halogenated products were high.
Several samples were collected from various parts of a water treatment
plant in a progressive manner identical to the path of the water as it is
processed through the plant. See Figure 2. Table II shows the quantitative
data obtained from these samples.
Large amounts of chloroform are stored and used in our laboratory. To
determine whether or not accidental contamination of the samples was occurr-
ing in the laboratory, several analyses were performed upon the raw river
water. These analyses were made, throughout the day, alternately with the
analyses of the samples from the water treatment plant (Table II). The raw
river water concentrations averaged 0.9 ± 0.2 yg/1. Based on these results,
little or no contamination of the samples occurred in the laboratory.
The data reported in Table II show that the trihalogenated methanes
originate at the water treatment plant. It is interesting to note that each
time additional chlorine is added to maintain or increase the free chlorine
concentration of the water, a significant increase in the chloroform level
results. See Figure 2. The decrease in the concentration of trihalogenated
methanes after sampling point 4 may be due to the introduction of an acti-
vated carbon slurry at that point.
A second series of analyses were performed upon raw river water which
had been treated with alum and chlorine. The sample was collected at the
water treatment plant and held in the laboratory for 71 hours. It was
analyzed five times within the first 6 hours. After standing overnight, it
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20-
10-
0
I I I I I I
120 140
I ' I
160
100
i I i I ' I ' i ' i ' I ' i ' I '
0 20 40 60 80
SPECTRUM NUMBER
Figure 1. RECONSTRUCTED GC-MS CHROMATOGRAM OF
FINISHED WATER.
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Table I. TRIHALOGENATED METHANE CONTENT OF VARIOUS MUNICIPAL
WATER SUPPLIES
Sampling
Sites
iooa
iooa
ioib
102b
103b
104a
104a
105a
106b
Raw water
source
Surface
Surface
Surface
Surface
Surface
Well
Well
Well
Well
Date
collected
8-73
2-74
2-74
2-74
2-74
8-73
2-74
2-74
12-73
Concentration (yg/1)
Chloroform
94.0
37.3
70.3
152.0
84.0
2.9
4.4
1.7
3.5
Bromo-
dichloro-
me thane
20.8
9.1
10.2
6.2
2.9
No
data
1.9
1.1
No
data
Dibromo
chloro-
methane
2.0
1.3
0.4°
0.9C
<0.1
No
data
0.9C
0.8°
No
data
Sample age <4 hours.
Sample age unknown; >24 hours.
•»
"Approximate value, ±20%.
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CHLORINE ALUM
SETTLED WATER
'AVERAGE AGE -
3 DAYS
CHLORINE
CARBON SLURRY
FILTER
CHLORINE
-FINISHED WATER
INDICATES
SAMPLING POINT
Figure 2. WATER TREATMENT PLANT SAMPLING POINTS
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Table II. TRIHALOGENATED METHANE CONTENT OF WATER FROM WATER
TREATMENT PLANT
Sample Source
Raw river water
River water treated with
chlorine and alum-
chlorine contact time
i,80 min.
3-day-old settled water
Water flowing from .
settled area to filters
Filter effluent
Finished water
Sampling
point
1
2
3
4
5
6
Free
chlorine
ppm
0.0
6
2
2.2
Unknown
1.75
Concentration
Chloro-
form
0.9
22.1
60.8
127
83.9
94.0
Bromo
dichloro-
methane
a
6.3
18.0
21.9
18.0
20.8
(wg/D
Dibromo-
chloro-
me thane
a
0.7
1.1
2.4
1.7
2.0
None detected. If present, the concentration is <0.1 ug/1,
Carbon slurry added at this point.
8
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was analyzed at 26, 28, 29 and 71 hours. In Figure 3 can be seen the con-
centrations of halogenated methanes found. These data show that in this
static system, after a single addition of free chlorine, trihalogenated
methane compounds are formed. Their concentration increased with respect
to chlorine contact time up to approximately 15 hours. Little or no in-
crease was noted after that time. This observation and the previous obser-
vation that each addition of free chlorine produces an increase in the con-
centration of trihalogenated methanes show that these compounds are not
introduced as impurities contained in the alum or the chlorine used for
treatment of the water. It is apparent that a chemical reaction is taking
place between free chlorine and organic compounds present in the water. One
possible mechanism for the formation of chloroform is suggested by the com-
pounds detected in the tap water -- ethanol and trihalogenated methanes
only (no mono- or dihalogenated compounds). The ethanol oxidizes to
acetaldehyde that reacts with free chlorine to form chloral. The chloral
reacts with water to form chloral hydrate which then decomposes to form
chloroform.
0 0 H
CH -CH OH —> CH.-C-H —> C17-C-C-H —> Cl_-C-C-(OH),, —> CHC1,
J *• -5 o 3 Z 3
At this time, we have no experimental evidence to show that this is in fact
the mechanism by which the chloroform is produced.
The presence of the two brominated compounds listed in Table I prob-
ably results from bromine impurities contained in the chlorine. The bro-
mine would react in the same manner as chlorine to form the brominated
homologs. The concentration of the tribrominated homolog, bromoform, if
present, was below the detection limit of the method. Other researchers
have reported the presence of these trihalogenated compounds, including
bromoform, in finished waters, but the possibility that they may have re-
sulted from the chlorination process was not suggested.
Table III lists results of the analyses of grab samples collected at
several stages of treatment in a local sewage treatment plant. Since this
treatment plant serves a large industrial as well as a municipal area, a
multitude of diverse organic compounds should be present at all times. Be-
cause of the constantly changing composition of the water entering the plant,
drawing any comparisons between the quantitative data for the influent water
and the effluent water is difficult. The increase of the chloroform con-
centration in the chlorinated effluent, however, appears to be due to
chlorination. The variation in the concentrations of the chlorinated com-
pounds before and after chlorination ranged from 0.2 to 1.2 ug/1, except
for chloroform which increased by 5 yg/1. This increase, while small, is
well above the observed variation (±20%) of the method at its lower limit
of detection. The closeness of the results for the other chlorinated com-
pounds and the close proximity of the sampling points before and after chlor-
ination indicate that the increase in the concentration of chloroform re-
sults from the chlorination process. Since the amount of chlorine added
at the sewage treatment plant was low (0.25 ppm total chlorine) when com-
pared with that added at the water treatment plant and since the contact
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CHLOROFORM
--0-00
BROMODICHLORO METHANE
10
20 30 40 50 60
CHLORINE CONTACT TIME (HOURS)
70
Figure 3. CHLORINATED OHIO RIVER WATER.
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time between collection and analysis was less than 2 hours, the low
concentration of chloroform is not surprising.
Table III. ORGANOCHLORINE COMPOUNDS IN WATER FROM SEWAGE
TREATMENT PLANT
Concentration (yg/1)
Compound
a
Influent
before
treatment
Effluent
before
chlorination
Effluent
after
chlorination
Methylene chloride 8.2
Chloroform 9.3
1,1,1-Trichloroethane 16.5
1,1,2-Trichloroethylene 40.4
1,1,2,2-Tetrachloroethylene 6.2
E Dichlorobenzenes 10.6
Z Trichlorobenzenes 66.9
2.9
7.1
9.0
8.6
3.9
5.6
56.7
3.4
12.1
8.5
9.8
4.2
6.3
56.9
All confirmed by GC-MS
11
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REFERENCES
1. Christensen, H.E., Ed., "Toxic Substances List 1972," U.S. Dept. of
Health, Education, and Welfare, Health Services and Mental Health
Administration, National Institute for Occupational Safety 6 Health,
Rockville, Md. (1972).
2. Kleopfer, R.D., Fairless, B.J., "Characterization of Organic Components
in a Municipal Water Supply," Environ. Sci. Technol., 6^, 1036-1037
(1963).
3. Novak, J., Zluticky, J. , Kubelka, V., Mostecky, J. , "Analysis of
Organic Constituents Present in Drinking Water," J. Chromatog., 76,
45-50 (1973).
4. Friloux, J., "Identification of Hazardous Materials—Lower Mississippi
River," U.S. Public Health Service, Progress Report, Oct. 1970.
5. Friloux, J., "Petrochemical Wastes as a Pollution Problem in the Lower
Mississippi River," Environmental Protection Agency Report, Lower
Mississippi Basin Office, Water Quality Office, Baton Rouge, La.,
Oct. 1971.
6. Grob, K. and Grob, G., "Organic Substances in Potable Water and its
Precursor, Part II. Applications in the Area of Zurich," J. Chromatog.,
9£, 303-313 (1974).
7. "Industrial Pollution of the Lower Mississippi River in Louisiana,"
U.S. Environmental Protection Agency, Region VI, Dallas, Texas, April
1972.
8. Bellar, T.A., Lichtenberg, J.J., "The Determination of Volatile Organic
Compounds at the yg/1 Level in Water by Gas Chromatography," U.S.
Environmental Protection Agency, National Environmental Research Center,
Cincinnati, Ohio, Nov. 1974 (EPA-670/4-74-009).
9. Bellar, T.A., Sigsby, J.E., "Analysis of Light Aromatic Carbonyls,
Phenols, and Methyl Naphthylenes in Automotive Emissions by Gas Chro-
matography," Copies available from: John E. Sigsby, Jr., Division of
Chemistry and Physics, U.S. Environmental Protection Agency, Research
Triangle Park, N.C. (1970),
10. Bellar, T.A., Sigsby, J.E., "Non-Cryogenic Trapping Techniques for Gas
Chromatography," Internal Report, Copies available from: John E.
Sigsby, Jr., Division of Chemistry and Physics, U.S. Environmental
Protection Agency, Research Triangle Park, N.C. (1970).
12
-------
11. Heller, S.R., "Conservational Mass Spectral Retrieval System and its
Use as an Aid in Structure Determination," Anal. Chem., 44, 1951-1961
(1972). —
12. Dewar, R.A., "The Flame lonization Detector: A Theoretical Approach,"
J. Chromatog., £, 312-323 (1961).
13. Gallway, W.S., Steinberg, J.C., Jones, T.L., "A Theoretical Inter-
pretation of Hydrogen Flame lonization Detector Response," presented
at the 12th Pittsburgh Conference on Analytical Chemistry and Applied
Spectroscopy, Pittsburgh, Pa., Feb. 1961.
13
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-670/4-74-008
2.
3. RECIPIENT'S \CCESSION>NO.
4. TITLE AND SUBTITLE
THE OCCURRENCE OF ORGANOHALIDES IN CHLORINATED
DRINKING WATERS
5. REPORT DATE
November 1974; Issuing Date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Thomas A.
Robert C.
8. PERFORMING ORGANIZATION REPORT NO.
Bellar, James J.
Kroner
Lichtenberg, and
9. PERFORMING ORGANIZATION NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
10. PROGRAM ELEMENT NO.
lBA027;ROAP'09ABZ;Task 15
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
See also EPA-670/4-74-009, "The Determination of Volatile Organic Compounds at the
Ug/1 Level in Water by Gas Chromatography"
16. ABSTRACT
During the course of the development of an analytical method for the
determination of volatile organic solvents in water, it was observed that chloro-
form and other trihalogenated methanes consistently occur in drinking waters.
Water supplies originating from both surface and ground water sources contain these
compounds. Investigations reported here show that these compounds result from the
water treatment practice of chlorination. They further show that drinking waters
having surface water as their source contained higher concentrations of these com-
pounds than those having ground water as their source. The maximum concentrations
found were: chloroform - 150 ug/1, bromodichloromethane - 20 ug/1, and dibromo-
chloromethane - 2 yg/1. Application of the method to a sewage treatment plant
influent and effluent showed the presence of several other chlorinated aliphatic
and aromatic compounds.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Water analysis, Chemical analysis,
*Chlorination, Potable water, *Water
pollution, *Chloroform, Gas chromato-
graphy
*0rganohalogen compounds,
*Chlorinated solvents,
Organochlorine compounds,
Pollutant analysis,
Analytical techniques
13B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
20
2O. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
14
U.L GOVERNMENT HUNTING OFFKkl97'»-657-587/5315 Region No. 5-11
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