LOWER COLUMBIA RIVER
TRANSECT STUDY
FEDERAL WATER QUALITY ADMINISTRATION
NORTHWEST REGION
PORTLAND, OREGON
-------
A Working Paper presents results of
investigations which are to some extent
limited or incomplete. Therefore,
conclusions or recommendations—expressed
or implied—are tentative.
-------
LOWER COLUMBIA RIVER
TRANSECT STUDY
Station No. 403010
October 29, and 30, 1969
April 21, and 22, 1970
Prepared by
William B. Schmidt
Working Paper
No. 79
Technical Assistance and Investigations
Office of Technical Programs
Federal Water Quality Administration
Northwest Region
501 Pittock Block
Portland, Oregon
October, 1970
-------
BRADWOOD TRANSECT STUDY
INTRODUCTION
General
The Federal Water Quality Administration (FWQA), Pollution
Surveillance Branch, maintains a system of water quality sampling
stations on interstate waters in the Northwest Region. Throughout
the year water samples are collected at these stations and analyzed,
and the data are used to evaluate water quality. Knowledge of the
conditions peculiar to each station is valuable to the evaluation
of the data obtained.
This study documents conditions at Station No. 403010 located
on the Columbia River at river mile (RM) 38.9 near Bradwood, Oregon
(Figure 1). In September 1969, an automatic water quality monitor
was installed at this station. An initial survey was conducted on
October 29 and 30, 1969, to verify the location of the monitor. A
second survey was undertaken during April 21 and 22, 1970.
Objectives
The objectives of the studies were to answer the following
questions:
1. Is the Columbia River at the monitor site completely mixed
so that the point measurement of the monitor's probe is representa-
tive of the entire river cross section?
-------
2. What are the diurnal and tidal changes occurring in water
quality at the monitor location?
3. What are the influencing factors on water quality at this
location?
Authority
Authorization for this study was from the Federal Water Pollu-
tion Control Act (33 U.S.C. et seq.) as amended. The study was
performed by the Technical Assistance and Investigations Branch at
the request of the Pollution Surveillance Branch.
Sampling Program
The October, 1969, and April, 1970, transect surveys encom-
passed the Columbia River from river range marker "17" (RM 27.0)
upstream to range marker "57" (RM 43.0). The sampling stations for
the two surveys are shown on Figure 1. The sampling program for
each,survey is shown in Table 1.
During the October, 1969, survey, the dissolved oxygen (DO)
concentration at Station 12 was lower, suggesting a potential DO
depression. Station No. 7 was established for the April 1970 survey
to define the potential dissolved oxygen depression. To evaluate
the entire water quality condition in the monitor vicinity, Station
9, at the mouth of the Cathlamet Channel, was also added to the
April sampling program.
-------
GENERAL LOCATION MNP Fiql
LEGEND i J
O River Range MarKen
(S Station Locations
COLUMBIA RIVER
BRADIMOOD TRANSECT
STUDY
-------
TABLE 1
October 1969-April 1970 SAMPLING PROGRAM
Sample Station October 29-30, 1969
Survey
April 21-22, 1970
Survey
(Cross Section
1
2
3
4
5
6
7
8
9
10
11
12
X
X
X
Grab Sample ! Cross Section
(Single
Sample pt.)
X
X
X
X
X
X
X
X
X
X
X
Grab Sample
(Single
Sample pt.
X
X
X
X
River samples were to be collected periodically over a 24-hour
period during both surveys, but mechanical failures and extremely
dangerous night working conditions curtailed some of the collection
runs during both surveys. Figure 2 shows actual sampling times in
»
relation to the tidal cycle. Samples were taken at or near the high
and low tides, covering the most critical sampling periods. Sampling
periods are shown as cross-hatched areas on the figure.
Stations 3 through 7 each contain three sample points spaced
laterally across the river. Whenever possible, samples were taken at
three depths (2 feet, middle, and bottom) at each sample point (a
total of 9 samples per station). Sampling in this manner allowed
detection of changes in concentrations of water quality parameters,
-------
both vertically and horizontally.
Coliform samples were taken at all depths during the October
survey, but only from the surface sampling points during the April
survey.
The following water quality parameters were sampled and ana-
lyzed: pH, specific conductivity, dissolved oxygen, total alkalinity,
total coliform, fecal coliform, and temperature.
-------
SUMMARY
Findings
1. Complete mixing did not occur at any station sampled, but the
variations encountered were minor.
2. Monitor location depends upon site access in the lower Columbia
River.
3. Water quality changes resulting from diurnal and tidal fluctua-
tions are more pronounced during low flows than high flows.
4. Total coliform counts were greater during the April, 1970, sur-
vey than during the October, .1969, survey.
5. During the October, 1969, survey, totalocoliform counts were
greater (21,000 TC/100 ml avg.) downstream from the Wauna Mill
outfall than upstream (2,000 TC/100 ml avg.). Average total
coliform counts of about 19,000 TC/100 ml were recorded both
upstream and downstream fromvthe Wauna Mill outfall during the
April, 1970, survey.
6. During the October, 1969, survey, average dissolved oxygen con-
centrations were 9.3 parts per million (ppm) and the average
saturated values were 10.5 ppm. The average dissolved oxygen
concentrations during the April survey were about equal to the
saturated values of 11.5 ppnu
7. During low flows there appeared to be a dissolved oxygen sag
(low DO of 7.0 ppm) at the lower end of the study reach.
-------
SUMMARY
Conclusions
1. Complete mixing in the lower reach of the Columbia River is in-
hibited by tidal changes and unpredictable current patterns.
2. The monitor location is adequate to measure river water quality.
At present, access is the main reason for this location. River
mixing at this point is not complete, but it is adequate.
3. Because of the high volume of flow in the Columbia River during
runoff, changes in water quality parameter concentrations due
to tidal and diurnal fluctuations are minimal; however, during
low flow periods, water quality changes are more responsive to
these fluctuations.
4. The principal waste source in this reach of the Columbia River
is the Crown Zellerbach pulp and paper mill located at Wauna,
Oregon. Additional mills are located approximately 23 miles
upstream at Longview, Washington. Water quality in the study
area appears to be adversely affected by the Wauna Mill during
low flows and by the accumulation of upstream sources during
the.higher runoff periods.
Recommendations
1. The water quality monitor, Station No. 403010, at Bradwood,
Oregon, should be maintained at its present site.
-------
2. A 24-hour survey at sampling station 3 should be conducted during
both low and high flow to accurately define the mixed river con-
dition at the monitor site.
3. A survey should be conducted in this area, concentrating on the
relationship of pulp and paper mill waste effluent to bacterio-
logical contamination.
-------
SAMPLING AND ANALYTICAL METHODS
Sampling Methods
Water samples were collected at the locations shown on Figure 1.
The locations could not be sampled on a periodic basis during either
survey because of inclement weather and mechanical difficulties.
However, samples were obtained during high and low tides for each
survey. Samples were taken at three lateral points within the river
cross section at Stations 4, 5, and 6 during the first survey and
3, 5, 6, and 7 during the second survey. All other stations were
sampled in the middle of the stream (grab samples). Samples were
obtained by using Van Dorni' samplers. For sampling various depths,
a string of one to three bottles was used to sample top, middle and
bottom levels of the river, as appropriate. Each sampler provided
enough water to fill containers.for chemical (dissolved oxygen, pH,
alkalinity, conductivity) and bacteriological (total and fecal coli-
form) analysis. All analytical work was done in the lab on the sur-
»
vey boat H. W. STREETER which was anchored near the monitor site.
The dissolved oxygen samples were chemically stabilized at the time
of collection and were tritrated later in the floating laboratory.
I/ The mention of brand names is for identification only
and constitutes no endorsement by the U. S. Department
of the Interior, Federal Water Quality Administration.
-------
Analytical Procedures
The following laboratory methods were used for analysis:
1. pH was determined with a Beckman Zeromatic Model pH meter.
2. Specific conductivity analyses were performed with an Industrial
Instruments Model RC-16-B2 conductivity bridge.
3. Dissolved oxygen samples were titrated for quantity, using the
Modified Winkler with Full-Bottle Technique as found in FWPCA
Methods For Chemical Analysis (1)
4. Alkalinity was determined by titration with a Hach Model DL-ER
portable laboratory during the October 1969, survey and the
Potentiometric Titration Method in Standard Methods (2) during
the April, 1970, survey.
5. Fecal coliform determinations were conducted using the membrane
filter method according to the procedure described by Geldreich (3)
In studies by Geldreich (4) this method was confirmed as com-
parable to the Most Probable Number method for fecal coliform
described in Standard Methods (2).
6. Total coliform densities were measured by the membrane filter
method technique in Standard Methods (2).
7. All the bacteriological samples analyzed were incubated and
counted in the field.
-------
DISCUSSION
Water quality data for October 19, 1969, and April 21, 1970,
are shown on Tables 2 and 3, respectively. The average Columbia
River flow at Longview, Washington, during the October survey was
140,000 cubic feet per second (cfs). The average river flpw was
180,000 cfs during the April survey.
Location of the water quality monitor in the Lower Columbia
River depends upon site access and a completely mixed river cross
section. Complete mixing of the river in this area is uncommon
due to unpredictable current patterns caused by tidal fluctuations
occurring throughout the channel networks. These currents tend to
affect the distribution of water quality concentrations in the
water column.
Table 4 shows the average range of values for Station 5 caused
by the diurnal and tidal changes. Station 5 is representative of
the range of values at all stations sampled. The monitor site at
»
Bradwood (Station 3) has relatively easy access from the Oregon
shore and is fairly well-mixed, although the sample results show
that Station 5 has a higher degree of mixing throughout its cross
section. The absence of land access eliminates locating the monitor
near Station 5. Relocating the monitor upstream from the present
site would be limited by the Crown Zellerbach Pulp Mill outfall.
The present monitor site at Station 3 appears to be in the best
location in this vicinity of the Columbia River.
-------
SURVE.V PERIODS
O400 O80O I2OO I60O
2I; I97O
2A-OO O4OO O8OO I ZOO 160O
22., 1970
O40O 080O I20O /<5OO
24OO O4OO O8OO I2OO KbOO
, I9G3
OCTOBER
, 19G9
FIGURE. Z
-------
TABLE 2
OCTOBER 1969 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date
10-29-69
w
9
H
CJ
22
M
ea
w
W
Q
H
g
J
Time
0737
0755
0808
0827
0845
0855
0915
0923
0930
1110
1120
Station
6wt
6wb
6mt
6mm
6mb
6ot
6 ob
Sot
Sob
Smt
5mm
5mb
5wt
5wb
4ot
4ob
4mt
4mm
4mb
4wt
4wb
6wt
6wb
6mt
6mm
6mb
Depth
(ft.)
5
60
5
25
40
5
10
5
10
5
20
40
5
20
5
20
5
20
30
5
15
5
50
5
30
40
Temp.
°C
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13 0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.5
13.5
13.5
13.5
13.5
D.O.
(rag/1)
8.51
8.60
8.90
8.95
8.85
8.95
8.80
9.10
8.90
9.05
9.00
9.10
9.00
9.10
9.45
9.30
9.50
9.45
9.30
9.40
9.30
9.15
9.00
9.25
9.35
9.30
PH
6.6
7.3
6.6
6.9
7.0
6.9
7.0
7.0
7.3
7.1
7.2
7.1
7.1
6.9
7.4
7.4
7.1
7.3
7.4
7.1
7.3
7.1
7.5
7.5
7.6
7.5
Total '
Alkalinity
(mg/1 CaCoi)
62
64
60
54
60
60
64
62
60
64
64
56
66
62
, 65
68
60
64
68
62
60
68
64
64
60
64
Cond.
(umho/cm)
195
175
190
195
195
195
192
190
190
190
190
190
190
187
195
195
190
195
195
190
195
190
185
185
187
185
T.Coli.
/100ml
1220
1110
960
540
780
1840
1020
1920
1530
1150
-
740
1100
540
1480
700
910
950
1480
890
1420
1370
1050
1100
1950
1380
F.Coli.
/100ml
—
2
-
1
-
1
-
-
-
_
-
1
2
-
-
-
1
-
-
1
-
-
-
-
-
1
-------
TABLE 2
OCTOBER 1969 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date
10-29-69
w
Q
M
H
g
•J
w
Q
M
H
O
Z
M
Q
O
fn
W
a
n
H
fc^
u
<
j
CO
3C
O
1-1
33
Time
1125
1143
1150
1150
1210
1215
1223
1609
1614
1620
1637
Station
6ot
6ob
5wt
Swb
5mt
5mm
5mb
Sot
Sob
4wt
4wb
4mt
4mm
4mb
4ot
4ob
5wt
Swb
5mt
5mm
5mb
Sot
5ob
4ot
4ob
Depth
(ft.)
5
20
5
60
5 .
20
30
5
10
5
25
5
25
40
5
35
5
60
5
20
30
5
10
5
30
Temp.
°C
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.5
13.0
13.5
13.5
13.5
13.5
13.5
13.5
13.5
D.O.
(mR/1)
9.15
9.25
9.70
9.15
9.45
9.25
9.25
9.50
9.45
9.60
9.50
9.75
9.60
9.45
9.65
9.60
9.10
9.15
9.60
9.50
9.20
9.20
9.00
9.35
9.25
Total
Alkalinity
pH £mg/l CaCo3)
7.5
7.7
7.6
7.5
7.5
7.6
7.7
7.7
7.5
7.8
7.8
7.7
7.9
8.1
7.7
7.9
8.9
8.3
8.2
8.2
8.3
8.3
7.8
7.5
7.6
62
66
60
60
60
60
64
62
64
68
68
62
64
68
62
64
70
68
70
66
70
70
70
64
68
Cond.
(umho/cm)
185
185
185
180
185
190
185
185
185
190
190
190
185
185
185
190
180
180
175
170
175
170
155
150
150
T.Coli.
/100ml
1260
1300
1550
1590
1650
1300
1830
2110
2150
1280
990
1370
2120
1340
1520
1620
1470
2220
2480
1430
1560
2440
1770
2220
1650
F.Coli.
/100ml
.
1
_
-
-
-
1
-
-
—
-
_
-
-
-
-
—
-
1
1
-
• -
2
_
1
-------
TABLE 2
OCTOBER 1969 COLUMBIA RIVER
SURVEY DATA
RM 27.0 Co 43.0
Date Time
10-29-69 1642
PC ^ W
O U Q
S 3 H 1650
00
1745
u
9 1755
H
Z
n 1800
CQ
W
Station
4mt
4mm
4mb
4wt
4wb
6wt
6wb
6mt
6mm
6mb
6ot
6ob
Depth
(ft.)
5
25
35
5
35
5
70
5
25
35
5
15
Temp.
°C
13.5
13.5
13.5
13.5
13.5
13.0
13.0
13.0
13.0
13.0
13.0
13.0
D.O.
9.35
9.50
9.40
9.50
9.25
8.60
8.75
8.95
8.95
8.95
9.00
9.00
Total
Alkalinity
pH (mg/1 CaCoi)
7.6
7.4
7.8
8.1
7.7
_
7.6
7.7
7.6
7.5
7.5
7.9
70
70
70
66
68
70
70
72
70
68
68
' 70
Cond.
' (umho/cm)
155
155
155
155
155
160
157
155
156
155
159
158
T.Coli.
/100ml
2240
2120
1800
2170
2080
860
860
720 -
720
870
760
600
F.Coli.
/100ml
2
1
-
1
-
1
1
1
-------
TABLE 2
OCTOBER 1969 COLUMBIA RIVER
SURVEY DATA
PM 27.0 to 43.0
Date
10-30-69
w
Q
hH
H
O
2
M
oa
ca
w
Time
0742
0750
0800
0815
0825
0830
0845
0853
0900
Station
6wt
6wb .
6mt
6mm
6mb
6ot
6 ob
5wt
5wb
5mt
5mm
5mb
Sot
5ob
4ot
4db
4mt
4mm
4mb
4wt
4wb
Depth
(ft.)
5
70.
5
30
50
5
15
5
25
5
30
50
5
10
5
20
5
25
35
5
20
Temp.
°C
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0 '
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
13.0
D.O.
(mg/D
9.40
9.35
9.50
9.45
9.40
9.30
9.40
9.65
9.55
9.80
9.85
9.80
9.60
9.40
9.25
9.80
9.70
9.55
9.65
9.55
PH
7.6
7.7
7.8
7.7
7.9
7.7
7.9
8.0
7.6
7.8
7.6
7.6
7.8
7.9
8.1
7.5
7.7
7.8
7.7
7.8
Total
Alkalinity
(rag /I CaCo-0
70
70
72
68
66
68
68
70
66
70
68
68
64
70
68
68
70
70 .
68
66
Cond.
(umho/cm)
178
175
180
178
180
178
175
172
174
178
175
172
172
180
124
176
176
178
172
176
T.Coli.
/100ml
4000
3000
3100
2900
2900
4400
2800
4000
5500
4100
3700
3700
2000
3800
4200
4300
4700
3900
5200
5300.
F.C611.
/100ml
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
-------
TABLE 2
OCTOBER 1969 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date
10-30-69
10-29-69
10-30-6?
10-29-69
10-30-69
10-29-69
10-30-69
10-29-69
Time
1000
0810
1130
0815
0930
1210
1650
0900
1408
1755
0742
1745
Station
Iwt %nile above C-2 Wauna out-
fall north side
lot %mile above C-2 Wauna out-
fall south side
8mt At outfall (approx.)
2wt %mile below outfall
(north)
2ot ^mile below outfall
(south)
5 SAMPLES^
llmt % between Sta. #5 and
Sta. #6
% between Sta. #5 and
Sta. #6
lOmt
Above marker bouy 37
Above marker bouy 37
Above marker bouy 37
Above marker bouy 37
12mt Marker 26
Marker 26
Marker 26
3ot Off Bradwood Pier
Depth
(ft.)
2
2
2
2
2 '
2
2
2
2
2
2
2
2
2
2
2
D.O. ' Alkalinity Cond. T.Coli. F.Coli.
(°C) pH (mg/1 CaCo-O (umho/cm) /100ml /100ml
9.65 8.2' 68 180 1700
9.80 7.7 72 180 2000
9.70 8.0 70 180 14000
9.80 7.8 68 182 19000
9.75 7.9 68 178 21000
8.85
9.15
9.55
9.25
9.40
9.25
9.70
8.75
7.00
9.45
9.10
-------
TABLE 3
APRIL 1970 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date Time
4-21-70 0930
(U
3 0940
H
O
J 1010
1045
1050
-------
TABLE 3
APRIL 1970 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date Time
4-21-70 1212
. 1222
GO
c
3 . 1229
•r-l
"H
00
.5 1235
T3
O
O
,-1
ta ' 1402
1417
1435
o>
•o
•i-t
H
•o 1442
0)
r-l
oo
•g> 1451
•H
32
Station
4mt
4 mm
4mb
3wt
3wm
3wb
3mt
3mm
3mb
Sot
3om
3ob
Imt
1mm
1mb
2m t
2mm
2mb
3wt
3wm
3wb
3mt
3mm
3mb
3ot
3om
3 ob
Depth
ft.
2
25
50
2
15
30
2
25
50
2
20
40
2
30
60
2
25
50
2
20
40
2
30
60
2
25
50
Temp.
°C
10.2
10.1
10.1
10.2
10.2
10.2
10.1
10.1
10.1
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
10.2
D.O.
mg/1
11.5
11.5
11.6
11.9
11.6
11.6
11.4
11.5
11.6
11.6
11.6
11.6
11.6
11.7
11.7
11.4
11.6
11.7
11.7
11.6
11.6
11.6
11.6
11.7
11.7
11.6
11.6
Total
Alkalinity
pH mg/-l CaCoq
7.3
7.2
7.2
7.5
7.2
7.2
7.5
7.3
7.3
7.4
7.4
7.3
6.9
7.1
7.0
7.0
7.1
7.2
6.4t
6.5
6.6
6.8
6.8
7'. 0
7.3
7.2
7.3
60
57
57
57
60
57
56
64
55
57
58
58
50
53
54
•51
52
52
52
54
52
54
57
54
53
52
52
T.Coli.
Cond. /100ml
19000
-
-
21000
-
- -
26000
-
-
21000
-
_ _
19000
-
-
15000
-
-
- -
-
-
7000
_ _
- _
2000
_ _
-
F.Coli.
/100ml
-
-
.
-
-
-
-
_
-
_
-
.
-
-
-
-
_
-
_
M
_
_
-
_
-
-------
TABLE 3
APRIL 1970 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date
4-21-70
•o
•H
H
60
C
•H
w
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TABLE 3
APRIL 1970 COLUMBIA RIVER
SURVEY DATA
RM 27.0 to 43.0
Date
4-22-70
0)
-o
•H
H
W)
c
•rH
ft
o
W
0)
3 -0
O vH
J H
Time
0705
.0711
0716
0724
0740
0747
0759
1016
Station
3wt
3wm
3wb
3mt
3mm
3mb
Sot
3om
3ob
4m t
4mm
4mb
5wt
5wm
5wb
5mt
5mm
5mb
Sot
Depth
ft.
2
15
30
2
25
50
2
20
40
2
20
40 .
2
25
50
2
20
40
2
Temp.
°C
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
9.5
. 9.5
9.5
9/5
9.5
9.5
9.5
D.O. .
mg/1
11.3
-
11.3
11.5
-
11.6
11.6
11.7
11.7
11.6
11.4
-'
11.5
11.5
-
11.5
11.5
PH
7.2
7.0
-
7.1
7.2
7,0
7.2
7.1
7.0
7.2
7.2
7.0
7.1
7.1.
6.8
-
7.0
7.0
Total
Alkalinity
mg/1- CaCo3 Cond. '
51
55
51
56
50
50
55
54
50
49
54
51
52
49
52
4.6
-
51
54
T.Coli. F.Coli.
/100ml /100ml
24000
-
-
10000
_ • _
-
15000
9000
- -
10000
-
'
21000
-
-
-
GRAB SAMPLES
1205 (9)
10.2
11.5
7.5
58
18000
-------
The effects of diurnal and tidal changes were greater during
the October 1969, survey because of the lower river flow.
TABLE 4
AVERAGE SURVEY DATA RANGE
STATION NO. 5
Survey
Date
Oct. 69
Apr. 70
D.O. Temp. pH Alk. Cond. T. Coli.
9.1-9.7 13.0-13.5 7.1-8.3 61-69 172-189 1160-3800
11.5-11.6 9.5-10.2 6.6-7.1 51-59 19,000-23,000
The principal waste source in this reach of the Columbia River
is Crown Zellerbach's pulp and paper mill at Wauna. The kraft mill
provides primary treatment, diffusing the effluent into the Columbia
River near river range marker 51 (Station 8)'. Four additional mills
are located approximately 23 miles upstream (RM 66.0) at Longview,
Washington.
•During the October survey, the total coliform count upstream
from the Wauna mill outfall was 2000 TC/100 ml. This count in-
creased to 21,000 TC/100 ml immediately downstream from the Wauna
mill outfall, then gradually decreased farther downstream (Table 2).
In contrast, high coliform counts of about 19,000 TC/100 ml existed
both upstream (Station 1) and downstream (Station 2) from the out-
fall during the April survey. The high upstream coliform counts
probably came from waste discharges at Longview. Extended bacterial
survival due to low water temperature and a reduced time to travel
-------
due to high river flows could result in bacteria from Longview still
being viable as they reached the study area. This condition did
not occur in the October, 1969, survey since the water temperature
was higher (13.5°C) and river velocity was lower.
The high rate of microorganism metabolism which occurred during
the October, 1969, survey resulted in a dissolved oxygen (DO) demand
in this study reach. The lowest DO concentrations of::7.0 ppm
occurred about high tide at Station 12 near the lower end of the
reach. The DO saturation value throughout the study area was about
10.5 ppm at 13.5°C and the average DO concentration in the upper
part of the study area was approximately 9.3 ppm. It appears that
the DO depression was a result of the Crown'Zellerbach mill dis-
charge.
There was no DO reduction during the April, 1970, survey,
probably because of lower oxygen demand and a high rate of atmos-
pheric reaeration resulting from the turbulence associated with the
high river flow.
Average values of the remaining water quality parameters for
these two periods are approximately equal to the historical values
of samples taken upstream at the Clatskanie sampling point.
-------
REFERENCES
(1) Federal Water Pollution Control Administration.
FWPCA Methods For Chemical Analysis of Water and Wastes.
November 1969.
(2) American Public Health Assoc., Inc., Standards Methods for the
Examination of Water and Waste Water, 12th Ed. 1965.
(3) Geldreich, Edwin E., et al. Fecal coliform organisms medium
for membrane filter technique. Journal American Water Works
Assoc. 57:2, 208-214, 1965.
(4) Geldreich, Edwin E. Sanitary significance of fecal coliforms
in the environment. Water Pollution Control Research Series
Publication No. WP-20-3. U. S. Department of the Interior,
Federal Water Pollution Control Administration 1966.
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