660/3-74-016
1974
Ecological Research Series
The Significance And Control of
Wastewater Floatables
In Coastal Waters
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental studies
This report has been assigned to the ECOLOGICAL
RESEARCH series. This series describes research
on the effects of pollution on humans, plant and
animal species, and materials. Problems are
assessed for their long- and short-term
influences. Investigations include formation,
transport, and pathway studies to determine the
fate of pollutants and their effects. This work
provides the technical basis for setting standards
to minimize undesirable changes in living
organisms in the aquatic, terrestrial and
atmospheric environments.
EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policies of the Environmental Protection Agency,
nor does mention of trade names or commercial products
constitute endorsement or recommendation for use.
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EPA-66o/3-7^-Ol6
January
THE SIGNIFICANCE AND CONTROL OF WASTEWATER
FLOATABLES IN COASTAL WATERS
By
Robert E. Selleck
Lloyd W. Bracewell
Half Carter
Contract No. R-800373
Program Element 1BA025
Roap/Task 21 AIS l6
Project Officer
Walter F. Rittall
U.S. Environmental Protection Agency
National Environmental Research Center
Corvallis, Oregon 97330
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, DC 20U60
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ABSTRACT
The significance of flotage derived from submerged primary effluent plumes
in the Southern California Bight is evaluated in terms of three components:
particulates * 0.5 mm in size, particulates z 0.1 mm in size, and surface
film materials. The sampling methods utilized to collect the flotage from
the surface are described in detail. The surface film and micro-particulates
were captured by fabric screen samplers developed during the course of the
study.
It was found that the large particulates penetrated the ocean thermocline
and gathered on the surface in profusion. The grease and wax portions of
the particulates could be measured reliably with hexane extraction, with the
mass of HEM of sewage origin being in the order of a metric ton on the water
surface within the study area. Such particulates contained considerable
numbers of coliform bacteria but little PCB compounds or pesticides.
The surface film materials and/or micro-parti culates contained significant
concentrations of coliform organisms and PCB compounds, but not pesticides.
The HEM derived from this type of flotage may have amounted to 300 kg on
the water surface within the study area in July 1973.
Regulations for controlling the concentration of flotage on the ocean surface
are suggested after considerable discussion.
This report was submitted by the Sanitary Engineering Research Laboratory
of the University of California, Berkeley, in fulfillment of Grant Number
R-800373, under the sponsorship of the Office of Research and Development
of the Environmental Protection Agency.
111
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TABLE OF CONTENTS
Page
Abstract iii
List of Figures vii
List of Tables ix
Sections
I. CONCLUSIONS 1
Trawled Particulates 1
Micro-Particulates 2
Surface Screen Samples 3
II. RECOMMENDATIONS 6
III. INTRODUCTION 7
IV. DESCRIPTION OF OCEAN SURVEYS 10
Effluent Plume Submergence 12
Surface Conditions During Surveys 20
Discussion 29
V. TRAWLED PARTICULATES 34
Description of Trawls 36
Results of Surveys 39
Proof of Wastewater Derivation of Particulates ... 44
Measurement of Surface Pollution 46
Significance of Surface Pollution 54
Control of Surface Pollution ...... 65
VI. MICRO-PARTICULATES . 69
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TABLE OF CONTENTS (Continued)
Section Page
Sampling Procedure 69
Analytical Procedure 70
Results 70
Conclusions 75
VII. SURFACE SCREEN SAMPLES 76
Sampling Procedure 76
Sampling and Analytical Accuracy 77
Results of Surveys 79
Discussion of Results 85
Origins of Cloth Screen Fatty Acids 96
The Significance of the Surface Pollution 96
Control of the Surface Pollution 97
VIII. REFERENCES 100
IX. GLOSSARY 102
APPENDICES
A. Miscellaneous Tables 103
B. Analytical Methods 109
VI
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LIST OF FIGURES
F1gure Title Page
1. Study Area 11
2. Temperature Profiles Observed at Samping Stations:
April, 1971 13
3. Water Density Profiles: April, 1971 14
4. Temperature Profiles Observed at Sampling Stations:
August-September, 1971 15
5. Water Density Profiles: August-September, 1971 .... 16
6. Temperature Profiles Observed at Sampling Stations:
July 1973 17
7. Surface Conditions in Hyperion Outfall Region:
April 7, 1971 22
8. Surface Conditions in Control Areas: April 4 and
September 2, 1971 23
9. Surface Conditions in Hyperion Outfall Region:
August 31 and September 1, 1971 24
10. Surface Conditions Over JWPCP Outfalls:
September 3, 1971 26
11. Transport of Flotage Study: December 9, 1971 27
12. Surface Conditions Over JWPCP Outfalls: July 11, 1973 . 28
13. Surface Conditions Off Marineland: July 12, 1973 .... 30
14. Surface Conditions in Control Area: July 13, 1973 ... 31
15. Photographs of Sea Slicks 117
16. Trawl Net Sampler 35
17. Cumulative Frequency Distribution of Grease and
Wax, and Tar Particulates: August-September, 1971 ... 42
18. Rise of Large Particulates in the Vicinity of the L
Diffuser of the JWPCP Outfalls: July, 1973 ...... 119
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LIST OF FIGURES (Continued)
Figure Title
19. Fatty Acid Composition of Large Particulates:
July, 1973 119
20. Comparison of Grease and Wax Particulates With
Non-Extractable Sewage Types 47
24. Comparison of Grease and Wax Particulates with HEM . . 49
22. Fatty Acid Proportion of HEM 51
23. Comparison of Total Dry Weight with HEM 53
24. Example of Aesthetic Rating Sheet for Evaluating
Ocean Surface Pollution 55
25. Cumulative Frequency Distributions of Coliform
Bacteria Surface Concentration: 1971 57
26. Estimate of Mass of Wastewater HEM Present on Ocean
Surface - Trawl Samples 59
27. Cumulative Frequency Distribution of Clumps of Debris
Collected by the Nylon Netting: August-September 1971 . 73
28. Cumulative Frequency Distribution of Coliform
Bacteria Found in Screen Samples Taken Over the
Outfalls: April and September, 1971 87
29. Cumulative Frequency Distribution of HEM Found in
Cloth Screen Samples in Control Area: July, 1973 .... 91
30. Fatty Acid Composition of Cloth Screen Samples:
July, 1973 94
31. Analytical Approach to Characterizing Flotage and
Bulk Samples Ill
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LIST OF TABLES
Table
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Title
Characteristics of Outfalls Samples
Calculated Plume Submergence and Dilution Over
Marine Outfalls
Summary of Surface Trawls
Summary of Surface Trawls - Col i form Bacteria ....
Concentration and Sizes of Prevalent Trawled
Parti culates
Explanation of Figure 19, Fatty Acid Composition of
Large Parti culates
Comparison of Aesthetic Impact with HEM
Comparison of Col i form Bacteria with HEM
Mean Concentrations of HEM in Trawled Parti culates . .
Analyses of 24-Hr Composite Samples of Hyperion
Effluent During Ocean Surveys of 1971
Mass Emission Rates of Parti cul ate HEM From
Treatment Plants
Local Mass Balance on HEM of Trawled Parti culates . . .
Composition and Concentration of Parti culates
Captured by the Cloth Screen Sampler
Sizes of Prevalent Types of Parti culates Captured
by the Cloth Screen Sampler: August-September, 1971 . .
Concentration of Cloth Screen HEM
Concentration of Cloth Screen Fatty Acids:
July, 1973
Mean Concentrations of Cloth Screen HEM and
Fatty Acids .
Concentration of Col i form Bacteria: Cloth Screen
and Ocean Water Samples ...
Page
18
19
37
39
41
U5
55
57
58
60
62
63
71
74
80
82
83
84
IX
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LIST OF TABLES (Continued)
Table Title Page
19. Concentration of Cloth Screen PCB Compounds 85
20. Comparison of Ocean Water and Surface Concentrations
of Aroclor 1254: July, 1973 88
21. Pan Data for JWPCP Effluent ....... 92
22. Fatty Acid Composition of Cloth Screen Samples:
July 1973 93
23. Fatty Acid Composition of Bulk Ocean Samples:
July 1973 95
24. Estimated Concentration of HEM of Wastewater Origins
in Cloth Screen Samples 97
25. Ocean Currents at Hyperion Outfall 104
26. Ocean Currents in August-September 1971 Survey 105
27. Description of Trawled Particulates: Over Outfalls ... 106
28. Description of Particulates: 3.7 KM N of Hyperion
Outfall 107
29. Description of Particulates Collected: Control Area . . . 108
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ACKNOWLEDGMENTS
The continued interest and assistance of Dr. Donald J. Baumgartner, Program
Chief of the National Coastal Pollution Research Program, Environmental
Protection Agency, and Mr. Walter F. Rittall, Grant Project Officer, is
acknowledged with thanks. Also, the aid of Dr. Joseph Blazevich of the
Corvallis, Oregon Laboratory in supplying standards and suggestions for
methods of analysis is recognized and fully appreciated.
Professor Robert E. Selleck was the faculty investigator of the project,
acting in behalf of The Regents of the University of California, and
Dr. Ralf C. Carter was the project director during the 1971 studies and
Mr. Lloyd Bracewell during the 1973 work. Professor Pat Wilde, co-faculty
investigator, was primarily responsible for the conduct of the various oceano-
graphic studies and Professor David I. Jenkins aided in the development of
the analytical techniques.
Under the direction of Dr. George Hlavka, SCCWRP supplied the means for
conducting the survey work off the coast of Southern California in 1971.
The assistance of Mr. Chen-Shyong Young, Sanitary Engineer of SCCWRP,
during that time is especially acknowledged.
Mr. Al Leipzig, Chief Engineer, and Mr. William Garber, Assistant Chief
Engineer, and the staff of the Hyperion Wastewater Treatment Plant aided
the 1971 study greatly by collecting and analyzing samples of their
wastewater effluent during the field surveys, and by making arrangements
with the City of Los Angeles for the use of the survey boat "Marine
Surveyor" in the 1973 program of studies. The generosity of the City
Council of Los Angeles in permitting the use of their survey boat without
compensation in the 1973 survey is also gratefully acknowledged.
The cooperation of Mr. Roger Beeken, Plant Engineer of the County of Los
Angeles JWPCP, and staff in the collection of effluent samples and permission
XI
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for the use of their facilities during the 1973 study is likewise deeply
appreciated.
The advice and most generous assistance of Dr. Fred K. Kawahara, Special
Consultant - Oil Identification, Analytical Quality Control Laboratory
(Environmental Protection Agency), Cincinnati, Ohio, in the development of
the fatty acid analysis for hexane extractables is recognized and appreciated
fully.
xii
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I. CONCLUSIONS
The following applies to primary (or a combination of primary and secondary)
wastewater effluent plumes submerged 12 to 30 m beneath the ocean surface.
TRAWLED PARTICULATES (>0.5 mm in size)
1. Grease and wax particulates always predominated over all other sewage
types. The mean grease and wax particulate found over the marine outfalls
had the following characteristics:
Size = 1.3 mm
Hexane Extractable Materials (HEM) = 1.0 mg
Coliform Bacteria ^ 2 x 101* organisms
Composition of HEM
PCB < 0.10%
Free Fatty Acids =10%
Fats = 20%
Alkanes = 20%
Unidentified Long-Chain Organics = 10%
Bound Water = 40%
Their size remained constant regardless of distance from the outfalls but
their free fatty acid composition altered significantly.
2. The number of grease and wax particulates found in a sample usually
correlated directly with the mg of HEM extracted from the sample, regardless
of location. Interferences in the correlation were caused by pieces of tar.
3. The mass of HEM on the water surface within the study area may have
averaged approximately 840 kg during the surveys of 1971 and 1973. The concen-
tration of HEM ranged from a maximum of approximately 33 mg/m2 over the outfalls
to a minimum of 0.001 mg/m2 in the control areas.
4. The free fatty acid compositions of particulates strained from the JWPCP
effluent and collected over the outfalls at the same time were nearly identical.
1
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5. Local mass balances made about the marine outfalls indicated that an
appreciable portion of the large particulates must have attained the ocean
surface even when the effluent plumes were submerged.
6. Evidence indicates that the grease and wax particulates can persist for long
periods of time in the marine environment. Their ultimate destination was not-
ascertained definitively but a study using floating polyethelene pellets indi-
cated that the particulates could move with the band type of sea slicks. The
band slicks formed under wind speeds of less than 3-4 m/s. They always moved
toward the mainland, independent of the wind direction and probably were asso-
ciated with the internal waves, moving with the same speed and in the same
direction as the internal waves. When the wind speed exceeded 4 m/s the band
slicks were destroyed quickly and Langmuir mixing cells formed. The particulates
were then either transported downwind or submerged under the ocean surface.
7. The mass emission rate of particulate HEM from the Hyperion and JWPCP
outfalls was estimated to be approximately 1000 kg/day. In light of No. 3
above this implies a surface residence time of only one day in the study area.
Either the particulates clustered in regions not sampled, or they were moved
quickly out of the study area by wind and band slick influences of the type
described in No. 6 above.
8. The grease and wax particulates contained from 2 x 103 to 2 x 104 coliform
bacteria per mg of HEM within the vicinity of the marine outfalls. The bacteria
were found in particulates captured as far as 4 km from the Hyperion outfall.
9. A suggested surface pollution control requirement for HEM, based on
aesthetic and coliform bacteria considerations, is 1.0 mg/m2 or less (exclusive
of tar). This is 10 times lower than the current State of California require-
ment for ocean waters. No control requirement for nonextractable particulates
is suggested because their concentrations were too small to be aesthetically
objectionable, and their ecological significance was unknown to these investigate!
MICRO-PARTICULATES (<0.1 mm in size)
1. The surface concentration of the micro-particulates exceeded a million/m2
at times. Their overall volume per unit surface area may have been greater
than the trawled particulates and their sizes ranged from the minimum
detectable limit of approximately one y to 100 y.
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2. The concentrations and types of micro-particulates observed varied
grossly between the two surveys of 1971, Their overall concentration generally
was 2 to 3 times greater over the Hyperion outfall than elsewhere but their
sources or chemical composition were not ascertained. Sampling for micro-
particulates was discontinued after 1971.
SURFACE SCREEN SAMPLES
1. The glass cloth sampler collected duplex and stable monolayer surface
films accurately (within approximately 10% for duplex films and 5% for
monolayers).
2. PCB compounds appeared to be concentrated in the sea slicks found over
the marine outfalls. A volumetric concentration as high as 0.8 mg/£ as
Aroclor 1254 was found over the Hyperion outfall in April 1971.
3. The average surface concentration of PCB was estimated to be 2.8 yg/m2
(or 19 yg/£) as Aroclor 1254 in the study area in July 1973. The bulk ocean
water concentration 0.5 m below the surface averaged about 0.050 yg/£.
These data indicate that the PCB compounds were concentrated by a factor of
at least 380 times on the ocean surface.
4. The surface and bulk water concentrations of PCB were four times higher
in the region of the JWPCP outfalls than in the control area in July 1973,
or twice the average values found throughout the study area at that time.
The wastewater mass emission of PCB to the study area may have ranged from 3
to 10 kg/day as Aroclor 1254, but the significance of this material in terms
of ocean surface pollution could not be ascertained because the surface PCB
compounds could have been derived from atmospheric fallout as well as
wastewater discharge. Concentrations of pesticides were always at least
10 times less than the PCB compounds in the 1973 survey.
5. Coliform bacteria were found in the screen samples collected over the
wastewater outfalls in 1971. (No bacterial samples were collected in
1973.) The surface concentration very nearly exceeded 1000 organisms/m2
-------
in 20% of the samples taken. This level corresponds to a volumetric concen-
tration of at least 1000 organisms/100 ma. No coliform bacteria were found
in 100 ma bulk water samples collected 10 cm underneath the ocean surface,
nor in regions well removed from the marine outfalls.
6. The average surface concentration of free stearic acid (C18) was esti-
mated to be 4.0 yg/m2 (or 27 ygA) in the study area in July 1973. The
concentration was 20 times higher over the JWPCP outfalls than in the control
area, or more than three times the average study area value. The proportion
of free stearic acid in the HEM decreased from 1.4% over the JWPCP outfalls
to 0.33% in the control area. The bulk ocean water concentration of stearic
acid (salts and free) 0.5 m below the surface was approximately constant at
1.0 yg/Jt, regardless of location.
7. Very little free stearic acid was recovered from JWPCP effluent diluted
with sea water in a pan in July 1973. The diluted effluent contained 150 yg/fc
of stearic acid for a total of 5.4 mg, but only 0.3% of this free stearic
acid was recovered in six cloth samples taken consecutively from the water
surface. The free stearic acid comprised on the average about 2.0% of the
surface HEM.
8. In light of No. 6 and 7 above it was concluded that the free stearic
acid was recovered primarily from micro-particulates which inhibited the
salting out of this acid. This conclusion conforms to theory as well as
such theory is known.
9. Using the free stearic acid as a tracer of micro-particulates of wastewater
origin, the surface HEM derived from wastewater emissions was estimated to
be 300 kg in the study area in July 1973.
10. The HEM determinations proved of little value in ascertaining surface
pollution of wastewater origin, or the reason for the existence of sea slicks.
The observed concentrations were highly variable, ranging from 0.9 to 3.9
mg/m2 over the marine outfalls and from 0.16 to 2.0 mg/m2 in the control areas.
-------
11. The HEM analysis can be used only to control surface pollution resulting
from duplex (oil) films or unusually high concentrations of wastewater micro-
parti culates. It is too gross a measure to control any pollution existing
in the form of surface monolayers.
12. At the present time only the coliform bacteria analysis can be used to
reliably control surface pollution derived solely from wastewater discharges.
A criterion of 1000 total coliform organisms per m2 of ocean surface is
suggested but with reservation because such a criterion could prove to be
extremely difficult to meet.
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II. RECOMMENDATIONS
1. A great amount of work remains to ascertain the composition and mode
of formation of sea slicks. Much of this would be strictly of scientific
interest, but it would provide a better means of estimating the proportion
of the surface film material derived from wastewater discharges as well as
its ultimate destination. For example, reliable methods of acidifying and
saponifying the glass cloth samplers should be developed to increase the
yield of HEM and fatty acids. Also, the relationship between the fatty
acids and their salts at the ocean interface has to be more fully understood
with the aid of laboratory studies.
2. Reliable methods of sampling wastewater effluents for surface film
forming substances remain to be developed. Simply screening from the top
of effluent diluted with salt or fresh water yields information on the
composition of the flotage, but not its total amount because an equilibrium
appears to be established between the surface and bulk phase which is quickly
reestablished upon removal of material from the surface. This process appears
to continue indefinitely. It should be pointed out here that the composi-
tion of the flotage may differ appreciably between salt and fresh diluting
waters.
3. The characteristics of the flotage, if any, derived from secondary
effluents remains to be ascertained. It is possible that surfacing secondary
effluent plumes could produce measurable quantities of surface flotage.
4. The effect of wastewater effluent chlorination on coliform bacteria
contained in trawled and micro-particulates remains to be ascertained.
5. To complete the study discussed herein, measurements should be made on
surfacing primary effluent plumes. This would enable a more direct means of
establishing relationships between cause and effect. For example, the
quantities of surface PCB compounds derived from a wastewater effluent
could be determined quantitatively under such circumstances.
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III. INTRODUCTION
The general objective of the first year of this study was to develop sampling
and analytical techniques suitable for the evaluation of flotage at the sur-
face of marine waters. Only a minimum of ocean work was to be carried out,
primarily to determine the feasibility of the techniques developed and to
obtain data for an initial assessment of the surface pollution problem.
Emphasis was placed on the following items:
1. The development and evaluation of sampling and analytical techniques
for surface films.
2. The development and evaluation of sampling and analytical techniques
for floating particulates.
3. The development and evaluation of sampling and analytical techniques
for other components of the flotage.
4. Evaluation of ocean data obtained in order to provide an initial
assessment of the surface pollution problem.
The second year of the study was to be devoted primarily to ocean studies,
the specific objectives of which were:
1. The measurement of flotage found in the vicinity of a marine outfall
and comparison with that from a region free of water surface
pollution.
2. Investigation of the mechanisms responsible for the concentration
and movement of flotage on the sea surface during the periods of
sampling.
The study objectives were also to include suggestions for the establishment
of water surface quality requirements to be used for control of ocean surface
and beach pollution.
The terms of the award made by the Environmental Protection Agency to The
Regents of the University of California included the following conditions:
1. Both screen and trawled particulates will be characterized.
7
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2. Particulates will be classified according to size.
3. The analysis of inorganic and organic parameters will be conducted
on both film and particulates.
4. Coliform and, if possible, virus concentrations of film and parti -
culates will be enumerated.
5. The wastes sampled in the ocean will be correlated with raw water
samples, preferably by sampling from the same waste volume.
The only one of those conditions which modified substantially the proposed
work was item 4, i.e., "Coliform and, if possible, virus concentrations of
film and particulates will be enumerated." After consultation with the
Project Officer, it was agreed that virus enumerations could not be carried
out without considerable cost and therefore would not be included. Coliform
organism determinations were initiated immediately, however.
Subsequent to the awarding of this grant, the Southern California Coastal
Water Research Project (SCCWRP) requested that the sampling and analytical
techniques developed in the first year of this study be used in fairly
extensive ocean studies of surface conditions in the Southern California
Bight. This was well removed in distance from the sites envisaged originally
for the ocean studies and the costs were increased appreciably. SCCWRP
offered compensation in terms of furnishing the sampling craft and supporting
the personnel needed for the ocean studies. Three separate ocean surveys
were made in 1971 under this arrangement with the pertinent data being
presented and discussed in this report. The ocean work of 1973 was conducted
without any aid from SCCWRP but the studies were continued in the Southern
California Bight area to complement the results of the 1971 work.
The participation of SCCWRP made it possible to collect data in a region
of real concern to the public. Even so, the Southern California Bight region
was not ideal for the development of new sampling and analytical tools
because the large primary effluents were always submerged beneath
the ocean thermocltne during the ocean surveys and the region was remote
from the sample processing laboratory. A more orderly procedure would
have been the sampling of surfacing primary and secondary effluents first
8
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to establish firmly cause and effect relationships.
Section IV of this report describes the character of the area sampled in
the ocean surveys as well as the conditions encountered during each survey.
General information on the techniques employed in each survey is also presented
in that section. Sections V, VI, and VII deal almost exclusively with the
three types of sampling techniques evaluated during the study: surface
trawling, nylon netting screens, and glass cloth screens. Wastewater
effluent sampling of concern to each of those techniques is presented at the
appropriate time.
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IV. DESCRIPTION OF OCEAN SURVEYS
This study was conducted in the San Pedro Channel and Santa Monica Bay
regions of the Southern California Bight as shown in Figure 1. Sampling
Stations 1 and 4 were located over the marine outfalls of the Hyperion
Plant of the City of Los Angeles and the Joint Water Pollution Control Plants
(JWPCP) of the County of Los Angeles, respectively. Station 2 was located
3.7 km north of the Hyperion outfall and Station 5 west of the Palos Verdes
Peninsula at the latitude of the Marineland of the Pacific. This station
will be called "Marineland" at times in this report and it was located
approximately 14 km northwest along the coast from the JWPCP outfalls.
Stations 3a and 3b were selected as control areas. They were located at the
northern end of Santa Catalina Island and out of the main surface circula-
,-»
tion pattern of Santa Monica Bay. This region was approximately 44 km south
of the Hyperion outfall and 33 km southwest of the JWPCP outfalls.
Three field surveys were conducted in 1971. The objectives of the first two,
performed on April 7-8 and August 31-September 3, were to evaluate various
means of sampling the water surface for flotage, the identification of sur-
face pollution, and the significance of sea slicks in concentrating the flotage.
The third .survey of December 9 was for the purpose of tracing the movement
of flotage on the sea surface.
The data procured from the 1971 surveys were analyzed and a fourth survey
of the study area was made on July 11-13, 1973. The major emphasis of that
survey was placed on surface film sampling because the results of the 1971
surveys were inadequate in some respects for this type of sampling.
The two outfall systems sampled, JWPCP and Hyperion, had about equivalent
flows and contributed together about 71 percent of the total wastewater
flow released to the California Bight in 1971 [1]. The two other major
dischargers, Orange County and San Diego, were located many kilometers south
of the study area. The dimensions of the outfalls sampled are presented
10
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118°30'W
o
oo
oo
SANTA CATALINA
ISLAND
Figure 1. Study Area
n
-------
in Table 1 together with the average 1971 flows and effluent quality
characteristics.
The JWPCP outfall system was complicated, consisting of three separate
outfalls. Most of the flow was released from either the 90 inch (2.29 m)
or 120 inch (3.05 m) outfalls, with the split between the flows shown in
the table being an estimate.
The JWPCP effluent was a primary effluent containing significant portions
of industrial wastewater [1]. Table 1 shows that it was relatively strong
in terms of grease, BOD, and other routine measures of wastewater quality.
The Hyperion effluent, on the other hand, stemmed almost entirely from
domestic sources and a portion of it received secondary treatment (activated
sludge). Its quality was better than that of a normal primary effluent,
reflecting its domestic nature and the influence of the secondary treatment.
Commonly both effluents were chlorinated during periods of effluent plume
surfacing. No chlorine was being added to the effluents during the surveys
of 1971, but it was being added to the JWPCP effluent in July 1973. All
effluent samples collected at that facility were taken beyond the chlori-
nation process.
EFFLUENT PLUME SUBMERGENCE
Of great practical significance is the depth of effluent plume submergence
occurring during the field surveys. The depth of the effluent plumes were
not measured directly in this study but water temperature and salinity were
measured with depth at all the stations occupied during the first two sur-
veys. The results showed that most of the density structure resulted from
temperature variation and only the observed temperature and computed density
profiles are shown in Figures 2, 3, 4, and 5. Water temperatures only were
measured during the July 1973 survey with the results being presented in
Figgpe 6.
12
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U)
104
20
30 4
Q-
LjJ
Q
40
50
60
Station 1
Station 2 9
April 7, 1971
8 9 10 11 12 13 14 15 16
TEMPERATURE, °C
Bottom at 73 meters
Control Area
Station 3a - 8 April 1971
10 11 12 13 14 15 16 17
TEMPERATURE, °C
Figure 2. Temperature Profiles Observed at Sampling Stations: April, 1971
-------
10
20 -I
30 J
"40-1
CL.
LLJ
O
50
60 H
70 H
April 7, 1971
April 7, 1971
April 8, 1971
Figure 3. Water Density Profiles: April, 19?]
14
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1 Meter Observation Interval
0
10-
20-
E30-l
a,
LU
Q
40 -I
50-
60
_L
Station 1
Aug. 31, 1971
i Station 2 Sept. 1, 1971
T
T
_L
3b
Station 3b
Sept. 2, 1971
Station 4 Sept. 3, 1971
Station 3b Bottom 100 meters
11 12 13 14 15 16 17 18 19 20 11 12 13 14 15 16 17 18 19 20 21
TEMPERATURE, °C TEMPERATURE, °C
Figure 4. Temperature Profiles Observed at Sampling Stations: August-September, 1971
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10 J
20
30
40 H
50 J
60-^
70
Station
1
2
3b
4
Sampled
Aug. 31, 1971
Sept. 1, 1971
Sept. 2, 1971
Sept. 3, 1971
Sta. 1
Sta. 2
Sta. 4
Ocean
Bottom
Sta. 3b
X
100 meters
24
25
26
(7.
Figure 5. Water Density Profiles: August-September, 1971
16
-------
TEMPERATURE, UC
11 12 13 14 15 16 17 18 19
TEMPERATURE, C
10
20
30
Q_
LU
O
40
50
60
CONTROL AREA
Station 3b (13 July
1973)
Bottom at 80 m
11 12 13 14 15 16 17 18 19
Station 4 (11 July 1973)-o— Bottom at 54 m
Station 5 (12 July 19 73}-»—Bottom at 63 m
Figure 6. Temperature Profiles Observed at Sampling Stations: July 1973
-------
Table 1 . CHARACTERISTICS OF OUTFALLS SAMPLED
Outfall
Diameter, m
Length, m
Diffuser
Length, m
Shape
Av. depth, m
No. of ports
Effluent (av. for 1971 )a
Flow, m3/s
HEM, mg/a
BOD5, mg/a
SS, mg/a
VSS, mg/a
Hyperion
144"
3.66
8000
2414
Y
59
168
14. 7b
19
120
73
55
JWPCP
90" .
2.29
2600
732
Y
63
100
5.26C
outfalls
120"
3.05
3600
1353
L
56
740
11. Oc
70
320
330
210
Data from Ref.
4.4 m3/s of secondary effluent mixed with 10.3 m3/s of primary
effluent.
cPrimary effluent split between two outfalls, Flows in each
estimated.
The figures show that extensive ocean stratification existed during those
surveys with the overall change in temperature being at a minimum during
the April 1971 survey. With respect to the outfall stations, the vertical
profiles were always measured in the Y of the Hyperion outfall diffuser.
At the JWPCP outfalls the profile was measured at the seaward end of the
L shaped diffuser in the summer of 1971, and also in the July 1973 survey.
Only a few discrete water samples were collected for salinity measurements
in the summer survey of 1971, so the density structure shown in Figure 5
is only approximate except at the data points shown. A density structure
was estimated for the July 1973 survey using the salinity pattern observed
in August-September 1971.
The daily flows existing in the outfalls during the various survey periods
are shown in Table 2. Again the split of flow between the 90 and 120 inch
18
-------
Table 2 . CALCULATED PLUME SUBMERGENCE AND DILUTION
OVER MARINE OUTFALLS
Outfall
Hype ri on
JWPCP
90"
120"
Date
IV-7-71
VIII-31-71
IX- 3-71
VII-11-73
IX-3-71
VII-11-73
Daily
flow
itiVs
14.9
15.2
5.4
5.1
11.3
10.6
Plume
submergence
m
12
21
33
17
33
15
Initial
dilution
100
90
100
(a)
70
(a)
No submarine currents measured.
outfalls of the JWPCP facility was estimated. Using these data plus the
density gradients measured or estimated at each outfall, the rise of the
effluent plumes above the diffusers was estimated using the methods of
Brooks [2]. In the case of the two older Y shaped diffusers it appeared
that the jets derived from the rather widely spaced ports would rise more
or less independently without much overlap, but the jets from the L shaped
diffuser would soon overlap giving continuous curtains of rise. The results
of these computations in terms of plume submergence are presented in Table 2.
Initial dilutions over the outfalls were also estimated using the methods
of Brooks [2] as well as the continuity equation in those cases where the
currents had been measured with depth. In general the continuity approach
yielded the lesser initial dilution values and those estimates are presented
in Table 2 along with the estimates of plume submergence. The current data
utilized for this purpose are tabulated in Tables 1 and 2 of Appendix A.
The results shown in Table 2 indicate a minimum plume submergence over the
Hyperion outfall on April 7, 1971; being at a depth of only 12 m or so.
Maximum submergences of 20 m or greater may have occurred in the summer
survey of 1971. The plume submergences computed for the July 1973 survey
19
-------
appeared to be less than those obtained for the summer 1971 survey but the
latter computations have to be considered as being very approximate.
In most cases the initial dilution may have been nearly 100-fold over the
outfalls, checking with some of the observations of water quality made in
the Southern California Coastal Water Research Program Study [1].
The significant finding of all this is that the wastewater effluent plumes
were submerged beneath the pycnocline during the times when flotage was
collected from the ocean surface. A minimum submergence of 12 m may have
existed in the Hyperion area in April 1971. These computations check well
with visual observations of the sea surface made during the ocean surveys
as discussed below.
SURFACE CONDITIONS DURING SURVEYS
The success of a program of ocean surface sampling is dependent on the weather
conditions encountered. By far the most significant influence is the wind.
A strong wind will disrupt and disperse sea slicks quickly and eventually
submerge even fairly large floating particulates. A light breeze 1s not detri-
mental in some respects but the sea slicks become invisible quickly either
because the wind is insufficient to ripple areas not covered by a surface
film, or because the film itself has an opportunity to form across the
entire surface. Sea swell makes accurate surface sampling more difficult
but it has little effect on the sea slicks. The effects of water density
stratification and internal waves on sea slick visibility remains to be
ascertained. Because the wind plays a significant role in surface sampling
a detailed description of the wind conditions encountered during each survey
is given below.
April, 1971
The best wind conditions were encountered in the very first survey of April
7-8, 1971. Numerous well-defined slicks were observed despite an appreciable
sea swell. A 10 knot (5 m/s) wind did break up the slicks in the afternoon
of April 7.
20
-------
The most outstanding feature of the first survey was a large standing slick
outlining the Hyperion diffuser on the morning of April 7 as shown in
Figure 7. This slick was never observed subsequently. Other types of
sea slicks were also observed in the area including a broad meandering slick
directed more or less downcurrent from the diffuser and narrow band slicks
running parallel to the coast at Station 2, 3.7 km north of the outfall
diffuser. The slicks at Station 3a in the control area consisted of a large
ill-defined slick lying in the lee of Santa Catalina Island and several band
slicks as shown in Figure 8. The wind speed was ideal at 2-3 knots (1 to
1.5 m/s).
August-September. 1971
The wind was not particularly favorable for surface sampling during the
summer cruise of 1971 and the sea slicks commonly were rather poorly defined.
No wind existed in the Hyperion outfall region on the morning of August 31
and the slicks were nearly invisible. There was the hint of a series of
band slicks moving across the diffuser in the shoreward direction, however,
and these were sampled and called "slick samples." A strong southwest wind
rose in the afternoon destroying any slick patterns which might have existed
in the area.
Conditions were better in the early morning hours of September 1 and well-
defined band slicks were observed 3.7 km north of the Hyperion outfall as
shown in Figure 9. An east wind of 5 to 7 knots (2.5 to 3.5 m/s) existed
at the time but this soon disappeared and the slicks became nearly invisible.
At times the wind would gust briefly and a slick pattern would appear again.
At noon the wind veered to the southwest and increased to 11 knots (5.7 m/s)
and the surface was broken up entirely into downwind mixing cells.
The results of the first survey conducted in the control area on April 8,
1971 indicated that the surface may have been polluted slightly at Station
3a. The windward side of Santa Catalina Island was then selected as the
21
-------
f\>
ro
Nautical Mile
n8°30'
lT
O~ i April 7 p.m.
Sea Swell
W 2-3 ft, 4 sec
Wind SW (a 4-10
N Apparent Slic
v Movement
1,000/nr
Sludge
Station
1 /•
S\ Drogue
V \ Recovery
0.33 k
x April 7 a.m.
yC Swell NW 2-4 ft
' * 4 sec
Wind Light and Variable
^1-,Hyperion
" Sewage
' Treatment Plant
Figure 7. Surface Conditions in Hyperion Outfall Region: April 7, 1971
-------
2 September 1971
X
ro
Swell
NW 1.5'
4 sec
Slicks not to scale
50
100 Fath-dfflS_
Figure 8. Surface Conditions in Control Areas: April 4 and September 2, 1971
-------
Nautical Mile
6
\
Wind SW 11 k
i 1330
Station/
2 a
118030'
Slicks
0700
X Swell NW 1.5 ft,
5 sec
Wind E 0.5 k
Sludge Outfall
Slick
Station
1
Swell NW 2
>gue Drift
0.34 k
ft, 4 sec
Aug. 31, 1971
Wind L & V
••M Hyperion
;Sewage
^Treatment
,. Plant
Drogue Drift
0.38 k
Sept. 1, 1971
Wind E 3 k
Figure 9. Surface Conditions in Hyperion Outfall Region: August 31 and September 1, 1971
-------
control area and designated as Station 3b as shown in Figure 8, A steady
2.5 m/s east wind was favorable for sea slick visibility and a number of
narrow we11-defined slick bands were observed in the area.
The JWPCP outfalls were sampled on the morning of September 3, 1971 as shown
in Figure 10. The wind averaged only about 7 knots (3.6 m/s) from the east
during that time but no sea slicks were visible. The best that could be
done was to allow the sampling craft to drift over the 90 inch Y diffuser while
collecting film samples
December, 1971
A slick tracing study was conducted on December 9, 1971 as shown in Figure
11. A steady southwest wind in excess of 7 knots (3.6 m/s) persisted until
mid-afternoon when it gradually decreased to a light air by sunset. No
slicks were apparent anywhere along the coast until the wind began to decrease.
A series of sharply-defined band slicks then appeared in the region where
the sampling craft happened to be cruising at the time. Those slicks, shown
in Figure 11, ran parallel to the coast and increased in width as the wind
dropped until by sunset it appeared as if the entire surface was covered
by a single slick.
July, 1973
Wind conditions were never very ideal during the July 1973 survey. The
weather had been unsettled for weeks prior to the cruise, following a general
pattern of strong winds in the afternoon and evening and mild winds in the
early morning hours. The slicks themselves were always poorly defined and
seemingly on the verge of disappearing.
The wind was calm over the JWPCP outfalls in the early morning hours of
July 11, 1973 and no slick patterns were visible. Indeed, it appeared that
the entire surface was one large slick. A 2 to 3 knot (1 to 1.5 m/s) west
wind sprung up quickly after 8 a.m. and poorly defined patterns of broad,
diffuse band slicks formed as shown in Figure 12. The majority ran normal
25
-------
ro
en
San Pedro
Bay
SAN PEDRO CHANNEL
Nons1i ck
Samples
Figure 10. Surface Conditions Over JWPCP Outfalls: September 3, 1971
-------
ro
Manhattan
Beach
Hermosa
Beach
Figure 11. Transport of Flotage Study: December 9, 1971
-------
PO
00
SWELL W
1 FT 4 SEC
Nautical Miles
I
0
I I
Figure 12.
33°45' N
SAN PEDRO
BAY
250 FATHOMS
Surface Conditions Over JWPCP Outfalls: July 11, 1973
-------
to the coast but some paralleled the coast, suggesting two independent slick
patterns with one moving across the other. The wind increased to 7 knots
(3.5 m/s) by noon and the slick patterns disappeared.
On the following day an easterly morning wind was much too strong to permit
sea slick formation in the JWPCP outfalls area, but the land mass of the
Palos VerdesPeninsula sheltered the waters lying to the west of the
peninsula and a series of band slicks were found at the Marineland station
shown in Figure 13. The wind in this region was from the east, approximately
steady at 6 to 7 knots (3 to 3.5 m/s), and the slicks were broad and ill-
defined, with some running normal and others parallel to the coast. By
noon the slicks had been broken up and dispersed by the easterly wind.
A break in the wind pattern occurred on July 13, 1973 when unsteady westerly
winds dropped from an average of about 6 knots (3.m/s) in the early morning
hours to 4 knots ( 2 m/s) by noon. A series of band slicks were
observed in the control area northwest of Santa Catalina Island (Station
3b) as shown in Figure 14. No interfering slick band patterns were observed
and the slicks tended to run normal to the coast.
Photographs of the sea slicks observed in the summer 1971 and July 1973
surveys are shown in Figure 15 for the areas over the Hyperion and JWPCP
outfalls. Unfortunately, photographs were not taken of the large standing
slick found over the Hyperion outfall on April 7, 1971. (see page 117)
DISCUSSION
Very little information exists in the literature concerning the mode of
formation or significance of wastewater sea slicks. One recent paper by
Newton [3] describes the prevalence of sewage slicks in an estuary and some
attempts we re made to procure a mass balance on amounts of fats released
and the extent of the resulting surface sewage films. Unfortunately, there
exists orders of magnitude differences between that study and this, where
the grease content of the effluents were grossly less and the effluent
plumes remained submerged beneath the ocean thermocline,
29
-------
Figure 13.
WIND WEST
AT 6 K
Surface Conditions Off Marineland: July 12, 1973
(Note: Figure is only approximate)
-------
118U30' W
SMELL NW
1.5 ft 4 sec
SANTA
C A T A L I N A
ISLAND
Figure 14. Surface Conditions in Control Area: July 13, 1973
-------
A review of the state of visibility of the sea slicks and wind speeds recorded
in this study indicates that the slicks became invisible when the wind was less
than approximately 1/2 to 1 m/s. Speeds in excess of 5 to 6 m/s quickly
destroyed the slick patterns and formed surface mixing cells in accord with
the concepts of Langmuir [4].
The wind seldom permitted the sea surface in the Southern California Bight
to attain any state of equilibrium. Strong winds mixed the surface flotage
with the upper ocean layer, and once they ceased the flotage reformed. Winds
with speeds of 3 to 4 m/s may not disrupt a slick pattern quickly but if
given sufficient time the evidence indicates that the slicks will eventually
disappear. Finally, a non-surfacing wastewater plume may form a sea slick
if the thermocline is located sufficiently close to the ocean surface
(approximately 12 m for an outfall releasing 6.2 a/s of effluent per meter
of outfall diffuser length).
33
-------
V. TRAWLED PARTICULATES
Floating particulates greater than 0.5 mm in size were collected by straining
an ocean surface layer approximately 3 cm deep and 0.87 m wide through a
500 ]i pore size nylon screen fastened behind a trawling device. The charac-
teristics and dimensions of the trawl used in this study are shown in Figure
16.
The trawl was towed alongside the sampling craft at approximately 0.8 m/s
(1.5 knots). At the termination of a trawl the screen was removed from the
plastic cod and stored in a petri dish under refrigeration until ready for
analysis. The types of analyses conducted on the particulates varied from
survey to survey but included at times, 1) type, size, and number of parti-
culates captured; 2) total dry weight; 3) hexane extractable materials
(HEM) and the composition of the HEM in terms of fatty acids (FA), pesticides,
and polychlorinated biphenols (PCB); and 4) coliform bacteria.
The type, size, and number of particulates were determined visually under-
neath a dissecting microscope. The HEM were obtained by extraction with
hexane in a soxhlet apparatus and the fatty acids by reacting the hexane
extracts with a-bromo-2,3,4,5,6-pentafluorotoluene (BFT) to form fatty
acid esters. The esters were then determined quantitatively by techniques
of gas-liquid chromatography. The PCB and some pesticide compounds were
first separated from the HEM with the aid of an activated silica column,
then measured quantitatively in a gas-liquid chromatograph. The details
of these chemical methods of analyses are presented in Appendix B.
Unfortunately it was not possible to measure the coliform bacteria in a
trawl sample without destroying the sample. Such samples were first
homogenized in a blender and then filtered through membrane filters in
accord with the techniques described in Standard Methods [5]. For this
peason the coliform samples had to be collected and analyzed independently
of all the other analyses.
34
-------
CO
en
8 1/2
Tow Line
Screen Sampler
500^1. pore Size
Canvas
Profile View
FIGURE 16. TRAWL NET SAMPLER
-------
DESCRIPTION OF TRAWLS
The extent of each trawl is listed in Tables 3 and 4. Conditions at the
time of trawling are described briefly below.
April. 1971
All trawling at the Hyperion outfall was performed within the standing
slick shown in Figure 7. The trawling at Station 2, 3.7 km to the north,
was undertaken during a period of increasing wind. The slicks were destroyed
at that site before the final two trawls could be made. In the control
area (Station 3a) all the trawls except the last were made in the large
slick lying in the lee of Santa Catalina Island.
August-September, 1971
In this survey the trawls were duplicated as much as possible at a given
site with one being taken for coliform bacteria analysis and the other for
all the remaining analyses deemed necessary.
The trawling over the Hyperion outfall was commenced in the afternoon when
the wind was relatively strong. The sea slicks, ill-defined at best, were
destroyed as the trawling progressed. The trawls were conducted progressively
eastward commencing over the center of the Y diffuser and ending 700 m to
the east. The data shown in Tables 3 and 4 are listed in that order. At
Station 2, 3.7 km to the north, trawling was conducted during a period of
relative calm.
No slicks were observed over the JWPCP outfalls during the 1971 survey. The
order of trawling, as listed in Tables 3 and 4, was progressively westward
commencing near the seaward end of the L diffuser (see Figure 10). Three
of the four pairs of trawls were taken parallel with the L diffuser and the
last west of the Y diffuser. Trawls in the control area (Station 3b) were
made during a period of well-defined sea slicks.
July, 1973
No trawls were collected for coliform bacteria analysis during this survey.
All trawling was conducted in the morning when some rather ill-defined slicks
36
-------
Table 3- SUMMARY OF SURFACE TRAWLS
One m2 of Trawl Equals 30 £ of Strained Water
Location
Hyperion
outfall
JWPCP
outfalls
Hyperion,
3.7 km N
Sta.
No.
1
9
Date
IV-7-71
VIII-31-71
IX-3-71
VII-11-73
IV-7-71
IX-1-71
No.
3
4
4
4
3
4
Trawls
Area
m2
116
268
163
70
74
73
62
35
118
101
108
245
318
231
276
304
320
320
110
159
148
68
% in
Slicks
100
100
100
30
30
0
0
none
none
none
none
100
20
20
20
48
none
none
100
23
100
43
Counts
No./m2
5.2
3.4
18
0.37
0.78
1.2
1.4
0.80
0.75
3.4
9.0
0.93
0.55
0.30
0.88
0.36
1.5
1.6
V
h
Sewage
Type
92
82
89
78
94
82
93
46
41
85
91
61
49
37
56
83
73
99
Dry
Wt.
mg/m2
12
5.7
44
0.15
0.95
2.4
25.3
0.46
4.7
36
9.0
24
51
26
6.6
1.4
1.0
0.13
0.94
0.38
2.6
1.7
HEM
mg/m2
2.8
24
0.06
0.39
0.91
6.6
0.15
0.15
2.8
4.4
12
32.5
9.0
1.7
0.89
0.11
0.021
0.15
0.10
0.07
0.31
Fatty Acids
mg/m2
0.001
0.27
0.22
0.80
0.01
0.02
0.01
0.66
1.1
2.8
1.1
0.10
0.05
0.01
0.01
%
Cl6
36
22
27
26
32
29
31
16
21
34
25
27
64
31
42
%
C18
42
73
67
52
53
61
39
79
76
61
68
67
31
61
44
Aesthe-
tic
Rating9
3
2
2.3
1.5
CO
-------
Table 3 (continued). SUMMARY OF SURFACE TRAWLS
Location
JWPCP,
14 km NW
Control Areas,
Santa
Catalina Is.
Sta.
No.
5
3a
3b
3b
Date
VII-12-73
IV-8-71
IX-2-71
VII-13-73
Trawls
No.
4
4
4
4
Area
m2
162
213
170
263
200
200
106
526
391
314
229
242
161
187
220
263
% in
Slicks
N.R.
N.R.
25
25
100
100
100
6
60
40
100
50
N.R.
10
10
N.R.
Counts
No./m2
0.20
0.96
0.22
0.13
0.054
0.070
0.13
0.10
%
Sewage
Type
5
10
18
1.5
26
14
3
4
Dry
Wt.
mg/m2
0.36
0.29
0.22
0.50
3.6
8.5
0.13
0.024
0.25
0.59
3.3
0.44
6.0
2.3
1.4
0.033
HEM
yg/m2
27
38
16
54
24
73
22
8
0.1
3
1160
0.6
3.4
4.6
0.4
1.0
Fatty Acids
yg/m2
0.36
4.6
2.7
1.1
0.009
0.078
2.0
0.43
0.72
0.068
0.087
01
h
Cl6
58
47
47
38
67
40
100
48
46
62
47
%
C18
34
48
46
54
33
36
0
40
36
27
34
Aesthe-
tic
Rating
1.0
0
CO
CO
Note: N.R. means not recorded.
Average of judgments of aesthetic appearance made by the sampling crews. The higher the rating
number, the poorer the appearance (see Table 7).
-------
Table 4 . SUMMARY OF SURFACE TRAWLS - COLI FORM BACTERIA
One m2 of Trawl Equals 30 a of Strained Water
Location
Hyperi on
outfall
JWPCP
outfalls
Hyperion,
3.7 km N
Control areas ,
Santa Cata-
lina Is.
Sta.
No.
1
4
2
3a
3b
Date
IV- 7-71
VIII-31-71
IX-3-71
IV-7-71
IX-1-71
IV-8-71
IX-2-71
Trawls
No.
1
4
4
1
4
1
4
Area
m2
26.6
161
161
74
49
70
105
95
195
114
129
252
160
184
232
533
304
242
350
% in
slicks
100
30
30
0
0
none
none
none
none
22
100
none
100
35
100
30
40
100
50
Col i form Bacteria
No./m2
150,000
1,400
2,500
6,700
3,000
1 30 ,000
43,000
74,000
41 ,000
6,450
19,000
260
11,000
1,300
none
none
none
none
none
No./lOO ma
500
5
8
22
10
430
140
247
137
22
63
1
37
4
were visible. The first trawl listed in Table 3 for the JWPCP outfalls
station was taken 400 m north of the seaward end of the L diffuser, the
second parallel to the L diffuser, and the remaining two over the Y diffuser.
Trawls taken at the remaining two sampling stations were always made normal
to the band slicks visible at the time.
RESULTS OF SURVEYS
Visual Typing
Tables 3 through 5 of Appendix A give the numbers of each type of particulate
captured in the trawls made in 1971. Some types seemed likely to be of
39
-------
wastewater origin; consequently, they were called "sewage types." Included
in this category were such objects as pieces of grease and wax, plastic,
fiber, rubber, wood, seeds (several kinds), and unidentifiable tissue and
debris. The grease and wax particulates were always predominant, and the
seeds and plastic were usually prevalent.
Other types of particulates were obviously of natural origin. Pieces of
kelp and tar were the most prevalent in this category. In some samples the
kelp predominated over all the other types of particulates.
The particulates captured in the August-September survey of 1971 were measured
with the aid of a dissecting microscope and the size distributions of the
more, prevalent types were determined. The mean sizes of each type showed
some tendency to vary from location to location but the trends were not
pronounced except in the case of the kelp. Consequently, all of the size
data except kelp were lumped together without regard to sampling location,
with the results shown in Table 5 and Figure 17.
Two types of size distributions were obtained; log-normal and uniform. The
sizes of the grease and wax particulates, the tar, and the kelp were distri-
buted log-normally; implying a process of natural erosion [6]. The seeds
and pieces of plastic were more or less uniform in size although an occasional
large piece of plastic was recovered.
The side netting and collector screen used in the surface trawl had a pore
size of 0.5 mm; consequently, it might be expected that objects less than
0.5 mm would not be captured. Generally this proved to be the case but
Figure 17 shows that 15% of the grease and wax particulates captured had
sizes equal to or less than 0.5 mm. Some of these particulates were very
sticky, and they tended to adhere to everything in sight. They
seemed to favor the kelp, and in some instances the kelp had grown partially
or even completely around the grease. This proves that their association
did not always result from the sampling method utilized, and that those
particulates had persisted for some time in the environment. It also
40
-------
Table 5 . CONCENTRATION AND SIZES OF PREVALENT TRAWLED PARTICULATES
(no./TOO m2 trawled)
Particulate
type
Sewage types
Grease & wax
Seeds
Plastic
Other
Natural
Tar
Kelp
Hyperion outfall
IV-7-71
573
85
4.4
54
32
22
VII-31-71
60
7.4
4.7
9
4.0
0.3
JWPCP
outfalls
IX-3-71
234
11
88
9
13
23
Hyperion,
3.7 km N
IV-7-71
16
7.0
0.3
8.4
1.7
1.7
IX-1-71
52
20
1.0
4
3.5
16
Control areas
IV-8-71
0.48
0.29
0.10
1.8
1.8
14
IX-2-71
<0.08
0.08
0.25
0.53
0.84
0.51
(Summer, 1971 only)
Particulate size
Median Mean Max.
mm mm mm
1.0 1.3 10
(All 2 to 3 mm)
(Most 2 to 5 mm)50
1.5 1.9 35
2.5a 4.0a 150a
7.5b 16b 150b
aAt Hyperion, 3.7 km N for IX-1-71.
bAt JWPCP outfalls.
°The mean is the arithmetic mean.
-------
10
-£»
ro
5
M
1 —
0.5 —
0.3
5 10 20 30 40 50 60 70 80 90 95
PERCENT EQUAL TO OR LESS THAN
99
99.8
Figure 17. Cumulative Frequency Distribution of Grease and Wax, and Tar Particulates:
August-September, 1971.
-------
indicates that the growth of the kelp was not particularly hindered by the
adhering grease.
Graphs like Figure 17 have to be interpreted with care. It might be assumed
that the tar pieces were generally larger than the grease and wax parti-
culates on the ocean surface. This may not have been the case because the
small tar pieces may have slipped through the trawl screens without diffi-
culty whereas the grease and wax particulates tended to stick to the apparatus
or other debris, as described above. If 15% of the tar pieces equal to or
smaller than 0.5 mm in size had stayed in the collector the two size distri-
butions would have been identical.
In summary, Table 5 shows clearly that the grease and wax particulates
captured in the 1971 surveys were predominant in the samples collected over
the outfalls-and north of the Hyperion outfall. Natural types such as tar
and kelp dominated the samples taken in the control areas. The table also
shows that the mean size of the grease and wax particulates captured in the
summer survey of 1971 was 1.3 mm, and that the largest particulate had a
length of 10 mm. Most of the plastic pieces ranged from 2 to 5 mm in size
but pieces up to 50 mm in length were taken on occasion.
Dry Weight. HEM, and Fatty Acids
Table 3 summarizes the results of these analyses. The fatty acid analysis
was not conducted on the particulates collected in the first survey of
1971, and the degree of unsaturation was not determined until 1973. The
significance of these analyses will be discussed in detail subsequently.
PCB and Pesticides
A few samples collected in the August-September 1971 survey were analyzed
for PCB and pesticides. Aroclor 1254 was detected in one sample collected
over the Hyperion outfall, but it amounted to only 0.13% of the HEM found
in that sample. PCB was not detected in any of the ibther samples tested
and it had to amount to less than 0.10% of the HEM in any of them since
43
-------
that was the limit of detectability for PCB at that time. These fractions
were disproportionately small in comparison to those found in the ocean
film materials and the analysis was not pursued further. Pesticides, if
present, also were minute. These tests were not conducted on the non-
extractable particulates such as plastic.
PROOF OF WASTEWATER DERIVATION OF PARTICULATES
Proof that some of the trawled particulates were derived from wastewater
discharges is as follows:
1. The particulates could be seen rising to the ocean surface within the
vicinity of the marine outfalls. Photographic evidence is presented
in Figure 18. (See page 119)
2. Coliform bacteria were found in the particulates collected over and
near the outfalls, but not in the control area.
3. Figure 19 shows that the fatty acid compositions of the particulates
collected over the JWPCP outfalls on July 11, 1973 and those screened
from the JWPCP wastewater effluent on July 13, 1973 were nearly identical;
whereas the acid compositions in the Marineland and control areas were
grossly different. For example, the proportion of unsaturated C18
acids decreased from approximately 60% in the effluent particulates
to 25% or less in the control area particulates, and the proportion
of C16 acids increased from approximately 30% in the effluent particulates
to 65% in the control area. (See page 119)
Table 6 presents data pertinent to Figure 19. It shows that the average
concentration of HEM strained from the JWPCP effluent on July 13, 1973 was
0.65 mg/&. Both the HEM and the total fatty acid concentrations decreased
about 5000 times from the outfall area to the control area. Not all this
decrease may be ascribed to the wastewater discharges because the natural
background may have been higher close to the mainland.
The fatty acid composition of the HEM was also determined in the samples
collected in the August-September survey of 1971 but the degree of
44
-------
Table 6
EXPLANATION OF FIGURE 19
FATTY ACID COMPOSITION OF LARGE PARTICULATES
Bar
no.
(1)
(2)
(3)
(4)
Location
Strained
JWPCP
effluent
Over JWPCP
outfalls
14 km NW
of JWPCP
outfalls
Control
Date
VII-13-73
VII-11-73
VII-12-73
VII-13-73
No. of
observations
5
4
4
4
HEM
0.65
mg/Jl
15
mg/m2
36
yg/m2
2.1
yg/m2
FA
0.12
mg/A
1.3
mg/m2
2.2
yg/m2
0.29
yg/m2
% FA
18
9
6
14
unsaturation was not determined. Otherwise, those results were nearly
identical in all respects to those presented and discussed above.
MEASUREMENT OF SURFACE POLLUTION
Several different analyses were used in this study to evaluate the surface
flotage. The best means of measuring these particulates derived from
wastewater effluents is discussed below.
Visual Typing
The grease and wax particulates correlated fairly well with other non-
extractable "sewage types" as shown in Figure 20. The rapid drop off in
grease and wax particulates with low concentrations of the other types
indicates that either the grease and wax particulates did not spread as far
as the other types, or the other types had sources other than wastewater
discharges. The figure indicates a natural background of non-extractable
"sewage types" in the order of one particulate every 100 to 1000 m2.
1*5
-------
OVER OUTFALLS
AWAY FROM OUTFALLS
CONTROL AREAS
10
ID"3 ID'2 TO-1 1 10
OTHER "SEWAGE TYPES" OF PARTICULATES, no/m2
Figure 20. Comparison of Grease and Wax Participates with Non-Extractable Sewage Types
-------
From this it was deduced that most of the particulates classed as sewage
types correlated well with each other. Because the concentrations of these
types were much higher over the outfalls than elsewhere (see Table 5) it
may be safely assumed that most of them were derived from the wastewater
discharges.
Hexane Extractable Materials (HEM)
The HEM of the samples correlated closely with the numbers of grease and
wax particulates found in the samples in all cases where tar was not excessive
as shown in Figure 21. At first glance this is surprising but the size
distribution of the grease and wax particulates did not vary significantly
from location to location, .and if most of the HEM were derived from those
particulates then the correlation should be good.
Figure 21 also shows a 1 to 1 correspondence between the number of parti-
culates and the mg of HEM. This would arise only if most of the grease and
wax particulates dissolved into the hexane as explained below:
Table 5 shows that the mean size of the grease and wax particu-
lates was 1.3 mm. Their mean volume, therefore, must have been on the
order of 1 x 10~3 nu and with a specific gravity close to one their
mean weight must have been on the order of one mg per particulate.
Consequently, a 1 to 1 ratio would be obtained only if most of the
grease and wax was dissolved by the hexane.
The significance of Figures 20 and 21 should not be overlooked. They show
that most of the grease and wax was probably derived from the wastewater
discharges, that most of the HEM was derived from the grease and wax parti-
culates (exclusive of tar), and that most of the grease and wax dissolved
into the hexane and that there is possibly a background threshold of non-
extractable particulates classified as "sewage types." The HEM is, of
course, relatively easily determined in a soxhlet apparatus.
48
-------
ID
ID-2 10-1 1
HEXANE EXTRACTABLES, mg/m2
Figure 21. Comparison of Grease and Wax Partlculates With HEM
-------
Fatty Acids (FA)
The fatty acids (C12-C22) were determined directly on the HEM without
acidification or saponification. Only free fatty acids could be determined
in this manner.
It was believed that acidification, which is not easily accomplished with
soxhlet extraction, would not increase the yield of HEM appreciably because
the grease and wax particulates appeared to extract readily as discussed
previously and because little residue was left over in the soxhlet thimble.
Saponifi cation increased the yield of the fatty acids considerably when
an experiment was conducted on one trawl sample collected over the JWPCP
outfalls in July 1973. The results indicated that 12% of the HEM was composed
of free fatty acids and 18% of fats. The saponifi able fatty acids contained
large fractions of saturated C16 and C15 acids while those extracted directly
were preponderantly unsaturated C18 acids (see Figure 19). Carbon, hydrogen,
oxygen analyses indicated that 38% of the remaining HEM was simply bound
water, 21% alkanes (paraffins) and 10% unidentified long chain organic
compounds. Thus, the visual description was apt, the sewage particulates
were composed primarily of grease and wax.
Figure 22 shows that the total weight of the unsaponified fatty acids com-
prised about 10% of the HEM on the average. This proportion varied rather
grossly at times but no trend was evidenced with distance from the outfalls.
Thus, the FA analysis could be used as well as the HEM to measure the grease
and wax particulates but the results would be considerably less reliable.
The composition of the fatty acids altered considerably with distance from
the outfalls as shown in Figure 19. The proportion of C16 acids increased
at the expense of the C18 acids, but the proportion of saturated free stearic
acid remained approximately constant at 10 to 20%.
50
-------
O OVER OUTFALLS
X AWAY FROM OUTFALLS
n CONTROL AREAS
TO"5
TO'2 10-1 1
HEXANE EXTRACTABLES, mg/m2
Figure 22. Fatty Acid Proportion of HEM
51
-------
Coliform Bacteria
This method of analysis is easily performed and it can be used to ascertain
the origins of at least a portion of the flotage. It is sensitive but not
precise. For this reason it does not provide an adequate means for computing
mass balances on wastewater flotage.
Dry Weight
The State of California Water Quality Plan for Ocean Waters [7] places
restrictions on the dry weight of wastewater flotage which can be found
over a marine outfall. Such limits are necessary to control non-extractable
flotage of wastewater origin such as rubber or plastic. In this study the
grease and wax particulates always predominated, so it is not known what
the safe limits on such objects might be, aesthetic or otherwise.
The total dry weight of all the particulates gave a poor correlation with
HEM as shown in Figure 23. This might be expected because the samples
contained varying amounts of non-extractables, some natural and some of
wastewater origins. The types of parti culates classed as "sewage types"
were not separated and weighed independently in this study. Such a task would
have been difficult because some of the grease particulates were extremely
sticky. It appears that if this had been done a good correlation with HEM
would have been obtained because the grease and wax particulates correlated
well with other sewage types as well as the HEM. This would be an extremely
onerous task and is not advised in normal circumstances.
Figure 23 also shows that commonly nearly half of the total dry weight of the
flotage collected over the outfalls could be extracted, whereas this proportion
became very small and erratic in the control regions.
Recommendations
These studies indicate that HEM is by far the best analysis for ascertaining
the extent of surface pollution created by floating particulates having sizes
greater than 0.5 mm. The source of the HEM can be checked by the following
52
-------
en
co
O OVER OUTFALLS
X AWAY FROM OUTFALLS
10 3
ID'2 10-1 1
HEXANE EXTRACTABLES, mg/m2
Figure 23. Comparison of Total Dry Weight With HEM
-------
additional analyses; visual identification, fatty acid composition, and
coliform bacteria. In the case where non-extractable wastewater particu-
lates are preponderant, a dry weight analysis might prove to be of greater
benefit.
SIGNIFICANCE OF SURFACE POLLUTION
It has been demonstrated that particulates can reach the ocean surface through
a well defined ocean density structure. The significance of this type of
pollution is now evaluated in terms of HEM, the parameter believed to be
of greatest value in its control.
Aesthetic Impact
In the July 1973 survey it was possible to evaluate the aesthetic impact of
the particulates with a team of 6 to 7 observers composed of sampling personnel
and the ship's crew. (Prior to this time the number of sampling personnel
was too small to make very valid assessments of aesthetic impact.) A rating
sheet of the type shown in Figure 24 was used and the average response was
determined from a scale ranging from 0 to 3 points, with the points increas-
ing as the surface appearance deteriorated. The results are summarized in
Table 3.
It is difficult to relate surface appearance with any quantitative measure
such as HEM because the particulates seemed more objectionable when gathered
in a slick than when free, and any surface trawl tends to strike an average
through zones of both high and low particulate concentration. Even so, the
aesthetic evaluations tended to correlate with the HEM as shown in Table 7.
Remembering that 1 mg/m2 of HEM was approximately equivalent to 1 grease
and wax particulate/m2, it is apparent that a relatively high HEM concen-
tration is necessary before the surface becomes aesthetically offensive.
It may be appropriate to maintain an HEM concentration of less than 3 mg/m2
to be on the safe side at all times, however.
54
-------
No.:
Date:
Time:
OCEAN SURFACE AESTHETIC SURVEY
Location:
Categories: check one
0. No pollution - water surface appears to be in virgin condition
1. Trace pollution - some evidence of floating material - not
significant
2. Obvious pollution - readily observable amounts of debris -
unsightly
3. Offensive pollution - sufficient quantities of pollutants
present that you wouldn't go in the water
Recorder
Figure 24. Example of Aesthetic Rating Sheet for Evaluating
Ocean Surface Pollution
Table 7. COMPARISON OF AESTHETIC IMPACT WITH HEM
HEM, mg/m2 Average rating
0.005 0 - Water surface in virgin state
0.050 1 - Some flotage evident but insignificant
3 3 - Offensive (in standing slick over Hyperion
outfall, April 1971)
9 1.5 - Flotage obvious and somewhat unsightly
32.5 2.3 - Flotage obvious and unsightly - offensive to
some
55
-------
Bacteria
Table 4 lists the results of the bacterial analyses. All of these analyses
were made in 1971 when the effluents were not being chlorinated. An oppor-
tunity was missed to evaluate the effect of chlorination when these analyses
were eliminated in the 1973 survey.
The bacteria were collected on membrane filters and incubated in differen-
tiating media in accord with Standard Methods [5]. Only typical coliform
bacteria colonies were counted and recorded (green metallic sheen) but
many more atypical colonies appeared on the filters. The atypical colonies
were highly concentrated over the outfalls but a few were found in the
samples collected on the northeastern side of Santa Catalina Island (Station
3a) in the spring of 1971. As a result, the control area was shifted to the
seaward side of the island in the summer survey where no bacterial colonies
of any type developed on the membrane filters.
Figure 25 shows the cumulative frequency distributions of the coliform
bacteria surface concentrations found over the various outfalls in 1971.
The median values of the surface concentration varied widely, with that
observed over the Hyperion outfall in August 1971 being significantly less
than the others. All of the trawls of the August-September survey were
conducted during periods of high wind, when the sea slicks had
been, or were on the verge of being destroyed. Undoubtedly the counts would
have been higher during a calm spell when all of the particulates would
have been present at the air-sea interface.
The coliform samples were collected and analyzed independently of all the
other particulate analyses. Even so, an approximate relationship appears
to exist between the coliform organisms and the HEM as shown in Table 8.
Aside from the observations made over the Hyperion outfall in August 1971,
the table shows that the number of organisms found per mg of HEM was
remarkably consistent in the samples taken over or near the marine outfalls.
56
-------
200
eg
Hype ri on
A
April 7, 1971 o
100 —
CO
a:
o
S 50
oo
Q
CO
o
20 30 40 50 60 70 80 90
PERCENT EQUAL TO OR LESS THAN
95
Figure 25. Cumulative Frequency Distributions of Coliform Bacteria
Surface Concentration: 1971
Table 8. COMPARISON OF COLIFORM BACTERIA WITH HEM
Locati on
Hyperi on
JWPCP
3.7 km N
of Hyperion
(3a)
Control
(3b)
Date
IV-7-71
VIII-31-71
IX-3-71
IV-7-71
IX-1-71
IV-8-71
IX-2-71
HEM
mg/m2
(average)
10.8
2.0
2.2
0.34
0.13
0.025
0.0012
Coliform bacteria
no./m2
(median)
150,000a
3,000
63,000
6,450a
2,500
<0.0043
(some atypical)
<0.00070
No./mg of HEM
1.4 x 104
1.5 x 103
2.9 x 104
1.9 x 104
1.9 x 1011
<0.2
<0.6
One trawl sample only.
57
-------
The overall geometric mean value for those areas was 12,000 organisms/mg of
HEM. The coliform bacteria were not derived from the ocean bulk water
because water samples taken 10 cm underneath the ocean surface never indicated
the presence of any of those bacteria.
HEM Concentrations on the Ocean Surface
The average concentration of HEM varied grossly from station to station as
shown below.
Table 9. MEAN CONCENTRATIONS OF HEM IN TRAWLED PARTICULATES
Location
Hyperion
JWPCP
3.7 km N of
Hyperion
14 km NW of
JWPCP
Control (3a)
Control (3b)
April, 1971
10,800
340
25
Aug. -Sept., 1971
2,000
2,200
130
1.2
July, 1973
15,000
36
2.1
These data are much too few to estimate accurately the total mass of HEM of
wastewater origin present on the ocean surface at any given time. Still,
it is believed that even a crude estimate is better than none at all,
so a concentration distribution of HEM was assumed and the total mass of
HEM computed as shown in Figure 26.
The concentration distribution shown in that figure was estimated by sub-
tracting an assumed background concentration of HEM of 5 yg/m2 from the
average values presented in Table 9. (The HEM data of Aug.-September, 1971
were not used because of the unfavorable winds existing at the time of
sampling.) The zonep of highest concentration about the outfalls were
arbitrarily assumed to be about 3.5 km in diameter but they could have been
much more, or much less extensive than that.
58
-------
HYPERION OUTFALL
SANTA CATALINA ISLAND
Contours = yg/m2 of HEM
Calculations
HEM
cone.
yg/m2
0
20
30
300
12,500
Area
(km)2
2300
2300
700
90
20
Avg.
end area
(km) 2
2300
1500
400
55
Incremental
cone.
yg/m2
20
10
270
12,200
Incremental
weight
kg
46
15
108
671
Total 840
Figure 26. Estimate of Mass of Wastewater HEM Present on
Ocean Surface - Trawl Samples
59
-------
The results indicate a surprisingly small total mount of HEM of wastewater
origins on the ocean surface, only 840 kg or so. Even if this estimate is
in error by a factor of 10, the total amount of HEM still remains small.
To comprehend this more fully, the amount of HEM being discharged daily to
the area must be known. Two different methods of effluent sampling were
employed to obtain this information. They were:
1. In the surveys of 1971, 1.5 £ of composited effluent were mixed
with clean sea water and the flotage was separated in a specially designed
funnel. The separated flotage was then extracted with hexane in a soxhlet
apparatus. The details of this method are given in Ref. [8] and the results
for the Hyperion effluent are shown in Table 10. The results of this approach
are questionable because particulates with sizes greater than 0.5 mm were
relatively scarce in the effluents studied, and the flotage derived from a
sample as small as 1.5 i could have been composed primarily of particulates
smaller than 0.5 mm.
Table 10. ANALYSES OF 24-HR COMPOSITE SAMPLES OF HYPERION EFFLUENT
DURING OCEAN SURVEYS OF 1971
Measure
Measured by Hyperion staff
Grease and oil
Suspended solids
Vol. suspended solids
Col i form organisms9
AM
PM
Measured by this project staff
Bulk hexane extractables
Dry weight of floatables
Hexane extractables in floatables
April 6-7
1971
12 mg/£
64 mg/£
50 mg/£
260,000/m£
186, DOOM
10.7 mg/i
4.8 mg/£
0.15 mg/£
Aug. 30-31
1971
9 mg/&
81 mg/&
76 mg/fc
430, 000 /m A
930,000/m*
8.2 mg/A
3.1 mg/a
0.30 mg/£
Determined from grab samples.
60
-------
2. The sampling method was improved in 1973 by pumping a portion of
the JWPCP effluent through a screen identical to that used in the surface
trawl. The screen approach velocity was 0.8 m/s, the same as used in sur-
face trawling. A maximum of 18 A of the JWPCP effluent could be passed
through the screen before serious clogging occurred. The material collected
was then extracted with hexane in a soxhlet apparatus. The average HEM
concentration of 5 such samples collected through the day on July 13, 1973
is presented in Table 6.
This method could have been improved further by resuspending the captured
particulates in clean sea water and separating again in a funnel of the
type used in 1971 before extracting with hexane. In this way only those
particulates which float in sea water would have been extracted. It is
believed that such an improvement would not have altered the results
grossly.
The emission rates of HEM from the treatment plants were estimated by
multiplying the effluent concentrations of HEM by the plant flows existing
at the time of the ocean surveys (Table 2). The results, shown in Table 11,
indicate that a metric ton or so of HEM was being released daily to the
study area. Comparing this with the mass found on the ocean surface
(840 kg) indicates that either the residence time of the particulates on
the ocean surface was very short (order of a very few days), or the HEM
found in the effluents did not attain the surface. Other alternatives
might be a rapid decay in the particulates, which seems highly unlikely
because the grease and wax particulates were large and they obviously had
persisted for some period of time when stuck to kelp; erosion into smaller
particulates missed by the trawl screen; or concentrating in regions not
sampled in this study.
To determine if all of the HEM sampled in the plant effluents actually attained
the ocean surface a local mass balance was made about the outfalls using the
steady state continuity equation in the form
Vw = c Ub
61
-------
Table 11. MASS EMISSION RATES OF PARTICIPATE HEM FROM
TREATMENT PLANTS
Plant
Hyperion
Hyperion
JWPCP
Day
IV-7-71
VIII-31-71
VII-11-73
kg of HEM/day
190
390
880
where Q is the effluent flow rate, c the concentration of HEM in the
w w
effluent, c the concentration of HEM on the ocean surface, U the surface
current, and b the width of the diffuser projected normal to the direction
of U. The product Q c is the plant emission rate given in Table 11.
The main problem with this approach is determing U. Surface drogues were
used to measure the drift over the outfalls (see Figures 7 to 15) but those
drogues were set to a 2 m depth, and experiences of the tracer survey of
December 9, 1971 (Figure 11) showed that such drogues did not move with
pellets placed on the ocean surface. Even so, for want of better data, the
drifts measured by the drogues were used to compute U. These estimates
together with computed and observed concentrations of HEM are shown in
Table 12-
Considering all the assumptions which had to be made, the agreement between
computed and observed concentrations of HEM over the outfalls was good, and
the differences were in the right direction (the observed being less than the
computed). Some difficulty was encountered in computing the concentration
over the JWPCP outfalls in 1973 because the current measured by the drogue
was remarkably low (0.11 m/s) which in turn gave a remarkably high computed
concentration (114 mg/m2). Obviously if the current was this small, other
factors such as plume spread would increase the dispersion and reduce the
concentration from that obtained with the continuity equation.
The results of these analyses indicated that most of the particulates screened
from the effluents reached the ocean surface. Their residence time on the
ocean surface may have been remarkably short, a matter of a day or so. Their
62
-------
Table 12. LOCAL MASS BALANCE ON HEM OF TRAWLED PARTICIPATES
Outfalls
Hyperion
Hyperion
JWPCP3
Date
IV-7-71
VIII-31-71
VII-11-73
Surface current
U
m/s
0.17
0.18
0.11
Direct.
true
NNE
NE
NW
Diffuser
length
b
m
1100
1800
800
Concentration of HEM, mg/m2
Calculated
c
12
14
114
Observed
11 (slick average)
6.6 (eastern-most trawl)
32.5 (western leg of L diffuser)
5.4 (avg. over Y diffuser)
co
Y and L diffusers considered together.
-------
disappearance most likely was not caused by rapid bacterial decomposition
but rather some mechanism of removal from, or transport out of the entire
study area. For example, the particulates could have been filtered out on
the kelp, consumed by aquatic birds, or transported to the coast by the
wind or internal waves. All of these factors were observed in operation
during the various ocean surveys.
Transport Study
An attempt was made to measure the movement of large polyethylene pellets
(average size of 4 mm and a specific gravity of 0.985) on the ocean surface
on December 9, 1971. As usual the weather was not particularly conducive
for such work with the wind being onshore and in excess of 3.6 m/s in the
morning. This was sufficient to destroy any slicks which might have existed
in the study area.
The wind did decrease around 2 pm, however, and band slicks formed in the
area as shown in Figure 11. At 2:40 pm, 400 g of the pellets were seeded
along 12.5 m of the shoreward edge of a band slick at a density of approxi-
mately 900 pellets/m of slick. A surface drogue set for a 2 m depth was
also released at that location.
The pellets were followed for a period of 80 minutes and they remained more
or less undispersed along the shoreward side of the slick. The slick moved
shoreward with an average speed of 0.20 m/s while the wind steadily decreased
to values of less than 2.8 m/s. The drogue was not followed but it ended up
well southward and seaward of the pellets.
There was a comparatively slight amount of stratification in the water to a
depth of 80 m but internal waves were present [9] and the band slicks appeared
to be associated with the internal waves. Unfortunately, these observations
had to be terminated with the early onset of dusk (5 pm), and it is not clear
if the pellets and band slick were being moved shoreward by the onshore wind
or the internal waves. Also it would have been interesting to record the
fate of the pellets in the surf zone, and if pellets added between the
slick bands would eventually be incorporated into one of the slicks.
64
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CONTROL OF SURFACE POLLUTION
The suggestions made herein apply only to the conditions encountered in this
study; i.e., primary unchlorinated wastewater effluents submerged beneath
an ocean thermocline. Surfacing plumes should give concentrations of parti -
culates at least as great as those found in this study, however. Effects
of chlorination on the coliform bacteria contained in the large particulates
is unknown but it is likely that the particulates will protect the bacteria
from the disinfectant.
Hexane extractable materials (HEM) appear to be the best general analysis
for this type of surface pollution. The question remains as to what is a
reasonable and safe upper limit for the HEM on the ocean surface. The only
measures at hand which could aid in this judgment were aesthetic impact
(Table 7) and coliform bacteria (Table 8). Pesticides and PCB compounds
were not of great help because their proportions in the particulates were
very slight (although foraging aquatic birds might have obtained appreciable
doses of the chlorinated hydrocarbons if they consumed enough of the parti-
culates). Fatty acids, fats, and alkanes are benign in the ocean environment,
at least at the rates of emission estimated for the large particulates.
The aesthetic ratings given in Table 7 indicated a maximum safe level of perhaps
3 mg/m2 of HEM (see p. 54). The coliform data presented in Table 8 were far
more difficult to judge, their public health significance being unknown.
A commonly accepted standard for ocean bathing waters is less than 1000
total coliform bacteria/100 ma 80% of the time, but a surface concentration
cannot be expressed conveniently in terms of a volumetric concentration.
For example, the surface trawl used in this study strained the surface
water to a depth of approximately 3 cm, but the same particulates would
have been captured at a trawl depth of 2 cm or less. Thus, the volumetric
concentration increases in proportion with the decrease in the sampling
depth considered significant. The depth cannot be considered infinitesimally
65
-------
small, or there would be insufficient space to hold the particulates.
Figure 17 shows that about 99% of the grease and wax particulates captured
in 1971 had sizes equal to or less than 5 mm. It was assumed somewhat arbi-
trarily that a depth less than this would exclude a significant portion of
the grease and wax particulates.
It was found that 1 mg of HEM contained a median of 12,000 coliform bacteria
(Table 8 and subsequent discussion). Allowing for a depth of 0.5 cm, approxi-
mately 4 mg/m2 of HEM would give a median volumetric concentration of 1000
organisms/100 ma ([1000/100 m£] x [5,000 m£/m2] x [1/12,000/mg] = 4.2 mg/m2).
Figure 25 shows that the 80% value of the cumulative frequency distributions
for surface coliform concentrations was about twice that for the 50% value;
consequently, a median of about 2 mg/m2 of HEM would be necessary to insure
that 1000 organisms/100 ma would not be exceeded in 80% of the samples.
Intuitively, one feels that a coliform standard for floating parti-
culates should be more strict than for the bulk sea water. For example, one
grease and wax particulate may contain 12,000 coliform bacteria. This would
be equivalent to 1.2 £ of seawater at a concentration of 1000 bacteria/100 m.
No individual would swallow 1.2 £ of seawater voluntarily, but he might ingest
relatively easily a small floating grease particulate. Also, Table 8 indi-
cates that no appreciable coliform die-away occurred in the particulates
collected 3.7 km north of the Hyperion outfall. This is not too surprising
because the particulates may shield the bacteria and any pathogens present
against the rather hostile ocean environment. Some decay must occur but
apparently it is much less than that demonstrated for coliform organisms
in bulk seawater. Thus, the relatively rapid rate of bacterial decay usually
used in ocean outfall design cannot be relied upon in the case of floating
particulates.
The results of these studies indicated that wastewater pollution may be
detected to concentrations as low as 0.02 mg/m2 of HEM (Figure 26), The
maximum concentration observed was approximately 33 mg/m2 (Table 3). Both
the aesthetic ratings and col 1 form bacteria analyses indicated that a
reasonable concentration should be something less than 3 mg/m2 of HEM. A
66
-------
reasonable limit might be 1 mg/m2, about 50 times greater than the detectable
limit and 33 times less than the maximum concentration observed.
This recommendation may now be compared with the requirements of the Cali-
fornia State Water Quality Control Plan for Ocean Waters of California,
1972 (7).
Chapter II A
B. Physical Characteristics
1. Floating particulates and grease and oil shall not be visible.
Floating particulates at the Marine!and sampling station (14 km NW of the
JWPCP outfalls) were judged visible but not unsightly by the rating panel
used in this study (see Table 3). The HEM concentration was only 0.054
mg/m2, yet the fatty acid analyses showed that some of the HEM must have been
derived from wastewater outfalls (see Figure 19). If taken literally, the
above requirement is very strict. Its intent probably was to control gross
emissions of floatage of obvious wastewater origin over the outfall diffusers.
(Grease and oil slicks are discussed in a subsequent section of this report.)
2. The concentration of grease and oil (hexane extractables) on the water
surface shall not exceed 10 mg/m2 more than 50 percent of the time,
nor 20 mg/m2 more than 10 percent of the time. (The samples shall be
taken in the areas of maximum probable impact.)
The method of sampling is not specified in this requirement and in some
cases natural surface film concentrations may build up appreciably,
necessitating the use of rather liberal HEM limits. This requirement
probably was intended to control concentrations of surface film materials.
It is nearly useless in controlling large grease and wax particulates, being
much ten liberal.
67
-------
3. The concentration of floating particulates of waste origin on the water
surface shall not exceed 1.0 mg dry weight/m2 more than 50 percent of the
time, nor 1.5 mg dry weight/m2 more than 10 percent of the time. (The
samples shall be taken in areas of maximum probable impact.)
In this study the dry weight of the sewage types generally was not determined
separately from that of the natural types. Over the outfalls the HEM repre-
sented about 50 percent of the total dry weight when pieces of seaweed, tar,
etc. were not prevalent (see Figure 23). The requirement therefore implies
limits on HEM about half those stated for dry weight, or about half the
level recommended herein for HEM.
If the experiences of this study are valid, the above requirement would be
difficult and expensive to enforce with primary effluents because dry weight
is not the appropriate analysis for grease and wax particulates, yet they
were found to be the predominant sewage type in all of the trawl samples taken
during the study. The requirement could be used to control the emission of
non-extractable sewage types (plastic, rubber, etc.) but no reasonable
criterion can be suggested based on the results of this study because the
non-extractable sewage types were encountered relatively infrequently.
Obviously the requirement should be rewritten in terms of HEM, not dry
weight. Stipulations on dry weight should specify the types of non-extractables
to be weighed; making it possible to pick such objects out of the sample and
to clean and weigh them without the services of an expert or the expenditure
of a great amount of effort.
68
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VI. MICRO-PARTICULATES
SAMPLING PROCEDURE
Nylon netting was used to collect coliform bacteria from the ocean surface.
At the request of the Southern California Coastal Water Research Project,
who had furnished some of the funds and sampling craft used in the 1971
ocean surveys, the netting was also used to collect samples for neuston
(surface plankton). Upon analyzing the neuston samples it was observed that
the samples contained debris, some being colored and of an obvious artifi-
cial nature. Particulates captured in this manner are called "micro-particulates"
in this report.
The nylon netting used in this type of sampling had a two-filament knit with
0.75 to 1 mm openings when purchased new. A sample was obtained by spreading
the netting carefully over the water surface and collecting the surface
layer into the cloth via capillary action. Being coarsely woven, this
netting lost the water collected easily so it had to be lifted from the
water surface and inserted into the sample container with great care. Even
so, much of the water was lost in the process. Laboratory tests conducted
under ideal conditions showed that the netting collected a surface layer
averaging 0.1 mm deep from sea water at 22°C when no water was lost from
the cloth. This information was used to compute the surface area sampled
at sea by dividing the volume of sample collected by 0.1 mm.
The nylon netting was used to collect the coliform bacteria and neuston
because the organisms had to be separated from the cloth for further analysis,
and laboratory tests showed that this netting released such organisms readily
upon repeated washing. The organisms could then be collected on a membrane
filter by passing the water released from the cloth together with the wash
water through the filter. Samples for coliform bacteria were then incubated
in accord with Standard Methods [5] while the neuston and micro-particulate
samples were examined directly on the filter with the aid of a microscope.
69
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At first the cloths used to collect the neuston and micro-particulates had
an area of 0.4 m2 but this size proved awkward to handle at sea. All of the
cloths were reduced to a uniform area of 0.1 m2 in the August-September 1971
survey. (The cloths used to collect the bacteria samples were always 0.1 m2
in area.) Neither coliform bacteria nor micro-particulate samples were col-
lected in the July 1973 survey.
ANALYTICAL PROCEDURE
The resolution employed to count and identify the neuston and micro-particulates
in the April 1971 survey was 200X, and approximately 0.3% of the membrane
filter area was examined. One sample was collected in slick areas at each
station and the average volume of water collected was 36 nu. Thus, the
area of sea surface actually examined was approximately 0.0011 m2 per
sample. This gives a least count of approximately 1000 particulates of a
given type/m2.
The area of the cloths was reduced to 0.1 m2 and the magnification increased
to 430X in the August-September 1971 survey. In this case the netting was
spread over the water surface several times at a given location until a
sample volume deemed sufficient was collected. Eight independent samples
were collected at most of the stations; four in slick areas and four in
non-slick areas. The average volume of water collected per sample was 32 ma,
about the same as collected in the April survey.
The proportion of the filter examined was reduced to 0.1% from the 0.3%
used in the April survey. Thus, the area of the sea surface actually analyzed
was approximately 0.0003 m2 per sample. The results presented in Table 13
represent the average of four such samples; consequently the actual coverage
was approximately the same for both surveys.
RESULTS
The composition and concentration of the micro-particulates varied grossly
between the two surveys. The differences in concentration can be explained,
70
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iable 13. COMPOSITION AND CONCENTRATION OF PARTICULATES CAPTURED BY
THE CLOTH SCREEN SAMPLER
(concentrations in thousands/m2)
Location
Hyperi on
outfall
JWPCPa
outfalls
Hyperion,
3.7 km N
Control
areas
Type
S
NS
S
NS
S
NS
S
NS
April, 1971 (200X)
No.
of
obs.
1
1
1
A
37
1
B
1
C
1
D
46
1
E
15
11
9
Aug. -Sept., 1971 (430X)
No.
of
obs.
2
4
8
4
4
4
4
D
6.5
0
2.6
1.8
3.2
0.7
5.8
F
1635
328
260
310
411
243
560
G
299
42
21
20
30
30
35
H
1.7
0.3
1.6
Windy day
Classification Code:
A Blue
B Purple
C Irradiant
D Fibers
E Metallic
F Clumped or flocculated minute debris
G Black
H Other
S Slick
NS Non-slick
at least in part, by the differences in magnification employed, but the
particulates found in the August-September 1971 survey should also have
been observed in the April survey, and vice-versa, because the field coverage
was about the same. For example, the large numbers of blue and metallic
appearing particulates found in the vicinity of the Hyperion outfall in
April 1971 did not appear at all in the samples collected in August-September,
The black and clumped particulates observed so frequently in the August-
71
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September survey, on the other hand, were not noticed at all in the April
survey.
The particulates forming the clumps of debris observed in the second survey
of 1971 were packed too tightly together to permit individual counting or
typing. The sizes of the clumps were distributed in a log-normal manner as
shown in Figure 27. The size distributions changed from location to location
but not from slick to non-slick areas at a given location. The black parti-
culates evidenced similar trends in sizes.
The nylon netting can sample at best only 0.1 m2 of water surface area.
For the analytical procedures used in this study a given type of particu-
late would have to have a surface concentration in excess of approximately
1000/m2 to be counted. Figure 27 shows that for the prevalent clumps of
debris particulates, at least 99% of the particulates were smaller than 100 y.
Thus, a gap existed in the sampling and analytical techniques
employed in this study to characterize the particulates. Particulates
greater than 0.5 mm in size were collected by the surface trawl and
those smaller than 0.1 mm and in concentrations greater than 1000/m2 were
collected with the nylon netting. Particulates smaller than 0.5 mm and in
concentrations less than 1000/m2 generally were missed.
Tables 13 and 14 summarize the results of the micro-particulate studies
made in the August-September 1971 survey. The tables show that their
concentrations were surprisingly great, and that their average volume/m2
may have been greater than that observed for the trawled particulates
during the same survey (assuming that the specific gravity of the trawled
particulates was close to one). The predominant type of micro-particulate
found in the August-September 1971 survey was the clumps of debris. The
black particulates were also very prevalent.
72
-------
OVER HYPERION OUTFALL
20 30 40 50 60 70 80
PERCENT EQUAL TO OR LESS THAN
90 95 98 99
Figure 27. Cumulative Frequency Distribution of Clumps of Debris Collected By The Nylon Netting:
August-September, 1971.
-------
Table 14 SIZES OF PREVALENT TYPES OF PARTICULATES CAPTURED BY THE
CLOTH SCREEN SAMPLER: AUGUST-SEPTEMBER, 1971
Clumps of debris
Median size, y
Mean size, y
Concentrati on, k/m2
Black parti culates
Median size, y
Mean size, y
Concentrati on ,k/m2
Hyperion
outfall
5.5
12
581
4
5.5
92
JWPCP
outfalls
2.5
6.5
260
4
5.5
21
Hyperion,
3.7 km N
3.5
8.2
363
4
5.5
25
Control
area
2.5
6.5
388
3
4.1
33
The particulates tended to increase in numbers over the Hyperion outfall
(Table 14), but those collected over the JWPCP outfalls had about the same
concentrations as observed in the control area, and north of the Hyperion
outfall. (It should be recalled that samples were collected over the
JWPCP outfalls on a windy day.) Again with the exception of the-samples
collected over the Hyperion outfall, no significant differences in the
concentrations of particulates were found between slick and non-slick areas
(Table 13).
The sizes of the micro-particulates tended to decrease with distance from
the Hyperion outfall (Table 14) but again the samples collected over the
JWPCP outfalls contained micro-particulates whose sizes were nearly equal
to those found in the control area. No significant differences in participate
size were noted between slick and non-slick areas at a given location.
74
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CONCLUSIONS
The project staff decided to abandon the micro-particulate sampling after
the rather inconclusive results obtained in the August-September 1971 survey.
Obviously the source of the particulates found in that survey could very well
have been atmospheric fallout with the clumped debris being dust blown from
the mainland. The ocean surface appeared very clean in the July 1973 survey
and possibly micro-particulate sampling conducted at that time would have
revealed more about the nature of the micro-particulates. The best that can
be stated at this time is that the numbers and volumes of such particulates
were gross and it appears that some of them were truly derived from the
wastewater effluents as discussed in the following section.
75
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VII. SURFACE SCREEN SAMPLES
SAMPLING PROCEDURE
Surface films have been collected on solid surfaces and metal screens for
years. A solid surface dipped vertically through a surface film will collect
one coat of film material on the way down and another on the way up. The
thickness of the coating will depend on the speed with which the solid is
passed through the film and the ability of new film to move into the areas
of film depletion. This makes a quantitative estimate of the surface concen-
tration of the film difficult, if not impossible.
Metal screens are an improvement because the closely spaced solid surfaces
insure that most of the film contained between the wires will be collected
while at the same time they inhibit the movement of new film into the area
being sampled. Metal screens have the drawback of not being easily extracted
from grease and oil, and they tend to sag from the center no matter how
tightly stretched. Cloth screens, first used in this study, could be
extracted relatively easily with hexane by folding and inserting into a
soxhlet apparatus. They also tended to conform to the ocean surface and
could be handled easily at sea. Their major disadvantage was that most
fabrics could not be stripped of their background of hexane extractables
even after hours of extraction [10]. Glass fabrics could be cleaned rela-
tively easily, and they were used to collect surface film samples
for HEM analysis. The glass cloth utilized had a 0.003-inch (7.6 y) thread
diameter, a 40 x 39 warp and fill, and a 2.12 oz/sq yd (72 gm/m2) weight
when purchased new. It was commonly used in the construction of fiberglass
boat decks and generally referred to as "deck cloth."
Individual sampling cloths were cut to an area of 0.1 m2. The cloths were
cut slightly oversized because they shrank slightly when subjected to the
initial cleaning procedures. Once cleaned, the cloths released grease and
oil collected from the water surface easily, and they were reused until they
76
-------
unraveled. Their life could have been prolonged greatly by sewing about
the edges.
The glass cloth was relatively heavy and closely woven. Water, bacteria,
and micro-particulates collected into the fabric were not released easily
when washed with water. For this reason the cloth could not be used to
collect those samples which required easy release to analyze; i.e., coliform
bacteria, neuston, and micro-particulates.
The cloths were applied to the ocean surface with clean wooden tongs and
allowed to rest on the surface under their own weight. Clean fiberglass
rods were then inserted under the center of the cloths as quickly as possible
and they were raised from the surface and rolled about the rods for insertion
into individual sample containers. Some water dripped from the cloths in
the process but measurements showed that most must have remained in the
cloths. The average volume of water held on the 0.1 m2 cloths in the July
1973 survey was 12.8 ma with a coefficient of variation of 11%. Laboratory
tests indicated a pickup of about 15 ma without rolling, but some of this
water could have been excess fluid lying on the surface of the cloth. It
appears that the water was bound tightly in the cloth by surface tension
and the depth of water sampled may have varied between 0.128 and
0.15 mm.
SAMPLING AND ANALYTICAL ACCURACY
The analytical methods utilized paralleled those employed for the trawled
particulates. The glass cloths were first air-dried and extracted with
hexane in a soxhlet apparatus without prior acidification or saponification.
The long-chain fatty acids (C12-C22) present in the HEM were analyzed by
reacting the HEM with the BFT reagent to form fatty acid esters which were
then identified and measured quantitatively by techniques of gas-liquid
chromatography. The PCB compounds and some pesticides were separated from
the HEM in an activated silica column and determined by methods of gas-liquid
chromatography.
77
-------
These approaches measured insoluble duplex films adequately. A vegetable
oil composed primarily of unsaturated C16 and C18 fatty acid esters was
dissolved into hexane and spread on clean sea water at 20°C. The hexane
was allowed to evaporate and the average surface concentration was computed
to be 71 mg/m2. The film was sampled with a 0.1 m2 glass cloth and extracted
with hexane. The results indicated a surface concentration of 76 mg/m2,
within 7% of that computed.
A duplex film is also created in oil spills and is commonly thought of as
being surface pollution. Natural sea slicks are formed by films one molecule
thick, and such monolayers are not well understood.
Palmitic acid (saturated C16) was added to the surface of distilled, care-
fully cleaned water employing the classical procedures of Langmuir [11] and
Adam [12]. The bulk water had a pH of 5.5 and a stable monolayer was formed
having an area of 19.7 A2 per acid molecule (slightly less than the commonly
accepted value of 20.5 A2 for any normal saturated fatty acid). The layer
was sampled with 0.1 m2 glass cloths with the reduction in the surface area
of the film being measured after each sampling. The reduction in area
averaged 0.095 m2 with a coefficient of variation of 3.7%. This indicates
that the cloths consistently collected 95% of the palmitic acid monolayer.
Stearic acid (saturated C18) would undoubtedly have behaved in the same way.
The pH of sea water is normally relatively high and only tiny fractions of
the fatty acids will remain undissociated in the bulk water phase. Depending
on the concentrations involved, the dissociated acids can form insoluble
salts with the divalent cations present in the sea water. Magnesium salts
probably would predominate because their solubility products are the
smallest of all the cations commonly encountered in sea water. Such insoluble
salts can move to the water surface to aid in the formation of sea slicks.
The stability of fatty acid salt films seems to be dependent on the
concentrations and proportions of cations and acids present. Fatty acid
salt films are poorly understood and have been investigated little in the
past.
78
-------
In sumnary, it is believed that the glass cloth sampler collected insoluble
duplex and stable monolayer surface films accurately. The divalent acid
salts probably were not extracted to any significant extent with the hexane
because the samples were not acidified. Alkanes, fats, free fatty acids,
alcohols, etc. were extracted to become a part of the HEM but only the free
fatty acids were analyzed because the fatty acid esters were not decomposed
first by saponifying. Acidification and saponification were not easily
performed on the minute quantities of material collected in the cloth screens,
and every additional analytical step introduced the spectre of more back-
ground contamination. It should also be recalled that micro-particulates
were found in great profusion on the sea surface and that they also would
be captured by the glass cloth sampler; consequently, it was difficult to
assess which portions of the HEM or fatty acids were derived from the surface
film and which from the micro-particulates.
RESULTS OF SURVEYS
Hexane Extractable Materials (HEM)
Four individual glass cloth samples were collected at each station in the
April 1971 survey. These samples were taken in slick areas only. The
sampling was extended to both slick and non-slick areas in the August-
September 1971 survey with rather inconclusive results. The sampling
frequency was then increased greatly in the July 1973 survey as shown in
Table 15.
The table shows that the HEM concentrations were extremely variable and that
they decreased grossly on the average from 1971 to 1973. That decrease
might have been caused in part by increasing analytical precision in the
second year, but it could have stemned as well from actual seasonal and
weather effects. Some of the HEM concentrations found in the 1973 survey
were so low they approached the background levels still existing in the
glass cloths (0.10 mg/m2 or less). Those particular observations are
indicated by dashes in Table 15. (The 1973 observations were corrected for
a background of 0.10 mg/m2 which stemmed from the glass cloth screens
employed.)
79
-------
Table 15. Concentration of Cloth Screen HEM
(cone, in mg/m2)
Type
C 1 -i /-I/
O 11 CK
Mean
Non-
i • i
slick
Mean
Hyperion Outfall
IV- 7-71
12.60
0.25
1.40
1.35
3.90
VIII-31-71
1.60
2.15
1.55
3.05
0.85
1.84
0.30
1.20
2.12
1.30
1.23
JWPCP Outfalls
IX-3-71
1.45a
1.80
1.10
0.95
0.50
2.30
3.60
1.50
0.65
3.10
1.70
VII-11-73
0.35
1.50
1.00
0.40
0.64
0.32
0.38
1.29
0.71
3.41
0.82
0.73
0.60
1.00
0.45
0.91
0.26
0.45
0.41
0.23
3.96
0.60
1.08
1.10
1.03
0.82
0.82
0.98
Hyperion,
3.7 km N
IV-7-71
2.10
5.75
1.20
1.70
2.69
0.12
IX-1-71
1.25
0.80
1.45
3.30
1.70
0.75
1.40
1.05
1.85
1.26
JWPCP
14 km NW
VII-12-73
0.33
0.40
1.95
0.54
0.12
0.64
0.47
0.64
_
0.20
0.25
0.24
0.34
0.25
0.47
0.21
0.13
0.23
Control Areas
3a 3b 3b
IV-8-71
1.30
2.65
2.80
1.40
2.04
IX-2-71
0.80
0.75
2.25
1.60
1.35
1.05
3.35
1.30
-
1.43
VII-13-73
0.23
-
0.32
0.29
0.36
0.38
-
_
0.15
0.23
0.58
0.18
0.62
0.27
0.26
0.40
0.16
0.35
0.06
0.08
0.13
0.13
0.20
0.25
0.12
0.08
0.10
0.16
aWindy conditions, no slicks present. See Table 16 for location over diffusers.
-------
Fatty Acids (FA)
Table 16 lists the overall weights of the long-chain fatty acids (C12-C22)
found in the cloth screen samples collected in the July 1973 survey. The
ranking of the observations is identical to that presented for HEM concen-
trations in Table 15, so direct comparisons can be made if so desired. No
significant background of FA existed in the glass cloth screens.
Fatty acids were not determined on the samples collected in the April 1971
survey and the fatty acid composition was not fully evaluated in the
August-September 1971 survey. The average values of total fatty acid con-
centration found in the latter survey are presented in terms of percent of
HEM in Table 17. (The means listed in Table 17 do not always compare with
those given in Table 15 because not all of the HEM samples were analyzed for FA.)
Coliform Bacteria
Surface coliform bacteria were collected independently with the nylon net
sampler as described previously in Section VI. Bulk water samples for
coliform organisms were collected 10 cm underneath the surface screen
samples with the aid of a sterile Cornwall continuous pipetting device.
The bacteria were separated and incubated on membrane filters in accord
with Standard Methods [5]. Bacteria samples were not collected in the 1973
survey.
The screen samples were always taken in slick areas in tandem with the glass
cloth samples except in the region of the JWPCP outfalls on September 3,
1971 when no sea slicks were visible. The results of these observations are
presented in Table 18.
PCB Compounds
Glass cloth samples collected in a given region were pooled to obtain suffi-
cient HEM to analyze for PCB compounds and pesticides. Small quantities
of such pesticides as DDE and DDT were observed frequently but their concen-
trations were always very much less than the PCB compounds so their magnitudes
were not ascertained. The results of the pooled screen samples are presented
in Table 19.
81
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Table 16. CONCENTRATION OF CLOTH SCREEN FATTY ACIDS: JULY, 1973
(cone, in yg/m2)
Type
Slick
Mean
Non- Slick
Mean
Over JWPCP
Outfalls
VII-11-73
_i
>-
31.0
lost
160.2
47.5
128.2
49.4
26.3
223.0
28.1
112.4
114.5
45.3
82.9
94.3
61.4
86
_i
>-
20.2
87.3
68.7
27.0
286.7
49.1
100.5
65.8
139.5
90.5
62.5
91
JWPCP
14 km NW
VII-12-73
17.3
13.3
73.1
12.1
14.2
8.4
2.4
20.1
4.7
10.1
20.0
11.4
11.7
14.5
3.1
1.3
-
8.5
Control
VII-13-73
5.9
1.0
8.6
1.2
15.8
8.9
6.4
1.4
-
1.3
1.2
3.0
6.1
2.9
4.6
12.4
9.7
7.6
3.6
5.8
5.2
1.7
12.5
3.5
14.3
1.8
5.7
11.9
7.4
82
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Table 17. MEAN CONCENTRATIONS OF CLOTH SCREEN HEM AND FATTY ACIDS
(concentration in mg/m2)
CO
CO
Location
Hyperion
outfall
JWPCP
outfalls
Hyperion,
3.7 km N
JWPCP,
14 km NW
Control
areas
Y
L
Type9
S
NS
S
NS
S
NS
S
NS
S
NS
S
NS
April, 1971
No. of
Samples
4
4
4
HEM
3.9
2.7
2.0
*
FA
_
-
-
Aug. -Sept., 1971
No. of
Samples
5
3
9b
4
3
4
3
HEM
1.8
1.5
1.7
1.7
1.4
1.3
1.9
%
FA
12
5
14
14
15
13
21
July, 1973
No. of
Samples
8
6
6
5
7
9
14
13
HEM
1.13
0.91
0.52
1.06
0.64
0.23
0.26
0.16
%
FA
8.4
9.3
14.3
9.2
3.2
3.7
1.8
4.6
aS = slick and NS = non-slick.
Windy day - no slicks.
-------
Table 18. CONCENTRATION OF COLIFORM BACTERIA: CLOTH SCREEN
AND OCEAN WATER SAMPLES
Location
Hyperion
outfall
JWPCP
outfalls
Hyperion,
3.7 km N
Control
areas
Date
IV- 7-71
VIII-31-71
IX-3-71
IV- 7- 71
IX-1-71
IV-8-71
IX-2-71
Cloth Screenings
No.
of
Samples
4
4
4
4
4
4
4
m£b
Fi 1 tered
4.7
4.7
4.5
7.2
14.9
1.94
10.0
4.8
5.2
5.4
5.1
5.4
33.2
total
35.1
total
33.9
total
28A
total
No. of
Colonies
41
34
none
none
none
100
none
none
21
none
none
30
none
none
none
none
No.
100 ma
880
720
<22
<14
<7
5150
<10
<21
405
<19
<20
555
<3
<3
<3
<3.5
No.
m~2~
880
720
f22
<14
<7
5150
<10
<21
405
<19
<20
555
<3
<3
<3
<3.5
Bulk Water3
No.
of
Samples
4
4
4
4
4
4
4
Total
ma
Sampled
75
400
400
100
400
200
400
No.
of
Colonies
none
none
none
none
none
none
none
No.
100 ma
<1.3
<0.25
<0.25
<1
<0.25
<0.5
<0.25
Collected 0.10 m under ocean surface.
"W of sample actually filtered, not ma of sample collected.
-------
Table 19. CONCENTRATION OF CLOTH SCREEN PCB COMPOUNDS
(concentration in yg/m2 as Aroclor 1254)
Locati on
Hyperi on
JWPCP
outfalls
Y
1
Hyperion,
3.7 km N
JWPCP,
14 km NW
Control
areas
Type9
S
NS
S
NS
S
NS
S
NS
S
NS
S
NS
April, 1971
b
1
1
PCB
120
<10
% of
HEM
0.96
<0.83
Aug. -Sept. ,
1971
b
4
3
gc
4
4
4
4
PCB
39
3.3
3.1
5.7
5.8
7.5
6.4
% of
HEM
2.2
0.23
0.18
0.36
0.44
0.60
0.35
July, 1973
b
5
6
6
5
7
8
12
12
PCB
8.7
4.7
2.5
3.2
2.0
2.1
1.1
1.3
% of
HEM
0.77
0.52
0.49
0.30
0.31
0.89
0.42
0.80
aS = slick and NS = non-slick.
No. of samples pooled to obtain PCB analysis
°Windy day - no slicks.
DISCUSSION OF RESULTS
Coliform Bacteria
The coliform bacteria provided the only direct evidence that some of the
flotage collected by the cloth samplers was derived from the wastewater
discharges. Large numbers of coliform bacteria were found at times in the
nylon net samples collected over the outfalls in the 1971 surveys, but the
results were highly variable with either large numbers being recovered or
none, as shown in Table 18. No coliform organisms were found in the
85
-------
bulk water samples taken 10 cm underneath the screen samples, and any such
concentration had to be less than approximately one organisms/100 mi.
The variable nature of the data suggests that the bacteria were contained
in fine debris of wastewater origin. The nylon net sampler collected a
layer about 0.1 mm deep and the maximum size of the particulates captured
was less than 100 y as shown in Figure 27. It appears that the bacteria
containing debris had sizes of less than 100 y. If they averaged 100 y then
the volumetric concentration of bacteria in numbers/100 ma would be equal
to the surface concentration in numbers/m2. If they were smaller then the
volumetric concentration would be proportionately greater.
Figure 28 shows the cumulative frequency distribution of coliform bacteria
found over the outfalls in 1971 in terms of number/100 ma (or number/m2).
The frequency distribution was close to exceeding a bathing water standard
of 1000 organisms/TOO ma for 80% of the time. These concentrations probably
would be superimposed on those found for the trawled particulates (Figure
25).
PCB Compounds
PCB compounds as Aroclor 1254 were highly concentrated in the slick areas
over the outfalls as shown in Table 19. Extraordinary concentrations of
120 and 39 yg/m2 were found over the Hyperion outfall in 1971. These would
be equivalent to volumetric concentrations of 800 and 260 yg/£, respectively,
assuming a sampling depth of 0.15 mm for the glass cloth screens. These
appear well in excess of the solubility of PCB compounds in water [13],
suggesting that the PCB compounds were dissolved in the film material and/
or micro-parti culates. With the exception of observations made directly
over the various outfalls the PCB fraction of the cloth screen HEM was
fairly consistent, averaging about 0.58% by weight. In the trawled parti-
culates, the PCB fraction of the HEM was generally less than 0.10%. The
PCB compounds apparently tended to concentrate to a greater degree in the
substances collected by the glass cloth sarrplers than in the trawled
particulates.
86
-------
103 _
o
o
Figure 28.
102 _
o
o
o
INDICATES
LESS THAN
v
o
10
40 50 60 70 80 90 95 98
PERCENT EQUAL TO OR LESS THAN
Cumulative Frequency Distribution of Coliform Bacteria
Found in Screen Samples Taken Over the Outfalls:
April and September, 1971
An appreciable source of PCB compounds could have been atmospheric
fallout [1]. The fallout along the coast within the study area might
have averaged 0.26 yg/m2-day as Aroclor 1254 during the months of
June and July 1973 [14]. Information concerning decrease in fallout with
distance from the coast was unavailable to this study but DDT compounds
decreased by a factor of about 4 from the coast to Santa Catalina Island.
Assuming a similar decrease in PCB compounds, the fallout may have averaged
approximately 0.5 kg/day on the study area.
Data of the SCCWRP study [14] indicated average concentrations of Aroclor
1254 of 2.0 ygA or so for the JWPCP effluent during the period July 6-125
1973, and 0.36 yg/£ for the Hyperion effluent during the week of June 18-24,
87
-------
1973. Daily composites of the JWPCP effluent were also collected for this
study during the week of July 6-12, 1973. These samples were acidified and
extracted in a liquid-liquid extraction apparatus for three hours with hexane
followed by separation on an activated silica column. The output on the GLC
column was gross, and the typical PCB patterns were masked by large
quantities of unidentified compounds. Further separation and identification
procedures were not pursued.
A grab sample of the JWPCP effluent was taken in the afternoon of July 13,
1973 and diluted 17 times with clean sea water, extracted and analyzed for
PCB. In this case Aroclor 1254 patterns were distinct on the GLC output and
a concentration of 6.5 yg/£ was indicated after correction for dilution and
sea water background. This was for only a single grab sample, but
the analysis was deemed accurate because of the unusual care taken in the
liquid-liquid extraction and separation procedures. Using this concentration
and those reported in the SCCWRP study the wastewater effluent PCB mass
emission rate was found to range from 3.3 to 9.6 kg/day to the study area,
depending on whose data were used. These results indicate that the wastewater
mass emission rate of PCB was considerably greater than the rate of atmos-
perhic fallout in the study area.
Four 4.5 a bulk ocean water samples were collected 0.5 m beneath the ocean
surface at each station occupied in the 1973 survey. The average results
are compared with the surface screen samples in Table 20.
Table 20. COMPARISON OF OCEAN WATER AND SURFACE CONCENTRATIONS
OF AROCLOR 1254: JULY, 1973
Location
JWPCP outfalls
14 km NW of JWPCP
Control area
Bulk Samples
ygA
0.103b
0.025
0.018
Cloth Screen
Samples
yg/m2
4.8
2.1
1.2
yg/*a
32
13.7
8.0
Concentrating
Effect
310
540
440
Assuming a sampling depth of 0.15 mm.
\ diffuser.
88
-------
The results show that the PCB compounds tended to concentrate strongly on
the ocean surface. The concentrating effect remained relatively constant
throughout the study area; or in other words, the bulk and screen concen-
trations of the PCB compounds corresponded fairly closely with each other.
In this regard the PCB results differed greatly from those found for the
fatty acids to be discussed subsequently.
The average bulk water PCB concentration found over the L diffuser of the
JWPCP outfalls was approximately 50 times higher than that reported by
SCCWRP for bulk samples collected in the same area at a depth of 3 m in
May 1973 [14]. The reason for such a wide discrepancy is unknown except
that a more efficient hexane extraction technique was employed in this
study.
The approximate computational methods shown in Figure 26 and the data pre-
sented in Tables 19 and 20 were used to estimate the mass of PCB present on
the ocean surface in the surveys of August-September 1971 and July 1973.
The mass computed was 24 and 6.4 kg (as Aroclor 1254)5 respectively. These
results reflect the greater concentration of PCB found everywhere in the
study area in the 1971 survey; the cause being unknown but possibly due to
restrictions being placed on the use of PCB by the manufacturers after 1970.
The July 1973 results indicate a surface residence time in the order of
13 days if the PCB compounds were derived solely from atmospheric fallout.
The presence of significant atmospheric fallout makes it difficult to
estimate the proportion of surfaced pollution derived from the marine
outfalls. Both the bulk water and surface screen results shown in Tables
19 and 20 indicate that the contribution of the marine outfalls must have
been significant, otherwise the appreciable decrease in the PCB concentrations
with distance from the outfalls could not be logically explained. For this
reason the PCB results were taken as a second proof that some of the
substances collected by the glass cloth screens were derived from the
wastewater discharges.
89
-------
HEM and Fatty Acids
The HEM and fatty acid results were much less amenable to analysis than were
the PCB or coliform results. The variations were so great it was difficult
to judge if the differences found in average concentrations were truly signi-
ficant. When a sufficient number of observations were taken, the differ-
ences proved significant as shown in Figure 29 for the HEM concentrations
found in the slick and non-slick areas of the control station in July 1973.
The HEM and fatty acid concentrations did decrease markedly with distance
from the JWPCP outfalls in the July 1973 survey as shown in Table 17. No
such pronounced decrease was observed in the August-September 1971 survey.,
Again the causes of this are unknown. In nearly all cases the observed
HEM concentrations were surprisingly low in sea slick areas.
A free fatty acid occupies approximately 20.5 A2 of surface area in a stable
monolayer. Palmitic acid, for example, would produce a surface concentration
of 2.08 mg/m2 as HEM under such circumstances. Most of the observed HEM and
fatty acid concentrations were much lower than this.
To understand the role of wastewater fatty acids in the formation of sea
slicks, 2 a grab samples of the JWPCP effluent were collected on July 13,
1973 and added to an aluminum pan containing clean sea water. The effluent
was added in sufficient quantity to give an overall sea water dilution of
18, about 5 times less than that being achieved over the outfall diffusers.
The depth of the diluted effluent in the pan was 17 cm and the pan had a
surface area of 0.224 m2. The contents of the pan were agitated gently with
magnetic stirrers and six cloth screen samples were taken at approximately
20 minute intervals of time after an initial waiting period of about one
hour. Bulk samples were taken from the undiluted effluent and from the pan
mixture after completion of the surface screening and acidified. Surface
tension was also measured during the course of the experiments. The results
of one such experience is presented in Table 21 and discussed in detail below,
with the results of all the experiments being essentially the same.
90
-------
O)
0.8
0.6
0.5
0.4-
0.3 —
0.2 —
>
o
o
0.1 _
0.05 —
0.04 -
O
X X
X
/
XyX
10
20 30 40 50 60 70 80 90 95 98
PERCENT EQUAL TO OR LESS THAN
Figure 29. Cumulative Frequency Distribution of HEM Found in
Cloth Screen Samples in Control Area: July, 1973
The concentration of stearic acid (saturated C18) was 5.8 mg/£ in the bulk
effluent sample, or 8.1% of the total HEM. This includes the salts of the
acids because the sample was acidified before extraction. The concentration
of the acid in the pan after dilution should have been approximately 0.32 mg/2,
instead of the 0.15 yg/ji observed. It appears that some of the stearic
acid salts had migrated from the mixture before the onset of pan screening.
91
-------
Table 21. PAN DATA FOR JWPCP EFFLUENT
(grab sample of July 13, 1973)
Type of sample
Bulk effluent3
(mg/AJ
Diluted bulka'b
in pan (mg/£)
Glass cloth0
samples (mg/m2)
HEM
71.4
2.36
1.49
FA
29
0.48
0.10
% of
HEM
41
20
6.7
Stearic acid
Cone.
5.8
0.15
0.030
% of
HEM
8.1
6.4
2.0
'Acidified.
Diluted 17:1 with clean sea water.
cMeans for 6 cloth samples - cloths not acidified.
The stearic acid was reduced to 6.4% of the HEM and the proportion of all the
fatty acids in the HEM was reduced from an initial 40% to 20% in the diluted
pan sample. In other words, more than half of the fatty acids had disappeared
from the diluted mixture.
After a period of one hour of waiting the surface tension had dropped by
more than 20 dynes/cm, far more than needed to depress capillary waves and
form sea slicks. The glass cloth samples indicated an average surface concen-
tration of HEM of only 1.5 mg/m2, and the concentration of stearic
acid was only 30 yg/m2. By this time the acid comprised only 2% of the HEM
extracted from the glass cloths. The glass cloths were not acidified prior
to extraction, and the acid salts would not be extracted with the
hexane. It is probable that appreciable quantities of the acid were missed
in this way, but exactly how much cannot be estimated from a mass balance
because some of the salts went to the sides of the pan as well as the water
surface, and because new film formed quickly after a cloth sample was taken
from the water surface. Indeed it appeared as if surface sampling could
have been continued indefinitely with significant HEM recovered until all
92
-------
of the film forming substances had been removed from the pan.
It is possible that the method of sampling and analysis employed to measure
the surface films altered the fatty acid-salt relationships actually existing
at the air-water interface. For example, the cloths were air-dried prior to
extraction and the sea salts would concentrate as the water evaporated. This
could produce additional fatty acid salts depending on the pH of the evaporat-
ing solution.
In summary, it appears that the ocean fatty acid salts were not extracted
from the screen samples and it may have been that additional salting-out
occurred during the air drying stage. The recovery of saturated long-chain
free fatty acids should be very small therefore, as indicated by the results
of the effluent sampling experiments.
Figure 30 and Table 22 show the mean compositions of the fatty acids found in
the screen samples collected during the July 1973 survey. Palmitic acid
predominated in all areas sampled and stearic acid was relatively prevalent.
The concentrations of both of those acids decreased grossly with distance
from the JWPCP outfalls, with stearic acid decreasing some 20-fold from
the outfalls to the control area. The proportion of stearic acid found in
the HEM decreased from 1.4% over the outfalls to only 0.33% in the control
area.
Table 22. FATTY ACID COMPOSITION OF CLOTH SCREEN SAMPLES: JULY, 1973a
(concentrations in yg/m2)
Location
JWPCP outfalls
14 km NW of JWPCP
Control area
HEM
910
410
210
FA
88
13.6
5.9
% of
HEM
9.6
3.3
2.8
Palmitic
acid
27
5.2
1.9
Stearic acid
Cone.
13
1.9
0.69
% of
HEM
1.4
0.46
0.33
Weighted means of the data presented in Table 17.
93
-------
100 —
o
O-
o
o
o
LU
a.
50
Ffflupnt.
'18
Y
et
o;
17
Over
outfall
-18
JWPCP
14 km Nl
Control
area
17
17
•16
17
0 —I
'16
Cl6
Cl5
15
'Ik
12
Cl2
'16
'15
•1"+
'12
Cl5
12
Figure 30. Fatty Acid Composition of Cloth Screen Samples: July, 1973
-------
Bulk ocean water samples collected 0.5 m underneath the surface were also
analyzed for HEM and fatty acids with the average results being shown in
Table 23. Those samples were acidified at the time of collection.
Table 23. FATTY ACID COMPOSITION OF BULK OCEAN SAMPLES: JULY, 1973a
(concentrations in
Locati on
JWPCP outfalls
(L diffuser only)
14 km NW of JWPCP
Control area
HEM
54
51
31
FA
6.4
9.1
3.3
% of
HEM
12
18
11
Palmitic
acid
2.7
3.6
1.1
Stearic acid
Cone.
0.92
0.92
M
% of
HEM
1.7
1.8
3.6
Samples taken 0.5 m beneath ocean surface and acidified for preservation.
The table shows that the bulk water concentrations of palmitic and stearic
acid were nearly constant in the study area during the July 1973 survey.
Stearic acid had an average concentration of only 1 yg/£ or so, and palmitic
2.5 yg/£. Even so, a water depth of only one or two meters would be suffi-
cient to produce a fatty acid slick at those concentrations if the acids
could attain the water surface. A direct comparison cannot be made between
the acids found in the bulk water and in the screen samples because the bulk
samples were acidified and the screen samples were not.
The change in the fatty acid composition of the cloth screen samples with
distance from the JWPCP outfalls in the July 1973 survey tended to parallel
that noted for the trawl particulates captured at the same time (Figures 19
and 30). The major differences were a greater proportion of the lighter
acids and a smaller proportion of unsaturated C18 acids in the screen samples.
95
-------
ORIGINS OF CLOTH SCREEN FATTY ACIDS
It appears that the fatty acids found in the unacidified and unsaponified
screen samples may have been derived primarily from micro-particulates rather
than surface film materials. Some of the reasons for this belief are as
follows: the surveys of 1971 showed that micro-particulates were profuse and
of significant volume, and that the coliform bacteria were distributed in a
spotty manner; the free fatty acid concentrations found at a given site were
highly variable but almost always too small to form a sea slick; differences
in fatty acid concentrations between slick and non-slick areas were usually
relatively minor; the acidified bulk water palmitic and stearic acid concen-
trations were fairly constant in the study area, implying that their surface
concentrations (either free or as salts) should be reasonably uniform, but
the surface concentration of stearic acid decreased 20-fold from the JWPCP
outfalls to the control area; and the methods of analysis employed might make
any free stearic acid very scarce unless protected by being incorporated in
some type of micro-particulate.
THE SIGNIFICANCE OF THE SURFACE POLLUTION
The coliform bacteria and PCB analyses demonstrated clearly that some surface
wastewater pollution existed in the study area. The PCB data could not be
used to trace that type of pollution because of interferences derived from
atmospheric fallout. Only the fatty acid data could be used to obtain such
an estimate, and then only very crudely.
Of all the fatty acids recovered from the ocean surface stearic acid will
salt out the most readily and possibly be the most persistent in the marine
environment. Assuming that this acid was derived primarily from wastewater
micro-particulates and that it was relatively inert inside the micro-parti-
culates, the mass of HEM of wastewater origin could be estimated grossly.
Obviously these assumptions are highly questionable. For example, free
stearic acid could have been contained in the particulates falling from
the atmosphere but no information on such a phenomenon was available.
96
-------
Tables 21 and 22 show that the stearic acid proportion of the HEM decreased
from 2.0% in the effluent pan samples to 0.33% in the control area. Assuming
that the stearic acid proportion would have been 2.0% over the JWPCP outfalls
if all of the HEM had been derived from wastewater micro-particulates, the
following ratios of wastewater HEM to total HEM are observed.
Table 24. ESTIMATED CONCENTRATION OF HEM OF WASTEWATER ORIGINS
IN CLOTH SCREEN SAMPLES
Location
Over JWPCP outfalls
14 km NW of JWPCP
Control area
Proportion of
wastewater
origin
0.75
0.22
0.16
HEM (yg/m2)
Wastewater
origins
690
90
34
Background
230
320
177
Using this information and the computational methods shown in Figure 26, the
mass of HEM in the study area was estimated to be 312 kg, or about the same
order of magnitude as the HEM derived from the trawled particulates.
The surface materials collected by the cloth samplers proved of pollutional
significance in terms of the PCB compounds and coliform bacteria as well as
the above. All of the remarks made in Section V concerning the coliform
bacteria found in the trawled particulates apply here as well, only more so,
because the particulates carrying the bacteria were much smaller (100 y or
less in size) and generally more dispersed on the ocean surface.
CONTROL OF SURFACE POLLUTION
The requirements of the California State Water Quality Control Plan for Ocean
Waters of California [7] specify that the concentration of hexane extractables
on the water surface shall not exceed 10 mg/m2 more than 50% of the time, nor
20 mg/m2 more than 10% of the time. The methods of sampling and analysis
were not specified. It was decided in Section V of this report that this
requirement was much too liberal to control adequately trawled grease and
97
-------
wax particulates of sewage origins, and that it probably was intended to
control concentrations of surface film materials.
Table 15 shows that only one cloth sample out of the many taken had en HEM
concentration in excess of 10 mg/m2, and even a primary effluent diluted
17 times with sea water produced a surface concentration of only 1.49 mg/m2
after an hour of agitation (Table 21). An HEM concentration of 10 mg/m2 can
be encountered only with: 1) a chance encounter with a large grease and
wax particulate, or 2) a duplex film. It represents very gross surface
pollution indeed.
The HEM analysis, as performed in this study, proved not to be a sensitive
measure of the pollution collected by the glass cloth screens. Coliform
bacteria and massive concentrations of PCB compounds were found over the
outfalls at HEM concentrations ranging from 0.9 to 3.9 mg/m2 on the average,
and a similar range in HEM concentration was observed in the control areas
(0.16 to 2.0 mg/m2). Also, the HEM concentrations tended to vary grossly
from survey to survey, indicating either a poorly developed method of
analysis or unknown seasonal effects.
It could be that further development of analytical methods
(cloth sample acidification, for example) would improve the reliability of
the HEM determination. A few experiments on cloth acidification (data not
shown) indicated that the HEM may not be increased grossly, however, although
the fatty acids increased appreciably.
If the HEM analysis cannot be used to control the type of pollution collected
by the cloth screens (except in the case of duplex films) then the question
remains as to what type of measure might be appropriate. Free stearic acid
may indicate micro-particulate pollution but little experience has been
obtained with this measure and the analysis is not easily performed. The
coliform bacteria analysis, however, is both definitive and easily performed
and the results can be judged to some extent in terms of their pollutional
significance. Considering the accessibility of this type of pollution to the
98
-------
public, it seems logical to restrict the surface bacteria to concentrations
of 1000 organisms/100 ma or less as total coliforms, or 1000 organisms/m2
assuming a sampling depth of 0.10 mm with the nylon netting screens. This
might raise havoc with present ocean outfall disposal methods, necessitating
the disinfection of the entire effluent prior to release even when the
effluent plume is well submerged beneath the ocean thermocline. Also, it
is not known if the bacteria present in the micro-particulates would be
killed even with effluent disinfection, and it may be that even a disinfected
surfacing secondary effluent plume would not meet this requirement. For
these reasons the requirement suggested above for coliform bacteria is offered
with considerable trepidation.
PCB concentration requirements could also be established, regardless of the
source of the compounds. These investigators are unable to judge what an
environmentally safe level of such compounds might be at the ocean surface.
Concentrations on the order of one mg/ji as Aroclor 1254 appear excessive,
however, and such a level was approached in some samples collected over the
Hyperion outfall in 1971.
99
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VIII. REFERENCES
1. The Ecology of the Southern California Bight: Implications for Water
Quality Management. Final Report. Southern California Coastal Water
Research Project. TR 104. March 1973.
2. Brooks, N. H. Conceptual Design of Submarine Outfalls - I. Jet Diffusion
Program VII, Water Resources Engineering Educational Series. University
of California, San Francisco. January 1970.
3. Newton, J. R. Factors Affecting Slick Formation at Marine Sewage Out-
falls. Conference on Pollution Criteria for Estuaries, University of
Southampton, England. July 19, 1973.
4. Langmuir, I. Surface Motion of Water Induced by Wind. Science. 87_:
119-123, 1938.
5. Standard Methods for the Examination of Water and Wastewater, 12th
edition. APHA, AWWA, WPCF, 1965.
6. Hahn, G. J., and S. S. Shapiro. Statistical Models in Engineering.
New York, John Wiley and Sons, 1967.
7. Water Quality Control Plan: Ocean Waters of California. State of
California Water Resources Control Board. July 1972.
8. Determination and Removal of Floatable Material from Wastewater.
Engineering Science, Inc. Public Health Service Contract 120-64,
November 1965.
9. Selleck, R. E., and R. Carter. Surface Phenomena Study. Sanitary
Engineering Research Laboratory, University of California, Berkeley.
Report No. 72-9. June 1972.
10. The Significance and Control of Wastewater Floatables in Coastal Waters.
Interim Report for the Environmental Protection Agency. Grant No.
16070 FKO. Sanitary Engineering Research Laboratory, University of
California, Berkeley. July 1971.
11. Langmuir, I. Fundamental Properties of Solids and Liquids, II.
J. American Chem. Soc. _38:1858-1898, 1917.
12. Adam, N. K. The Physics and Chemistry of Surfaces. Dover edition,
New York, 2^-33, 1968.
13. Rizwanul, H., D. W. Schmedding, and V. H. Freed. Aqueous Solubility,
Adsorption, and Vapor Behavior of Polychlorinated Biphenyl Arochlor 1254.
Environmental Science and Technology. 8:139-142, 1974.
100
-------
14. A Synoptic Survey of Chlorinated Hydrocarbon Inputs into the Southern
California Bight. Annual Progress Report to the Environmental Protec-
tion Agency. Southern California Coastal Water Research Project, El
Segundo, California. August 1973.
15. Kawahara, F. K. Microdetermination of Pentafluorobenzyl Ester Derivatives
of Organic Acids by Means of Electron Capture Gas Chromatography.
Analytical Chemistry. jW:2073-2075, November 1968.
16. Kawahara, F. K. Gas Chromatographic Analysis of Mercaptans , Phenols,
and Organic Acids in Surface Waters with Use of Pentafluorobenzal
Derivatives. Environmental Science and Technology. .5(3):235-239,
March 1971.
17. Carter, R. C. Surface Pollution of Coastal Waters. Thesis of University
of California, Berkeley, pp. 151-158, 1973.
18. Reynolds. L. M. Polychlorobiphenyls (PCB's) and Their Interferences
with Pesticides Residue Analysis. Bulletin Environmental Contamination
Toxicology. 1(3): 128-143, 1969.
19. Veith, G. D. Environmental Chemistry of the Chlorobiphenyls in the
Milwaukee River. Theses of University of Wisconson, 1970.
101
-------
IX. GLOSSARY
Band Slicks - Long, narrow sea slicks running parallel with each other.
Fleatables or Flotage - All foreign substances collected from the water
surface by the sampling devices developed herein.
Grease - A general term used to designate the hexane extractables found in
domestic wastewater or in a polluted sea slick.
Langmuir Cell - One pair of alternating (right and left) series of longitu-
dinal vortices at the water surface with their horizontal axes parallel to
the wind. Generally such vortices are produced at wind speeds in excess of
3.4 m/sec.
Micro-Particulates - Microscopic particulates captured by the nylon netting
sampler. Generally these particulates were less than 100 y in size.
Slick - Flotage so concentrated that capillary waves are dampened visibly
(or the surface tension is depressed significantly). A slick may contain
the surface film material proper, particulates, plankton, debris, froth,
foam, etc.
Surface Film - A collection of foreign molecules on the water surface.
Trawled Particulates - Particulates larger than approximately 0.5 mm in
diameter collected by the trawl net.
102
-------
APPENDIX A
MISCELLANEOUS TABLES
103
-------
Table 25. OCEAN CURRENTS AT HYPERION OUTFALL
(6:20 to 7:14 a.m., April 7, 1971)
Depth
m
0-1
10
20
30
40
50
60
Speed
knots
0.30
0.42
0.30
0.25
0.15
0.07
0.12
Bearing
L_ °Mag.
360
180
320
300
Rotating
Reversing
90
104
-------
Table 26. OCEAN CURRENTS IN AUGUST-SEPTEMBER 1971 SURVEY
o
en
Station 1
(7 to 8 a.m., Aug. 31)
Depth
m
1
10
15
20
30
40
50
55
Speed
knots
.30
.15
.15
.20
.20
.25
.10
-
Di recti on
true
N
SW
SW
SW
SW
SW
W
-
Station 2
(10 to 11 a.m.,
Sept. 1)
Speed
knots
.25
.30
.35
.15
.10
.20
.25
.10
Direction
true
W
W
W
NW
N
SW
SW
SW
Station 3b
(9:40 to 10:15
a.m. , Sept. 2)
Speed
knots
.20
.20
.20
.05
.20
.10
-
-
Direction
true
W
NW
E
NW
E
N
-
-
Station 4
(7:41 to 8:21
a.m., Sept. 3)
Speed
knots
.40
.20
.25
.20
.30
.20
.20
.10
Direction
true
NW
N
NW
N
N
N
NW
N
-------
Table 27. DESCRIPTION OF TRAWLED PARTICULATES: OVER OUTFALLS
(no./TOO m2 trawled)
Trawl No.
Sewage Types
Grease and wax
Seeds
Misc. tissue
Wood
Plastic
Fiber
Rubber
Unidentified
debris
Natural Types
Tar
Insects
Charcoal
Kelp
Eel grass
Surf grass
Sea lettuce
Pumi ce
Feathers
Eggs
Crab
Mysid
Siphonophore
Copepod
Sponge
Nauplius
Dinoflagellate
Barnacle
part. (?)
Eucarida
Di atom
Others9
Total
Station 1
IV- 7- 71
1
380
43
31
13
3.5
3.5
6.7
6.7
14
2.6
0.9
0.9
1.7
0.9
2.6
0.9
1.7
2.6
417
2
233
27
2.6
7
0.7
0.4
12
31
12
5.6
0.8
1.5
0.4
1.1
0.3
0.8
0.8
0.3
337
3
1270
209
69
31
11
3.1
1.8
6.1
52
62
1.2
63
3
0.6
1.2
1.2
0.6
2.5
1.8
4.9
1790
VIII-31-71
1
2.5
1.2
14
11
1.2
1.2
1.2
2.5
2.5
37
3
46
12
8
2.7
4.1
2.7
1.4
1.4
78
5
85
6.9
2.7
4.1
11.4
4.1
4.1
5.5
1.4
115
7
111
11
6.5
3.2
1.6
1.6
3.2
139
Station 4
IX-3-71
2
14
5.7
2.9
14
2.9
2.9
2.9
34
80
4
23
0.9
4.2
1.7
0.9
0.9
1.7
0.9
36
4.2
1.7
75
6
213
6
5
4
54
2
1
8.9
15
1
2
29
4
1
345
8
557
27
238
27
47
3.7
3.7
903
Pollen, fish, sea spiders, etc.
106
-------
Table 28. DESCRIPTION OF PARTICULATES:
3.7 KM N OF HYPERION OUTFALL
(no./lOO m2 trawled)
Trawl No.
Sewage Types
Grease and wax
Seeds
Misc. tissue
Wood
Plastic
Fiber
Rubber
Unidentified
debris
Natural Types
Tar
Insects
Charcoal
Kelp
Eel grass
Surf grass
Pumi ce
Feathers
Eggs
Crab
Mys i d
Siphonophore
Copepod
Isopod
Hydroid
Sponge
Larvae
Barnacle
part. (?)
Others9
Total
IV-7-71
1
39
7
5.6
4.3
0.7
0.3
2.3
11
1
4
16
0.7
0.7
93
2
7
11
0.3
6.3
0.3
0.9
1.6
2.2
8.5
1.2
0.9
0.9
2.2
0.3
5
4.7
0.3
0.9
0.3
55
4
2
3
0.6
0.6
0.6
0.9
2.8
0.6
11
0.9
0.3
0.6
0.9
2.5
0.3
0.6
0.6
0.3
0.3
30
IX-1-71
1
38
5.5
1.8
2.7
0.9
5.5
4.6
0.9
21
0.9
1.8
1.8
2.7
88
3
23
4.4
1.3
0.6
0.6
1.3
1.9
1.9
0.6
0.6
36
5
77
25
1.4
4.1
4.7
1.4
0.7
34
0.7
149
7
90
69
1.5
2.9
163
Pollen, fish, sea spiders, etc.
107
-------
Table 29. DESCRIPTION OF PARTICULATES COLLECTED: CONTROL AREA
(no./100 m2 trawled)
Trawl No.
Sewage Types
Grease and wax
Seeds
Misc. tissue
Wood
Plastic
Fiber
Unidentified
debris
Natural Types
Tar
Insects
Charcoal
Kelp
Eel grass
Surf grass
Sea lettuce
Red algae
Feathers
Eggs .
Crab
Mysid
Siphonophore
Copepod
Isopod
Hydroid
Sponge
Nauplius
Larvae
Barnacle
part. (?)
Coelenterata
Eucarida
Others3
Total
IV-8-71
1
0.5
0.5
0.5
1
16
0.5
1
0.5
20
.2
0.5
1.5
0.5
2
0.5
2.5
2.5
3
7.5
54
3.5
1
1.5
0.5
0.5
0.5
0.5
0.5
11
2.5
96
4
2.8
0.9
3.8
1.9
4.7
0.9
0.9
0.9
2.8
0.9
0.9
0.9
22
5
0.2
1.5
9.3
1
0.2
0.2
0.8
0.2
13
IX- 2- 71
1
0.5
0.5
0.3
0.3
0.3
0.8
0.3
0.3
0.8
0.3
1.3
5.4
3
0.3
0.6
1.9
0.6
0.3
1.6
0.6
1.0
7.0
5
0.4
3.9b
0.9
0.4
1.3
1.3
4.4
13
7
0.4
1.7
0.4
0.4
7.0
9.9
Pollen, fish, spiders, etc.
'includes one piece 35 x 15 x 2 run in size,
108
-------
APPENDIX B
ANALYTICAL METHODS
109
-------
The ocean surface and bulk samples, and the 24-hour composited bulk effluent
samples, were processed as indicated in the scheme of analyses shown in
Figure 31. Details of sample collection were presented in the appropriate
sections of the report. The processing of samples collected by the various
samplers and the methods of analyses are presented below.
CLOTH SCREEN SAMPLES
The hexane extractables were obtained from the glass cloth screens by removing
the cloths from their containers and allowing them to air dry in a hood.
The cloths were then extracted for one hour in a standard soxhlet apparatus
and concentrated to 5 ma for transfer. The residue was dried under nitrogen
at 40°C and weighed for hexane extractables. This material was retained for
subsequent fatty acid and chlorinated hydrocarbon analyses.
The coliform organisms, surface plankton, and micro-particulates were washed
from the nylon netting screens and filtered. Sterile buffer solution
(150 ma} was used to wash the coliforms from the net screens and appropriate
aliquots were then filtered immediately through membrane filters and incubated
for later counting in the laboratory in accord with Standard Methods [5].
For the surface plankton and micro-particulate determinations, however,
the wash water was filtered sea water and the sampler washing procedure
was repeated twice with the filtered material being counted and identified
directly on the membrane filter.
FLOATING PARTICIPATES
The floating particulate samples were washed with distilled water, dried at
35°C, and weighed. For the first two surveys the particulates were counted
and identified directly under a dissecting microscope. The particulates were
then extracted with hexane for one hour in an alumina thimble in a standard
soxhlet apparatus. The residual was then evaporated and weighed for hexane
extractables.
110
-------
SAMPLES
MICROSCOPIC
EXAMINATION
10-100 X
MICROSCOPIC
EXAMINATION
400-430 X
Figure 31. Analytical Approach to Characterizing Flotage and Bulk Samples
m
-------
Participate samples selected for coliform organism analysis were processed
as soon as possible at dockside. The participates were homogenized in a
sterile buffer solution of known volume, and appropriate aliquots of the
homogenized mixture were filtered through membrane filters in accord with
the procedures described in Standard Methods [5].
BULK WATER SAMPLES
The bulk sewage effluent and ocean samples were acidified with hydrochloric
acid to a pH between 1 and 2 and extracted in a Pearson-Thomas liquid-liquid
extraction apparatus [8]. The 1 liter sewage effluent samples were extracted
for 3 hr and the 4 liter sea water samples were extracted for 9 hr. The
hexane extractables fraction of the bulk samples was concentrated in a tared
vial and weighed following hexane evaporation.
FATTY ACID ANALYSIS
The hexane extractables were characterized for their fatty acid composition
by applying the techniques of electron capture gas chromatography using the
novel esters prepared by reacting a-bromo-2,3,4,5,6-pentafluorotoluene
(BFT) with the fatty acids in the hexane extract residues [15,16,17].
Weighing
The flasks containing the hexane extracts from either soxhlet or liquid-
liquid extraction were concentrated to 1 or 2 tn£ using a rotary evaporator
with a water bath at 40°C and an applied vacuum of 50 mm of mercury. A
one gram, 1.3 ma, glass, tared vial was heated to 40°C. The concentrated
sample was transferred to the vial quantitatively with hexane using a jet
of high purity nitrogen gas to assist in the evaporation of the solvent in
the vial. After cooling in a dessicator the vial was weighed to ± 10 pg.
Reaction
After weighing, the sample was quantitatively transferred back to its
original flask using 10 nrn hexane and dried on the rotary evaporator. To
112
-------
the flask were then added approximately 12 mg of K2C03 (powdered and dried at
103 C) followed by 10 m£ of acetone( Sano Grade ) and 0.1 nu of 5 percent
cx-bromo-2,3,4,5,6-pentafluorotoluene (BFT) dissolved in absolute ethanol.
The flask was then connected to a condenser, the ground glass fitting wetted
with acetone, and the open end of the condenser covered with aluminum foil.
The mixture was refluxed for one hour and cooled in a 20°C water bath for
approximately 10 minutes before disconnecting the flask from the condenser.
(Note: Any water present in the sample grossly inhibits this reaction.)
The acetone was removed on the rotary evaporator as before and the reacted
sample was then quantitatively transferred with hexane to a 10 m£ volumetric
flask.
Chromatography
One micro-liter samples were then injected into two gas chromatographs.
Model 1200 Varian Aerographs were employed in the study, both equipped with
concentric tube electron capture detectors ( H, 250 mCi). Two different
analytical GLC columns were used, one in each chromatograph. The columns
were 1/8 inch by 6 ft Pyrex glass packed with 2.5 percent QF-1 on Varaport
30 (80/100 mesh) and 5 percent QF-1 plus 3 percent DC 200 on Chromosorb Q
(80/100 mesh). The use of both columns permitted resolution of the fatty
acids into saturated and unsaturated components and provided presumptive evi-
dence for identification of compounds by comparison of retention times with
standards. The carrier gas (purified N2) was maintained at approximately
50 mi min"1; and the injector, column, and foil temperatures were 230°C,
190°C, and 200°C, respectively, in both chromatographs.
CHLORINATED HYDROCARBON ANALYSES
The cleanup of hexane extracts for chlorinated hydrocarbon analysis was
conducted with liquid chromatography in Florisil as described by Reynolds
[18] and Veigh [19]. The media was purchased from Varian Aerograph in the
purified and activated (at 650°C) form and kept at 130°C prior to use. The
column was 25 mm o.d. with a narrow discharge neck at the bottom fitted
with hexane extracted glass wool and a 250 ma solvent reservoir at the top.
113
-------
Twenty grams of Fieri si 1 were added to the column topped with ten grams of
anhydrous sodium sulfate for removal of possible trace water present in
the extract. The column was washed with 70 ma hexane which was discarded,
followed by 20 ma hexane used as a blank. The extract was then placed on
the column and eluted with 200 m£ hexane to recover DDE and PCB primarily.
A second fraction was then collected by eluting with 20 ma of 20 percent
ethyl ether in hexane to obtain DDT, dieldrin, and other more polar chlorinated
hydrocarbons. If the hexane extract had been reacted with BFT, these esters
were also eluted in the second fraction. Control showed that PCB's were not
affected during the BFT reaction.
The eluants were then concentrated to volumes of 1 ma or 10 ma, and one
micro-liter volumes were injected into the same columns used for the fatty
acid analysis.
STANDARDS
Fatty acids of 99+ percent purity were purchased from Applied Science
Laboratories, Inc. These were weighed and reacted with crbromo-2,3,4,5,6-
pentafluorotoluene, Puriss Grade (molecular weight 260.99) purchased from
Aldrich Chemical Compnay, Inc. The completion of the reaction and recovery
of the ester was confirmed by comparison with known amounts of similar esters
supplied by Dr. Kawahara of the Analytical Quality Control Laboratory,
EPA in Cincinnati, Ohio.
PCB standards for Aroolor 1242, 1248, 1254, and 1260 were obtained from
Dr. Joseph Blazevich of the EPA Laboratory in Corvallis, Oregon. Chlori-
nated insecticide standards were purchased from Varian Aerograph.
CONTROLS
All hexane purchased was of Nano Grade quality and redistilled in glass
before use. Potassium hydroxide pellets were placed in the distilling flask.
All glassware was cleaned with a hot dichromate in sulfuric acid cleaning
114
-------
solution, rinsed with distilled water, baked out at 103°C, and purged with
nitrogen gas while still hot. Blanks were run frequently on reagents and
glassware for contamination monitoring.
The fiberglass cloth samplers were washed in distilled water and then air
dried in a hood. The cloths were then soaked in a 60°C dichromate and acid
cleaning solution (heated initially only) for twenty four hours after which
they were removed, washed with tap water, rinsed with distilled water and
then air dried as before. The cloths were then placed in a 4 liter bottle of
hexane with a few pellets of KOH in the bottom, a reflux condenser fitted
to the bottle's tapered glass joint and the hexane refluxed on a hot plate
for 4 hours. The cloths were then extracted in soxhlet extractors, 2 to a
soxhlet for 4 hours with hexane plus a few pellets of potassium hydroxide.
Fresh hexane, distilled in glass from pesticide quality hexane was then used
to extract the cloths for 2 more hours (no potassium hydroxide present).
The extracts from 6 soxhlets were then combined, dried, and weighed to deter-
mine the cleanliness of the extracted cloths. The hexane residue was then
reacted with BFT and the fatty acids present determined by 6LC to determine
cloth background levels.
115
-------
Hyperion, September 1, 1971
JWPCP, July 11, 1973
Figure 15. Photographs of Sea Slicks Over Hyperion and JWPCP Outfalls
117
-------
Figure. 18. Rise of Large Participates in the Vicinity of the L Diffuser
of the JWPCP Outfalls: July, 1973
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
/. Report No.
2,
W
"The Significance and Control of Wastewater Floatables
in Coastal Waters."
Selleck, Robert E., Lloyd W. Bracewell, and Ralf Carter
Sanitary Engineering Research Laboratory
College of Engineering & School of Public Health
University of California, Berkeley
12. Sp ~>nsorin Organ?-ation
5. Report Date
8. Performing Organ:z»tton
Report No.
1BA025
800373
IS. Type <.-/ Repo/c and
Period Covered
Environmental Protection Agency Report No. EPA 660/3-74-016, January
Significance of flotage derived from submerged primary effluent plumes in
the Southern California Bight is evaluated in terms of three components: particulates >^
0.5 mm in size, particulates j< 0.1 mm in size, and surface film materials. The sampling
methods utilized to collect the flotage from the surface are described in detail. The
surface film and micro-particulates were captured by fabric screen samplers developed
during the course of the study.
It was found that the large particulates penetrated the ocean thermocline and gath-
ered on the surface in profusion. The grease and wax portions of the particulates could
be measured reliably with hexane extraction, with the mass of HEM of sewage origin being
in the order of a metric ton on the water surface within the study area. Such particu-
lates contained considerable numbers of coliform bacteria but little PCB compounds or
pesticides.
The surface film materials and/or micro-particulates contained significant concen-
trations of coliform organisms and PCB compounds, but not pesticides. The HEM derived
from this type of flotage may have amounted to 300 kg on the water surface within the
study area in July 1973. Regulations for controlling the concentration of flotage on
the ocean surface are suggested after considerable discussion.
This report was submitted by the Sanitary Engineering Research Laboratory of the
University of California, Berkeley, in fulfillment of Grant No. R-800373, under the spon-
sorship of the Office of Research & Development of the Environmental Protection Agency.
Water pollution, ocean outfalls, surface floatables, surface films, surface slicks,
waste water disposal, collection methodology
California, ocean outfalls, surface pollution
05A, 05B, 05C
19. Security Class.
(Repot :)
*S. Se..'trityC;..ss.
(Page)
21. No. of
Pages
::3. Pm«
Send To :
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