-------
TABLE 4
Enterococcus Bacteria at Each Sample Station Showing Actual Count per 100 ml
and Count Adjusted for Dilution
c
o
r
+-J
ID
M
00
C-100
T-800
T-700
T-600
T-500
T-400
T-300
T-200
T-100
Actual Count/100 ml
o
r-
P
C
r tO
&M ^tf
M 0)
oo o
530
1.7
19
4.7
14
6.7
2.7
6.4
4.4
O -M C
r- _J^-
440
1.6
18
8.0
11
6.4
2.6
6.1
4.2
Count/100 ml Adjusted for
Dilution with Water Loss
o
+J
QJ
JC
4-> C
r- id
M V
(/) O
--
--
6.1
23
8.3
3.9
10
5.8
0)
O *-N
C 1
0)
o s-
i- O
M-
c +
i- tO
u?.E "
01 1]«
10
19
7.9
3.7
9.5
5.5
Count/ 100 ml Adjusted for
Dilution Without Water Loss
o
P*
4J
"O (^
C !
10 >
co a
--
12
5.2
13
9.0
C
r- (O
i5s
~-
--
--
--
n
5.0
13
8.6
-------
Method II - Count/100 ml Adjusted for Dilution Without Water Loss
With this method, it was assumed for dilution purposes that no water
was lost from the river channel. Thus, the discharge either increased
(as indicated by actual measurement) or remained constant (where actual
discharge decreased) at each station proceeding downstream. This
resulted in stations T-700 through T-100 having discharges of 5630,
7280, 9770, 9770, 10750, 11510 and 11510 cfs respectively. The dis-
charges presented here for stations T-400 through T-100 differ from
the actual discharge measurements shown in Table 1. Therefore, the
dilution adjustment factors for these stations differ from those
used in Method I and the calculation for T-400 is as follows:
563^ els rt ETOO -1-74 dilution factor
Again, as with Method I, the actual counts obtained each day were
adjusted with the dilution factor to obtain the results in the
appropriate sections of Tables 2, 3 and 4.
The total coliform, fecal coliform and enterococci counts at T-700
were considered to be 100 percent survival because this was the sur-
vival study starting point. Proceeding downstream (stations T-600
through T-100), a percent survive! range was established from the
arithmetic means in Tables 2, 3 and 4. Sample calculations showing
the possible range of total coliform survival at station T-400 are
as follows:
(1) Based on actual count/100 ml:
1,100/100 ml at T-400
12,000/100 ml at T-700 x lco = 9-2 Percent survival
(2) Based on count/100 ml adjusted for dilution with water
loss:
1,300/100 ml at T-400
12,000/100 ml at T-700 x 10° = 10-8 Percent survival
(3) Based on count/100 ml adjusted for dilution without water
loss:
1.900/100 ml at T-400 v lnrt lc o
12,000/100 ml at T-700 x 10° = 15-8 percent survival
20
-------
The total coliform percent survival range at each station from T-700
to T-100 is shown in Figure 7. These data indicate that the most
rapid reduction in numbers occurred during the first 1.2 days of
flow time (T-700 to T-600) with 26.7-35.0 percent remaining viable.
The percent survival continued to decrease at each of the remaining
stations with 18.3-32.5 percent remaining viable at T-500 (2.2 days
of flow time), 9.2-15.8 percent at T-400 (3.4 days), 4.9-9.2 percent
(4.7 days), 3.8-7.8 percent (5.8 days), and 3.2-6.5 percent (7.0
days) at T-300, T-200 and T-100 respectively.
The percent survival range for fecal coliforms at each station is
presented in Figure 8, with composite winter data from Ballentine
and Kittrell (5) shown for comparison. The most rapid reduction in
numbers again occurred during the first 1.2 days of flow time with
20.2-25.6 percent remaining at T-600. The percent survival continued
to decrease at a slower rate downstream from T-600 with 12.8-22.3
percent, 8.8-15.6 percent, 4.0-7.7 percent, 2.8-5.8 percent and
2.1-4.2 percent remaining viable respectively at T-500 through
T-100. After the first 1.2 days of flow time, the fecal coliform
decrease in the Tanana River proceeded at a much slower rate than
suggested by the composite data from Ballentine and Kittrell (5).
They indicated that 0.78 percent of these bacteria remained viable
after 6 days of flow time, while the Tanana data showed that 2.1-4.2
percent remained viable after 7 days.
The enterococcus data presented in Figure 9 indicate that reduction
in numbers of these bacteria proceeds at a much slower rate than
observed with total or fecal coliforms (Figures 7 and 8). The 47.0-
60.2 percent survival at T-600 after 1.2 days of flow time contrasts
to 26.7-35.0 and 20.2-25.6 percent for total and fecal coliforms.
Because the numbers of enterococci per 100 ml did not change be-
tween T-600 and T-500 or between T-300 and T-200 (Table 4), the
percent survival either remained essentially constant or snowed an
increase depending on the method of handling discharge. In spite
of the possible discrepancies caused by the discharge measurements,
the enterococci decreased at a much slower rate than either coliform
group. This is manifested by the much higher percent survival at
all stations, 47.0-60.2, 48.2-83.1, 34.9-61.5, 24.1-44.6, 22.9-45.8
and 18.1-37.3 percent survival at stations T-600 to T-100 respectively.
The data from figures 7, 8 and 9, in which survival with dilution
and water loss was considered, are compared in Figure 10 to show
the relative rates of total coliform, fecal coliform and entero-
coccus decrease throughout the 7 days of flow time. In general,
fecal coliforms in the Tanana appear to decrease somewhat more
rapidly than total coliforms with the difference in rate becoming
more accentuated during the third through the seventh day of flow
time. Winter data from Ballentine and Kittrell (5) is also shown.
21
-------
100
50
D
(XI
h- 10
z
ui
U
tt
111 - A
a. 5.0
1.0
I
© WITHOUT DILUTION
^ WITH DILUTION (HATER Loss)
Q WITH DILUTION (No WATER Loss)
I
123456
DAYS OF TRAVEL TIME
Figure 7. Percent Survival of Total Coliform Bacteria
With and Without Discharge Consideration
22
-------
100
o WITKDW DIULTTION
0 WITH DILUTION (WATER Loss)
0 WITH DILJTION (No WATER Loss)
A COMPOSITE WINTER DATA FROM
BALLENTINE AND KITTRELL (5)
Figure 8.
1234567
DAYS OF TRAVEL TIME
Percent Survival of Fecal Coliform Bacteria
With and Without Discharge Consideration
23
-------
100
80
60
>
40
Z
ui
U
tt
ui
20
o WITHOUT DILUTION
$ WITH DILUTION (WATER Loss)
a WITH DILUTION (No WATER Loss)
I . I . I . I . I . I . I
1 234567
DAYS OF TRAVEL TIME
Figure 9. Percent Survival of Enterococcus Bacteria
With and Without Discharge Consideration
24
-------
100
o TOTAL COLIFORM
A FECAL COLIFORM
Q ENTEROCOCCUS
$ WINTER FECAL COLIFORM
BALLENTINE AND KITTRELL (5)
) 1 2 3 4 5 6 7
DAYS OF TRAVEL TIME
Figure 10. Comparison of Total Coliform, Fecal Coliform
and Enterococcus Survival
25
-------
Their composite data indicate that warmer temperatures (up to 15°C)
result in a much more rapid reduction of fecal coliform numbers than
observed in 0°C water under total ice cover. It is obvious from
this data that enterococci have a much greater capability to survive
than either total or fecal coliforms.
Several chemical parameters were measured during this study. The
results indicated that the concentration of these components in the
Chena River differed considerably from the Tanana River in nearly
all cases as shown in Table 5. Perhaps the most significant dif-
ferences were the pH and the concentrations of dissolved oxygen and
ammonia nitrogen at C-100 and T-700. As the water moved downstream
from T-700, a continuous change took place in all chemical parameters*
except for the total phosphorus concentration which remained constant.
The magnitude of these changes was small and no correlation with
bacteria survival was established.
26
-------
TABLE 5
Arithmetic Mean of the Conductivity and pH,and Concentration of
Dissolved Oxygen, Alkalinity and Nutrients at Each Sample Station
c
o
r
rtJ
C/1
C-100
T-700
T-600
T-500
T-400
T-300
T-200
T-100
a
E
.r- 0
o to
3 O
a jc
c E
o
0 3.
277
304
314
323
333
333
338
345
4-5
r
C CO
r- fO
(O
< SO
123
122
126
131
133
138
139
143
n:
OL
6.72
7.32
7.19
7.18
7.08
7.07
7.04
6.96
c
0) OJ
4J O>
10 O
i. %-r-
4^ 4^ "**v.
- -I- 0)
JSZ E
0.02
0.05
0.06
0.05
0.07
0.05
0.08
0.07
c
(d i
-> o ->.
O -c en
1 Q- E
0.05
0.01
0.01
0.01
0.01
0.01
0.01
0.01
IV3
-------
SECTION V
DISCUSSION
No doubt, the discharge measurements (Table 1) accurately reflect
the water in the river channel. However, these measurements did
indicate that the river suffered a net flow reduction in two reaches.
In view of this information, it is suggested that some volume of
water may also have been gained in these two reaches and that water
may well have been lost as well as gained in others. It was not
possible to determine the volume of water contributed by each tri-
butary and groundwater source or the volume of water lost to ground-
water reservoirs, so the actual exchange of water must remain in
the realm of speculation.
It was assumed that the fecal indicator bacteria were uniformly dis-
tributed throughout the water column. Hence, water leaving the channel
would carry bacteria with it and the effect of water entering would
be to dilute the numbers of bacteria per unit volume. Therefore,
any loss or gain in discharge would affect the apparent bacterial
survival. Because of the discharge indeterminates, the real discharge
effect on bacterial numbers could not be assessed. However, discharge
adjustment did permit a range of possible effects to be established.
Minimum survival was observed when the number of bacteria counted
per 100 ml of sample were examined without regard for discharge.
Thus, any dilution effect would tend to increase survival and the
actual percent survival probably lies somewhere between the minima
and maxima shown in Figures 7, 8 and 9. A preliminary survey, con-
ducted on the Tanana under similar conditions in 1968 (18) suggested
that survival of fecal indicator bacteria was, closer to the maxima
shown here.
These data (Figures 7, 8 and 9) show that significant numbers of
fecal indicator bacteria survive for an extended period in 0°C river
water under total ice cover. This is in agreement with previous
laboratory and field studies which indicated that survival rates
at temperatures below 15°C were greater than above 15°C (5, 9, 14,
19, 20, 21, 22, 24, 25, 30). However, the extent of survival demon-
strated in this study (Figure 10) appeared to exceed that reported
in previous field work (5, 14, 25). This higher survival rate may
have been caused by one or more factors such as lower water tempera-
ture, total ice cover, physical or chemical characteristics of the
water, or a longer time in which to conduct the study without inter-
ruption by sewage from additional sources.
29
-------
The actual disposition of the bacteria in water leaving the river
channel is unknown, but there are at least two possibilities which
are dependent on the porosity of the river bed. If the water passed
through silt, the bacteria would probably have been filtered out
in the silt. If sand or gravel were exposed, the bacteria would
have been carried some unspecified distance as the water percolated
down. The bacteria trapped in the silt constitute a potential source
of increased numbers in the river channel under flow conditions which
would resuspend the silt, and those carried through sand or gravel
represent a source of contamination for groundwater reservoirs.
The role of fecal indicator bacteria is to indicate the possible
presence of enteric pathogenic bacteria. Traditional concepts of
the indicator-pathogen relationships are being questioned in the
more temperate portions of the United States where this water quality
parameter was developed (6, 15). Thus, it is imperative that similar
questions be asked here in Alaska where lower water temperatures
occur for longer periods. Most of the available data concerning
survival of enteric pathogenic bacteria in water deal with Salmonellae.
This group of bacteria are the only enteric pathogens which can be
isolated from water with any degree of reliability; even so, satis-
factory quantitative methods for their isolation have not been developed
(15). Laboratory studies have shown that Salmonellae are capable
of growth at 5°C (23, 26). These organisms were isolated from the
Red River of the North during the winter (14), and there are indications
that they persist in streams for at Least as long as the fecal coliforms
or possibly even longer (5). Because of the much larger numbers
of coliforms than pathogens initially present, the longer survival
of coliforms relative to pathogens may be more apparent than real
(6). The presence of enteric infections in Alaska has been well
documented (11, 12, 27, 29, 35), and Salmonellae have been isolated
from the Chena River (27, 33). Since fecal indicator bacteria survive
in large numbers for extended periods in at least one subarctic river,
it is probable that pathogens can also be isolated at the same sample
stations. However, when Gallagher and Spino (15) summarized the
data from several field studies, they found little correlation between
quantities of total or fecal coliforms and the probable isolation
of Salmonellae. Thus, the question: Is there any number of fecal
indicator bacteria below which raw water can be considered safe for
human consumption? People in many villages along the rivers in Alaska
still use raw water for drinking purposes without benefit of any
form of treatment. Water consumed in some villages probably contains
enteric pathogens, and may be a source of enteric infection.
The Water Quality Standards for Alaska (1) do not cover raw water
used for drinking purposes. The minimum treatment specified is dis-
infection, and the raw water for this purpose must average less
30
-------
than 50 total coil-forms per TOO ml in any month. Since total coliforms
survive for an extended period, numbers may be far in excess of 50
per 100 ml. Therefore, it is necessary to increase awareness of
the problem, provide proper drinking water treatment facilities and
adequately disinfect effluents from sewage treatment plants.
31
-------
SECTION VI
ACKNOWLEDGEMENTS
The discharge measurements and dye study results were provided by
James Meckel, Steven Swingle, and Vernon Norman of the Fairbanks
Office, U. S. Geological Survey.
33
-------
SECTION VII
REFERENCES
1. Alaska Department of Health and Welfare, Water Quality Standards
for Interstate Waters within the State of Alaska and a Plan for
Implementation and Enforcement of the Criteria (1967).
2. Allen, L. A., Pasley, S. M., and Pierce, M. A. F., "Some Factors
Affecting the Viability of Faecal Bacteria in Water," Journal
General Microbiology, 7, pp. 36-43 (1952).
3. American Public Health Association, Standard Methods for the
Examination of Water and Wastewater, 2nd Edition, American Public
Health Association, Inc., New York (1965).
4. Anderson, G. S., "Hydrologic Reconnaissance of the Tanana Basin,
Central Alaska," U. S. Dept. of the Interior, U. S. Geological
Survey, Hydro!ic Investigations Atlas, HA 319, Sheet 2 (1970).
5. Ballentine, R. K., and Kittrell, F. W., "Observation of Fecal
Coliforms in Several Recent Stream Pollution Studies," Proceedings
of the Symposium on Fecal Coliform Bacteria in Water and Waste-
water, Bureau of Sanitary Engineering, California State Department
of Public Health (1968).
6. Berg, G., Scarpino, P. V., and Bergman, D., "Survival of Bacteria
and Viruses in Natural Waters," Dept. of the Interior, Federal
Water Pollution Control Administration (1965).
7. Brezenski, F. T., "State of the Art, Microbiological Pollution
Indicators," Dept. of the Interior, Federal Water Pollution
Control Administration, pp. 1-72 (1968).
8. Buchanan, T. J., and Somers, W. P., "Discharge Measurements
at Gaging Stations," Techniques of Water-Resources Investigations
of the United States Geological Survey, Book 3, Chapter A8, Dept.
of the Interior, U. S. Geological Survey (1969).
9. Das, H. D., and Goldstein, A., "Limited Capacity for Protein
Synthesis at Zero Degrees Centigrade in Escherichia Coli," Journal
of Molecular Biology, 31, pp. 209-226 (19687!
10. Federal Water Quality Administration, FWPCA Methods for Chemical
Analysis of Water and Wastes, Dept. of the Interior, (1969).
35
-------
11. Fournelle, J. H., Rader, V., and Allen, C., "A Survey of Enteric
Infections Among Alaskan Indians," Public Health Reports, 81,
pp. 797-803 (1966).
12. Fournelle, J. H., Wallace, I. L., and Rader, V., "A Bacterio-
logical and Parasitological Survey of Enteric Infection in an
Alaskan Eskimo Area," American Journal of Public Health, 48,
pp. 1489-1497 (1958).
13. Freeman, H. M. "Current Practices in Water Microbiology," U. S.
Dept. of the Interior, Federal Water Pollution Control Admin-
istration (1970).
14. Gallagher, T. P., Hagan, J. E., Thomas, N. A., and Spino, D. F.,
"Report on Pollution of the Interstate Waters of the Red River
of the North (Minnesota-North Dakota)," U. S. Dept. of Health,
Education and Welfare, Public Health Service (1965).
15. Gallagher, T. P., and Spino, D. F., "The Significance of Numbers
of Coliform Bacteria as an Indicator of Enteric Pathogens,"
Water Research. Pergamon Press, 2, pp. 169-175 (1968).
16. Geldreich, E. E., "Sanitary Significance of Fecal Coliforms in
the Environment," U. S. Dept. of the Interior, Federal Water
Pollution Control Administration, WP-20-3 (1966).
17. Geldreich, E. E., "Applying Bacteriological Parameters to Recrea-
tional Water Quality," Journal American Water Works Association,
62, No. 2, pp. 113-120 (1970).
18. Gordon, R. C., Unpublished Data, Environmental Protection Agency,
Alaska Water Laboratory (1968).
19. Gyllenberg, H., Niemela, S., and Sormunen, T.,- "Survival of
Bifid Bacteria in Water as Compared with that of Coliform Bac-
teria and Enterococci," Applied Microbiology. 8, No. 1, pp.
20-22 (1960).
20. Haines, R. B., "The Minimum Temperatures of Growth of Some
Bacteria," Journal Hygiene. 34, pp. 277-282 (1934).
21. Halton, J. E., and Nehlsen, W. R., "Survival of Escherichia
Coli in Zero-Degree Centigrade Sea Water," Journal Water Pol-
lution Control Federation, 40, No. 5, Part 1, pp. 865-868 (1968).
22. Hanes, N. B. Rohlich, G. A., and Sarles, W. B., "Effect of
Temperature on the Survival of Indicator Bacteria in Water,"
Eutrophication Symposium, University of Wisconsin (1966).
36
-------
23. Hendricks, C. W., and Morrison, S. M., "Multiplication and
Growth of Selected Enteric Bacteria in Clear Mountain Stream
Water," Water Research, Pergamon Press, 1, pp. 567-576 (1967).
24. Ingraham, J. L., "Growth of Psychrophillic Bacteria," Journal
of Bacteriology. 76, No. 1, pp. 75-80 (1958).
25. Kittrell, F. W., and Furfari, S. A., "Observations of Coliform
Bacteria in Streams," Journal Water Pollution Control Federation.
35, No. 11, pp. 1361-1385 (1963).
26. Matches, J. R., and Listen, J., "Low Temperature Growth of
Salmonella," Journal of Food Science, 33, pp. 641-645 (1968).
27. Miller, L., Personal communication, U. S. Public Health Service,
Arctic Health Research Center (1970).
28. Natrella, M. G., Experimental Statistics, National Bureau of
Standards Handbood 91, U. S. Dept. of Commerce, National Bureau
of Standards, pp. 2-2 and 2-3 (1963).
29. Pauls, F. P., "Enteric Disease in Alaska," Arctic, 6, pp. 205-212
(1953).
30. Shaw, M. K., "Formation of Filaments and Synthesis of Macro-
molecules at Temperatures Below the Minimum for Growth of
Escherichia coli," Journal of Bacteriology, 95, pp. 221-230
(1968).
31. Shaw, M. K., Marr, A. C., and Ingraham, J. L., "Determination
of the Minimal Temperature for Growth of Escherichia coli,"
Journal of Bacteriology, 105, pp. 683-684 (1971).
32. Skoog, D. A., and West, D. M., Fundamentals of Analytical
Chemistry, Holt, Rinehart and Winston, New York, pp. 58-60
(1963).
33. Van Donsel, D., Personal communication, U. S. Public Health
Service, Arctic Health Research Center, College, Alaska (1970).
34. Weiss, C. M., "Adsorption of E. coli in River and Estuarine
Silts," Sewage and Industrial Wastes, 23, No. 2, pp. 227-237
(1951).
35. Williams, R. B., and Dodson, M. W., "Salmonella in Alaska,"
Public Health Reports, 75, pp. 913-916 (1960).
37
-------
SECTION VIII
GLOSSARY OF TERMS
aftergrowth - increase of coliform bacteria numbers in the receiving
water after effluent discharge from a waste treatment plant.
arctic - area north of the 10°C isotherm for the warmest month and
the -10°C isotherm for the coldest month of the year.
background count - the number of coliform and enterococcus bacteria
in the water upstream from the major source of these organisms.
BOD bottle - a bottle designed for biochemical oxygen demand (BOD)
determinations and to contain samples for dissolved oxygen determina-
tion by the Winkler method.
braided - a stream flowing in several dividing and reuniting channels
resembling the strains of a braid.
count per 100 ml - standard method for reporting the numbers of bac-
teria of sanitary significance in water.
discharge - volume of water passing a given point in a stream per unit
time.
dissolved oxygen (DO) - elemental oxygen in solution.
effluent - flowing out; i.e., a sewer outfall into a stream.
enteric - pertaining to the lower intestinal tract.
enterococcus - a bacteria commonly found in significant numbers in
feces of human or other warm-blooded animals.
enteropathogen - microorganism which causes diseases in the intestinal
tract of humans or other warm-blooded animals.
fecal coliform - a total coliform bacteria subgroup which is specifically
found in the feces of humans and other warm-blooded animals.
filament - a continuous protoplasm filled tube produced by some bacteria
when cross walls, which produce normal cells, are not formed during cell
division.
gaging station - location at which the discharge of a stream is measured.
39
-------
groundwater - all water found beneath the surface of the ground.
indicator - bacteria generally found in large numbers in feces of
humans and other warm-blooded animals and when found in water indicate
the probable presence of enteropathogenic bacteria.
infiltration - movement of surface water into the ground.
isolation - separation of a species or strain of bacteria from other
bacteria which may be present as contaminants.
membrane filter method - a standard method for obtaining bacterial
cells from large volumes of water for enumeration of the number
present.
parameter - any one chemical or biological determination which defines
the condition of the system relative to that determination.
pathogen - an organism which causes a disease.
percolate - movement of water through the ground.
permeability - measure of the capacity of a material to transmit
water through its interstices.
pollution - addition to any material which tends to degrade water
quality with respect to a particular use.
primary treatment - a waste treatment process designed to remove
floating and settleable solids, and removes 30-40 percent of the
oxidizable organic material in solution, before discharge.
ure culture - a single strain or species of bacteria free from other
cteria.
raw domestic sewage - the water carried wastes from households before
it has received any form of treatment.
raw water - fresh water which is potentially useful for drinking
purposes but has received no treatment to remove foreign substances
which may be present.
Salmonellae - pathogenic bacteria which belongs in the genus Salmonella.
sterile - free from any form of life.
subarctic - areas where the mean temperature is higher than 10°C for
less than four months of the year and the mean temperature for the
coldest month is less than 0°C.
40
-------
suspending medium - any liquid in which particles are suspended; e.g.,
bacteria in water.
temperate climate - any area north of the Tropic of Cancer not pre-
viously defined as arctic or subarctic.
total coliform - heterogeneous group of bacteria which meet certain
morphological and biochemical criteria, and are found in feces of
human and other warm-blooded animals, as well as in other environ-
mental situations.
viable - bacterial cells capable of growth and reproduction if appro-
priate conditions are present.
water column - a volume of water extending from the surface to the
bottom of a water body.
water mass - a unit volume of water traveling more or less as a
discrete unit.
41
-------
SELECTED WATER i. Report No.
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
2. 3. Accession No.
w
4. Title WINTER SURVIVAL OF FECAL INDICATOR BACTERIA 5. ReportDate
IN A SUBARCTIC ALASKAN RIVER ,.
8. Performing Organization
7. Author(s) , Report No.
RONALD C. GORDON
10. Project No.
16100 FHB
11. Contract/Grant No.
9. Organization
ENVIRONMENTAL PROTECTION AGENCY, OFFICE OF RESEARCH AND
MONITORING, ALASKA WATER LABORATORY, COLLEGE, ALASKA
13. Type of Report and
. Period Covered
12. Sponsoring Organization
IS. Supplementary Notes
Environmental Protection Agency report
number EPA-R2-72-013, August 1972.
i . bstract survival of fecal indicator bacteria in a subarctic Alaskan river was
studied during the winter of 1969-70 when there was total ice cover and the water
temperature was 0°C. Most of the domestic pollution entered downstream from this
source. Since no additional pollution entered downstream from this source, an uninter-
rupted study covering 7 days of flow time (210 river miles) was possible. Nine sample
stations were established to obtain total coliform, fecal coliform, enterococcus and
water chemistry data. Samples were collected four to eight times from each station
during the 2-week period of data collection, and a discharge measurement was made at
each station during the same period. Bacteria survival was examined with and without
consideration for the effect of dilution. After 7 days flow time, total coliforms
were reduced to 3.2-6.5 percent of the initial count, fecal coliforms to 2.1-4.2
percent, and the enterococci to 18.1-37.3 percent depending on dilution consideration.
17a. Descriptors
*Rivers,*Enteric Bacteria, *Winter, *Coliforms, *Bioindicators, *Streptococcus,
*Bacteria, Alaska, Water Pollution, Water Temperature, Discharge Measurement,
Dissolved Oxygen, Conductivity, Alkalinity, Nitrogen Compounds, Hydrogen Ion
Concentration, Phosphorus Compounds
17b. Identifiers
*Subarctic, *Total Coliforms, *Fecal Coliforms, *Enterococcus, *Survival
17c. COWRR Field & Group
18. Availability 19. Security Class.
(Report)
20. Security Class.
(Page)
Abstractor I Institution
21. No. of Send To:
Pages
22 Price WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OFTHE INTERIOR
WASHINGTON. D. C. 20240
WRSIC 102 (REV. JUNE 1971) GPO 913.261
*U. S. GOVERNMENT PRINTING OFFICE : 1 972 514-11(6 (27)
-------