S&A-TSB-6
BACTERIOLOGICAL INVESTIGATIONS
OF THE UPPER SOUTH PLATTE RIVER BASIN
MAY 1972
JULY 1972
SEPTEMBER 1972
BACTERIA
COLONIES
SOUTH
\\\ DENVER
W\W,\
TECHNICAL SUPPORT BRANCH
SURVEILLANCE AND ANALYSIS DIVISION
ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
DECEMBER, 1972
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BACTERIOLOGICAL INVESTIGATIONS
of the
UPPER SOUTH PLATTE RIVER BASIN
MAY, 1972
JULY, 1972
SEPTEMBER, 1972.
TECHNICAL SUPPORT BRANCH
SURVEILLANCE AND ANALYSIS DIVISION
ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
DECEMBER, 1972
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TABLE OF CONTENTS
Section Page
I. Summary 1
II. Introduction . 1
III. Study Description and Field Procedures 2
IV. Results and Discussion
General 4
Comparison With Present Class "A" Standards .... 6
Comparison With Proposed Class "B3" Standards ... 18
Rainfall Effects ..... 22
Comparison With 1971 Survey 29
V. Conclusions and Recommendations 29
VI. Acknowledgements 30 -
VII. References 31
VIII. Appendix A - Data Presentation 32
IX. Appendix B - Sample Station Descriptions 43
ii
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3
5
7
10
13
15
16
19
20
21
23
26
LIST OF FIGURES
Map of Water Quality Survey Areas
Map of the South Platte River Study Area
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For May, 1972 Survey
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For All Days During July, 1972 Survey
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For September, 1972 Survey
Map of Bear Creek Study Area
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For Bear Creek Survey
Average Total and Fecal Coliform Concentrations vs River
Miles For May, 1972 Survey
Average Total and Fecal Coliform Concentrations vs River
Miles For July, 1972 Survey
Average Total and Fecal Coliform Concentrations vs River
Miles For September Survey
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For Days Affected By Rainfall—July 17-18, 1972 .
Log-Mean Total and Fecal Coliform Concentrations vs River
Miles For Days Unaffected By Rainfall—July 12, 13, 14,
19, 20, 1972
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LIST OF TABLES
Number Page
1. Summary of Total and Fecal Coliform Concentrations For
Selected Stations on the South Platte River - Survey of R
May, 1972
2. Summary of Total and Fecal Coliform Concentrations For
Selected Stations on the South Platte River - Survey of
July, 1972 11
3. Summary of Total and Fecal Coliform Concentrations For
Selected Stations on the South Platte River - Survey of
September, 1972 14
4. Summary of Total and Fecal Coliform Concentrations For
Selected Stations - Bear Creek Survey - September and
October, 1972 17
5. Summary of Total and Fecal Coliform Concentrations For
Selected Stations on the South Platte River For Days
Affected By Rainfall - July 17-18, 1972 24
6. Summary of Total and Fecal Coliform Concentrations For
Selected Stations on the South Platte River For Days
Unaffected By Rainfall - July 12, 13, 14, 19, 20, 1972 . . 27
i v
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SECTION I
Summary
The Region VIII EPA office has proposed upgrading the South Platte River
above Denver, Colorado from Class "A" to Class "B3" to provide for body-contact
water recreation. To determine if the present water quality is within the pro-
posed compliance level (B3 - average of 100 fecal coliform/100 ml) three field
surveys were conducted on a 13 mile reach of the river during different flow
conditions and different seasons of the year. Results from these surveys
indicate that the proposed upgrading to Class "B3" is feasible if severfl
abatement actions are taken. A tributary stream, Bear Creek, was found to be
highly contaminated with fecal coliform originating from the area of Evergreen,
Colorado.
SECTION II
Introduction
Headwaters of the South Platte River originate on both the east slope of
the Rocky Mountains and also on the west slope via transbasin diversions. A
portion of this high quality water is impounded in storage reservoirs upstream
of major urban areas and the remainder flows directly down to Denver through
the Platte Canyon. As the water flows toward the highly urbanized Denver Metro
area it is impacted by increasing numbers of waste discharges and natural
tributaries.
The South Platte River upstream from Denver is presently used for body
contact recreation (wading, swimming, and tubing), and additional water-oriented
recreation projects are proposed (Littleton Flood Plain Park) or under con-
struction (Chatfield Dam and Reservoir). Although the river is used for body-
contact recreation, the present stream classification (Class "A") does not
provide for such use. The present Class "A" stream classification provides for
a bacteriological quality in the river "not to exceed a log-mean fecal coliform
density of 1000 per 100 ml or 2000 per 100 ml in more than 10% of the samples
collected in any 30 day period" (Ref. 1). Water of this quality is not currently
recognized as being safe for body-contact recreational use.
In a continuing movement toward improved water quality, the South Platte
River Basin has been selected as one of Region VIII's highest priority areas
for an abatement and control program (Ref. 2). Accordingly, it is a primary ¦
regional objective to upgrade the classification of the South Platte River
upstream from Union Avenue in Littleton, Colorado, to the "B3" level - that
which safely permits body-contact water recreation. This "B3" classification
calls for a bacteriological standard as follows:
1
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"Total coliform density shall not exceed 1000 per 100 ml as a monthly
average or exceed this number in 20 percent of the samples examined during
any month-, nor exceed 2400 per 100 ml in a single sample. The fecal coli-
form shall not exceed 100 per 100 ml and fecal streptococcus shall not exceed
20 per 100 ml, both of these fecal coliform limits are to be the average of
five consecutive samples within a month" (Ref. 1).
SECTION III
Study Description and Field Procedures
There is a small amount of existant data which indicates that the
bacteriological quality of this 13 mile reach of the South Platte River may
be less than the "Bo" compliance level. Therefore, the Region embarked on a
field study program to accurately determine bacteriological quality during
different flow conditions and different seasons of the year. The basic
objective was to determine whether, in fact, the bacteriological quality was
within the compliance level or whether reduction in total and fecal coliform
levels is required by abatement and control actions.
Field surveys were conducted in May, July, and September, 1972, as a
part of the study program. Each of the three surveys covered the 13 mile
stretch of the South Platte River from Union Avenue to Waterton, Colorado
(RM 328 to 341). The general study area is depicted in Figure 1 which shows
the South Platte River and several tributaries in the Denver Metropolitan
area. The first study was initiated during May in conjunction with an in-
plant survey at the Littleton Sewage Treatment Plant. The timing of the
survey also coincided with a relatively high flow condition on the South
Platte River (about 200 cfs near the treatment plant). Sampling occurred
on May 15, 16, 18, 22, and 23. A total of 20 river samples were collected
from four sample locations within the reach and one sample site downstream
from river mile 328. At each sample location daily grab samples were taken
using a sterile 250 ml wide-mouth bottle. Each sample was identified with
the following field data: station number, temperature, time, and remarks;
e.g.,^depth and visual condition of water being sampled, chlorine content,
etc. The samples were then analyzed for total and fecal coliforms by the
millipore filter technique at the Littleton Sewage Treatment Plant.
A second, more intensive study was conducted during July to gather
additional bacteriological data at lower flow conditions as well as to locate
and sample all significant waste discharges to the river. It was determined
after the survey, however, that the river flow during the survey averaged
about 210 cfs, or slightly more than during the May survey. Approximately
25 separate discharges were identified during a foot reconnaissance of the
13 mile study area conducted in conjunction with the water sampling on
July 12, 13, 14, 17, 18, 19, and 20. Of these 25 discharges only seven were
considered significant enough to warrant sampling. In order to determine the
bacteriological impact on the river from these seven discharges, river samples
were collected above and below the individual discharge points. In total, 120
river samples and 3 Brush Creek (tributary stream)samples were collected from
2
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3
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20 locations during the July survey.
The final survey was initiated during the last week of September
to provide additional bacteriological data during low flow conditions.
USGS flow measurements indicate that river flow averaged about 46 cfs
during the survey. Sampling was conducted from September 25 to 29 with
a total of 50 samples collected at 11 locations on the South Platte River,
Bear Creek, and Brush Creek. Most of the South Platte and Brush Creek
locations had been previously sampled during the May and July surveys,
but the Bear Creek locations were being sampled for the first time. The
Bear Creek samples yielded fecal coliform counts of sufficient magnitude
to warrant a closer look at bacteriological conditions in the stream.
Therefore, a one day sample run was made on October 5 covering 12 Bear
Creek locations between Morrison and Evergreen, Colorado.
Each of the three South Platte River surveys included sample stations
which are sampled periodically by the Denver Water Board and/or the Denver
Regional Council of Governments. These stations include the following:
SP-7 Bowles Avenue Bridge
SP-25 Highway 470 Bridge
SP-30 Waterton USGS Stream Gaging Station
All sampling locations for these surveys are shown on the map in
Figure 2 and are described in Table 1 in Appendix B.
SECTION IV
Results and Discussion
General
The findings of the foot reconnaissance conducted during the July
survey help to explain the bacteriological results from each of the three
surveys. This reconnaissance pinpointed the location of about 25 discharges
to the South Platte River in the 13 mile study area. The majority of these
discharges were attributable to irrigation return flow from residential
areas, agricultural areas, parks, and golf courses. These flows were
estimated to range from 5 to 75 gpm. Sampling for bacteriological analysis
was conducted at seven locations during July where discharges were thought
to have a significant impact on the river water quality. These discharges
included the following:
1 - 5 to 10 gpm of surface runoff from the horse barns at the Centen-
nial Racetrack grounds just upstream from Belleview Avenue. Located
between stations SP-2 and SP-3.
4
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2-20 gpm of irrigation return flow located 100 yards upstream from
the Crestline Avenue bridge. Located between stations SP-4 and
SP-5.
3-20 gpm of irrigation return flow located just upstream from the
Littleton water storage ponds, Located between stations SP-6
and SP-7.
4 - Lee Gulch containing an estimated flow of 100 - 150 gpm. Located
between stations SP-14 and SP-15.
5 - A $mall moss-choked creek carrying 100 - 150 gpm through farm and
pastureland upstream from the Bowles Avenue bridge. Located between
stations SP-16 and SP-17.
6-75 gpm of irrigation return flow just upstream from the Cooley
Gravel Company bridge. Located between stations SP-18 and SP-19.
7 - Brush Creek, containing an estimated flow of 100 gpm, most of which
is wastewater from the Martin Marietta Company. Located between
stations SP-29 and SP-30.
Another significant discharge noted in September but not sampled was the
effluent from the filter sand washing operation at the Kassler Water Treat-
ment Plant at Wgrterton. It consisted of about 75 gpm of highly turbid
wastewater which has caused silt buildup for 100 yards or more along the
north bank of the South Platte River. This discharge is in violation of the
State of Colorado Narrative Water Quality Standard (Section B) which states
that all waste must be "free from substances that will form objectionable
bottom deposits" (Ref. 1). Two gravel washing operations (Peter Kiewit
and Sons and Cooley Gravel Company) also discharge small, fairly clear
wastewater flows to the river just below the Highway 470 bridge (SP-25).
Comparison With Present Class "A" Standard
The findings of the foot reconnaissance presented above explain many
of the irregularities evident in Figures 3, 4, and 5 showing coliform con-
centrations vs. river miles for each of the three surveys. Figure 3 and
Table 1 present the results of the May survey where coliform concentrations
are log-mean values and river miles begin with zero at the Union Avenue
bridge (SP-1) and increase in the upstream direction. A degradation of
water quality in passing from upstream to downstream stations is evident
from Figure 3. This is expected because of increasing urbanization and
the associated surface discharges noted in the foot reconnaissance. Table
1 in Appendix A shows that on May 18 an unusually high total coliform
count was obtained for some unexplained reason at the Bowles Avenue station
(SP-7). This caused the log^mean total coliform value at Bowles Avenue to
be higher than the downstream station at Union Avenue (SP-1) (See Figure 3).
6
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FIGURE 3
Log-Mean Total and F^cpl Coliform Concentrations vs
River Miles For May, 1972 Survey
7
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TABLE 1
SUMMARY"OF TOTAL AND FECAL COLIFORM CONCENTRATIONS FOR SELECTED
STATIONS ON THE SOUTH PLATTE RIVER - SURVEY OF-MAY-, 1972
Total Col i forms/100 ml Fecal Col iforms/100 ml
Sta.
#
#
Samples
Maximum
Minimum
Log-Mean
Value
#
Samples
Maximum
Mi n i mum
Log-Mean
Value
SP-0
3
5600
180
566
3
480
27
128
SP-1
2
200
170
184
2
170
90
124
SP-7
5
1100
72
241
5
130
45
70
SP-25
5
280
47
139
5
110
5
29
SP-30
5
270
10
64
5
30
<5
14
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Approved Colorado water quality standards for the South Platte River
upstream from the Union Avenue bridge (SP-1) specify that "fecal coliform
densities must not exceed a log mean value of 1000 per 100 ml nor 2000 per
100 ml in more than 10% of the samples collected in any 30 day period"
(Ref, 1). This bacteriological standard (Class "A") was not exceeded at
any station during the May survey.
The results of the July survey are presented in Figure 4 and Table 2.
Figure 4 shows that fecal and total coliforms were higher at the upper and
lower stream reaches than in the middle.
As mentioned earlier in discussing the May survey, the lower stream
reach is affected by increasing urbanization and the associated surface
runoff from irrigation and other sources. The discharges noted in the foot
reconnaissance impact the river and produce the erratic plot shown in
Figure 4. The bacteriological quality of the upper stream reach is affected
primarily by Brush Creek (carrying Martin-Marietta Company wastewater) and
pther undefined sources further ud the South Platte Canyon. Althouah
increased coliform levels were found in both the upper and lower stream
reach, the approved (Class "A") Colorado water quality standard was not
exceeded during the July survey.
The results of the September survey are presented in Table 3 and shown
graphically in Figure 5. As in the July survey a trend can be observed which
shows higher coliform levels at the upper and lower stream reaches than in
the middle. Again, this increase in the lower stream reach (around Bowles
Avenue) is due to increased urbanization and associated runoff, while the
upper reach appears to be most affected by the discharge from the Martin
Marietta Company (in Brush Creek). In neither reach, however, were there
sufficiently high coliform concentrations to produce violations of the present
Class "A" bacteriological standard.
As mentioned earlier, a one day sample run covering 13 stations was made
on October 5 on Bear Creek between Morrison and Evergreen, Colorado. These
stations are located on the map in Figure 6 and are described in detail in
Table 2 in Appendix B. The survey was initiated to try to determine the
cause of the high fecal coliform counts (2600 per 100 ml) observed at
Morrison during the South Platte River survey of July, 1972. A summary of
the bacteriological data is presented in Table 4 and has been used to plot
coliform concentrations vs. river miles in Figure 7. The complete survey
data is presented in Table 4 in Appendix A.
Except for stations BC-1 and BC-2, the data in Figure 7 is based upon
only one bacteriological analysis at each station. However, the results in
Figure 7 are quite clear - domestic wastes (in terms of fecal coliforms) from
the Evergreen, Colorado, area cause gross pollution of Bear Creek for several
miles downstream. The sewage treatment facility at Evergreen was evidently
not providing adequate disinfection of the treated effluent on October 5.
Increased operational efficiency and control (hopefully to be accomplished
through a proposed plant expansion) is necessary at this plant if the present
Class "A" compliance level for Bear Creek (less than a log-mean value of
1000 .fecal coliforms per 100 ml) is to be achieved. There is currently no
plan for upgrading Bear Creek above the "A" level.
9
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LOG-MEAN COLIFORM VALUE PER 100 MLS
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TABLE 2
SUMMARY OF TOTAL AND FECAL COUFORM CONCENTRATIONS FOR SELECTED
STATIONS ON THE SOUTH PLATTE RIVER - SURVEY OF JULY, 1972
Total Coliforms/100 ml Fecal Col iforms/100 ml
#
iples
Maximum
Minimum
Log-Mean
Value
#
Samples
Maximum
Minimum
7
1200
100
238
7
230
30
7
5700
65
345
7
1300
28
7
320
67
157
72
30
1800
110
265
7
180
-19
7
360
45
136
7
94
28
7
.450
68
201
7
200
39
7
2700
34
111
7
260
8
6
2100
46
214
€
250
25
6
1700
18
150
6
57
15
6
290
25
75
6
100
20
6
210
16
65
6
80
8
7
240
22
87
7
75
TO
7
830
17
94
7
130
2
7
470
29
90
7
40
4
6
2600
C 4
238
6
150
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Table 2
- 2 -
Total CoTiforms/100 ml Fecal Col iforms/100 ml
Sta. $ tog-Mean # Log-Mean
#
Samples
Maximum
Minimum
Value
Samples
Maximum
Minimum
Value
SP-29-A
3
5400
140
1526
3
95
<4
29
SP-29-B
3
400
220
291
3
40
25
33
SP-30
7
290
40
137
7
110
16
43
SP-31
5
290
88
179
5
78
33
50
SP-32
5
330
68
159
5
150
51
77
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FIGURE 5
RIVER MILES ABOVE UNION AVENUE
13
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TABLE 3
SUMMARY OF TOTAL AND FECAL COL IFORM CONCENTRATIONS FOR SELECTED
STATIONS ON THE SOUTH PLATTE -RIVER - SURVEY OF SEPTEMBER, 1972
Total Coliforms/100 ml
Sta.
' #
Log-Mean
#
Samples
Maximum
Minimum
Value
SP-1
5
330
92
169
SP-2
5
380
140
221
SP-7
5
450
-68
196
SP-18
5
650
62
116
SP-25
5
160
44
106
SP-29
5
2700
100
712
SP-29-A
1
59
59
59
SP-30
5
110
61
80
Fecal Coliforms/100 ml
# Log-Mean
Samples Maximum Minimum Value
5 320 40 85
5 180 23 70
5 170 36 82
5 40 12 19
5 40 14 26
5 130 25 49
1 9 9 9
5 76 12 35
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FIGURE 6 Map of Bear Creek Study Area
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FIGURE 7
Log-Mean Total and Fecal Coliform Concentrations
vs River Miles For Bear Creek Survey
2000 -
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BEAR CREEK MILES ABOVE CONFLUENCE WITH SOUTH PLATTE
16
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TABLE 4
SUMMARY OF TOTAL AND FECAL COLIFORM
CONCENTRATIONS FOR SELECTED STATIONS
BEAR CREEK SURVEY - SEPTEMBER & OCTOBER, 1972
Sta.
Total Coliforms/100 ml
Fecal Coliforms/100 ml
Log-Mean
#
Samples
Maximum
Minimum
Value
Samples
Maximum
Minimum
BC-1
7
8,800
2,000
4,360
7
2,600
100
BC—1-A
1
470
470
470
1
56
56
BC-2
7
18,000
350
4,090
7
3,300
90
BC-3
1
10,000
10,000
10,000
1
1,200
1,200
BC-4
1
12,000
12,000
12,000
1
1,200
1,200
BC-5
1
25,000
25,000
25,000
1
1,400
1,400
BC-6
1
42,000
42,000
42,000
1
2,600
2,600
BC-7
1
85,000
85,000
85,000
1
5,000
5,000
TG-1
1
150
150
150
1
16
16
BC-8
1
170,000
170,000
170,000
1
140,000
140,000
BC-9
1
160,000
160,000
160,000
1
34,000
34,000
BC-10
1
100
100
100
1
5
5
Log-Mean
Value
620
56
580
1 ,200
1 ,200
1,400
2,600
5,000
16
140,000
34,000
5
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Comparison With Proposed_C1ass "Bg" Standard
As the three South Platte River surveys have shown, there has been no
violation of the present Class "A" stream standard in the reach upstream
from the Union Avenue Bridge (SP-1). However, a primary concern is to check
the survey results against the proposed "B311 stream standard for this same
reach.
In order to compare the bacteriological results from the three surveys
with the proposed "B3" stream classification for fecal coliforms, it is
necessary to plot the arithmetic average of five consecutive samples at
each station, choosing the sample grouping which will produce the highest
average fecal coliform count. To compare total coliform values with the
"B3" standard, the arithmetic average of total coliform counts for all
sample days of the month must be calculated and plotted. These two plots
have been made for each of the three surveys in Figures 8, 9, and 10 re-
spectively.
When the results of Figures 8, 9, and 10 are compared to the total
coliform standard under the proposed "B3" classification, it is observed
that all total coliform concentrations were in compliance at all stations
during the May survey. The same was the case during the July survey with
the exception of the Belleview Avenue station (SP-2). As discussed later,
this high value is thought to be due to rainfall effects. During the
September survey the only station showing a total coliform concentration in
excess of the "63" standard was SP-29, located just below the confluence with
Brush Creek. The cause of the high total coliform concentration is attrib-
utable to either the discharge from the filter sand washing operation at the
Kassler Water Treatment Plant or the discharge coming down Brush Creek from
the Martin-Marietta Company. The exact cause was not conclusively identified.
Fecal coliform concentrations were found to be within the "B3" compliance-
level at all but one station (SP-1) during the September and May surveys.
An unexplained high fecal coliform count (320 per 100 ml) at SP-1 on Septem-
ber 25 caused the calculated five-day average value to exceed the "B3" level
at this station during September. During the May survey, only two samples
were collected at SP-1, as opposed to the five which are required by the
"B3" standard. The results at this station during May must, therefore, be
considered questionable.
During the July survey, non-compliance levels were observed at four
stations:
(1) Union Avenue (SP-1)
(2) Belleview Avenue (SP-2)
(3) 150 yards downstream from the Bowles Avenue Bridge (SP-6)
(4) Bowles Avenue (SP-7)
The explanations for these violations are discussed in the following section
under rainfall effects.
18
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FIGURE 8
Average Total arid Fecal Col iform Concentrations vs
River Miles For Hay, 1972 Survey
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RIVER MILES ABOVE UNION AVENUE
19
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1000 -
FIGURE
Average Total and Fecal Coliform Concentrations vs
River Miles For July, 1972 Survey
500
400
CO
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RIVER MILES ABOVE UNION AVENUE
20
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FIGURE 10
1000 -
Average Total and Fecal Coliform Concentrations vs
River Miles For September Survey
1330
500 -
250 "
100
75
50
TOTAL COLIFORMS
(ALL DAYS)
PROPOSED "B3" FECAL COLIFORM STANDARD
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^ FECAL COLIFORMS
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RIVER MILES ABOVE UNION AVENUE
21
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An arithmetic average concentration of 222 fecal coliforms per 100 ml
was also obtained at the Hamilton Street Bridge (SP-0). However, this loca-
tion is downstream from that reach of the South Platte River for which an
upgrading to the "B3" classification is proposed.
Rainfall Effects
Rainfall on the upper South Platte drainage basin has been suggested
as one of the possible reasons for the bacteriological degradation of the
river during part of the July stream survey. Significant rainfall occurred
throughout the survey area on July 17 and in the upper foothills area on
July 18. In order to determine the impact of this rainfall and the associated
surface runoff on the river water quality, bacteriological data for only these
two days has been listed in Table 5 and plotted as an average in Figure 11.
All other data for the July survey is listed and plotted in Table 6 and
Figure 12, respectively.
An examination of Figures 11 and 12 reveals that total and fecal
coliform densities were higher by as much as a factor of six at station
SP-19 (RM4.6) on the days affected by the rainfall when compared to data
from days unaffected by rainfall. This trend is discernible to a less
extent at.most of the other stations. In particular, station SP-2 (RM 0.8)
which is located about 100 feet below the discharge from the Centennial
Racetrack horsebarns (identified during the foot reconnaissance) had unusually
high coliform concentrations due to increased surface runoff from these barns.
A similar condition existed at stations SP-6 and SP-7 (RM 1.7 and 1.8,
respectively) below the reach of stream to which several small runoff sources
(irrigation return flows) are tributary. It is likely that higher than
normal coliform concentrations will be found in the upper South Platte during
most periods of significant rainfall because of runoff from adjacent urban
and agricultural lands.
If the proposed "B3" compliance level is to be achieved the surface
runoff from the Centennial Racetrack horsebarns must be prevented from
entering the river. A small leaching pond would adequately serve to catch
this runoff under most conditions. The other reach of stream in violation
of the "B3" standard (RM 1.7 to 1.8) during runoff conditions would not be
so ammeanable to control and/or abatement action because of the scattered
locations of the surface runoff sources (including irrigation return water)
in the immediate residential area. The Dumb Friends League maintains an
animal shelter near the ditch carrying this surface runoff to the river,
and any wastewater sources at the shelter should be controlled to prevent
fecal coliform contamination of nearby surface waters. Since the proposed
"B3" standard was exceeded by only about 2% due to the sources mentioned
above, it is unlikely that severe bacteriological pollution of the South
Platte River in this reach (RM 1.7-1.8) will occur even during periods of
rainfall.
22
-------
FIGURE 11
5000
log-Mean Total and Fecal Coliform Concentrations vs River
Miles For Days Affected By Rainfall—July 17-18, 1972
2500
4 6 8 10
RIVER MILES ABOVE UNION AVENUE
23
-------
TABLE 5
SUMMARY OF TOTAL AND FECAL COLIFORM CONCENTRATIONS
FOR SELECTED STATIONS ON THE SOUTH PIATTE RIVER
FOR DAYS AFFECTED BY RAINFALL - JULY 17 AND 18, .19.72
Total Col i forms/100 ml Fecal Coli forms/100 ml
Sta.
#
#
Samples
Maximum
Mi ni mum
Log-Mean
Val ue
#
Samples
Maximum
Minimum
Log-Mean
Value
SP-1
2
1200
500
775
2
190
90
131
SP-2
2
5700
320
1350
2
1300
80
322
SP-3
2
320
270
294
2
60
30.
42
SP-4
2
1800
210
615
2
150
52
88
SP-5
2
360
250
300
2
55
52
53
SP-6
2
450
280
355
2
200
97
139
SP-7
2
2700
740
1413
2
260
57
122
SP-14
2
2100
720
1230
2
250
25
79
SP-15
2
1700
170
538
2
57
40
48
SP-16
2
290
160
215
2
100
55
74
SP-17
2
210
170
189
2
80
35
53
SP-18
2
240
190
216
2
75
45
58
SP-19
2
830
410
583
2
130
40
72
SP-25
2
470
240
336
2
40
37
38
SP-29
2
2600
1000
1612
2
100
39
62
-------
Table 5
Total Coliforms/I00 ml
Sta. If Log-Mean
# Samples Maximum Minimum Value
SP-30 2 290 230 258
SP-31 2 290 220 253
SP-32 2 330 230 275
PO
cn
! Fecal Col i forms/100 ml
1 Log-Mean
Samples Maximum Minimum Value
2 62 47 54
2 78 50 62
2 150 110 128
-------
FIGURE 12
Log-Mean Total and Fecal Coliform Concentrations vs River Miles
For Days Unaffected By Rainfall—July 12, 13, Ik, 19, 20, 1972
RIVER MILES ABOVE UNION AVEInIUE
i
26
-------
¦1
-2
-3
-4
-5
¦6
•7
-14
¦15
¦16
•17
18
19
•25
29
j-ii
far
86
65
56
53
56
58
34
36
23
36
15
16
12
12
26
TABLE 6
SUMMARY OF TOTAL AND FECAL COLIFORM CONCENTRATIONS
FOR SELECTED STATIONS ON THE SOUTH PLATTE RIVER
FOR DAYS UNAFFECTED BY RAINFALL - JULY 12,13,14,19 AND 20, 1972
Total Col iforms/100 jnl Fecal Col i forms/100 ml
Log-Mean I
Samples
5
5
5
5
5
5
5
4
4
4
4
5
5
5
4
Maximum
Minimum
Value
Samples
Maximum
Minimum
370
100
149
5
230
30
640
65
200
5
100
28
260
67
122
5
72
32
330
no
189
5
180
19
210
45
99
5
94
28
400
68
160
5
120
39
310
34
110
5
110
8
140
46
90
4
44
25
180
18
79
4
32
15
84
25
44
4
62
20
78
16
38
4
32
8
130
22
61
5
24
10
120
17
45
5
22
2
100
29
53
5
27
4
770
4
91
4
150
4
-------
Table 6
-2-
Total Coliforms/100 ml
Sta. # Log-Mean
_# Samples Maximum Minimum Value
SP-30 5 260 40 107
SP-31 3 220 88 143
SP-32 3 210 68 111
ro
Co
Fecal Col iforms/100 ml
I Log-Mean
Samples Maxi mum Minimum Value
5 110 16 40
3 72 33 43
3 56 51 54
-------
Comparison With Earlier Survey
The National Field Investigations Center - Denver (NFIC-D) conducted
a short term water quality survey on the upper South Platte River in late
August, 1971 (Ref. 3). During that survey three bacteriological samples
were collected at Bowles Avenue (SP-7) and at Waterton (SP-30). The log-
mean values for total and fecal coliforms were 1200 per 100 mis and 280
per 100 mis, respectively, at Bowles Avenue and 580 per 100 mis and 20 per 100
mis, respectively, at Waterton. The fecal coliform log-mean values for the
NFIC-D survey are shown by the dotted line in Figure 12. Also shown in
Figure 12 are the log-mean fecal coliform values determined during the
Region VIII survey of July, 1972, for only those days unaffected by rainfall.
The fecal coliform data from the July survey indicates a two-fold decrease
in concentration at Bowles Avenue (SP-7) when compared to results from the
May and September surveys, and an eight-fold reduction when compared to the
1971 NFIC-D survey. A variety of explanations are possible for the differ-
ences in the survey results, including insufficient data collection during
the NFIC-D survey, variations in river and wastewater flows, underground
seepage, construction in the survey area, and other factors. The fact that
the river flow in July, 1972 was only 50% of the flow in August, 1971 (during
the NFIC-D survey) may be the most plausible explanation, however.
SECTION V
Conclusions and Recommendations
The survey findings which relate to the occurrance and distribution
of total and fecal coliforms are the following:
1. The existing fecal coliform standard for that portion of the
river classified as a potable water supply (Class "A") was not
exceeded during the May, July, or September surveys.
2. The proposed fecal coliform standard for body-contact water
recreation (Class "B^") was exceeded at one out of four stations
in May, four out of nineteen stations in July, and one out of
seven stations in September.
3. The proposed total coliform standard (Class "B3") was exceeded
at no stations in May, 1 out of 19 stations in July, and one
out of seven stations in September.
4. Violations of the proposed total and fecal coliform standards
(Class "B3") during the July survey may be attributed to the
occurrance of rainfall in the survey area on July 17 and 18.
5. Total and fecal coliform concentrations in the upstream Waterton
area (RM 13.1) were higher than in the lower stream reach (RM 6.0)
because of discharges from the Martin-Marietta Company (via Brush
Creek) and other undefined sources further upstream. The observed
29
-------
coliform concentrations near Waterton did not exceed the
proposed "B^" compliance level, however.
6. Inadequately treated domestic sewage from the Evergreen, Colorado,
area produces gross bacteriological pollution in Bear Creek
(14,000 fecal coliforms per 100 mis) which exceeds the present
Class l!A" stream standard. An expansion program is being developed
at this facility and should abate much of the existing pollution.
7. Data from the three surveys of May, July, and September does not
confirm the high fecal coliform counts found in the upper South
Platte River at Bowles Avenue (RM 1.8) during the September, 1971,
NFIC-D survey. Variation in river flow is the most plausible
explanation for the differences in coliform concentrations.
8. The upstream reach of the South Platte River above the Union Avenue
Bridge (SP-1) meets the "Bo" standard for body-contact water recrea-
tion at most times except during periods of storm runoff. Abatement
actions necessary to achieve the proposed "B3" bacteriological
standard as well as the present narrative standard at all times
(except during major runoff periods) are the following:
(a) Control the periodic discharge from the Centennial Racetrack
horse barns by diversion into a leaching pond.
(b) Construct a settling pond to hold the suspended solids
contained in the wastewater from the filter sand washing
operation at the Kassler Water Treatment Plant.
If these abatement actions can be effected, a "63" classification
of this reach of the South Platte River is feasible.
SECTION VI
Acknowledgements
The assistance and cooperation of the personnel at the Littleton,
Colorado Sewage Treatment Plant is gratefully acknowledged.
30
-------
SECTION VII
References
1. Colorado Mater.Quality Standards Summary, Water Pollution Control
Commission, Colorado Department of Health, May 1, 1972.
2. Accomplishment Plan - Water Quality Region VIII, South Platte River
Basin, by the'Environmental Protection Agency, Rocky Mountain - Prairie
Region, Denver, Colorado, June 5, 1972.
3. Report on Water Quality Investigations in the South Platte River Basin,
Colorado, 1971-72 by National' Field Investigations Center - Denver and
Region VIII, Denver, Colorado, June, 1972.
31
-------
SECTION VIII
Appendix A
Data Summaries
32
-------
TABLE 1
SOUTH PLATTE RIVER SURVEY DATA
MAY, 1972
Station Coliform Counts/100 ml
#
Date
Time
Total
Fecal
SP-0
5-18
0930
5600
480
5-22
1110
180
160
5-23
1236
180
27
SP-1
5-22
0950
200
170
5-23
1152
170
90
SP-7
5-15
1525
72
62
5-16
1207
140
60
5-18
1125
1100
130
. 5-22
1020
430
80
5-23
0930
170
45
SP-25
5-15
1615
90
5
5-16
1110
47
24
5-18
1025
280
no
5-22
1005
220
30
5-23
0900
200
50
SP-30
5-15
1600
10
<5
¦ 5-16
1130
25
6
5-18
1045
120
25
5-22
0955
130
30
5-23
0915
270
22
33
-------
TABLE 2
SOUTH PLATTE RIVER SURVEY DATA
JULY, 1972
Water Chlorine
Station Temp. Coliform Counts/100 ml Residual
# Date Time QC Total Fecal mq/1
SP-1
SP-2
SP-3
Date
Time
OC
Total
Feca"
7-12
0943
17
150
100
7-13
0956
18.5
100
84
7-14
0820
16
120
30
7-17
0942
14
1200
190
7-18
0927
15.5
500
90
7-19
0842
16
370
230
7-20
0821
16.5
110
80
7-12
0957
17
180
28
7-13
0947
18.5
640
100
7-14
0826
16
65
52
7-17
0949
14
320
80
7-18
0935
15
5700
1300
7-19
0849
16.5
330
72
7-20
0831
16.5
130
110
7-12
1008
17
67
32
7-13
0937
19
85
70
7-14
0833
16
140
56
7-17
1006
15.5
320
30
7-18
0943
15
270
60
7-19
0858
16
260
72
7-20
0842
16
130
60
34
-------
Table 2 - 2 -
Water Chlorine
Station Temp. Coliform Counts/100 ml Residual
# Date Time °C Total Fecal mq/1
SP-4
SP-5
SP-6
7-12
1056
18
110
19
7-13
0930
19
160
48
7-14
0838
16.5
330
180
7t17
1013 :
16
1800
150
7-18
0950
15.5
210
52
7-19
0903
16.5
320
60
7-20
0848
16
130
44
7-12
1101
18.5
45
28
7-13
0925
18
74
55
7-14
0840
15.5
86
74
7-17
1016
15
360
52
7-18
0953
15
250
55
7-19
0904
T6.5
210
52
7-20
0851
15.5
160
94
7-12
1124
19
95
40
7-13
0916
19
130
70
7-14
0847
15.5
68
39
7-17
1028
14.5
450
200
7-18
1007
16.5
280
97
7-19
0918
16.5
400
52
7-20
0906
16.5
310
120
35
-------
Table 2
- 3
-
Station
#
Date
Time
Water
Temp.
oc
Coliform Counts/100 ml
Total Fecal
Chlorine
Residual
mg/1
SP-7
7-12
1132
19
34
8
7-13
0908
18.5
100
29
-
7-14
0854
15.5
88
40
-
7-17
1023
15
2700
260
-
7-18
1000
15.5
740
57
-
7-19
0911
17
310
48
-
7-20
0858
16
170
110
-
SP-14
7-13
0943
-
100
40
-
7-14
0943
16
46
25
-
7-17
1110
14.5
2100
250
-
7-18
1025
16
720
25
-
7-19
0942
17
100
44
-
7-20
0933
16.5
140
40
-
SP-15
7-13
0915
-
71
21
-
7-17
1123
14.5
1700
40
-
7-19
0951
17.5
170
30
-
7-20
0943
- 16.5
180
32
-
.
7-14
0953
16.5
18
15
-
7-18
1035
15.5
170
57
-
SP-16
.7-13
1044
19
84
62
-
7-14
1037
18.5
43
42
-
7-17
1330
15
290
100
-
7-18
1120
17
160
55
-
7-19
1034
18
25
20
-
7-20
1033
17
42
33
-
36
-------
Table 2 - 4 -
Water Chlorine
Station Temp. Coliform Counts/100 ml Residual
#
SP-17
SP-18
SP-19
SP-25
Date
Time
°C
Total
Fecal
mq/1
7-13
1046
19
16
26
-
7-14
1040
17.5
25
8
-
7-17
1337
15
210
80
-
7-18
1126
16
170
35
-
7-19
1038
18
70
8
-
7-20
1038
17
78
32
-
7-12
1143
17.5
29
10
-
7-13
1022
17
130
24
-
7-14
1019
16.5
22
10
-
7-17
1132
14
240
75
-
7-18
1047
15
190
45
-
7-19
1002
17
84
19
-
7-20
0955
16,5
120
21
-
7-12
1152
17
19
2
-
7-13
1013
17.5
120
22
-
7-14
1014
16
17
17
-
7-17
.1142
14
830
130
-
7-18
1056
15
410
40
-
7-19
1010
17
120
20
-
7-20
1002
16
42
14
-
7-12
1205
16.5
29
4
-
7-13
1201
17.5
40
24
-
7-14
1212
17
40
9
-
7-17
1152
14
240
40
-
7-18
]103
14.5
470
37
-
7-19
1017
17
90
27
-
7-20
1016
17
100
13
_
37
-------
Table 2 - 5 -
Stati on
#
Date
Time
Water
Temp.
°C
Coliform Counts/100 ml
Total Fecal
Chlorine
Residual
mg/1
SP-29
7-13
1140
16
76
20
-
7-14
1120
15.5
<4
<4
-
7^17
1410
13.5
2600
100
-
7-18
1315
16
1000
39
0.0
7-19
1252
18.5
770
40
-
7-20
1308
16
300
150
0.15
SP-29-A
7-18
1322
26.5
4700
63
0.0
7-19
1255
28.0
5400
95
-
7-20
1322
24.0
140
<4
0.5-1.0
SP-29-B
7-18
1327
15.5
280
25
-
7-19
1259
17
400
37
-
7-20
1330
16
220
40
-
SP-30
7-12
1222
16
110
50
-
7-13
1124
14.5
40
32
-
7-14
1106
14.5
81
36
-
7-17
1400
13.5
230
62
-
7-18
1303
15
290
47
-
7-19
1237
17
150
16
-
7-20
1258
15
260
110
-
SP-31
7-14
1153
14
88
34
-
7-17
1425
13
290
78
-
7-18
1349
14.5
220
50
-
7-19
1317
16
150
33
-
7-20
1402
15.5
220
72
-
38
-------
Table 2
- 6 -
Water Chlorine
Station Temp. Coliform Counts/100 ml Residual
# .
Date
Time
°C
Total
Fecal
mg/1
SP-32
7-14
1146
14
68
56
-
7-17
1432
12.5
330
110
-
7-18
1355
15
230
150
-
7-19
1325
16
95
51
-
7-20
1410
15.5
210
56
-
39
-------
TABLE 3
SOUTH PLATTE RIVER SURVEY DATA
SEPTEMBER, 1972
Station
§
Date
Time
Water
Temp.
°C
Coliform Counts/100 ml
Total Fecal
Chlorine
Residual
mg/1
SP-1
9-25
1100
11.5
330
320
-
9-26
1125
11.5
320
90
-
9-27
1035
14
92
60
-
9-28
0945
13
150
65
-
9-29
1015
11.5
96
40
-
SP-2
9-25
1047
11.5
380
180
-
9-26
1110
11.5
330
100
-
9-27
1027
13.5
150
60
/
9-28
0930
12
200
70
-
9-29
1010
11.5
140
23
-
SP-7
9-25
1113
12
450
170
-
9-26
1055
12
290
170
-
9-27
1020
13
180
76
-
9-28
0920
12
180
48
-
9-29
0955
11
68
36
-
SP-18
9-25
1157
13.5
650
12
-
9-26
1045
12
89
14
-
9-27
1005
12.5
68
40
-
¦
9-28
0910
12
62
19
-
9-29
0945
11
88
20
-
-------
Table 3 - 2 -
Water Chlorine
Station Temp. Coliform Counts/100 ml Residual
#
Date
Time
°C
Total
Fecal
mg/1
SP-25
9-25
1140
12
130
40
-
9-26
1035
12
120
24
-
9-27
0956
12.5
120
29
-
9f?8
0855
13
44
14
-
9-29
0930
11
160
28
-
SP-29
9-25
1230
17.5
1000
44
0.0
9-26
1005
16.5
260
25
0.3
9-27
0926
15.5
100
44
0.5
9-28
0830
12
2700
45
0.1
9-29
0920
13.5
2600
130
- 0.1
SP-29-A
9-27
0915
17.5
59
9
0.75
SP-30
9-25
1244
13
100
12
-
9-26
' 0930
11
110
76
-
9-27
0901
10
61
45
-
9-28
0810
10.5
63
38
-
9-29
0900
9.5
76
32
-
CC-1
9-28
1020
13
4800
260
-
Cherry
9-29
1050
13.5
30000 .
350
-
Creek at
University
Ave. Bridge
41
-------
TABLE 4
BEAR CREEK SURVEY DATA
afion
#
Date
Time
Water
Temp.
°C
BC-1
9-25-
1412
11.5
9-26
1330
12
9-27
0823
7.5
9-28
1100
-
9-29
0825
8
9-^29
1505
12.5
10-5
0824
10.5
:-l-A
10-5
0835
11
BC-2
9-25
1404
11
9-26
1320
12
9-27
0817
7
9-28
1055
10
9-29
0815
8
9-29
1500
12
10-5
0844
10.5
BC-3
10-5
0906
10
BC-4
10-5
0930
10
BC-5
10-5
0943
10
BC-6
10-5
1025
10
BC-7
10-5
1041
10
TG-1
10-5
1206
11
BC-8
10-5
1117
11.5
BC-9
10-5
1151
11.5
BC-10
10-5
1132
10.5
Chlorine
Coliform Counts/100 ml Residual
Total
Fecal
mq/1
4900
220
-
2000
370
-
7100
2600
-
8800
2100
-
4400
1200
-
3000
100
-
3700
630
-
470
56
-
2400
170
-
2300
260
-
8500
3300
-
18000
2000
-
7900
1100
-
350
90
-
8200
730
-
10000
1200
-
12000
1200
-
25000
1400
-
42000
2600
0.0
85000
5000
-
150
16
0.0
170000
140000
-
160000
34000
-
100
5
.
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SECTION IX
APPENDIX B
SAMPLE STATION DESCRIPTIONS
43
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SOUTH PLATTE RIVER SAMPLE STATION DESCRIPTIONS
TABLE 1
Station River
Number Mileage
-p»
SP-0
SP-1
SP-4
SP-5
SP-6
SP-7
SP-14
SP-15
SP-16
-2.5
0.0
SP-2 0.8
SP-3 0.9
1.3
1.4
1.7
1.8
2.9
3.0
3.6
SP-17 3.7
Location
Hamilton Street Bridge
Union Avenue Bridge
Just upstream from Littleton STP discharge
Belleview Avenue Bridge
50 yards upstream from Belleview Bridge
100 yards upstream from Crestline Ave. Bridge
120 yards upstream from Crestline Ave. Bridge
150 yards downstream from Bowles Ave. Bridge
Bowles Avenue Bridge
100 ft. downstream from Lee Gulch
150 yards upstream from Lee Gulch
1.8 miles above Bowles Avenue
1.9 miles above Bowles Avenue Bridge
Sample Point Description
East bank between Hamilton & Hampden St.
bridqes
Upstream side of bridge
Downstream side of bridge near west bank
West bank approx. 30 ft. upstream from
drainage ditch from Centennial Racetrack
West bank approx. 50 ft. below drainage
ditch effluent
West bank approx. 50 ft. above drainage
ditch effluent
West bank approx. 30 ft. below drainage
pipe effluent
Downstream side of bridge
East bank of river
East bank of river
West bank approx. 150 yards below small
creek
West bank approx. 100 ft. upstream from
small creek
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Table 1
- 2 -
Stati on Ri ver
Number Mileage
SP-18 4.5
SP-19 4.55
SP-25 . 6.0
SP-29 12.9
SP-29-A 12.9
SP-29-B 12.9
SP-30 13.1
cn
SP-31 13.8
SP-32 14.3
Locati on
Cooley Gravel Company Bridge
50 yards upstream from Cooley Gravel Co.
Bridge
Highway 470 Bridge
30 yards downstream from Brush Creek
Brush Creek - 10 ft. above confluence with
South Platte River
South Platte - 5 ft. above confluence with
Brush Creek
USGS Gaging Station at Waterton
Low-Head Diversion Dam
Denver Water Board Aquaduct over South Platte
Ri ver
Sample Point Description
Upstream side of bridge
East bank 50 ft. above small drainage
di tch
Upstream side of bridge
North bank
Middle of Brush Creek
North Bank
North Bank
North end of dam
North bank of river
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BEAR CREEK SAMPLE STATION DESCRIPTIONS
TABLE 2
-p»
CTi
Station
Number
BC-1
BC-l-A
BC-2
BC-3
BC-4
BC-5
BC-6
BC-7
T6-1
BC-8
BC-9
BC-10
River
Mileage
Locati on
, 10.7 Soda Lake Road Bridge below Morrison, Colorado
11.1 Mount Vernon Creek in middle of Morrison
11.4 USGS - Gaging Station - 150 ft. upstream
from bridge on Colo. #8
12.0 First road turnout above Morrison on
Highway #74
14.4 About 1/2 mile below Idledale, Colorado
15.5 Little Park, 1/4 mile above Idledale
18.7 100 yds. downstream from Sewage Treatment
Plant Discharge
19.1 250 ft. inside 0'Fallon Mtn. Park - 250 yds,
above STP discharge
20.6 Troublesome Gulch Creek, 150 ft. above
confluence with Bear Creek
20.9 1/4 mile upstream from Kittredge, Colorado
at K. I. Skaddon Driveway
21.9 1/4 mile below Evergreen city limits
23.2 100 ft. below Evergreen Lake Dam
Sample Point Description
South bank of stream, 10 ft. upstream
from bridge
5 ft. above confluence with Bear Creek
At the gaging station on north bank
North bank on the rocks
North bank of creek
West end of Little Park on the north bank
Middle of Low Head Dam, 10 ft. above
Kerr Gulch
East bank on the rocks
West bank, 40 ft. uDStream from Highway
#74 bridge
North bank
Upstream side of driveway bridge at the
J. Corbin residence
South bank of Bear Creek on the gravel bar
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