Environmental Protection
Agency
"
-------
Bacteriological Ambient Water Quality Criteria
for Marine and Fresh Recreational Waters
U.S. Environmental Protection Agency
Office of Research and Development
Microbiology and Toxicology Div.
Cincinnati, Ohio
Office of Water Regulations
and Standards
Criteria and Standards Div.
Washington, D.C.
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:ONTENTS
Foreword .« • • • iii
Acknowledgements ^v
Introduct ion • • « 1
Study De s i g n • < ^
Data Base for Marine and Fresh Water 4
Basis of Criteria for Marine and Fresh Water 6
Recommendation on Bacterial Criteria Monitoring 7
Development of Recommended Criteria Based on E. coli
and enterococci '• • • 8
Limitations and Extrapolations of Criteria 10
Relationship With the Criteria Contained In Quality
Criteria for Water ••• .• 10
Tables 12-15
National Criteria 16
References •» •• • •*•'
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DISCLAIMER
This report has been reviewed by the Criteria and Standards
Division., Office of Water Regulations and Standards, U.S. Environ-
mental" Protection Agency, and approved for publication. Mention
of trade names or commercial products does not constitute endorse-
ment or recommendation for use.
AVAILABILITY NOTICE
This document is available to the public through the National
Technical Information Service (NTIS), 5285 Port Royal Road,
Springfield, VA 22161. NTIS Access Number is PB 86-158045.
ii
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L 95-217)
„
have
by
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AC KN1 OW LE DGEM E NTS
Alfred P. Dufour
(research-author)
Health Effects Research
Laboratory
Cincinnati, OH
Theadore H. Ericksen
(review)
HERL
Cincinnati, OH
Richard K. Ballentine
(author)
OWRS - Washington, D.C.
Victor J. Cabelli
(research)
Health Effects Research
Laboratory
West Kingston, RI
Miriam Goldberg
(statistical assistance]
OWRS
Washington, D.C.
William E. Fox
(coordinator)
OWRS - Washington, D.C.
iv
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BACTERIOLOGICAL AMBIENT iVATER QUALITY CRITERIA FOR
MARINE AND FRESH RECREATIONAL WATERS
Introduction
Federal water quality criteria reccmmendations w=re first proposed
in 1968 by the National Technical Advisory Committee (NTAC) of the
Department of the Interior (1). The microbiological criterion suggested
by the NTAC for bathing waters was based on a series of studies conducted
during the late 1940's and early 1950's, by the United States Public
Health Service, the results of.which were "sumnarized by Stevenson in 1953
(2). Ihe studies were conducted at bathing beaches located on Lake Michi-
gan at Chicago, Illinois; on the Ohio River at Dayton, Kentucky; and on
Long Island Sound at Mamaroneck and New ftochelle, New York. All of the
studies followed a similar design. Two beaches with different water
quality were selected at each location except at the Dayton location
where a beach with high quality water could not be found. A large public
swimming pool was used as a substitute. Each location was chosen because,
in addition to beaches having suitable water quality, there was a large
residential population nearby that used the beaches. Cooperating families
used a calendar system which allowed them to record their swimming activity
and illnesses on a daily basis for the entire summer. Gastrointestinal,
respiratory, and other symptoms such as skin irritations were recorded.
The water quality was measured on a routine basis using total coliform
bacteria as the indicator organism.
The results of the Lake Michigan beach study indicated that there
was no excess illnesses of any type in swimmers at beaches that had
median coliform densities of 91 and 180 per 100 ml over a swimming season
when compared to the number of illnesses in the total study population.
The water quality similarity at the two Chicago beaches was unexpected
since previous experience had indicated that there was a difference in
water quality at the beaches. A second method of analysis compared the
illness observed in the week following three days of high coliform density
with that observed following swimming on three days of low coliform
density. The analyses showed that there was a significantly greater
illness rate in individuals who swam on the three days when the geometric
mean coliform density was 2300/100 ml when compared to the illness in
swimmers who swam on the three days when the geometric mean coliform
density was 43 per 100 ml. A difference was not observed when the geo-
metric mean coliform density per 100 ml on high and low days was 732 and
32 respectively. Data fron the Ohio River study indicated that swimmers
who swam in water with a median coliform density of 2300 coliforms per
100 ml had an excess of gastrointestinal illness when compared to an
expected rate calculated from the total study population. No other
associations between swimming and illness were observed. The results of
two marine bathing beach studies showed no association between illness
and swimming in water containing 398 and 815 coliforms per 100 ml.
The coliform water quality index used during the USPHS epideralologi-
cal studies was translated into a fecal coliform index in the mid-'60s
by using the ratio of fecal coliforms to coliforms at the location on the
Chio River where the original study had been conducted in 1949. The NTAC
commit'tee suggested that the change was necessary because fecal coliforms
-------
were more fecal specific and less subject to variation than total .oil-
forms which were greatly influenced by storm water runoff. About 18% of
the coliforms were found to be fecal conforms and this Proportion was
used to determine that the equivalent of 2300 conforms per 100 ml , the
density at which a statistically significant swHtming-assccia ted gastro-
intestinal illness was observed, was about 400 fecal colifoms per 100
ml. The OTAC suggested that a detectable risk was undesirable and,
therefore, one-half of the density at which a health risk occurred, 200
fecll coliforms per 100 ml, was proposed. The NTAC also suggested that
tS use of tte 4er should not cause a detectable health effect more -
than W% o£ the tine. Thus, the reconverted criterion for recreational
waters was as follows:
"Fecal coliforms should be used as the indicator organism
for evaluating the microbiological suitability of recreation
waters. As determined by mul tiple-tube fermentation or ™2m-
brane filter procedures and based on a minimun of not less than
five ssamples taken over not more than a 30-day period, the
fecal coliform content of primary contact recreation waters
shall not exceed a log mean of. 200/100 ml, nor shall more than
10 percent of total samples during any 30-day period exceed
400/100 ml."
This criterion was recotmended again in 1976 by tte USEPA (3), even
SA22- - -
the poor quality of the data base, the derivation of the
and the indicator system used,,
«. £
lumped togiether.
suggested other weaknesses in the USPHS study
«>» u» "^'061"
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variability in the pollution levels at the beaches increased the probabi-
lity of a given individual's exposure to different levels of pollution
during the incubation period of the illness.
The deficiencies in the study, design and in the data used to _
establish the 200 fecal coliforms per 100 ml criterion were noted oy
the National Academy of Science - National Academy of Engineers Cormattee
in their 1972 report which stated that they could not recotmend a
recreational water quality criterion because of the paucity of epideni-
ological information available (7).
The fecal coliform indicator used to measure water quality under the
current system has also been faulted because of the non-fecal sources of
at least one member of the fecal coliform group. For example, the^o-
tolerXt Slbsiella species have many sources. They have been ^served
in pu^ and paper nillef fluents (8,9), textile processing plant effluents
(10), cotton mill wastewaters (11), and. sugar beet wastes (12), in the
absence of fecal contamination.
The Ehvirormental Protection Agency, in 1972, initiated a series of
studies at marine and fresh water bathing beaches which were designed to
correct the Reived deficiencies of the Public Haalth Service studies.
XS Joal of the EPA studies was to determine if swinging in sewage-
SntaTinatid wtter carries a health risk for bathers; and, if so, to what
tvne of illness. If a quantitative relationship between water quality
and health risk was obtained, two additional goals were to determine
which bacterial indicator is best correlated to swuraing-associated
health effects and if the relationship is strong enough to provide a
criterion.
Study Design
The marine studies were conducted at bathing beaches in New York
Citv
y
arne s
York, Boston, Massachusetts, and at lake Pontchartrain, near
s? Louisiana. Two beaches ware selected at each site, one that
d very little or no contamination and the other whose water quali-
barSy acceptable with respect to local recreational water quality
HQ Tn the New York City and Boston Harbor studies, the "barely
accple" SacSs ^re^o/tamLaterf with pol lut ion f ran multiple point-
SurXs, usually treated effluents that had been disinfected.
The freshwater studies were conducted on Lake Erie J*5ie'
Pennsylvania and on Kfeystore Lake outside of Tulsa, ^f^'
acceptable" beaches at both sites were contaminated by effluents
charged from single point-sources.
The eoideniolcgical surveys were carried out on weekend days and
-------
study has teen described elsewhere (13,14). Specific steps taken to
correct the; deficiencies of earlier studies were noted earlier.
In tte initial phases of the overall study,
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earlier USPHS studies. The only .evidence,,that sewage-contaminated water
carried a risk for gastroenteritis in those studies was observed at the
Ohio River beach where swimmers had an excess of gastrointestinal illness
when the" median coliform density in the water was 2300 per 100 ml. This
was counter to the results found at freshwater beaches in 'Chicago and at
marine beaches on Long Island Sound where swimmers had no more gastro-
intestinal illness than nonswiirmers even when days of "high" and "low"
colifom densities were selected. Therefore, other than the occasional
association of an outbreak of disease with swimming (17), the data frcm
•labelLi (15)'and Dufour (16) are the only available'evidence linking
sewage contaminated water with a health risk for bathers.
Although the association of illness in swimmers using bathing water
contaminated by treated sewage is an important aspect of the process for
developing recreational water quality criteria, it is the establishment
of a quantitative relationship between the two variables that provides a
useful relationship for regulating water quality. A part of this process
is the development of suitable methods for measuring the quality of the
water.
A comprehensive discussion of microbial water quality indicators is
beyond the scope of this document, even as the basis for the selection of
those examined in the epidemiological studies. The reader is referred
for this to the reports of the studies (15,16) and to reviews on the
subject (18,19). The exanination of a number of potential indicators,
including the ones most commonly used in the United States (total colifdrms
and fecal coliforms), was included in the studies. Furthermore, the
selection of the best indicator was based on the strength of the relation-
ship between the rate of gastroenteritis and the indicator density, as
measured with the Pearson Correlation Coefficient. This coefficient
varies between minus one and plus one. A value of one indicates a
perfect relationship, that is, all of the paired points lie directly on
the 1ine which defines the relationship. A value of zero means that
there is no linear relationship. A positive value indicates that the
relationship is direct, one variable increases as the other increases.
A negative value indicates the relationship is inverse, one variable
decreases as the other increases. The correlation coefficients for
gastroenteritis rates as related to the various indicators of water
quality from both marine and fresh bathing water are shown in Table 2.
The data frcm the three years of the New York City study were ana-
lyzed in two ways. The first was by grouping trial days with similar
indicator densities from a given swimming season and the second was by
looking at each entire summer. The results from both analyses are shown
in Table 2. For either type of analysis, enterococci shoved the strong-
est relationship to gastroenteritis. E. coli was a very poor second and
all of the other indicators, including total coliforms and fecal coli-
forms, showed very weak correlations to gastroenteritis. Enterococci and
E. coli were used in subsequent studies including the freshwater trials.
Fecal coliforms also were included in subsequent studies because of their
status as an accepted basis for a criterion.
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— D "~
freshwater studies were analyzed only by sunmer. The correla-
Baals of Criter*- «~
Fresh Recreational Waters
CabeUi (15) defined a recreational water quality criterion as a
risks for swinmers.
The Quantitative relationships between the rates of swimming-associ-
-------
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95%
water =""*--- p coli-
confirmed as £• . successfully -~--- t LaboratoL
SS: sast-r8^. -. - --ss.
-^£SS.«&^.^a.T-
-------
— 8 —
improves the likelihood of correct decisions on whether to close
or leave open a beach.
Waters, with more casual and intermittent swimming use need fewer
samples because of the reduced population at risk. Such sampling may
IT£ be used in establishing trends in the bacterial water quality so
that the necessary improvements in the sanitary quality can be identified
before disease risks becone acute.
Thp following compliance protocol is one recomended by SPA for
monitoring recreational bathing waters. It is based on the assumption
t tte currently accepted risk level based on the CCW recommendation
been d Smined to be appropriate and that the mo"it°rinJ.^^S'1
i e bacterial enumeration techniques are imprecise, and environmental
cc^it^s such as rainfall, wind and 'temperature will vary temporally
and soatially. The variable nature of the environment, which affects
£ne dte-Sff a^d transport of bacterial indicators, and the inherent
imprecision of bacterial enumeration methods, suggests an approach that
eTSXS elects into account. Nbrcompl iance with the criterion
signaled when the maximun acceptable geometric mean is exceeded or
n^1ndS!dual sample exceeds a confidence Innit, chosen accordingly
or to a level of swiimung use. The mean log standard deviation for £.
.
.with the proposed monitoring protocol and upper percentile values
It is recormended that sampling frequency be related to the intensity
use of the water body. In areas where weekend use is substantial,
s^ollecSX during the peak use periods are reasonable. In
used areas perhaps bi-weekly or monthly samples nay be
to decide bacterial water quality,
£
(25).
nevelocment of Recotnended Criteria Based on B. coli/Enterccocci
Currently EPA is not recomnending a change in the stringency of its
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- 9 -
EPA's evaluation of the bacteriological data indicated that using the
fecal colifonn indicator group at the maximum geometric mean of 200 per
100 ml, recommended in Qiality Criteria for Water wold cause an estimated
8 illness per 1,000 swimners at fresh water beaches and 19 illness per
1,000 swimmers at marine beaches. These relationships are only approximate
and are based on applying ratios of the geometric means of the various
indicators from the EPA studies to the 200 per 100 ml fecal coliform
criterion. However, these are EPA's best estimates of the accepted
illness rates for areas which apply the EPA fecal•coliform criterion.
The E_. coli and enterocccci criteria presented in Table 4 were deve-
loped using these currently accepted illness rates. The eouations deve-
loped by Dufour(16) and Cabelli(lS) were used to calculate the geometric
mean indicator densities corresponding to the accepted gastrointestinal
illness rates. These densities are for steady state dry weather conditions.
The beach is in nonconpliance with,the criteria if the geometric mean
of several bacterial density samples exceeds the Value listed in Table 4.
Nonconpliance is also signalled by an unacceptably high value for
any single bacterial sample. The maximum acceptable bacterial density
for a single sample is set higher than that for the geometric mean, in
order to avoid unnecessary beach closings based on single sanples. In
deciding whether a beach should be left open, it is the long term geometric
mean bacterial density that is of interest. Because of day-to-day fluctu-
ations around this mean, a decision based on a single sample (or even
several sanples) may be erroneous, i.e., the sanple may exceed the recom-
mended mean criteria even though the long-term geometric mean is protective,
or may fall below the maximum even if this mean is in the nonprotective
range.
To set the single sample maximum, it is necessary to specify the
desired chance that the beach will be left open when the protection is
adequate. This chance,"or confidence level, was based on Agency judgment.
For the simple decision rule considered here, a smaller confidence level
corresponds to a more stringent (i.e. lower) single sanple maximum.
Conversely, a greater confidence level corresponds to less stringent
(i.e. higher) maximum values. This technique reduces the chances of
single sanples inappropriately indicating violations of the reconnended
criteria.
By using a control chart analogy (26) and the actual log standard
deviations fron the EPA studies, single sample maximum densities for
various confidence levels were calculated. EPA then assigned qualitative
use intensities to those confidence levels. A low confidence level (75%)
was assigned to designated beach areas because a high degree of caution
should be used to evaluate water quality for heavily used areas. Less
intensively used areas would allow less restrictive single sample limits.
Thus, 95% confidence might be appropriate for swiramable water in remote
areas. Table 4 sutimarizes the results of these calculations. These
single sample maximum levels should be recalculated for individual areas
if significant differences in log standard deviations occur.
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standard deviation of log
sities^ Du historically accepted
maximun has been
indicates how the conflde
be applied to multiple
4aP?hflimit for the measured geometric
lations of Criteria
Tl-imit-*fions and Extra
of —rality
health effects
CabellidS). Briefly, the major
observed relationship may not be
contributing the fecal
are present in a c.
which is approximately constant
and therefore, the r
based
of the criteria are that the
size of the population
z if epidSuic conditions
pathogen to indicator ratio,
Ti becomes unpredictable
r these circunstances,,
importance of sanitary surveys and
^
presence of these i^icators
of warm blooded animal
application of these
^idemiological studies
be no^-hunan and that the
subsequent revisions
rv-ii-ftria for Water •
with the Criterion contained in Quali
. criterion
and shellfish harves ting watery ^^ing m this criterion is
. «S«h into the
Criteria and cux. etandard
office of Water Regulations and Standard
Envirormental Protection Agency
401 M St., S.W.
Washington, DC 20640
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the
application of the enterococci and E. coli indicators for
quality of shellfish harvesting watersT-lhe Food and iS
is also reviewing the results of these studies. A changeto nw
indicators may be forthcoming if the studies show a correlation between
gastrointestinal disease and the consumption of raw shellfish fW^ters
with defined densities of the new indicators. However, these s^Siel
have not sufficiently progressed to justify any change 'at tSstSe -
Thus, the recommendations in QCW for shellfish waters must remain unchanged,
The QCW recomendations for swinging waters were based on fecal
conforms. Data subnitted to EPA during the public ccrrnent period showed
that^witnin sane beaches, a correlation could be shown between E. coli
densities and fecal coliform densities. Such a site-specific correlation
£££ 5U1Sri™9,beCaUSZ - ^ is part of the e«al^oliform grJu^. '
However, the EPA tests show that no general correlation exists acrosS
different beaches. Therefore, EPA believes that the newly recotmended
i££!,tor8 are S^rri°r t0 the fecal c°lifo^ group. Therefore, EPA
strongly recomtends that states begin the transition process to the new
indicators, ttule either E. coli or enterococci may be used for fresh
waters, only enterococci is recotmended for marine waters.
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Table 1. Itelationship Between Significant Swiirming-Associated
Gastroenteritis and the Degree of Pollution at Marine
and Fresh Nater Bathing Beaches
Beach Water Quality
No. Trials
xt>. Trials with
Excess Illness in
Swiiraners 1
% Trials with
Excess Swiitsner
Illness
Barely Acceptable Relatively Unpolluted
8
17
41
iDifference between swininer and nonswimer illness rates during a
trial period statistically significant at p <0.05 level
- 12 -
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Marine''
enterococci
. coU.
/Citr
cbacter:
Fresh
en
teroccjcci
.52
.32
.26
.19
.19
.19
^.01
-.09
-.20
-.23
.74
.80
-.08
.96
.56
.61
.64
.65
.01
.59
.51
.60
.42
.60
- 13 -
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EPA Criteria for Bathing (Full
Body Contact) Recreational Waters
Freshwater
p*«*>rt on a statistically sufficient nunber of samples (generally not
S £55 1
other of the followir^U). ' 126 ^ 100 ml; or
rufprrr-'orci 33 per 100 ml;
m sa-sle should excel?™^ cenjfdence Unit
-------
.References
1. National Technical Advisory Cprmittee. 1968. Water Quality Crite-
ria... Federal Water Poll. Control Adm., Dept. of the Interior,
Washington, DC. ' ' u . •
2. Stevenson, A. H. 1953. Studies of Bathing Water Quality and Health.
Am. J. Public Hlth. Assoc. 43:529.
3. U.S. Environmental Protection Agency. 1976. Quality'criteria for
Water, rj/s. Environmental Protection Agency, Washington, DC.
4. Henderson, J. M. 1968. Enteric Disease Criteria for Recreational
Vvaters. J. San. Eng. Div. 94:1253.
5. Moore, B. 1975. The Case Against Microbial Standards for Bathing
Beaches. In: International Symposium'on Discharge of Sewage From
Sea Cutfalls. Ed. A. L. H. Gameson. Pergamon Press, London, p. 103.
6. Cabelli, V. J., M. A. Levin, A. P. Dufour, and L. J. McCabe. 1975.
The Development of Criteria for Recreational Waters. In: Interna-
tional Symposium on Discharge of Sewage Fran Sea Outfalls. Ed. A.
L. H. Gameson. Perganon Press, London, p. 63.
7. Committee on Water Quality Criteria. 1972. National Academy of
Sciences-National Academy of Engineering. Water Quality Criteria.
U.S. Environmental Protection Agency, EPA-R3-73-033, Washington, DC.
8. Huntley, B. E., A. C. Jones, and V. J. .Cabelli. 1976. Klebsiella
Densities in Waters Receiving Wood Pulp Effluents. J. Water Poll.
Control Fed. 48:1766.
9. Caplenas, N. R., M. S. Kanarek, and A. P. Dufour. 1981. Source and
Extent of Klebsiella pneumoniae in the Paper Industry. Appl. En-
viron. Microbiol. 42:779.
10. Dufour, A. P., and V. J. Cabelli. 1976. Characteristics of Kleb-
siella Fran Textile Finishing Plant Effluents. J. Water Poll.
Control Fed. 48:872.
11. Campbell, L. M., G. Michaels, R. D. Klein, and I. L. Roth. 1976.
Isolation of Klebsiella pneumoniae From Lake Water. Can. J* Micro-
biol. 22:1762.
12. Nunez, W. J., and A. R. Colmer. 1968. Differentiation of Aerobacter-
Klebsiella Isolated from Sugar Cane. Appl. Microbiol. 16:875.
13. Cabelli, V. J., A. P. Dufour, M. A. Levin, L. J. McCabe, and P. W.
Haberman. 1979. Relationship of Microbial Indicators to Health
Effects at Marine Bathing Beaches. An. J. Public Hlth. 69:690.
14. Cabelli, V. J., A. P. Dufour. L. J. McCabe, and M. A. Levin. 1982.
Swimming-Associated Gastroenteritis and Water Quality. Am. J.
Epidemiol. 115:606.
15. Cabelli, V. J. 1983. Health Effects Criteria for Marine Recreation-
al Waters. U.S. Environmental Protection Agency, EPA-600/1-80-031,
Cincinnati, QH.
- 17-
-------
16. Dufour, A. P. 1984. Health Effects Criteria for Fresh Recreational
Waters. U.S. Environmental Protection Agency, Cincinnati, OH.
EPA 600/1-84-004
17. Cabelli, V. J. 1983. Water-borne Viral Infections. In: Viruses
and Disinfection of Water and Wastewater. Eds. M. Butler, A. R.
Medlen, and R. Morris. University of Surrey, Surrey, England.
1R. Cabelli, V. J. 1976. Indicators of Recreational Water Quality.
In: Bacterial Indicators/Health Hazards Associated with Water.
Eds. A. W. Hoadley and 8. J. Dutka.- .ASTM, Philadelphia, PA.
19. Cabelli, V. J. 1982. Microbial Indicator Systems for Assessing
Water Quality. Antonie van Leeuwenhoek. 48:613.
20. Cabelli, V. J. 1981. Epidemiology of Enteric Viral Infections.
In: Viruses and Wastewater Treatment. Eds. M. Goddard, and M.
Butler. Pergamon Press, New York. p. 291.
21. Dufour, A. P. 1976. E. coli; The Fecal Coliform. In: Bacterial
Indicators/Health HazaFds Associated with Water. Eds. A. W. Hoadley,
and; B. J. Dutka. ASTM, Philadelphia, PA. p. 48.
22. Fattal, B., R. J. Vasl, E. Katzenelson, and H. I. Shuval. 1983.
Survival of Bacterial Indicator Organisms and Enteric Viruses in the
Mediterranean Coastal Waters Off Tel-Aviv. Water Res. 17:397.
23. Levin, M. A., J. R. Fischer, and V. J. Cabelli. 1975. Membrane
Filter Technique for Enumeration of Enterococci in Marine Waters.
Appl. Microbiol. 30:66.
24. Dufour, A. P., E. R. Strickland, and V. J. Cabelli. 1981. _Membrane
Filter Method for Enumerating Escherichia coli. Appl. Environ.
Microbiol. 41:1152.
25. American Public Health Association. 1975. Standard Methods for the
Examination of Water and Wastewater. 14th Ed. Washington, DC.
26. ASTM. 1951. Manual on Quality Control of Materials. Special Tech-
nical Publication 15-C, American Society for Testing and Materials,
Philadelphia, PA.
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