OXYGEN BLOCK IN THE

MAIN -STEM WILLAMETTE RIVER

i.iiit' I'.iological Labordtory

B R A tl Y

OCT 9-1950

WOODS HOLE. MASS.

SPECIAL SCIENTIFIC REPORT: FISHERIES No. 41

UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE

Explanatory Note

The series embodies results of investif;ations, usually of
restricted scope, intended to aid or direct management or
utilization practices and as guides for administrative or
legislative action. It is issued in limited Quantities for the
official use of Federal, State or cooperating agencies and in
processed form for economy and to avoid delay in publication*

Vfashington, D« C«
September 1950

Ur.ited States Department of the Interior
Oscar Lo Chapnan, Secretary
Fish and Wildlife Service
AlhertMo Daj', Director

Special Scientific Report - Fisheries
NOc 41
OXYGEN BLOCK IN THE MAIN-STEM WILIA^TETTE RIVER

By

Frederic F. Fish
In Charge, Western Fish-Cultural Investigations

and

Richard A. Wagner
Biological Aid

CONTENTS

Page

Fore^ftard. oa»oo.oo 1

mtrOQUO ttLOn 0 ooooooeoo***oe»ooft»*»«»ft* 3

1S49 Main-Stsm Wilianette River Studies 5

iiirerpretation of Results 13

Ccnolusions oo>.oo.a.« 17

Litsraturs Citedo o».<i...«o.... 18

Foreword

The studies included in this report were conducted at the
Corvallis Laboratory, Section Western Fish-Cultural Investigation,
TJ» S. Fish and Wildlife Service. The laboratorj'- facilities, equip-
ment, and supplies contributed to these studies by the Section of
Sanitary Engineering, School of Engineering and Industrial Arts,
and by the Department of Fish and Game Management at Oregon State
College are gratefully acknowledged. The invaluable advice and in-
terest contributed to the study by Professors R<, E. Dimick and Fred
Merryfield were particularly helpful as were the stream flow data
provided by the Portland District Office, Corps of Engineers o

RIVER DISCHARGE IN THOUSANDS OF SECOND FEET

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INTRODUCTION

Pollution of the Willamette River of Orepon has attracted
nationwide attention not only for the outstanding; example of an
overloaded major river that it offers but, also, because of its
impact upon economically important and hif^hly publicized run of
spring-chinook salmon.

Pollution of the Willamette River is a problem that has received
considerable attention over the past two decades. The initial organized
studies of Willamette pollution stemmed from a conference called by the
Oregon State Board of Health in September, 1926. Following that con-
fe^encq^ the Portland City Departments of Health and Engineering routinely
sampled the river in the Portland harbor area extending from the Sellwood
Bridge, at river mile 16.5, to the confluence with the Columbia. These
studies were conducted betv/een October, 1926 and December, 1928 and re-
vealed that less than three parts per million of dissolved oxygen were
present in the river water during August, 1927, and during both August
and September of 1928.

Rogers, Mockaore, and Adams (1930) reported more extensive studies
of the Willamette pollution after surveying the main stem and major
tributaries between July, 1929, and May, 1930, These authors reported
an oxygen block (io©., less than five parts per million of dissolved
oxygen) existed between Wilsonville (river mile 37) and the Sellwood
Bridge in Portland in August, 1929, but had disappeared by the time
they next studied the river in the following October.

Gleeson (1936) mad© an extensive study of the pollution and tidal
complex betv/een the Sellwood Bridge and the Columbia River, September
5 to 27, 1934o Gleeson obtained no samples exceeding five parts per
million of dissolved oxygen over the entire reach of river that
he studied except in the extreme lower end where Columbia River back-
water was involved. Gleeson also demonstrated by calculation that
an oxygen block would develop in the lower Portland harbor area even
though all wastes from that city were excluded from the river. He
likewise determined that 7.6 days were required for the passage of
water between the Sellwood Bridge and the Colimibia River when the
river discharge vms at 4,000 second feet.

Craig and Townsend (1946) reported a series of seven spot samplings
at the Sellwood Bridge and at the St. Johns Bridge, Portland^ between
February 4 and July 28, 1941, and four additional samplings betv/een
May 2 and August 21, 1942. Their findings indicated that the oxygen
block had formed in the VJillamette at the St. Johns Bridge sometime
between March 18 and May 1, 1941. The oxygen block had extended up-
stream to the Sellwood sometime between Fay 29 and July 17, 1941.
The oxygen block had formed at both stations sometime between May
2 and early August, 1942.

More recent studies in the Willamette River v/ere reported
by Merryfield and Wilmot (1945) and by Dimick and Merryfield
(1945) o Insofar as the main stem is concerned, their studies
were conducted dovm to the Sellwood Bridge between Aup;ust and
Decembers lS44j with bi-monthly samplings at the critical stations
continued until the I'ollowing Marcho Merryfield and Wilmot demon=
strated that the oxygen block extended upstream to approximately
river mile 60 at the time their studies were undertaken in late
August of 1944c. The block had been forced dovmstream to river mile
44j presumably by increasing water flows, by October and it disappeared
entirely sometime late in the snme month*

Fish and Rucker (1950) reported a reconnaissance of the main stem
Willamette from Springfield to the Steel Bridge (river mile 12) in
Portland during mid^October, 1948o They obtained no evidence of
an oxygen block at that time, the lowest dissolved oxygen concentra-
tion obtained on the survey being 7*4 ppmo at the Steel Bridge*

It is apparent from the studies made to date that the pollution
burden of the Willamette River is of sufficient magnitude to over-"
load the lower reaches during periods of low flows and high temper>=
atureso The lowest reach of the river is degraded to the point where
oxygen deficiency precludes any movement of migratory fishes through
the affected areao Because the Willamette River currently supports
important runs of salmon and steelhead trout -- fishes of high conrni"
ercial and recreational value — the impact of pollution upon the
fishery resources is of considerable importance o

The impact of pollution upon the fisheries resources of the
Willamette Valley is of major conseauence not only under existing
conditionSj, but it bids fair to become increasingly more so in the
near futureo Increasing population and industrialization of the
Willamette Basin -- with an accompanying additional pollution burden
to the already overloaded main stem — appears inevitable » Some loss
of potential dilution water through evaporation has accompanied the
great increase in the quantity of main stem water diverted for the
irrigation of croplands during the past decade o This trend undoubted^
ly will continue, and probably steepen, with the obvious shifting of
agriculture in the Valley from grain and pasturage to truck and specialty
farmingo

Perhaps the greatest crisis of all, insofar as the fisheries of
the immediats future are concerned, lies in the acute need for the main
stem and certain tributaries of the Willamette as spawning and nursery
areas for fall-chinook salmon relocated from the main Columbia Rivero
A serious threat to the upper Columbia River salmon runs is forming in
the multiple -purpose programs of water development currently in progress
by the Corps of Engineers, the Bureau of Reclamation, and by private
interests 0 The Fish and Wildlife Service, together with the fishery
agencies of Oregon and Washington, are engaged in a 20-million dollar
"Lower River Program" designed to perpetuate the Columbia River salmon

4

resources despite the use of the upper river waters for purposes
incompatable with the existence of the salmono Briefly, this
program proposes through various measures the maximum rehabilita-
tion of native and/or relocated salmon runs in the lower river
sections below the areas of intensive water development and
utilization.)

The success of the Lower River Program is predicated upon
complete utilization of every available, as well as every re-
habilita table, fish-producing tributary of the Columbia River
below McNary Dam. The potentialities of the Willamette River are
too great to allow pollution to remain a factor limiting its full
usage for fish production.

TTone of the Willamette pollution studies made to date reveal
the circumstances under which the main stem oxygen block forms or
lifts, nor do they indicate more than vaguely, the time. Until the
limits of the pollution problems have been more accurately defined,
it remains impossible to determine if, or under what circumstances,
the Willamette can be utilized in the Lower River Program however
great the need for the waters may be.

1949 Main Stem Willamette River Studies

A study of the main stem Willamette was undertaken jointly
by the Fish and Wildlife Service and Oregon State College during
Water Year 1949, in an effort to determine current postwar conditions.
It was recognized at the outset that available funds and personnel
would not permit as exhaustive a study as obviously is needed for a
complete appraisal of the many facets of the pollution problem.

A series of stations was established over the length of the
main stem and on each major tributary close to its confluence with
the Willamette River. The geographical location of these stations
is listed on Table 1. Duplicate samples were collected at half depth
from a single point on the river. It was recognized that the results
obtained by spot samplings would be affected by many factors but,
under the limiting circumstances, it was assumed that spot sampling
would prove sufficiently representative of the actual conditions to
serve the intended purposes.

Each sampling station was visited periodically throughout Water
Year 1949. The results obtained are listed in Table 2.

The summer of 1949 proved somewhat atypical for, as shovm on
Table 3, water flows in the main stem were somewhat above average
and considerably above those prevailing during the 1944 survey of
Merryfield and Wilmot. The July and August flows, however, were
substantially equal to those of 1929 when Rogers, Mockmore, and
Adams made their studies of stammer conditions.

5

Table I

SAMPLING STATIONS FOR 19^+9 S'RIDIES.

- Main Stem Willamette -

River Mile

155.6 Highway 28 Bridge near Springfield, 3 miles above Eugene.

178.6 Wilbur Revetment, k miles below Eugene

1614-.3 Highway 99-E Bridge at Harrisburg

122.5 Adair Village water intake, 7-5 river miles below
Corvalli.s and 3 miles above Albany

116.5 Ufford Revetment, 3 miles below Albany

96.2 At Independence Ferry, 11 miles above Salem

72.5 At Wheatland Ferry, 12 miles below Salem
38.8 At Wilsonville Ferry

30.8 At boathouse, right bank, k miles above Oregon City

25.6 At boathouse, right bank, 1 mile below Oregon City
16.5 Sellwood Bridge, Portland

12.1 Morrison Bridge, Portland

- Tributaries -

3 McKenzie River at Armitage Bridge

h Long Tom River at Burnett Bridge

3 Luckiamute River at Davidson Bridge

5 Santiam River at Highway 99-E Bridge

5 Yamhill River at Dayton Bridge

3 Pudding River at Highway 99-E Bridge

3 Molalla River at Highway 99-E Bridge

1 Tualatin River at Athey Bridge

2 Osw, ^o Creek at Leike Oswego outlet

2 Clackamas River at Highway 99-E Bridge

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IZ

TABLE NO- 3

MAIN STEM VflLLMIETTE RIVER AT WILLAJTETTE FALLS
Mean monthly flows in cubic feet per second *

Month June July August September

1926-1945

Mean

15,658

6,659

4,081

4,394

1929

20,410

6,830

4,110

3,640

1944

10,510

5,230

3,430

3,630

1949

14,200

7,000

4,5B0

5,160

* Data supplied by Portland District Office, Corps of Engineers

Interpretation of Results

Reviewing the dissolved oxygen profiles listed in Table 2, the
combined effects of reaeration and dilution appeared fully adequate
to maintain the quality of the main stem water above Wilsonville well
within the accepted tolerance limits of cold-water fishes. Below
Wilsonville, however, a rapid deterioration in water quality occurred
during the low-flow period. The degradation of water culminated in an
oxygen block (i.e., less than five parts per million) which appeared
in the lower river betv;een July 6 and 19, 1949o Between those dates,
the block developed over its maximum range, namely upstream to a point
below Wilsonville or, roughly, within the confines of the slackwater
reach locally known as the "Newberg Pool**. The block persisted through^
out the entire lower river area until it was dissipated by increasing
river flows sometime between September 2 7 and October 12. More than
five parts per million of dissolved oxygen were found throughout the
river to its confluence with the Columbia on October 12,

Patently, the formation and lifting of the Willamette River oxygen
block is not a function of water flows exclusively for such factors as
hours of sunshine, water temperature and turbidity, and the seasonal
variations in pollution loading also play important roles. Generally
speaking, however, water flows would be a — 'if not the — dominant
factor.

The station at Sellwood Bridge has been selected as a reference
point to illustrate the formation and lifting of the block. River
flow data supplied by the Portland District Office, Corps of Engineers,
and dissolved oxygen concentrations are plotted in Figure 1. These data

13

indicate that the block formed at Sellwood Bridge about July 12
when the river discharge approximated 9^200 oofoS„ and the water
temperature 20°Co They likewise show that the dissolved oxygen
concentration remained below five parts per million throughout
the balance of the summer and momentarily rose to that concentra-
tion with a minor crest of 7j, 900 cofoSo passing the station Septem-
ber i9o The block lifted for the season about September 30 when
river flows rose above approximately 7j, 500 CofoSo and the water
temperature fell to approximately 17o5°Co

The approximate picture of the formation and lifting of the
Tlillamette oxygen block during 1949 within the reach covered by
these studies can be tabulated as follovirs s

Block Formed s s Block Lifted

s- Approxo gApproxo gApproxo sgApproxo ? Approxo j Approx,
Location ? date ? River -* Water ss Date ; River ; Water
s ? Flow s Tempo s % % Flow s Tempo

i S CofoSoJ C S8 S CofoSo 8 c

Above

Willamette

g

July

s 7p300

g

21

o <^

Oct.

s 8,000

s

15

Falls

t

15

•

S

t ;

6

§

o

Below

9

g

s

o 0

t

o

Willamette

a

July

s 6,850

s

21

ss

Oeto

t 6,700

%

18

Falls

%

1?

s

e

s %

4

*

s

^

o

»

: s

s

s

Sellwood

t

July

» 9,200

»

20

% s

Septo

g 7,500

8

18

Bridge

8

12

o-

i>

s:

30

2

8

Morrison

S

July

t 9,500

o

20

o •

Oct

sll,600

t

15

Bridge

%

11

8

t

o •

8

%

i>

One point illustrated by the data from the tributaries will be
of interest to both fishery interests and sanitary engineers » Apparently
none of the Willamette tributaries is a significant contributor to the
maia stem pollution burden in spite of the fact that certain of them--
notably the Tualatin^ the Yamhill, and the South Santiam— -are known to
be seriously polluted from the work of Dimick and Merryfield and that
by Fish and Ruckero

These data indicate thatj, at least under the conditions prevailing
during the summer of 1949, the tributaries are absorbing to an amazing
degree any oxygen-consisning pollution added to their upper reaches
before the water reaches the main stem. The Tualatin offers a good
example of the point in questiono Although pollution of the Tualatin
in sufficient intensity to kill fish was reported below the cities of
Hillsboro and Forest Grove during the summer of 1949, nevertheless the
dissolved oxygen concentration at the Athay Bridge sampling station
near the mouth remained consistently above saturation during most of

14

the simmer o This apparent anomaly stemmed in large part, no doubt,
from effective reaeration by biological growth which vras stimulated
by the organic fertilization received in the polluted reach upstream,
A very profuse phvtoplankton growth was apparent in the water at the
Athay Bridge station throughout the period of supersaturatione With
the exception of a single sample from the Yamhill, at no time during
1949 did any tributary fail to meet the accepted criteria of a re-
latively clean stream (ioe., a BOD of less than 3 ppm. with a DO
exceeding 5 ppmo) near its confluence with the main stem. Only
the Yamhill approached, but did not exceed, these arbitary thresholds o

It would appear, therefore, that tributary pollution — however
severe it may have been diiring the summer of 1949 and irrespective
of its adverse effects upstream, was not a major factor contributing
to the main stem pollution loading. The main stem pollution problem
appears to be a distinct entity in itself.

The probable magnitude of pollution abatement measures necessary
to eliminate the main stem oxygen block warrents considerationo At
the present time, two measures of pollution abatement are in progress.

Three of the smaller impoundments of the Corps of Engineers'
Willamette Valley Project are in operation which have added per-
ceptibly to the low flows — and thus the dilution water available--
in the main stem Willamette. Two major impoundments of the Project
currently are vinder construction and scheduled for completion within
four years and each of these will further increase minimum flows.
Fifteen additional impoundments are scheduled for construction by
the Corps of Engineers, plus several by the Bureau of Reclamation,
in the program of ultimate water development within the Willamette
Basin. The completed units have altered the water regimen of the
main stem and the major impoundments now under construction are
anticipated to increase minimum flows much more and, in addi+:ion,
reduce water temperatures to some extent as well. The completed
Willamette Valley Project will profoimdly affect water conditions
in the main stem but all effects--at least as the Project is tent-
atively scheduled for operation—should prove beneficial towards
pollution abatemento The degree to which the changes in main stem
conditions will improve water quality cannot be accurately fore-
cast with available information.

The second corrective measure currently in progress is the
demand by the Oregon State Sanitary Authority that all main stem
communities must provide primary treatment of domestic wastes as
rapidly as adequate plans and financing can be secured. At the
present time, all wastes from these communities are discharged
directly into the Willamette River without treatment. As a con-
sequence of their action, the City of Portland is installing sewerage
facilities to divert all wastes to the Columbia River. The remain-
ing communities along the main stem have facilities for primary treat-
ment of their domestic wastes in various stages of planning or financ"
ing. The ultimate phase of the pollution abatement program of the

15

Oregon State Sanitary Authority calls for the treatment of the
oxygen-cons uning industrial wastes, principally sulphite liquor
and cannery offal, as rapidly as feasible methods can be developed.

Primary treatment of domestic sewage will reduce its subsequent
oxygen demand in the order of thirty percent. When effected, this
measure woijld improve lower river conditions materially although it
still appears insufficient to lift the o::ygen block all the way to
the Columbia River. Insofar as the migratory fishes are concerned,
an oxygen block several hundred yards in length probably would prove
just as effective a barrier as one of many miles in extent.

Gleeson, it will be recalled, found that 7.6 days were required
for the Willamette River water to flow from Sellv/ood Bridge to the
Columbia when river discharge was 4,000 second feet. The assumption
appears tenable, therefore, that the full oxygen demand indicated by
the 5-day biochemical oxygen determimttion of water at the Sellwood
Bridge will be consumed — at least during the low flow periods — before

that water reaches the Columbia.

»

Using the 1949 determinations obtained at the Sellwood Bridge
on August 29, September 5, and September 12 (which represent the
approximate time when relocated runs of fall-chinook salmon would be
entering the lower Willamette) as exsnnpleB, the future river conditions
between the Sellwood Bridge and the Columbia that may be grossly antici-
pated under conditions comparable to the 1949 river flows and tempera-
tures and with various degrees of pollution abatement can be calculated
as follows :

Date of Determination ----------- Aug« 29 Sept» 5 Sept. 12

River flow at Sellvrood Bridge, second feet 5,260 5,080 5,476

River water temperatures (°C.) 21 23 20.5

Dissolved oxygen available, 1949 conditions;

ppra. 2,8 2.0 3.3

pounds per day 79,531 54,864 97,583

dissolved oxygen deficit, lbs/day 175,819 183,244 170,980

Dissolved oxygen available:

with 1949 deficit reduced 60% (lbs/day) 1^2,564 109,837 148,897

with 1949 deficit reduced 50?? (lbs/day) 167,728 146,486 183,073

16

88 „ 052

106, 984

112,369

61,636

74,889

78,658

44,026

53,492

56,185

Date of Determination- - = --- = --"= Augo 29 Sept. 5 Sept. 12

Biochemical Oxygen demand, Sellwood Bridge;

1949 conditions (lbs/day)

1949 conditions reduced 30^ (lbs/day)

1949 conditions reduced 50^ (lbs/day)

Anticipated minimum dissolved oxygen present
below Sellwood Bridge;
Ae In terms of pounds per days

1949 conditions septic septic septic

mth 02 deficit and BOD reduced 30^ 70,928 34,948 70,219

With 02 deficit and BOD reduced 50?? 123,702 92,994 126,888

B. In terms of parts per millions

1949 conditions septic septic septic

With O2 deficit and BOD reduced ZOfo 2,5 1.3 2.4

With O2 deficit and BOD reduced 50^ 4.4 3.4 4.3

Admittedly, data obtained by weekly spot samplings constitute an
insecure basis, at bestj for definite conclusions regarding any problem
as complicated as pollution abatemento These data do strongly indicate,
however, that the primary treatment of domestic wastes alone will not
prove sufficient to lift the Willamette pollution block. An overall
r<«iu<B41on exceeding fifty percent of the 1949 waste load of the river
appears necessary to assure clearance of the lower reaches for the
passage of migratory fishes during the low flow stages. It appears
most probable, therefore, that the utilization of the Yfillamette River
by fall-chinook salmon must await either sufficiently increased minimum
river flows that may be provided by the Corps of Engineers' Willamette
Valley Project and/or the effective treatment of many of the oxygen-
consuming industrial wastes.

CONCLUSIONS

1» Pollution of the main stem Willamette River is a problem
cf long standing and one that seriously threatens the fall utiliza-
tion of the river's potentialities for fish production. Above
WiloOnville, the quality/ of the main stem water is being maintained
well within the accepted tolerance limits of cold-water fishes by
effective reaeration and dilution, in spite of a heavy pollution
burden. Below Wilsonville, however, where the stream gradient
decreases a rapid degradation in water quality develops during the
low water stages. During 1949, as in earlier years, an oxygen
block developed throughout the entire reach of the lower Willamette.
Under the conditions prevailing during 1949, the block developed
throughout its maximum range between July 6 and 19, The block per-
sisted throughout the sumner until it was dissipated by increasing
river flows sometime betv/een September 27 and October 12. More than
five parts per million of dissolved oxygen were found throughout the
river to its confluence with the Columbia on October 12,

2* The main stem oxygen block appears to be a distinct
entity quite unrelated to the pollutional loading of the major
tributaries. Vftiatever pollutional overloading; received by the
major tributaries apparently is quite well stabilized before it
reaches the main Willamette.

3. To the extent that data obtained by spot sampling provide
a representative base for calculations, it may be concluded that an
overall reduction exceeding fifty percent of the 1949 oxygen-consuming
waste loading of the main stem Willamette must be effected to maintain
a minimum dissolved oxygen concentration of five parts per million
throughout the river. As the primary treatment of domestic sewage will
not provide the degree of pollution abatement required, the use of the
Willamette River by fall-ohinook salmon must await sufficiently increased
minimum river flows that may be provided by the Corps of Engineers*
Willamette Valley Project and/or the effective treatment of a signifi-
cant fraction of the oxygen- consuming industrial wastes.

4. Available data will not permit more than an extremely gross
prediction of the minimum degree of pollution abatement required to
eliminate the oxygen block of the lower Willamette, This point is of
considerable interest to the communities end industries of the Willamette
Valley for, presumably, neither are anxious to finance a greater degree
of pollution abatement than conditions warrant. A detailed study of the
sources, magnitude, and subsequent effects of the pollution loading of
the river, coordinated with that of the absorption capacity of many
reaches of the river under varying conditions of flows and temperatures
is a prerequisite to any accurate analysis of the Willamette pollution
problem and its effective and most economical solution.

LITERATUHE CITED

1946. Craig, J. A., and L. D. Townsend. An Investigation of
Fish-Maintenance Problems in Relation to the Willamette
Valley Project. U. S. Fish and Wildlife Service, Washington,
D, C», Special Scientific Report Number 33, 78 pages. (Mimeo-
graphed) •

1945. Dimick, R, E., and Fred Merryfield. The fishes of the Willamette
River System in Relation to Pollution. Oregon State College,
Engineering Experiment Station, Corvallis, Oregon, Bulletin 20,
58 pages.

1950» Fish, Frederic F., and Robert R. Rucker. Pollution in the
Lower Columbia River Basin in 1948-with Particular Reference
to the Willamette Basin. U» S. Fish and Wildlife Service,
Washington, D. C, Special Scientific Report - Fisheries
Number 30, 22 pages. (Mimeographed).

18

SSSCo Gleeson, G. W. A Sanitary Survey of the Willamette River
from Sellwood Bridge to the Colimbia River« Oregon State
College, Engineering Experiment Station, Corvallis, Oregon,
Bulletin Number 6, 32 pages,

lS45o Merryfield, Fred, and W. Go Wilmoto 1945 Progress Report on

Pollution of Oregon Streams. Oregon State College, Engineering
Experiment Station, Corvallis, Oregon, Bulletin Number 19, 62 pages,

i930o Rogers, H, S«, C. A. Mockmore, and C. D. Adams, A Sanitary Survey
of the Willamette Valle;;-, Oregon State College, Engineering Ex-
periment Station, Corvallis, Oregon, Bulletin Numbers, 32 pages.

19

Interior-=Duplicating Section, Washington, D.C,
82518