HomeMy WebLinkAboutCouncil Reading File - 1966 CDFW SLO Creek SurveyRLE:
State of California
The Resources Agency
DEPARTMM OF FISH AND GAM
Region 3
A BIOLOGICAL SURVEY OF J
SAN LUIS 0BISP0 CREEK,,
Project No. 4103-053
Prepared for
Central Coastal Regional Water Quality Control Board
by George D. Nokes
Pollution Bioanalyst
September 15, 1966
State of California
The Resources Agency
DEPARTMENT OF FISH AND CAME
Region 3
A BIOLOGICAL SURVEY OF
SAN LUIS OBISPO CREEK
Project No. 4103-053
Prepared for
Central Coastal Regional Water Quality Control Board
by George D. Nokes
Pollution Bioanalyst
September 15, 1966
6
F
0
TABLE OF CONTENTS
rA E
SUMUY
1
INTRODUCTION
2
ACKNOWLEDGMENTS
3
DESCRIPTION OF DRAINAGE AND FISHERY RESOURCES
4
SCOPE OF SURVEY
5
METHODS
6
Sampling Station Selection
6
Bottom Fauna Sampling
6
Fish Sampling
6
Filamentous Algae Sampling
7
Water Sampling and Chemical Analysis
7
Dissolved Oxygen
7
Residual Chlorine
7
Detergent
7
Hydrogen -ion Concentration (pH)
7
Physical Conditions and Analysis
7
Stream Flow
7
Transparency
7
Water Temperature
7
Toxicity Bioassay
8
OBSERVATIONS AND RESULTS
9
Waste Discharges to Stream
9
Trash
11
Chemical and Physical Conditions
11
Bottom Fauna
15
Fish Population
15
TABLE OF CONTENTS (Continued)
PAGE
OBSERVATIONS AND RESULTS (Continued)
Filamentous Algae 19
Toxicity Bioassay 19
DISCUSSIONS 22
CONCLUSIONS 26
RECONMENDATIONS.. 27
REFERENCES 28
APPENDIX 30
Data Sheets 1 - 15
ST&IA.RY
The Department of Fish and:Game, at the request of the Central
Coastal Regional Water Quality Control Board, conducted a biological
survey of San Luis Obispo Creek to determine the effect of existing
waste discharges upon the aquatic life, particularly the sport fishery,
of San Luis Obispo Creek. The survey was'conoucted using standard
biological, physical and chemical methods* Aquatic insects, fish,
filamentous algae, and physical and chemical conditions of the stream
were used as parameters of the water quality conditions.
We found that San Luis Obispo Creek and
adversely effected by waste discharges
that the Board take action to abate tble
fish and wildlife resources of San Luis
its aquatic life are being
into the stream. We recommend
pollution and protect the
Obispo Creek.
INTRODUCTION
Recent observations by the Central Regional Water Quality Control
Board and the Department of Fish and Game have indicated that a water
quality problem may exist in San Luis Obispo Creek.
By letter of April 5, 1966, the Board requested the Department of
Fish and Game to conduct a biological survey of San Luis Obispo Creek.
The purpose of this survey was to determine the effect of existing
waste discharges upon the aquatic life, particularly the sport fishery,
of this stream.
This report is a summary of findings of the Departmentts survey.
y2-
ACIMOTT EDGME17S
The Department of Fish and Game thanks the Central Regional Water
Quality Control Board staff and the San Luis Obispo Sewage Treatment
Plant staff, respectively, for their cooperation and assistance in
supplying certain information concerning water qualtty conditions in
San Luis Obispo Creek and for analy es, of water samples.
"13—
DESCRIPTIOYI OF Di'.AINAGE AND FISimm, RESOuP.CES
San Luis Obispo Creel: is a picturesque, tree -shaded stream that originates
in a small coastal canyon north of the City of San Luis Obispo. It flows
westerly paralleling Highway 101, passes through the center of San Luis
Obispo, meanders through low, grass -covered hills and flows gently into
the Pacific Ocean at Avila.
San Luis Obispo Creel: is approximately 15 miles long, 1 to 20 feet wide
and 1 inch to 3 feet deep during non -flood stages. The stream becomes
intermittent in a 2 to 3 mile area immediately downstream from San Luis
Obispo during summer and fall low flow periods. The principal sources
of water in the stream are surface runoff and underground springs in
the surrounding areas.
There are eleven tributaries to San Luis Obispo Creel., and all are inter-
mittent during the summer and fall months of dry years.
San Luis Obispo Creel, receives treated effluent from the San Luis Obispo
Sewage Treatment Plant at a daily average of 5.07 cubic feet per second
(3.279 MGD). This is the only lcnoem waste discharge which receives
treatment before discharge to the stream.
Steelhead, Salmo &airdnerii, is the most important fishery resource of
San Luis Obispo Creels. The significance of this resource is illustrated:
by the heavy fishing pressure of an -lens fishing for this elusive fish.
Average fishing effort on a weekend day during the fall -winter steelhead
fishing season is 70 anglers.
The stream also provides a good fishery for juvenile steelhead during
the general summer trout. season. It is not uncomzuon to see 15 to 20
anglers on a weekend day fishing 'or juvenile steelhead. In total,
San Luis Obispo Creel-, receives an estimated use of approximately 2,500
angler days per year.
San Luis Obispo Creel_, drainage is an important spawning and nursery
grounds for steelhead. During the winter, mature steelhead ascend
San Luis Obispo Creel: tributaries to spawn. Previous surveys have
indicated that there is abundant gravel suitable for spawning throughout
the drainage. During summer and fall, young steelhead utilize the
continuous flowing areas of San Luis Obispo Creel-, and its tributaries
for nursery Grounds. The location and extent o= these nursery grounds
are dependent upon the dry weather conditions of that particular year.
Young steelhead require good quality water and an abundance of food
(aquatic insects) for normal growth and survival. Field surveys have
shown that the San Luis Obispo Creel: drainage, without pollution, has
an abundance of food and natural water quality conditions suitable for
steelhead production.
Other species of fish which contribute to the fishery resources of the
San Luis Obispo Cree', drainage include: sculpin, Cottus beldingii;
three -spine sticiclebacl:, Gasterosteus acu_leatus; golden shiner,
Wotemn ggnus cgysoleucus; spec;cled dace, Rhiniethys osculus carrin tonii.;
green. sunfish., L_ epcL ic aellus; blue gill, Lepomis macrocicirus; and
Pacific lamprey, Entosphenus tridentatus.
-4-
SCOPE OF SURVEY
To accomplish the objectives of this study, investigations were
conducted as follows:
1. A review of past biological surveys of San Luis Obispo Creek_was
made.
2. Information concerning known existing waste discharges was reviewed.
3. A biological reconnaissance of San Luis Obispo Creel-, drainage wAs
made.
4. Stations on'San Luis Obispo Creek were established to sample stream
biota and water, as well as waste discharges.
5. Samples of the stream water, aquatic life, and waste discharges
were collected and analyzed.
o. Data from the field surveys and laboratory analyses were compiled
and evaluated.
7. A report was ;prepared for the Central Coastal Regional 'Jater Quality
Control Board which presents the findings of the survey and states
conclusions and recommendations.
5-
0
r0THOD S
Sampling Station_ Selection
Sampling stations were selected to represent areas of the stream that
appeared either unaffected or affected by waste discharges. To accomplish
this, a reconnaissance was made of the San Luis Obispo Creep, drainage.
Stream sections that had a comparatively substantial change in aquatic
life or dater conditions, were selected as stations. Fifteen sampling
stations were selected, and their locations are illustrated in Figure 1
and described in tine rata sheets.
Bottom Fauna Sampling
Bottom fauna were collected with a Surber square -foot bottom sampler �l)
With the e-ception of Station 5, three square -foot samples were taken
at each bottom sampling station. Because the first two samples taken
at Station 5 did not contain any aquatic organisms, a total of five
square -foot saml;les were ta?:en to insure representation of the bottom
fauna population.
The width and gradient of the stream, type of stream bottom, uniformity
of stream flow, and distribution of aquatic insects were the criteria
used to determine the number of samples needed to describe the bottom
fauna population. The amount of available time and funds was also an
important factor in determining the number of samples which could be
taken. After considering these criteria, it was our judgment that three
square -foot samples at each station would adequately represent the bottom
fauna population.
�Y The samples were preserved in 70% ethyl alcohol for identification and
enumerateq in the laboratory. "A Guide to the S udy of Freshwater
Biology" ` and 'Aquatic Insects of Californiawere used to identify
the bottom fauna.
Fish Sampling
Samples of the fish population were made at Stations 3, 6 and 10. These
stations were selected to obtain an indication of the fish population
in the affected and unaffected areas of San Luis Obispo Creek downstream
from Prado Road.
At each station, a 100 -foot section of stream was measured and bloci.ed
off with "stop nets" or seines. Each 100 -foot section was relatively
similar with respect to cover, number of pools and riffles, and general
appearance. Cresol, a sampling agent frequently used by biologists,
was used to collect the fish. An appropriate amount of Cresol was meas-
ured and mixed into the stream immediately above the upstream stop
net (4). Fish within the enclosure were stunned, captured, identified,
measured, and then returned to the stream above the treated section.
Cresol affects a fish's ability to respire oxygen. Complete recovery
in fresh water is usually effected in 3 to 5 minutes. A sample of each
species was preserved in 10"/ formalin for positive identification in
the laboratory.
-6-
Filamentous Algae. Sampling
At Stations 3 through 10, a 16 square foot plot of stream bottom was
denuded of filamentous algae. Each 15 square foot plot was similar
with respect to position in the stream. After removing the algae,
excess water was pressed from each sample, and the sample was weighed
on a Chatillion utility spring scale. Because of the luxuriant growth
of filamentous algae at Station 11 through 14, a visual estimation was
made of the relative abundance rather than the time-consuming method of
denuding an area.
Water Sam linty and Chemical Analysis
(A) Dissolved Oxygen - idater samples Vere taken at each station with
a ICemmerer.bottle. The dater samples were analyzed for dissolved
oxygen concentration by the Hach modification of the ,Iin?tler Method.
The Hach Method uses PAO (Phenylarsene Oxide) for titration rather
than the unstable thiosulfate solution, and also uses chemical
powder pillows rather than liquid reagents. Identical results are
obtained with the Hach Method as compared with the unmodified
Winkler method.
(B) Residual Chlorine - Residual chlorine was measured with a Wallace
and Tiernan Hellige Comparator immediately after each water sample
was taken. This is an accurate standard method for analyzing
residual chlorine
(C) Detergent - ,dater samples were gathered in one gallon bottles and
taken to the San Luis Obispo Sewage Treatment Plant for detergent
analysis. The quantity of detergent was determined by thg
Methylene Blue Test as described in "Standard Methods".(5) This
test,is accurate to 40.127 ppm per 1 ppm.
(D) Hydrogen -ion Concentration (pH) - The pH at each station was meas-
ured by a Beckman Pocket pH Meter, Model No. 1vO. This instrument
measures pH accurately to 0.05.
Physical Conditions and Analysis
(A) Stream Flow - Volume of stream flow was measured by the float
method (6) at a majority of the stations. The float method is a
simple, accurate method commonly used by biologists to estimate
the flow volume of small streams. At Stations 9, lla, and 12, the
volume of flow was determined by visual estimation.
(B) Transparency - The transparency at each station was determined by
visual observations of the clarity of the water and the visibility
of an emersed 50p piece. This method gives a unique on -the -spot
index of the clarity of water for comparing the transparency at
different sections of the stream. The transparency was recorded
as clear, slightly turbid, moderately turbid, or very turbid.
(C) Water Temperature - Water temperatures were measured with a
Fahrenheit thermometer.
-7*-
Toxicity Bioassa
A 96 hour toxicity bioassay was conducted in San Luis Obispo Creek at
Stations 8, 9, 10. Station 8 is immediately downstream from the San
Luis Obispo Sewage Treatment Plant discharge; Station 9 is the sewage
treatment plant discharge, and Station 10 is immediately upstream from
the sewage treatment plant discharge.
The bioassay was conducted to determine if the waste discharge was
toxic or non-toxic. The use of a bioassay as a test of waste quality
or toxicity is extremely valuable. Chemical examination of complex
wastes frequently does not give sufficient information on its toxicity.
The toxicity of the sewage treatment plant waste discharge to the local
fish in their natural medium was determined by conducting the bioassay
in the stream. `Chlorine, a component of the San Luis Obispo Sewage
Treatment Plant waste discharge, is volatile and has been reported to
be toxic at 0.05 ppm(7). Its volatile characteristics make it difficult
to test for toxicity in the laboratory. Therefore, the bioassay was
conducted in the stream so that all the waste components and variables
which influence the toxicity of the San Luis Obispo Sewage Treatment
Plant waste discharge could have an effect on the test fish.
A "live cage", 3' x 3' x 111, was submerged at each station. Thirty
rainbow trout, Salmo gairdnerii, at 4.2 fish to the pound, were placed
in each live cage. The trout were observed for 3 hours immediately
after starting the bioassay and thereafter at every 24 hour interval
for 96 hours. Water temperature, residual chlorine, dissolved oxygen
and pH were measured at each station.
OBSERVATIONS AVD RESULTS
Discharges
The San Luis Obispo Sewage Treatment Plant effluent is the only known
discharge into San Luis Obispo Creek below Metropolitan San Luis Obispo;
For approximately 1k miles downstream from the discharge, the stream had
a sterile appearance. The bottom was almost void of aquatic insects and
algae. Consequently, the rocks and gravel in the stream were virtually
"clean". At the time of our survey, San Luis Obispo Creek in Metropolitan
San Luis Obispo, was receiving numerous discharges which varied in volume,
appearance and odor. The location of these discharges began in the
general vicinity of California Boulevard in San Luis Obispo and extended
downstream for approximately 2 miles (see Figure 1),
Approximately 100 yards downstream from the California Boulevard over -
crossing, there is a 4 -inch pipe which was discharging warm (820) water
which had a strong chlorine odor. The volume (approximately 2 cfs) of
discharge was equal to the total stream flow on July 18, 1966. This dis-
charge appeared to emanate from the Huss Municipal Swimming Pool.
A walk along San Luis Obispo Creek from the vicinity of Osos and Marsh
Streets downstream to the San Luis Obispo Mission is an esthetically
disgusting experience-, Although most of this section of San Luis Obispo
Creek is tunneled, the stream flows in its natural streambed through the
city, The stream is being used as an open sewer. There are many pipes
which sporadically spew untreated wastes of unknown quality into the
stream, During the survey of this section of stream on July 18 and 19,
19660 we counted 89 pipes, culverts and drains of various sizes which
opened to San Luis Obispo Creek, We observed.10 of these pipes dis-
charging untreated waste directly into the stream,
One discharge, which emanated from the T -Bone Grill restaurant, was hot
(960 F) soapy water containing an abundance of food particles. A 15 -foot
section of stream below the T -Bone Grill was covered with a 4 to 6 inch
layer of decomposing food matter, This material on the bottom of the
stream had a strong poignant sulfide odor, A white scum on the surface
of the water covered most of this area. An exceptionally large population
of aquatic snails was distributed over the layer of decomposing food matter,
Aquatic snails, particularly a large population, are typical indicators
of organic pollution.
Inside the tunneled stream and approximately 50 feet downstream from the
T -Bone Grill, there was a storm drain which was discharging about 0.25 cfs
Of soapy, resin -smelling water into the stream. Two hundred feet down-
stream from the confluence of the storm drains the stream had a pH of 6.6,
as compared to a pH of 7.6 above this area.
Between Morro and Chorro Streets, we observed a 3 -inch pipe suddenly dis-
charge waste water into the stream for five minutes and then stop as
quickly as it had started.
-9-
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RG _N �,IIJROpc.
I - -)
7
�."*w
ow
v ow
met s" tirM11LVI (MOM". ""AgMN
-A A
f ,
k
10
n
May anei 4
in the approximate vicinity of Chorro Street, we observed a pile of de-
caying garbage in the streambed. Directly above the garbage were several
open pipes and a hole in the floor of what appeared to be a kitchen.
Trash
Trash in San Luis Obispo Creek seems to be the rule rather than the
except.on within the city limits. The greatest concentrations of trash,
incluzl:.ng shopping carts, broken glass, beer cans, and oil cans, are near
the various scream cross-tngs. Several small random trash dumping areas
along the sltream were observed near the downstream limits of the City.
One small trash dtmip, im;nediately upstream and on the opposite side of
the San Luis Obispo Sewage Treatment Plant discharge (Station 10)2 ex-
tended into the stream. Broken bottles, cans, paper, and old appliances
littered the stream bottom.
San Luis Obispo Creek Tributaries
On M,my 3, 1966, a reconnaissance of the major tributaries of San Luis
Obispo Creek was made. The purpose of the reconnall.ssance was to determine
if any of the tributaries were affecting the water quality of San Luis
Obispo Creek.
Of all the tributaries, Laguna Creek was the only stream which had deter-
gent bubbles on the surface and a substantial difference in aquatic insects.
Amphipods, leeches, and planaria were abundant; mayflies were not as abun-
dant as in other streams of the San Luis Obispo Creek drainage.
Chemical and Physical Conditions
Dissolved oxygen concentrations ranged from 5.5 ppm at Stations 2 and 3
to 9.0 ppm at Station 12. The highest recorded residual chlorine con-
centration was greater than 10.0 ppm in the Sari Luis Obispo Sewage
Treatment Plant waste discharge. On August 242 1966, the residual
chlorine concentration at Station S, immediately below the waste dis-
charge, was approximately 3.0 ppm. The stream above the waste discharge
had less than 0.1 ppm residual chlorine. The highest concentration of
detergent (0.1 ppm) in San. Luis Obispo Creek was recorded at Station S
immediately below the sewage treatment plant discharge on May 4, 1966.
During our survey, stream temperatures ranged from 600 to 700. pH ranged
from 7.3 at Station 6 to 3.0 at Station 12. A pH of 6.6 was recorded on
July 13, 1966,in San Luis Obispo Creek in metropolitan San Luis Obispo,
San Luis Obispo Creek was most turbid at Station S. The stream became
less turbid as the downstream distance increased from the sewage treatment
plant discharge. At Station 4 the water was relatively clear. The
chemical and physical data collected during sample runs for the 15 stations
are enumerated in Tables 1, 2, and 3. These data present chemical and
Physical conditions which occurred in the stream on May 4 and 5, 1966s
and August 24, 1966.
-11-
Table 1. Susonary of Chemical Conditions IiL San Luis Obism (reel-ibm:1.n
Daylight Morning Hours of May 4 and 51 1966.
(1) $4m Luis ObiW Sewage Treatment Plant Discharge
Residual
Dissolved
Chlorine
Oxygen
Detergent
stat on
1
7.9
1 0105
9.,0
0.1
2
7.8
0.05
5.50
-
3
7,9
0.05
5.50
•
4
7.8
0.05
7.25
0
5
7
0,05
8.0
0.
6
7.3
7 0.05
8,.40
0.03
8
7,2
01.05
8.30
0,,1
90)
7,6
0.l
10.20
0.05
10
7,2
0„05
680
0
11
7..4
„�
-
6.50
0
12
810
-
910
0
13
r_
7.7
-
•
14
7.8
-
-
-
(1) $4m Luis ObiW Sewage Treatment Plant Discharge
a
(1)
Table 2• Summary of Physical and Chemical Conditions in San Luis Obispo
Creek, August 24, 1966
Dissolved
Oxygen Temperature
_ _IP -1n)— (?F)--.
7.5 68
10.2 70
6.8 68
(1) San Luis Obispo Sewage Treatment Plant Discharge
-13-
Residual
Chlorine
Station
Time
P,
(Ppm)
8
0900
7.4
Approx 8.0
9(l)
0944
7.6
X10.0
10
1030
6.4
% 0.1
Dissolved
Oxygen Temperature
_ _IP -1n)— (?F)--.
7.5 68
10.2 70
6.8 68
(1) San Luis Obispo Sewage Treatment Plant Discharge
-13-
Table 3,, Summary of Physical Conditions in San Luis Obispo Creek,
May 3 and 4. 1966
(1) C - Clear
S - Slightly Turbid
M - Moderately Turbid
T - Very Turbid
(2) Station 7 is on Laguna Creek tributary to San Luis Obispo Creek
(3) San Luis Obispo Sewage Treatment Plant Discharge
-14-
Water
Flow
Temperature
Transparency(l)
Station
Time (cfs)
(OF)
3
1100 11.9
62
C
4
1225 12.4
64
C
5
1330 14.0
65
S
6
'.1450 x.1.4
67
M
7(2)
1540 2.9
65
S
S
1620 14.9
64
T
9(3)
1640 Approx9.0
69
T
10
1700 6.1
63
C
11
0945 6.0
60
C
Ilk
1300 Approx5.0
70
T
12
1050 Approx4.0
61
S
13
1513 0.5
65
C
14
1630 0.5
60
C
(1) C - Clear
S - Slightly Turbid
M - Moderately Turbid
T - Very Turbid
(2) Station 7 is on Laguna Creek tributary to San Luis Obispo Creek
(3) San Luis Obispo Sewage Treatment Plant Discharge
-14-
,Bottom Fauna Observations
Representatives of six orders of aquatic insects, two orders of
crustaceans, one order of gastropods, two classes of annelids, one class
of platyhelminthes, and one class of nemethelminthes were collected and
identified during the survey. The data collected on these organisms are
enumerated in Tables 4 and 5.
Ephemeroptera (mayflies), typically clean water species, exhibited the
greatest variation in numbers from station to station.- (See Table 4)
Mayflies were also the most abundant species of the aquatic insects.
Dipteras or fly larvae, a group which is adapted to live under a wide
variety of environmental conditions(8) were numerous at Stations 3, 43,-
6, 7, 10 and ll.— They Caere least abundant at Station 12 near the down.
stream limit of San Luis Obispo and at Station 3 immediately below the
San Luis Obispo Sewage Treatment Plant waste discharge.
Trichoptera (caddis fly) larvae were relatively numerous at Stations 3
and 14, and were least abundant of all aquatic insects at the other
stations on San Luis Obispo Creek. Caddis fly larvae are generally
considered clean water inhabitants, although certain species are able
to live in a variety of water quality conditions.
Cladocerans (water fleas) were found only at Stations 6 and 8. Hirudinea
(leeches) and Turbellaria (planaria) were most abundant at Station 7.
Pulmonata (aquatic snails) were found at almost all the stations, but
were most numerous in the section of stream which runs through metro-
politan San Luis Obispo,
Fish Population
Eight -species of fish were collected and identified during the survey..
Three -spine stickleback was the most abundant species at each station.
One Pacific lamprey was found at Station 3.
There was a large variation in the total number of game and forage fish
between Station 10 and Station 6. Only 35 forage fish (stickleback,
golden shiner, and speckled dace) were found at Station 6 below the
San Luis Obispo Sewage Treatment Plant waste discharge, whereas 375
were found at Station 10 above the waste discharge.
There were 50 game fish (steelhead, green sunfish and bluegill) at
Station 10 and only 5 game fish at Station 6.
A summary of the data collected on the fish populations at Stations 3,
6 and 10 are presented in Table 6.
-15-
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ioq
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1632
A
a
TMbla 4a SUMMy of Aquatic Insects per square foot, San Luis Obispo
Creek, ! 1956
(2) Station 7 is on Laguna Creek tributary to San Luis Obispo Creak
Numbers of:
d ation Ephemeroptera
Trichoptera
Hemiptera Dipt Odonata
Coleoptera
3
210
j
_
635
1
2
4
1",
235,
2
15
5
2
1
0
6c1i
$5
1
,[
1,14
0
2
60
3S
0
8a
0
0
1-Q
891
!
U
2
1
22
su�®
_
33
4
1
114
1
0
0
0
0
0
23
32
1
0
11
1
5
14
74
67
0
9
,� 1
12
(2) Station 7 is on Laguna Creek tributary to San Luis Obispo Creak
Tablej,54--s"llary of Bottom fauna other then 4 a,t$P_ Ivaects, per Square foot,,
San Luis Obispo Creek, May 3 and 4„ 1966
P.Tmbers oft
S� on Pulmonata Amphipoda Cladocera Ciiochaeta Hirudinea Turbellaria Ne{natoda
(1) Station 7 is euLagma Creek tributary to San Luis Obispo Creek
12
7
0
1
1
0
0
0
4
0
1
1
b
0
s
2
0
0
,[
/1
0
0
6
7(1-)
1
4
0
30
b
1
Q
0
4
0
22
.[ 1
1
g
0
0
54
10
0
0
0
10
4
4
0
1
/ 1
4
0
11
5
5
0
1
0
6
0
12
13
5
1
5
1
0
0
0
1
0
1
0
0
0
0
14
1
1
0
2
0
2
0
(1) Station 7 is euLagma Creek tributary to San Luis Obispo Creek
Table 6. Summary of Fish Population in San 'Luis Obispo Creek,
May 5, 1966
Station No-
Species
Number
Size
Range.(inches)
3
steelhead
4
2
1/2
- 6 1/2
sculpin
11
3
- 4
1/2
three pine
stickleback
251
1
- 3
Pacific lamprey
1
18
267
6
steelhead
4
6
- 8
1/2
sculpin
7
1
1/2
- 3
three -spine
stickleback
30
2
1/2
- 3
golden shiner
1
4
1/2
opeckled dace
4
2
1/4
- 3
green sunfish
1
5
3/'4
47
10
steelhead.
8
2
5/8
- 12
sculpin
41
3
- 6
three -spine
stickleback
302
1
1/2
- 3
golden shiner
31
3
- 5
speckled dace
42
2
- 3
1/4
green sunfish
1
5
bluegill
41
2
1/2
- 5 1/2
466
-18-
Filamentous Algae
Filamentous algae, Cladophor_a, was present in abundance at Stations 3,
4, 10, 11, 12, 13, and 14. There was no Cladophora at Stations 5, 62
and S, These stations represent the 1� mile area immediately below the
San Luis Obispo Sewage Treatment Plant waste discharge.
TheCladophora, at Station 12 and throughout the section of stream which
runs through the city, was deteriorating. Large pieces of dead algae
were easily removed from the stream bottom and broken apart. At Stations
3v 4, 10, 11, 13, and 14, the filamentous algae was green and healthy.
Cla ora is a typical clean water genera of algae. Its relative
abundance or absence is a good indicator of pollution(9).
A summary of the filamentous algae data is enumerated in Table 7.
Toi-cicityBioassay
All test fish exposed to the San Luis Obispo Sewage Treatment Plant waste
discharge died violently within 10 minutes. All test fish exposed to the
stream at Station S below the sewage plant waste discharge died within
25 minutes.
Twenty nine of the 30 test fish exposed to the stream at Station 10 above
the sewage plant waste discharge survived for 96 hours. The one fish that
died was found entangled in the wire of the live cage.
All test fish that were exposed to the sewage plant waste discharge and
the stream below the discharge, swam erratically and frequently jumped
out of the water. The body and gill colors of the fish faded rapidly
to a pale grey. Their eyes appeared to have been coated with a white
film.
A summary of the toxicity bioassay data is presented in Table S.
1510
t
Table. 7. Summary of Filamentous Algae, Cladophora, per square foot,
may 3 and 4, 1966
Station No. Pounds of algae per square foot (1)
3 0.3
4 0.03
5
0
6
0
7
0
g
0
10
0.05
11
approx.
0.05
12
approx.
0.3 (2)
13
7
0.3
14
6
0.03
(1) Damp weight
(2) Algae was deteriorating
20•-
Table 8. Summary of Toxicity Bioassay Data
Location: San Luis Obispo Creek, Stations 8, 9, and 10
Test species: Rainbow trout, Salmo gairdnexii
Source: San Joaquin Hatchery, Friant, California
Condition of fish: Excellent
Size of fish: 4.2 per pound
Number of fish per live cAge; $0
Start
Date: 8/24/66
Time:
1300
Station
8(1
9
10
Number alive
4 )
0
(2) 30 Egpntrol)
% Survival
0
0
100
24
Hours
Date: 8/25/66
Time:
1300
Station
8
9
10
Number alive
0
0
30
% Survival
0
0
100
48
Hours
Date: 8/26/66
Time:
1300
Station
8
9
10
Number alive
0
0
29 (4)
% Survival
0
0
96.6
72
Hours
Date: 8/27/66
Time:
1300
Station
8
9
10
Number alive
0
0
2.9
% Survival
0
0
96.6
96
Hours
Date: 8/28/66
Time:
1300
Station 8 9 1.0
Number alive 0 0 2.9
% Survival 0 0 96.6
(1) All fish were dead within 25 minutes.
(2) All fi,:h. were -dead within 10 min-; tes.
(3) All fish were alive after 3 hours.
(4) Fish that died was entangled in wire mesh of live car.
-21-
DISCUSSION
The primary purpose of this survey was to determine the effect of
existing waste discharges upon the aquatic life of San Luis Obispo
Creek. Data in Tables 4, 6, 7, and 8, concerning the abundance of -
aquatic insectso fish and filamentous algae, and toxicity, respective-
ly, present substantial evidence that sewage and waste water being
discharged into the stream are adversely affecting the aquatic life
and sport fishery of San Luis Obispo Creek.
The use of aquatic insects as indicators of stream pollution is an
accepted method by biologists. The merits of using this method have
been well documented by Gaufin and 'rarzwell (10).
The relative abundance and variability of the aquatic insect population
of San Luis Obispo Creek, particularly the mayfly nymphs, indicate the
polluted condition of the stream (see Figure 2). There were 691 mayfly
nymphs per square foot at Station 10 immediately above the San Luis
Obispo Sewage Treatment Plant waste discharge. Ima►ediately downstream
of the discharge at Station 82 there were only 12 mayfly nymphs per
square foot. The number of mayfly nymphs per square foot did not
substantially increase until Station 4 downstream from the -waste dis-
charge. A large variation in the number of mayflies per square foot
also occurred in that section of stream from Station 13 to Station 12.
Station 13, approximately a mile above downtown San Luis Obispo, had
32 mayfly nymphs per square foot. Station 12 at Nipomo Street, which
was representative of stream conditions through most of metropolitan
San Luis Obispo, had only one mayfly nymph per square foot.
Although a variety of aquatic bottom fauna were observed, we chose
the mayfly nymph as the primary water quality indicator organism.
Mayfly nymphs are very sensitive to water quality conditions; con-
sequently, their absence or relative abundance is a good indication
of water quality conditions.
The relative abundance of all aquatic insects showed a very similar
variance from station to station as the mayfly nymphs showed.
Differences in the aquatic insect population of Station 7 (Laguna
Creek) and any station in San Luis Obispo Creek may be attributed
to the natural dissimilarity of the bottom characteristics between
both streams.
Aquatic insects are not only indicators of water quality conditions,
b'lt also serve as a very important food for fish. Without sufficient
quantities of aquatic insects, fish soon disappear for lack of food
whether they can or cannot; physically survive in the water(ll).
Doudoroff(l2) states that the absence or scarcity of fish in a stream
immediately below a point of waste discharge and not above the point
of discharge, strongly suggests that the discharge is somehow detri-
mental to these fish. If valuable food and game fish species are among
tho$e fish relieved to be adversely affected, pollution is indicated.
-22-
STATION NUMBER
h
FIGURE 2. AQUATIC INSECTS AND FISH POPULATIONS
Ir
6
8
Mayfly Nymphs
Total Aquatic Insects
Total Fish (sampled at
Stations 3, 6, 10 only)
San Luis Obispo Sewage
Treatment Plant Discharge
Metropolitan San Luis Obispo
13
14
- 450
- 400
350
300
250
200
-150
-100
-50
The results of our fish sampling show that a large variance in the total
number of fish, including food and game species, existed between the
stream area immediately above the San Luis Obispo Sewage Treatment plant
discharge, Station 10, and the stream area just below the discharge,
Station 6. There were approximately 10 times as many fish at Station 10
as at Station 6. An approximate ratio of 10:1 also existe-d between the
numbers of forage fioh at Station 10 and Station 6. Three-spine.stickle-
backs, which are able to live in a wide range of water quality conditions,
were abundant at Stations 3 and 10, but were relatively scarce at Station
6 below the sewage treatment plant discharge. This indicates that the
discharge was adversely affecting these fish.
We were not able to draw a valid conclusion concerning the abundance
of steelhead observed. Only a limited number were collected and the
relative variation in abundance, among the stations sampled, was not
significant.
The results of our in -stream toxicity bioassay at Stations 8, 9 and 10
confirm that the San Luis Obispo Sewage Treatment Plant waste discharge
is detrimental to fishlife.
At the time of the survey, approximately four miles of San Luis Obispo
Creek, through metropolitan San Luis Obispo and below the San Luis Obispo
Sewage Treatment Plant discharge, had been adversely affected by waste
discharges. (See Figure 3) We believe that the damaged or pollution
affected sections of San Luis Obispo Creek "'M be increased with the
existing waste discharges and a decrease in stream flow. During summer
and fall,'the volume of stream flow in San Luis Obispo Creek decreases
and consequently loses its capacity to buffer the detrimental effects
of pollution. Therefore, it appears that a biological survey, made
during the critical low flow periods, would be valuable in determining
the total effect of existing waste discharges upon the aquatic life of
San Luis Obispo Creek,
-24-
FIGURE 3. EXTENT OF STREAM AFFECTED BY POLLUTION
SAN LUIS QBISPO-CREEK, SAN LUIS OBISPO COUNTY
13-- ----------- 7`1
-----
---------T.R.
----- --- --12
l k'
' SAN LUIS OBISPO
\ J
!t---------------11
------���.,.�-a--� '-------------10
7- --------
8---------- - «---------------------6
�`'-------------- \------5
--------_-- ___-4
-.l
Area of stream affected by
pollution on May 3 & 4, 1966.
t
Scale: 1 inch = 1 mile
2---__.. ,- -,--------------------------------3
AV ILS,
25
CONCLUSIONS
As a result of the biological survey of San Luis Obispo Creek, we conclude
the following:
1. Waste discharges emanating in metropolitan San Luis Obispo dre
polluting San Luis Obispo Creek to the detriment of its aquatic life.
2. The waste discharge from the San Luis Obispo Sewage Treatment Plant
is adversely affecting the aquatic life of San Luis Obispo Greek.
Residual chlorine, a component of the sewage plant waste discharge,
is suspected as being a cause of the relative "sterile" conditions
in the stream below the discharge.
3, The tributaries to San Luis Obispo Creek were not adversely affecting
stream biota in San Luis Obispo Creek at the time of the survey.
4;. The numerous small heretofore unknown waste discharges and garbage
Rumps in San Luis Obispo Creek throughout metropolitan San Luis
Objspo, indicate that some citizens of San Luis Obispo are using
the stream as a sewer for their trash and garbage.
w26•-
RECO12MIMATIOIIS
We recommended that the Central Coastal Regional Water Quality Control
Board carry out the following actions:
Determine the sources, quality and quantity of all the existing
waste discharges into San Luis Obispo Creek.
Require all establishments that dispose of waste in San Luis Obispo
Creek to connect to the modern San Luis Obispo Sewage Treatment Plant.
Require the City of San Luis Obispo to determine and reduce to a non-
toxic level the specific components in their sewage treatment plant
waste discharge which are adversely affecting the aquatic life of
San Luis Obispo Creek. This would be in accordance with Section 3-f
of the City of San Luis Obispo's waste discharge requirements.
Request the City of San Luis Obispo to enforce their ordinance
against dumping trash or rubbish within the city limits.
Take legal action against those dischargers who continue to discharge
into San Luis Obispo Creek and consequently cause detriment to the
stream's biota and fishery resources.
Conduct an additional biological survey of San Luis Obispo Creek
after corrective action has been taken, to determine the effect
1tf any remaining waste discharges upon aquatic life. This survey
should be conducted during the low scream flow period.
-27-
REFERENCES
1. Welch$ P.S.
1948, Limnological Methods. Phila., Pa., The Blakiston-Co., 381 pp,
2, Needham, James G., and Needham, Paul R.
1962, A Guide to the Study of Freshwater Biology. San Francisco,
Calif., Holden -Day, Inc., 107 pp.
3, Usingers Robert L.
1963, Aquatic Insects of California with Reqs to North American
Genera and California Species. Berkeley and Los Angeles,
Calif., Univ. Calif. Press, 508 pp.
4. Wilkins., L. Price
1955. Observations on the Field Use of Cresol as a Stream -Survey
Method, The Progressive Fish Culturist, Vol. 17, No. 2,
pp. 85-86.
5, American Public Health Association
1965, Standard Methods for the Examination of Water and Warmwater,
Twelfth Ed, New York, New York, American Public Health
Association, Inc., 769 pp.
6, Robins, C. Richard, and Crawford, Ronald W.
1954, A Short Accurate Method for Estimating the Volume of Stream
Flow. The Journal of Wildlife Management, Vol. 18, No. 3,
pp. 366-369.
7. McKee, Jack Edward, and Wolf, Harold W.
19630' Water Quality Criteria, 2nd Ed. The Resources Agency of
California, Publication No. 3-A, 548 pp.
•., 8. Gaufin, Arden R.
1957. The Use and Value of Aquatic Insects as Indicators of
Organic Enrichment, U. S. Department of Health, Education,
and Welfare. Transactions of a Seminar on Biological
Problems in Water Pollution, pp. 136-140.
V 9. Palmer, C. Mervin
1959.. Algae in Water Supplies. U. S. Department of Health,
Education, and Welfare, Public Health Service.
Publication No. 657, 88 pp.
-28-
10. Gaufin, Arden R., Ph.D., and Tarzwell, Clarence M., Ph.D.
1952, Aquatic Invertebrates as Indicators of Pollution.
U. S. Public Health Reports, Vol. 67, No. 1, pp. 57-64.
1. Rounsefell, George A., Ph.D., and Everhart, W. Harry, Ph.D.
1953. Fishery Science. Its Methods and Applications. New
York, New York, John Wiley and Sons, Inc., 444 pp.
12. Doudoroff, Peter, and Warren, Charles E.
1957, Biological Indices of Water Pollution, with Special
Reference to Fish Populations, U. S. Department of
Health, Education, and Welfare. Transactions of a
Seminar on Biological Problems in Water Pollution,
pp. 144-163.
-29-
APPEMIX
The appendix contains data sheets No. 1 through No. 15. These
sheets present the actual data taken in the field during the
survey.
..3(?..
DATA SHEET 1
STATION ISO. 1
Description: San Luis Obispo Creek estuary at Avila Sanitation
District Sewage Treatment Plant, Avila.
May 4, 1966:0530
Residual Chlorine / 0.05 ppm
Dissolved Oxygen 9.0 ppm
May 5, 1966:0615
Dissolved Oxygen 8.7 ppm
Detergent 0.1 ppm
DATA SHEET 2
STATION N0. 2
Description: San Luis Obispo Creek at San Luis Obispo -Avila Road
Bridge.
May 4, 1966;0545
Residual Chlorine / 0.05 ppm
Dissolved Oxygen 5.5 ppm
Stream Flow Approximately 20 cfs
Algae Abundant thriving filamentous algae
DATA SHEET 3
;ON NO. 3
Description: San Luis Obispo Creek opposite Belleve Santa Fe School,
and approximately 400 yards upstream from Highway 101
Bridge,
May 32 1966:1100
Air Temperature 70 degrees F.
Water. Temperature 62 degrees F.
Stream Flow 11.9 cis
Transparency Clear
PH 7.9
Bottom Characteristics Sand, gravel to 3 inches, very little
silt.
Cover
Algae
Bottom Samples
Notes
May 4, 1966:0605
Residual Chlorine
Dissolved Oxygen
Way 5, 1966:1000
Fish Sample
Not much cover, some Typha along stream
bank, riparian willows
Filamentous algae abundant, 0.3 lbs/sq ft
3 Surber samples taken, aquatic insects
abundant (see Tables 4 and 5)
Pastured land area
/ 0.05 ppm
5 a 5 ppm
100 feet section sampled with Cresol
(see Table 6)
DATA SHEET 4
STAvw N0. 4
Description: San Luis Obispo Creek, 101 yards upstream from the San
Luis Obispo -Monterey Road (Higuera Street continuation)
Bridge.
play 3, 1966:1225
Air Temperature 72 degrees F.
Water Temperature 64 degrees F.
Stream Flow 12.4 cfs
Transparency
pH
Bottom Characteristics
Cover
Algae
Bottom Samples
Notes
May 49 1966:0625
Residual Chlorine
Dissolved ftygen
Detergent
Clear
7.8
Sand, gravel to 3 inches, very little
silt, moderate amount of organic debris
Moderate ccver of willows and Scirpus;
Juncus, Cyperus, watercress, and water
grass present
Filamentous algae moderate, 0.03 lbs/sq ft.
3 Surber samples taken (see Tables 4 and 5)
Area subject to cattle use
/ 0.05 ppm
7.3 ppm
0 ppm
DATA SMET 5
STATION vol. 5
Description: San Luis Obispo Creeks apprcdmately half Way bete
the San Luis Oolspo-Ybntelr7 Road Bridge and Laguna
Creek -San Luis Obispo Creek confluence.
May 30 1955:.1330
Air rc'empera,i ura
Water Temperature
8trean Flow
Transparency
69 degrdes F.
65 degrees 1'.
1400 cfs
Slightly turbids but relatively clear;
detergent foam on, surface
pg 7.9
Bottom Characteristics Sand, gravel to 3k inches, no silt, bottom
almost "clean"s no organic sediment
Cover Good Pover, heavy willow shadings slight
amount of watercress and water grass
Algae No areas of filamentous algae growths
slig�I.t algae growth on larger stones
Bottom Samples 5 Surber samples taken because of lack of
bott= fayo.as no aquatic insects in 2
samples (cee Tables 4 and 5)
Notes occasional pools to 2 feet in depth#
little if amy cattle usages comparatively
few stickbacks observed, those seen were
large
May 42 1966:0645
Residual Chlorine ,� 0.05 ppm
Dissolved Oxygen 8.0 ppm
Detergent 0 Ppm
DATA SHEET 6
STATION M. 6
Description: San Luis Obispo Creek immediately downstream of confluence
with Laguna Creek.
May 3, 1966:1450
Air Temperature 66 degrees F.
Water Temperature 67 degrees F.
Stream Flow 11.4 cfs
Transparency Cloudy, 500 piece not visible below 1 7/10
feet, large amounts of foam on surface and
collecting on willow branches in water
6
PH 70
Bottom Characteristics Gravel to 3 inches, occasional stone to 6
inches, no organic sediments, bottom
almost "clean".
Cover
Good covers abundant willow shading, no
aquatic plants except 1 or 2 strands of
water grass in a 50 foot section, few
pools to 3 feet in depth.
Algae
No filamentous algae present, slight
encrusting algae growth on stones in
lentic margin of stream
Bottom Samples
3 Surber samples taken, very few aquatic
insects in this section (see Tables 4
and 5 )
Notes
Chlorine odor present
966:0725
Residual Chlorine
/ 0.05 Ppm
Dissolved Oxygen
8.4 Ppm
Detergent
0.03 ppm
DATA SHEET 6 (continued)
May 51 1966:1030
Detergent 0,05 ppm
May 59 1966;1400
Fish Sample 100 feet section sampled with Cr000l
(see Table 6)
DATA SHEET 7
SUTTON No'. 7
Description: Laguna Creek between divided Highway 101 Bridges.
may 32 1966:1540
Aix Temperature
57 degrees F.
Water Temperature
65 degrees F.
Stream Flow
2.9 of$
Transparency
Slightly turbid, some detergent bubbles
present on surface
PH
7.9
Bottom Characteristics
Hard grey clay, thin silt layer covering
bottom, occasional rocks 1 to 4 inches,
riffle every 200 feet
Cover
No cover except for occasional undercut
bank
Algae
No filamentous algae, brown-green en-
ncrusting
crustingalgae growth on rocks
Bottom Samples
3 Surber samples taken, a multitude of
chironomide larvae (see Tables 4 and 5)
Fish
No sampling, sticklebacks and dace
observed
Notes Stream shows sign of fluctuations
May 4, 1966:0705
Residual Chlorine / 0.05 ppm
Dissolved Oxygen 7,7 ppm
Detergent 0.1 ppm
way 5, 3966:1025
Detergent 0..3 ppm
DATA SBEET 8
sTATiON NO'., 8
Description: San Luis Obispo Creek approximately 25 yards upstream of
Laguna Creek confluence
May 30 1966:1620
Air Temperature 57 degrees F.
Water Temperature 64 degrees F.
Stream Flow 14.9 cfs
Transparency (see Motes)
ph 7.2
Bottom Characteristics Sand, gravel to 3 inches, occasional rock
to 6 inches, good gradient
Cover Abundant willow covers relatively few
pools
Algae None in effluent effected side, moderate
algae in opposite clear water side of
stream before complete mixing
Bottom S mples 3 Sieber samples taken in area of mixed
water., very few aquatic insects in effluent
affected side of stream (see Tables 4 and 5
Fish No fish observed in affected side of
stream, a small school of sticklebacks
were observed in the healthy side of
stream; a dead 7 inch steelhead was found
at this station on May 21 1966, no apparent
cause of death
Notes The stream, before complete missing of the
S'L,O. Sewage Treatment Plant effluent and
upstream waters, is divided into two
different environmental conditions One
side affected by the effluent is relatively
sterile, very cloudy, 504., piece not visible
below 7/10 feet, has strong chlorine odor,
detergent foam on the surface and no algae
or aquatic insects on the bottom, The
normal uneffected side is clear, no
chlorine odors abundant algae., watercress,,
aquatic insects and sticklebacks present.
DATA SST 8 (continued)
Ma► 41 1966:0735
Residual Chlorine 0.05 Fpm
Dissolved Oxygen 8.,3 ppm
Detergent 0,1 ppm
May 59 1966;1025
Detergent 0 ppm
DATA SHEET 9
STATION NOS. 9
Description: San Luis Obispo Sewage Treatment Plant discharge at
confluence of San Luis Obispo Creek,,
May 31 1966:1640
Air Temperature 47 degrees F.
Effluent Temperature 69 degrees F.
Discharge Flow Approximately 9 cfs
Transparency Effluent is cloudy and light yellow in
color; detergent foam 2 to 4 feet thj.ek
at confluence with stream
Notes
May 4, 1966:0740
Residual Chlorine
Dissolved Oxygen
Detergent
May 5, 1966:1020
Detergent
Strong chlorine odor
0.1 ppm
10.2 ppm
0.05 Ppm
Duplicate samples �8.1ppm.
r -
DATA SHEET 10
STATION NO. 10
Description: San Luis Obispo Creek immediately upstream of the San,
Leis Obispo Sewage Treatment Plant discharge.
May 3, 1966:1700
Air Temperature 57 degrees F,
Water Temperature 63 degrees F.
Stream Flow 6.1 cfe
Transparency Crystal clear
PH 7,2
Bottom Characteristics Sand,"gravel to 3 inches, occasional large
rocks,, no silt, abundant organic detritus
Color Moderate cover, willows along banks;
several large pools to 4 feet, no aquatic
higher plants
Algae Abundant algae growth, filamentous algae
0.05 lbs/sq.ft„
Bottom Samples 3 Surber samples taken, many mayfly
nymphs in filamentous algae (see Tables 4
and 5)
Notes Trash in the strewn
May 4, 1966:0705
Reeidual Chlorine / 0,05 ppm
Dissolved Oxygen 6..8 ppm
Detergent 0 ppm
May 5, 1966:1530
Fish Sample 100 feet sectlan sampled with Cresol
(See Table 6)
DATA SHEET 11
STATION Mi. 11
Description: San Luis Obispo Creek at Silver City Trailer Park
May 4p 1966;0945
Air Temperature
Water Temperature
Stream Flow
Transparency
62 degrees F.
60 degrees F.
6 eft
Clear, no turbidity
PH 7.,4
Bottom Characteristics Sand, gravel to 3 inches, occasional
rocks to 6 inches, very little silt,
moderate amount of organic sediments
Cover Excellent cover of willows and other
strean side growth, undercut banks,
no water grasses
Algae Abundant filamentous algae, approximately
0.05 lb/sq..,ft.
Bottom Samples 3 Surber samples taken, mayfly nymphs
abundant (see Tables 4 and 5)
Fish No sample taken; observed small school of
cyprinids possibly dace; sticklebacks
abundant, observed 3 steelhead 6 to 7
inches in length
Notes Very large mayfly hatch occurring
DATA SHEET 12
STATION NOS. 11k
Description: San Luis Obispo Creek at Elks Lane
May 4, 196611300
Air Temperature 72 degrees V,
Water Temperature 70 degrees F.
Strewn Flow Approximately 5 cf.s
Transparency Water turbid and slightly yellow
Bottom Characteristics Bed rock, hard cemented c0%10merate
bottom, large rocks and boulders
Cover Slight cover, some willows and an
occasional pool to 3 feet
Notes AbunJ aat decaying matter, strong H2S
odor, very few aquatic insect larvae,
moderate amount of snails, debris and
trash in the stream, a few sticklebacks
observed
May So 1966
0550 - Dissolved Oxygen 6.5 ppm
1005 - Detergent 0 ppm
DATA SHEET 13
STATION NOI, 12
Description; San Luis Obispo Creek at Nipomo Street
May 4, 1966;1050
Air Temperature
Water Temperature
Stream Flow
Transparency
PR
67 degrees F.
61 degrees P.
Approximately 4 efs
Slightly turbid
8.0
Bottom Characteristics Gravel to 2 inches, mangy* rocks 6 to 12
inches, debris and organic sediments
abundant, black deposits with strong
H2S odor, good stream gradient.
Cover Little natural cover, strew shaded by
backs of buildings and occasional trees,
some overhanging berry and ivy vines,
very few pools
Algae Abundant filamentous algae, approximately
0'.3 lbs/sq.,ft.., most of the algae in state
of deterioration and decay
Bottom Samples 3 Surber samples taken, snails -and snail
egg cases abundant, very few aquatic in-
sects (see Tables 4 and 5)
Fish No sample taken, observed small schools
of sticklebacks and one steelhead ap-
proximately 6 inches in length.
Notes Many drain pipes present reading from
streamside buildings; observed sporadic
discharge from a milk distributor,
appeared to be milk waste and wash stater,
luxuriant growth of ISLEMA no water-
cress or water grasses
May 50 1966;0540
Dissolved Oxygen 9.0 ppm
May 5, 1966:0950
Detergent 0 ppm
DATA SEM 14
STATION ND. 13
Description: San Luis Obispo Creek, approximately 50 yards upstre"M
from Highway 101 Bridge north of San Luis Obispo city
limits,
May 4, 1466:1513
Air Temperature
Water Temperature
Stream Flow
Transparency
71 degrees F.
65 degrees F.
0.5 ofe
Clear, no turbidity
PH 7.7
Bottom Characteristics Gravel to 2k inchea! occasional rocks to
8 inches slight gradient, to alit
Cover Moderate cover of willows
Algae Stream covered with luxuriant growth of
filamentous algae, more than 0,3 Zbs/sq.ft.
Bottom Samples 3 Surber samples taken, initidl'observa
tions indicate a variety of aquatic
insectss but not an abundance of any one
species (see Tables 4 and 5)
Fish No samples taken, observed sticklebacks
and .two steelhead approximately 6 inches
in length
DATA SMMT 15
STATION NOT.. 14
Description: San Luis Obispo Creek, approkimately 100 yards Upstream
from confluence of Reservoir Canyon Creek,
May 4, 1966:1630
Air Temperature
Water Temperature
Stream Flow
Transparency
62 degrees F.
60 degrees F.
0,.5 cfs
Clear
PH 7.8
Bottom Characteristics Sand, gravel to 2 inches, occasional
rocks to 5 inches, silt in lentic areas,
taoderate gradient, bottom disturbed by
cattle use
Cover Very little cover, some shading by willows
and sycamore trees, occasional undercut
bank
Algae Slight amount of filamentous algae, less
than 0..03 lbs/sp.ft.
Bottom Samples 3 Surber samples taken, rocks covered
with trichoptera cases. (See Tables 4
and 5)
Fish No samples taken, several 2 to 3 inch
unidentified fish seen
Notes Banks erroded, decaying syc-amore leaves
in water, some watercress