WATER POLLUTION CONTROL RESEARCH SERIES • 15020 ENN 09/71
Control of Pollution From
Outboard Engine Exhaust:
A Reconnaissance Study
ENVIRONMENTAL PROTECTION AGENCY • RESEARCH AND MONITORING
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the results
and progress in the control and abatement of pollution in our
Nation's waters. They provide a central source of information on
the research, development, and demonstration activities in the
Environmental Protection Agency, through inhouse research and
grants and contracts with Federal, State, and local agencies,
research institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research Reports
should be directed to the Head, Project Reports System, Office
of Research and Monitoring, Environmental Protection Agency,
Room 801, Washington, D. C. 20242.
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CONTROL OF POLLUTION FROM OUTBOARD ENGINE EXHAUST:
A RECONNAISSANCE STUDY
by
Bio-Environmental Engineering Division
Rensselaer Polytechnic Institute
Troy, New York 12181
for the
ENVIRONMENTAL PROTECTION AGENCY
Project #15020 ENN
September 1971
For sale by the Superintendent of Documents, TJ.8. Government Printing Office, Washington, D.C., 20402 - Prico SO cents
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EPA Review Notice
This report has been reviewed by the Environmental Protection
Agency 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 recom-
mendation for use.
ii
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ABSTRACT
A reconnaissance study has been made to determine the extent of
pollution which results from the operation of a two-cycle outboard
engine. Comparisons have been made of engine operation with and
without a pollution control device attached. Studies have also
been made of the biodegradability of the fuel and exhaust products.
Tests made in a swimming tank with an untuned engine have shown
that the quantity of fuel wasted as exhaust varied from about 7
percent of the volume of fuel used at high speeds, to over 30
percent at low speeds. For a recently tuned engine, the quantity
of fuel discharged ranged from about 3 percent at high speeds to
about 26 percent at low speeds. When the Goggi pollution control
device was installed, these quantities were intercepted and col-
lected rather than discharged with the exhaust.
Analyses at various depths indicated that nearly all products
separated from the water in a short time and collected on the
surface. Very little dissolved or emulsified oil was noted.
Various analytical techniques were studied.
It appears that both fuel and exhaust products are capable of
supporting microbial growth. Growth rates, however, appear to
be limited by available oxygen.
This report was submitted in fulfillment of Project Number
15020 ENN, under the (partial) sponsorship of the Environmental
Protection Agency.
ill
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CONTENTS
Section
I Conclusions
II Recommendations
III Introduction
IV Review of Related Work
V Equipment and Materials
VI Procedure
VII Results
VIII Discussion
IX References
1
3
5
7
11
15
19
31
37
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FIGURES
Page
1 Water Column Sampler 12
2 Engine Testing Layout - Plan View H
3 Depth of Sampling Points 25
VI
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TABLES
Ms. Page
1 Fuel Wastage - Untuned Engine 19
2 Fuel Wastage - Engine Tuned 19
3 Summary of Data 20-24
4 Growth of Ps. flucrescens on Fuel Wasted
by Engine Operating at 2000 rpm (1600 ppm) 28
5 Effect of Shaker Speed and Volume on Oxygen
Transfer Capacity (Sulfite Value) 29
6 Effect of Increased Aeration on Cell Growth
(Ps. fluorescens) 29
7 Calculated Oil Concentrations in Top 1" 33
8 Cumulative Oil Concentration in Top 1" of Water 34
Vll
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SECTION I - CONCLUSIONS
Major efforts in this study have been directed towards defining
the nature and extent of the pollution problems as they originate with
outboard engines. Of necessity, the scope of this work has been limited
because of the short time available for this work. However, data ob-
tained by the operation of the two-cycle outboard engines in test tanks
under a variety of conditions have provided definitive information re-
garding the amount and kinds of exhaust products discharged to surroundings.
Tests were made with both an untuned and a tuned two-cycle out-
board engine at various engine speeds. These tests, were made with a Goggi
pollution control device attached to the engine. This device provides for
the collection of liquid fuel and exhaust products rather than their dis-
charge to the water. The results of these tests have shown that from
untuned engines to which a Goggi device is attached, the volume of exhaust
products collected ranged from about 7 percent of the volume of fuel used
at high speeds to over 30 percent at low speeds. The amount of fuel and
exhaust products collected from a recently tuned engine ranged from about
3 percent at high speeds to about 26 percent at low speeds. Without the
Goggi device attached to the engine, these quantities of fuel and exhaust
products would normally be discharged to the water.
Based upon test results from these studies, a calculation was made
to illustrate the effect that exhaust products have on the aquatic en-
vironment. If one takes a discharge of 4-00 ml of exhaust products per 30
minutes operation as typical of average operation, this may be transformed
into a waste load in terms of a population equivalent. Assuming that the
products contain 85 percent biodegradable carbon, the discharge based on
one engine-day would be equivalent to a population of 4-00 people.
For engines operated without an anti-pollution device, the exhaust
products were discharged directly to the water beneath the surface. Ob-
servations of the water in the tank have shown that the exhaust products
rapidly separated and accumulated in pools on the surface. Very little ex-
haust material was found to be retained in the water below the top few
inches. This was verified by several analytical techniques, including or-
ganic carbon determinations, use of the oil test papers, and the use of the
Esso oil analyzer.
A variety of analytical procedures for oil determination were in-
vestigated. A limited amount of work was done with a gas chromatograph.
It soon became apparent that while potentially capable of yielding extremely
useful data, the amount of preliminary testing and calibration required made
it impractical to use this device extensively in a reconnaissance study. It
was found that the Beckman carbon analyzer provided useful information re-
garding the presence of exhaust products. Analysis of samples taken at
various depths showed that the total carbon content increased with time of
engine operation. At the same time organic carbon content remained virtu-
ally constant both with respect to time and position except for the very top
surface. It is believed that the increase in total carbon was due primarily
to dissolved C0~.
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It was originally planned to investigate the amount of oil ad-
sorbed on suspended solids, such as muds. However, because of the very
low concentrations of oil found in the-regions.beneath the surface, and
because of the. time.required to clean and fill the tanks between runs
with muds-present, it was felt that the limited time available could
better be used in studying other aspects of the problem, and deferring
this work to future .studies.
Biodegradability studies of engine, fuel (50:1), as well as ex-
haust products from operation of an engine at various speeds indicate
that these materials are capable of supporting microbial growth. Com-
parative tests with and without supplemental nitrogen show the same growth
rates.. Growth rates with fresh fuel were less than with engine exhaust .
products, perhaps due to higher concentrations of low volatile gasoline
components. The studies indicate that growth rate is limited by available
oxygen. Tests at.various shaker speeds indicated a linear increase in cell
numbers with shaker speed, .which in turn is proportional to .oxygen transfer
capacity.
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SECTION II - RECOMMENDATIONS
The present reconnaissance study has provided preliminary data
on the quantity and distribution of exhaust products from outboard en-
gines , plus information on the rates of biological degradation. This
work has suggested a number of areas where further work should be done.
1. Further evaluation of analytical methods should be made
for both quantitative and qualitative purposes. Efforts
should be made to extend the method using the Esso
analyzer. This method has the potential of being a rapid
and convenient way of measuring the quantity of oil in
water samples, but requires refinements in technique.
The gas chromatograph can provide useful information on
the identification of specific products discharged to the
environment. Other methods need to be evaluated.
2. The tests to determine the amount of exhaust products,
with and without the pollution control device, need to
be extended over a wider range of operating conditions.
3. The effects of muds and suspended solids on the removal
of exhaust products should be further investigated be-
yond work being done currently.
4. Further work on biodegradability is indicated over a
wider range of environmental conditions. The preliminary
work has indicated that oxygen transfer rates may be
critical to degradation, and this needs to be studied.
5. Most importantly, this study should be extended to the
field, in order to judge acceptable limits of discharge.
These limits should be based on (a) the ability of the
body of water with its accompanying flora to purify the
pollutants; (b) the physical and chemical processes in-
volved in removing the pollutants from their area of
influence; and (c) a discharge that is unobjectionable
in terms of water usage and ecological balance.
6. The effect of engine discharges on primary production
should be studied by evaluation of periphytic and
planktonic algae.
7. Studies should be made of the effects of operation of
motors on the water quality, particularly with reference
to those factors which are important in microbial growth.
This includes all forms of nitrogen, phosphorus, dissolved
oxygen; pH, calcium, sodium and chloride.
8. Studies should include comparisons between natural waters
in which control devices are used and those where they
are not.
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SECTION III - INTRODUCTION
GENERAL
Increased usage of two-cycle outboard engines has directed at-
tention to the possibility that exhaust from these engines may be coming
to be a significant source of pollution to our lakes and rivers. An in-
dication of the magnitude of the problem may be gained by noting the rate
at which both the number of engines and their size is increasing. In
1959 there were 5.8 million outboard motors in use in the United States,
having an average horsepower of 23.7. In 1969 there were 7.1 million
outboard motors in use, and the average horsepower was 33.1.
Present fuel wastage from outboard motors has been variously re-
ported at from 100 million gallons(17) to 160 million gallons(lO) annually.
A conservative estimate of the portion of fuel used which is discharged to
the environment would be of the order of 10 percent of all outboard fuel
used. The cost of the wastage probably lies between 50 million dollars
and 100 million dollars just in out-of-pocket expense to boat owners.
While the effects of major oil pollution are obvious from such
sources as ship spills, industrial transfer and storage, pipelines, and
off-shore drilling(20,28), the effects of continuous low-level water pol-
lution by outboard motors tends to be overlooked. However, there is in-
creasing evidence that motor exhaust contributes to taste and odor in fish
flesh(15,23,32,24,9), and that adverse biological effects are the result
of this type of pollution.(27) The apparent persistence of oily wastes
in water is also relevant to the frequent discharge of the exhaust streams
from outboard motors. (14-)
SOURCE OF OIL POLLUTION IN OUTBOARD MOTORS
At the present time, over 98 percent of all outboard motors used
are two-cycle models. In this design a mixture of gasoline and oil is
used as both fuel and as a lubricant for engine parts. The oil-gasoline-
air mixture is valved directly from the carburetor to the crankcase which
serves as the intake manifold. The downward thrust of the power stroke
places the vaporized mixture under pressure. Due to this pressure the
vapor is forced up into the firing portion of the cylinder and this pushes
out the spent gases from the ignition stroke. During this process a por-
tion of the vapor condenses within the crankcase on the internal parts of
the engine. Most of the gasoline revaporizes since it is the more volatile
and this leaves a thin film of oil behind to coat the engine parts. This
process is repeated continuously while the engine is running.
Since the condensate does not reach the combustion chamber, it is
not burned and thus begins to collect in the lower portion of the crankcase.
If this liquid were allowed to accumulate in the crankcase, it would even-
tually build up to a point where the piston would be prevented from moving
downward during its power stroke. This condition is known as "hydraulic
lock" and may cause engine damage. To avoid this condition the liquid is
evacuated from the crankcase by means of pressure-actuated valves. These
valves are usually of the leaf or reed type.(28) When the liquid reaches
a specified volume the downward stroke of the piston forces the valve open
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by the pressure exerted and the liquid fuel is vented. From there the
waste fuel is led to the exhaust housing and downward to the water.
Therefore, the two-cycle engine is, by reason of its design,
conducive to the rejection of varying amounts of unused, unburned fuel.
The amount of this discharge will depend on the age and condition of
the engine and on the speed of the operation. Fuel wastage has been
estimated to range from less than 10 percent to over 50 percent of the
fuel originally entering the engine.(28)
SCOPE AND PURPOSE
As a preliminary to comprehensive studies of the impact of out-
board motors on a lake environment, a reconnaissance study has been made
for the purpose of gaining an insight into the nature and magnitude of
the pollution problem. The purpose of the present work has been to meas-
ure the quantity of exhaust products discharged from motors run in test
tanks, as a function of operating time, water depth, and engine speed.
Tests have been made both with and without a pollution control device at-
tached to the engines. The control device allowed for collection of exhaust
products instead of discharging to the water. Techniques for sampling and
analyzing exhaust products have been evaluated, and information gathered on
the distribution of discharged materials in the water environment. An ad-
ditional objective of this work has been to study the biodegradability of
outboard engine fuel and the exhaust products from outboard engines op-
erated in various modes. This work has been carried on in laboratory shake
flasks under a variety of environmental conditions.
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SECTION IV - REVIEW OF RELATED WORK
Significant studies in the area of pollution from outboard motors
have only recently become available. Perhaps the earliest of these was
made by English, Henderson, McDermett, and Ettinger in 1961.(6,7) In this
study two different outboard motors were tested in different volumes of
water. The motors were 5.4 and 10 horsepower models operated in 50 and
380 gallons of water, respectively. It was found that the amount of ex-
tractable hydrocarbons and oxidizable material in the water after'operation
increased in direct proportion to the amount of time the motor was operated
(at a constant speed). In addition, this'relation seemed to hold even when
the motors were operated in these small volumes until high contaminant con-
centrations were reached. An oil to fuel ratio of 1 to 17 was used for the
study.
The study also studied the effects of the exhaust on the quality
of the receiving water. This included measuring hydrocarbons, lead, effect
on odor, chlorine demand, interference with coagulation, fish toxicity, and
tainting of the fish flesh. Following a series of assumptions, an "ex-
treme situation" was formulated. Using this extreme situation, concentra-
tions of non-volatile and volatile oil, lead, phenols, and COD were cal-
culated based on the concentrations found in the water after running the
motors. From this it was concluded that "unusually low" water volume per
unit of fuel consumed was needed before severe pollution would result from
outboard motors alone. Apparently, the most noticeable effects were un-
pleasant taste and odor and the tainting of fish flesh.
Following the preliminary study, English, Surber, and McDermett
carried out studies to determine what effect a natural environment would
have on the waste products from outboard motors.(8) Three bodies of water
were used - a motor lake, a motor pond, and a control pond. Tainting of
fish flesh was found to occur at a combined fuel-use level of 8 gallons
per million gallons of water and a daily fuel-use rate of 0.17 gallons per
million gallons of water. It was also found that an increase in threshold
odor number of between 0..5 and 1.5 occurred for each gallon of fuel con-
sumed per million gallons of water. It was pointed out that temperature
has an important effect on natural purification processes and that this
should be taken into account when applying these figures to other areas
of the world.
As with other types of pollution, the rate at which contaminants
are added and the rate at which they are removed by natural processes de-
termines the level of accumulation of the contaminants. In this study it
was found that a higher fuel-use level was possible before fish flesh
tainting occurred as compared to laboratory studies. This difference was
attributed to the fact that less time was allowed for biological degrada-
tion of pollutants during the laboratory studies.
One other important conclusion of these field studies was that the
amount of lead contributed by outboard motor exhausts was "insignificant".
In 1964, Dietrick investigated the polluting effects of underwater
exhausts from outboard motors and the composition of the exhaust gases.(4)
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He outlined the studies of English, McDermett, and Henderson and calcu-
lated the quantities of damaging substances discharged into Lake Constance
per summer. His calculations were with reference to the possible effects
on use of the lake as a source of drinking water supply. (This seems to
be a recurring theme in most studies of this area.)
A significant advancement in outboard motor pollution abatement
was made by the Goggi Corporation(lO) in 1964. Using a patented device
known as the Kleen Zaust, normally wasted fuel could be redirected into
the fuel system. In this manner the discharge of unburned fuel into the
water was completely eliminated. The device was connected to the motor
in place of the crankcase bleeder valves and blocked off the segment of
the valve which allowed the unburned fuel to go into the water. The crank-
case pressure was utilized to redirect the flow to a mixing chamber and
immediately redirected to the motor along with the fresh fuel drawn from
the original mixture.
Tests run by an independent testing firm(25) were made on the
Goggi device. A 33 horsepower Johnson Motor was used with a fuel mixture
of 1 pint of oil per 6 gallons of gasoline. It was found that at engine
idling speeds of 650 ± 100 RPM the device returned over 30 percent of the
fuel drawn by the engine. With the engine in gear and using a test propel-
ler, tests were run at 1000, 2000, and 3000 RPM. With the Goggi device
connected, running time was increased by 68.8 percent, 66.7 percent, and
41.7 percent, respectively.
Extensive studies on pollution by outboard motors have also been
conducted in Europe as evidenced by the report of Kempf, Ludemann, and
Pflaum.(12) This study indicated that heavy and light hydrocarbons, lead,
phenols, and aldehydes were the primary contaminants being produced by out-
board motors. (It should be pointed out that these are basically the same
contaminants mentioned in earlier studies made by English.(7)) Tests were
run in the laboratory with the 6, 18, and 40 horsepower motors using oil
to gas ratios of 1:25 and 1:50. It was found that emissions were dependent
on engine speeds with minimums occurring between zero and half throttle.
Engine wear was also found to be significant in increasing the amount of
contaminants discharged from the motors. As in the English studies, phenols
and lead were found in significant amounts.
Muratori explained the general operating characteristics of the
two-cycle engine and pointed out the reason for its inherent polluting
capabilities.(17) The basic concept of a pollution control device was
mentioned along with the reasons for it being so long in becoming a reality.
He stated that with a conservative 10 percent fuel wastage, at least 100
million gallons of unburned fuel were being discharged annually (1968 esti-
mate) into the waters of the United States. This represented a cost of
about $50 million.
One of the more recent studies on pollution by outboard motors was
conducted by Stillwell and Gladding in October 1969.(28) This study was
to determine amounts of unburned fuel discharged and to ascertain whether
any changes can be made in the basic construction of the two-cycle engine
to reduce or eliminate these discharges. Tests were run on 5, 33, 40, 50
and 60 horsepower motors of different make and model (Johnson, Evinrude,
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and Gale). All .motors were operated at 1500 RPM + 100 with standard test
propeller in a test tank. The gasoline to oil ratio was 50:1. The fuel
waste percentage was 1.57, 31.25, 31.25, 53.1, and 54.7 percent, respectively.
It should be pointed out that one recent report by Environmental
Engineering, Inc. of Gainesville, Florida contradicts all previous pollu-
tion studies in the outboard motor field. This firm was commissioned by
Kiekhaefer Mercury to make a complete survey of Lake X, used extensively
by Mercury as a testing ground for outboard engines. According to the
report, nearly three million gallons of gasoline and oil have been used
there in the past ten years. This lake was compared to a nearby lake which
has "almost never" been used by power boats and has no exposure to con-
tamination. Numerous samples were collected from both lakes and analyzed
for organic compounds known to be found in exhaust emissions of internal
combustion engines. The result was that neither lake contained any of
these organic compounds. The conclusion was made that either the organic
compounds were readily broken down by bacteria or they are in such minute
quantities as to be undetectable.
About forty other chemical tests were performed including analysis
for iron, manganese, lead, zinc, copper, sulfate, chloride, silica, phos-
phate, nitrogen, available oxygen, and oxygen demand. Here again the re-
sults indicated no pollution occurring.
Biological studies were also undertaken at both lakes. Bacterial
counts were found to be normal and there was no observable effect on plank-
ton or bottom organisms.
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SECTION V - EQUIPMENT AND MATERIALS
The. following is a listing of principal items of equipment with
a brief statement of their purpose:
TEST TANKS
Two Bilnor Corporation swimming tanks were used for the tests.
The tanks were both Models No. 307.45582 and were 18 ft in diameter with
a 4- ft depth. The tanks were made with a vinyl plastic liner supported
by a steel frame.
ENGINE SUPPORT PLATFORM
A wooded walkway with access stairways was built just above the
tanks and used to support the engines. The walkway was bolted to the
floor and laterally braced against the concrete block wall of the building
in which the tests were conducted. Steel engine mounting plates were
located above the center of each tank.
OUTBOARD ENGINES
The engines used in this work included a l^g horsepower Evinrude
engine used for screening purposes, a 33 horsepower Evinrude, and a 65
horsepower Mercury engine. Accessory fuel tanks were used to supply the
engines.
TEST PROPELLERS
Because of extensive splashing, the standard propellers on the
Evinrude and Mercury engines were replaced with test propellers provided
by the engine manufacturers. The Evinrude propeller was satisfactory,
but the Mercury unit did not perform well and could not be used.
TACHOMETER
A Sea-Speed Tachometer, Model 564-3 was used in conjunction with
the 33 horsepower Evinrude engine to obtain engine speeds.
WATER COLUMN SAMPLERS (see Fig. 1)
Three samplers were used for obtaining depth samples. They con-
sisted of an aluminum support frame and a 5 ft section of 1% inch diameter
Pyrex glass pipe. The base of the support frame was a 6 inch by 6 inch
aluminum plate with a 5/8 inch I.D. copper tube fitted through the center
of the plate. A shut-off valve was connected to the tube. Two 6 ft
aluminum rods of \ inch diameter were threaded into the base plate to serve
as vertical supports for the glass pipe. Ring clamps attached to the rods
provided a guide and support for the glass pipe, which was seated on
a No. 9 rubber stopper mounted over the copper tubing outlet device.
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Figure 1
Water Column Sampler
I
0^
JL'
- Support Frame
- Ring Clamp
- Base
Glass Pipe -
Drain
Shutoff
\
A
12
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WATER SURFACE SAMPLERS
Samplers consisted of a 12 inch length of 25 mm glass tubing,
supplied with No. 6 rubber stoppers.
CARBONACEOUS ANALYZER
The carbon content of samples was determined by a Beckman Car-
bonaceous Analyzer with a Beckman Model 315 Infrared Analyzer and strip
chart recorder.
ESSO OIL ANALYZER
A device developed by Esso Engineering for determining low con-
centrations of oil in water was borrowed for this work. The instrument
depends upon measuring the change in frequency of vibration of a piezo-
electric quartz crystal, caused by the weight of oil from a sample ex-
tracted with methylene chloride, from which the methylene chloride is
evaporated. The instrument was calibrated with known samples.
OIL TEST PAPERS
Concentrations of oil were examined using test papers manufactured
by Machery, Nagal and Company, Germany, and distributed by Gallard-
Schlesinger Chemical Manufacturing Corporation, Carle Place, New York.
TANK PUMP
A 50 gpm centrifugal pump manufactured by F. E. Myers and Bros.
Co., Model 100M-1/3 was used to empty the tanks between runs. Flexible
PVC pipe was used for the suction line and polyethylene pipe used for
discharge.
PLASTIC GAS CANS
Three gas cans used for mixing and storage of fuel - 1^, 3, and
5 gallon cans from Will Scientific, Inc.
FUEL
Mobil regular gasoline and Formula 50 Quicksilver Motor Oil made
by Kiekhaefer Mercury were used. A 50:1 ratio of gasoline to oil was used
as specified by the engine manufacturer.
CRANKCASE EXHAUST COLLECTION DEVICE
A plug and by-pass tube device was used to collect the crankcase
drain exhaust. It is manufactured by the Goggi Corporation, Staten Island,
New York.
WARBURG RESPIROMETER
Used for oxygen-uptake measurements.
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Support Platform
XXXXXXXX X XXXXX XX XXX
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SECTION VI - PROCEDURE
ENGINE TEST RUNS
Test runs were made both with the crankcase exhaust collected
by the Goggi device, and with it discharged to the water as it would be
under normal operation of the engine. In both cases, the engine was al-
lowed to warm up at idle speed for approximately five minutes and was
then run for a half hour at each of three rpm levels. The rpm levels
used were usually 1000, 2000, and 3000 rpm. The fuel tank was filled to
a pre-set mark on the neck of the tank inlet before the engine was run
at each rpm level. At the end of each half hour run, the tank was re-
filled to the mark and the fuel usage was measured by the amount of fuel
needed to refill the tank. In the runs in which the crackcase exhaust
was collected, the waste was discharged into a beaker and the volume col-
lected was measured for each rpm level. All tests were made with the
engine engaged in forward gear.
SAMPLING PROCEDURE
Samples of water were taken before and after each run at each rpm
level. In those cases in which one half hour run was immediately followed
by another run, the last sample for the preceding run was used also as the
initial sample for the following run. When there was any time lapse be-
tween runs, separate before and after samples were taken. Samples were
taken from the 14" and 28" depths and from the surface. These depths cor-
respond to approximately the 1/3 and 2/3 depths of the pool since the total
pool depth was 4-3". In the initial runs, all samples were taken with the
water column sampler, but it was found that a satisfactory surface sample
could not be obtained in this manner. For this reason, the surface sampler
was developed and used in all subsequent runs. A sample was also taken
from a depth of 1" off the pool bottom in several of the final runs.
Samples taken with the water column sampler were collected by
resting the support frame on the pool bottom and then lowering the glass
pipe through the water column and snugly seating it on the rubber stopper
mounted on the base. With the drain shutoff closed, it was then possible
to remove the entire unit from the pool, and samples could be drawn from
any level by draining the level in the tube down to the desired level and
then drawing a sample into a sample bottle. Samples taken for analysis with
the carbonaceous analyzer were immediately refrigerated and analyzed within
24 hours. Methylene chloride was added to those samples which were to be
analyzed with the oil analyzer.
PROCEDURE FOR ANALYSES
Carbonaceous Analyzer
The carbonaceous analyzer consists of three sections: a furnace,
an infrared analyzer, and a strip chart recorder. A 40 pi sample is in-
jected through a sampling port into a 950°C constant temperature catalytic
furnace. The solution is vaporized and the carbonaceous material is oxi-
dized to (X>2 and steam. A stream of pure oxygen carries the CO- and steam
15
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mixture to a condenser and the condensates are removed. The C02 and the
remaining water in the oxygen stream then enter a Beckman Model 315 In-
frared Analyzer which measures the amount of CC>2 in the stream and the
amount is recorded on a strip chart recorder. The peak height is then
measured, and by reference to a calibration curve, a direct reading in
terms of milligrams of carbon per liter is obtained.
The procedure used in the analyses for total carbon followed that
recommended in the Beckman Carbonaceous Analyzer Instruction Booklet
(Bulletin 4059). Samples analyzed for organic carbon were first acidified
to a pH of approximately 2.0 and then were bubbled with nitrogen for five
minutes. This procedure effectively converts all the carbonates and bi-
carbonates to CC>2 and removes the C02 by purging with the nitrogen gas.
Once the inorganic carbon had been removed, the procedure followed was
the same as for the total carbon analyses.
Oil Analyzer
Oil measurements were made using an oil analyzer developed by Esso
Engineering and Research Company. Samples taken for analysis with this
machine were first extracted with an equal volume of methylene chloride.
This produced a solution of oil in methylene chloride that was of the
same concentration as was the water solution. A microliter syringe was
then filled with this solution, and a second syringe was filled with pure
methylene chloride. The analyzer contained two piezoelectric quartz crys-
tal resonators. These crystals vibrated at a very specific frequency when
subjected to an electrical current, and this frequency changed when a
weight was placed on the crystal. A 1 ul sample of the methylene chloride
and oil solution was injected onto one crystal and 1 yl of methylene chlo-
ride alone was injected on the other. The pure methylene chloride evaporated
to dryness, while the methylene chloride and oil solution left an oil resi-
due. The weight of this residue caused the frequency of vibration of the
one crystal to change and the difference in frequencies between the two
crystals was measured and the result read directly on a meter as ppm of oil.
The analyzer had four ranges of sensitivity. Each sample was analyzed four
times, and values from all four ranges were recorded. Results were ob-
tained by averaging the values from the two ranges which gave the best
agreement. The detailed procedure used was as follows:
1. Wash crystals in methylene chloride
2. Air dry
3. Set range to #1
4. Adjust zero
5. Insert empty syringes until the needle
tips just clear the crystals
6. Center the needle over the crystal
7. Readjust zero
8. Fill syringe #1 with sample and syringe
#2 with methylene chloride
9. Introduce 1 ul each of the sample and the
solvent at the same time and allow to evaporate
10. Read the value obtained for each of the four-
ranges
11. Repeat the entire procedure four times
16
-------
Oil Test Paper
The oil test paper was simply placed in contact with the sample
and the color change was noted. In the presence of oil, purple dis-
colorations appear. The intensity and size of the purple spots indicate
the quantity of oil in the water. When there is no oil in the water, the
paper is neither moistened nor discolored.
17
-------
SECTION VII - RESULTS
Initial fuel wastage tests were run on a 33 horsepower Evinrude
engine. Fuel and exhaust products being discharged were collected by
means of a plug and by-pass tube device manufactured by the Goggi Corpora-
tion. The engine was a 1968 model and had been used under normal boating
operation. No attempt was made to tune up or adjust the engine for these
first runs. Subsequent runs were made with the engine after tune-up.
The engine tune-up consisted of replacing the spark plugs and setting the
carburetor adjustments to factory specifications. The results of these
tests are tabulated in Tables 1 and 2.
Engine
Speed
rpm
1,000
2,000
2,500
Duration
min
30
30
30
Table 1
Fuel Wastage - Untuned Engine
Fuel Used
ml
2,229
3,445
4,965
Fuel Wasted
ml
680
245
370
Percent Wasted
30.51
7.11
7.45
Engine
Speed
rpm
1,000
2,000
3,000
Duration
min
30
30
30
Table 2
Fuel Wastage - Engine Tuned
Fuel Used
ml
1,976
3,000
4,215
Fuel Wasted
ml
515
180
125
Percent Wasted
26.06
6.00
2.97
A summary of all operating and analytical data is given in Table 3.
During the first several runs, all samples were taken using the water
column sampler. Samples were taken at points #1, #2, and §3 as shown
in Figure 3. This procedure was found to be satisfactory for points #1
and #2, but it was not possible to get a satisfactory surface sample
(point #3). There were two reasons why the surface samples obtained with
this procedure were not considered reliable. First, much of the surface
film adhered to the glass pipe as water was withdrawn from the sample.
Secondly, the design of the outlet device was such that there was always
a small amount of water remaining in the tube after the sample was taken.
These two factors made it impossible to obtain a reliable surface sample
with the water column sampler. To avoid these problems, it was decided
to use the surface sampler to sample the top layer rather than use point
#3 from the water column sampler. The surface sampler was used for all
samples after sample number 8.
19
-------
Table 3
Summary of Data
Total Carbon
mgC/1
Organic Carbon
mgC/1
Esso Analyzer
PP»"
Samole
1
2
3
4
5
6
7
8
RPM
clean pool
\ hr warmup
2000
4 days later
water sample
warm-up
1000
1 day later
water sample
2500
Used
ml
-
-
3445
-
-
2229
_
4965
Wasted % pt. pt. pt.
ml Wasted 012
- _ _ _
_ _ _ _
245 7.1 -
_ _ _ _ _
_ _
680 30.5 -
_ _ _ _ _
370 7.9
pt. pt. pt. pt
0121
5.
- 10.
33.
- - - 0.
18.
23.
18.
- 12.
•
62
80
00
50
66
00
00
pt
2
0.
0.
0.
14.
22.
57.
9.
5.
•
13
80
50
25
38
Pt
3
19.
0.
15.
25.
16.
55.
19.
0.
•
75
00
50
87
00
00
CLEANED POOL AFTER SAMPLE NO. 8
-------
Table 3 (continued)
Summary of Data
Total Carbon
mgC/1
Organic Carbon
mgC/1
Esso Analyzer
ppm
SamDle
9
10
11
12
13
14
15
RPM
warm-up
1000
2000
3000
5 days later
water sample
warm-up
1000
Used
ml
-
1976
3000
4215
_
-
2000
Wasted % pt .
ml Wasted 0
_
515 26.
180 6.
125 2.97
- - -
_
_ _ _
pt.
1
10.0
11.0
13.8
17.5
13.5
15.0
20.5
P
10
10
13
17
13
16
20
t. pt.
2 0
.3
.5
.0
.0
a j ™*
.25
.5
pt.
1
4.0
4.5
3.6
4.0
6.5
7.0
4.75
pt. pt.
2 0
4.0
3.0
4.0
4.5
4.75
4.75
4.50
pt.
1
0.
7.0
8.25
4.0
0.
29.0
0.
pt.
2
2.5
0.
11.2
17.0
0.
0.
0.
Top 1"
354.2
119.0
130.26
166.24
_
138.24
181.5
CLEANED POOL AFTER SAMPLE NO. 15
-------
Table 3 (continued)
Summary of Data
?o
Total Carbon
mgC/1
Organic Carbon
mgC/1
Esso Analyzer
Sample
16
17
18
19
20
20A
RPM
clean pool
warm-up
3000
2000
1000
4 days later
Used Wasted % pt.
ml ml Wasted 0
_ _ _
_ _
4645 -
3000 -
2000 -
_ _
pt.
1
15.75
10.5
18.5
29.5
31.0
-
pt. pt.
2 0
10.0
10.0
25.0
26.0
31.5
_
pt.
1
_
3.6
4.5
3.6
3.6
-
pt . pt .
2 0
4.50
3.8
3.5
3.6
4.0
-
pt.
1
6.13
-
0.
5.16
10.62
-
pt.
2
0.
-
0.
5.75
12.0
-
Top 1"
155.0
-
168.75
182.62
163.12
580.0
CLEANED POOL AFTER SAMPLE NO, 20A
-------
Table 3 (continued)
Summary of Data
Total Carbon
N>
Organic Carbon
Esso Analyzer
Sample
21
22
23
24
25
26
27
RPM
warm-up
1000
2000
3000
2 days later
4 days later
6 days later
Fuel Fuel
Used Wasted
ml ml
-
1850
3000
not
known
_
_
_
% pt.
Wasted 0
11.0
15.0
16.5
22.8
25.0
20.7
21.7
mgC/1
pt.
1
10.0
12.6
16.3
25.5
28.5
27.5
27.5
pt.
2
9.8
12.6
19.0
32.0
30.0
22.7
23.5
pt.
0
5.5
5.5
3.8
3.8
4.0
7.2
6.3
mgC/1
pt.
1
2.5
3.0
3.0
4.0
3.5
5.0
5.9
pt.
2
2.3
2.7
3.6
4.5
3.6
4.2
4.2
pt.
0
-
13.13
11.50
16.75
14.12
3.0
4.5
pprn
pt.
1
0.
14.5
0.
5.75
15.67
12.0
4.88
pt.
2
5.87
13.0
5.66
3.0
10.38
6.5
6.38
Top 1"
77.5
58.6
57.87
997.6
502.5
787.5
180.0
-------
Table 3 (continued)
Summary of Data
Total Carbon
Inorganic Carbon
Esso Analyzer
Sample
28
28
28
29
29
29
30
30
30
31
31
31
32
32
32
33
33
33
Location
#1
#2
Avg
#1
#2
Avg
#1
#2
Avg
#1
£2
Avg
#1
#2
Avg
#1
#2
Avg
RPM
clean pool
clean pool
clean pool
warm-up
warm-up
warm-up
warm-up
warmr-up
warm-up
1000
1000
1000
2000
2000
2000
3000
3000
3000
Fuel
Used
ml
l_t
-
-
-
-
—
_
-
_
2020
2020
2020
4150
4150
4150
5290
5290
5290
pt.
0
12.
11.
9,
9.
10.
10.
10.
11.
10.
10.
13.
13.
mftC/1
pt.
1
13.
11.
10.
10.
10.
10.
13.
10.
21.
12.
13.
30.
pt.
*2
10.
10.
9.
9.
9.
9.
10.
10.
13.
20.
16.
14.
pt.
0
5.5
4.0
3.5
3.0
2.5
2.5
3.0
2.8
4.0
4.0
6.0
5.5
mfiC/l
pt.
1
5.5
3.5
3.0
3.0
3.0
3.5
3.0
3.5
5.0
3.5
7.0
7.5
pt.
2
3.5
3.5
4.5
3.5
3.0
3.5
3.0
3.0
4.5
5.0
7.0
5.5
Pt.
0
0.
0.
0.
«*.
:':
"
1.0
0.
0.5
0.
4.0
2.0
0.
0.
0.
0.
2.75
1.375
ppm
pt.
1
0.
0.
0.
*
*"
i'{
0.
0.
0.
0.
0.
0.
1.75
0.
.875
0.
1.0
0.5
pt.
2
0.
0.
0.
*
*
;'{
0.
0.5
0.25
2.0
1.0
1.5
0.
3.25
1.675
.25
1.25
0.75
Too 1"
96.0
96.75
96.38
49.75
91.2
70.47
81.87
233.24
157.55
111.12
212.37
161.74
106.12
151.5
128.81
112.5
150.75
131.62
'•Analyses not run. Bottles used had plastic liner in top which dissolved in methylene chloride.
-------
Depth
Sampling
Point
Point #3
Water Surface
Point #2
Point §1
Point #0
Pool Bottom
Figure 3
Depth of Sampling Points
25
-------
Results obtained with the Esso Analyzer for the first eight samples
were erratic and indicated that a second method of analysis should be em-
ployed as a check. For this reason, carbon analyses were run on all subse-
quent samples except surface samples. Carbon analyses were not run on
the surface samples because it was not felt that oil on the surface could
be adequately dispersed throughout a water sample for use with the carbon
analyzer.
The last seven samples taken (Samples 21 through 27) included sam-
ples from 1" above the pool bottom. It was felt that these samples would
give additional information regarding the distribution of oil in the water.
Use of the oil test papers was initiated with sample number 16.
At first, they were used as directed by the manufacturer (samples 16 through
20). The procedure used was simply to wipe the papers along the water sur-
face several times. In the absence of oil no color change in the paper was
observed. When oil was present, purple discolorations occurred. Following
sample number 20, it was discovered that the oil test papers could be used
to demonstrate qualitatively the distribution of oil in the top two inches
or so of water. This had to be done carefully. If the test paper was
simply lowered lengthwise into the water, it became spotted along its entire
length. However, if the test paper was lowered inside an inverted test
tube, excellent visible results were obtained. The test paper was held in-
side the inverted test tube and lowered to the desired depth. The air in the
test tube kept the water from contacting the paper. Once at the desired
depth, the test tube was slowly removed and the test paper was held in place
for approximately five minutes. At the end of this time, the test paper was
quickly pulled out of the water. This procedure was performed on three occa-
sions, at forty minutes after sample number 20 was taken, twenty-three hours
after, and four days later. A decreasing color intensity was noted with in-
creased time.
It was then felt that this technique could be used for other depths
within the pool. Four oil test papers were placed at four depths. These
were 0", 14", 28", and 43" from the surface. The motor was then run for one
half hour at each of three different engine speeds (1000; 2000; and 3000
rpm). At the end of this run the papers were quickly removed. Surface wipe
samples were also taken after each individual engine speed run. The papers
indicated oil only in the surface layers.
The oil test papers were most helpful in indicating the presence of
various oil concentrations. The papers, however, faded rapidly and conse-
quently could not be reproduced for this report.
Biodegradability studies of the exhaust products from the operation
of outboard engines and also of the initial fuel were made. Preliminary
results indicate that motor oil (50:1 two cycle), as well as exhaust prod-
ucts, are able to support microbial growth. The initial rates of growth
of cultures utilizing non-volatile exhaust products (volatile removed by
heating to 90 C) as sole nutrients were the same as the initial growth
rates on these exhaust products supplemented with 10 percent.nitrogen as
26
-------
^PO^, 10 percent nitrogen plus growth factors, or water from Lake
George. Table 1 shows the data from a typical study of this type.
To determine the effect of increased oxygen transfer rate on the
conversion of carbon to cell mass, tests with various shaker volumes and
speeds were made. The results shown in Tables 5 and 6 show that increased
transfer capability resulted with decreased shaker volume and increased
shaker speed.
Preliminary studies were also made with a Warburg respirometer
apparatus which supported the above results.
27
-------
Table 4
Growth of PS. fluorescens on Fuel pasted by Engine
Operating at 2000 rpm (1600 ppm)
Nutrient Conditions
Fuel
Fuel + 10% N
Fuel + 10% N
+ 1% yeast extract
1% yeast extract
Fuel + filtered Lake
George water
Time (hours)
2
4
6
10
25
2
4
6
10
25
2
4
6
10
25
2
14
6
10
25
2
4
6
10
25
Cells/1
^ 10
4.8 x 10"
7.0 x 10
8.3 x 10
'v 10
5.8 x 10'
9.1 x 10'
5.3 x 10
1.9 x 10
3.4 x 10
^ 10'
2.8 x 10
1.0 x 10
2.4 x 10
3.0 x 10
10
15
10
14
15
10
13
16
17
0.9 x
1.2 x
10
1.4 x 10
1.5 x 10
2.5 x 10
4.2 x 10
5
7
10
11
14
15
28
-------
Table 5
Effect of Shaker Speed and Volume on
Oxygen Transfer Capacity (.Sulfite Value)
Speed
low
high
Volume
100 ml
50 ml
100 ml
50 ml
Sulfite Value
(mmoles O^/l/min)
0.46
0.61
1.00
1.15
Table 6
Effect of Increased Aeration on Cell Growth
(Ps. fluorescens)
Conditions
0% N
low speed
10% N
low speed
0% N
high speed
10% N
high speed
Time (hours)
4
6
10
4
6
10
4
6
10
4
6
10
Cells/1
4.8 x 10"
7.1 x 10
8.3 x 10
1.5 x 10
1.4 x 10
3.8 x 10
10
14
10
10
14
1.1 x 10
1.6 x 10
1.6 x 10
2.9 x 10
2.6 x 10
1.0 x 10
10
11
15
10
11
15
29
-------
SECTION VIII - DISCUSSION
A number of screening tests were made with, a Ih horsepower
Eyinrude motor for the purpose of ascertaining desirable water depths
in the tanks, the amount of splashing to be expected, the nature of the
exhaust discharges, and other pertinent information. It became apparent
that a considerable amount of splashing was to be expected and subse-
quent tests were made with test propellers substituted for standard
models. This allowed operation at any desired speed without injury to
the motors. The 33 horsepower Evinrude was particularly satisfactory
in this regard. Problems were encountered with the 65 horsepower Mercury
which splashed excessively. The test propeller sent with this engine was
not satisfactory and did not perform well. Consequently, the data with
this motor was not considered to be meaningful.
The tests made to measure the quantity of fuel wastage indicate
that an increase in engine speed decreases the amount of exhaust products.
They also point up the importance of engine tuning. These results agree
closely with the results of others for similar engines.(23,26)
From the data shown in Table 3 it will be noted that total carbon
results show a consistent increase with engine operation. On the other
hand, organic carbon results, while fluctuating somewhat, remained essen-
tially unchanged during engine operation. This suggests that the increasing
values of total carbon were due to entrainment of carbon dioxide by turbu-
lent mixing of the water by the engine propeller. This hypothesis is
supported by the fact that the relative increase of total carbon was greater
at higher values of engine rpm. This seems to be independent of the order
in which a series of rpm runs is performed. It should be pointed out that
the level of total carbon six days after a 1000, 2000, 3000 rpm series run
had not dropped to the original value and, indeed, seemed to level off at
this point. This is due to the fact that saturation values for carbon
dioxide in water were well above concentrations produced during engine runs.
The fact that inorganic carbon concentrations in water seemed to increase
as a result of the operation of outboard motors could be significant in the
overall pollution contribution made by these engines. This is an area for
possible future concern but it is not directly related to this study.
Results with the Esso Analyzer on samples taken below the surface
were rather erratic and did not seem to follow any consistent trend that
could be compared to engine operation. It is believed that this behavior
is due in part to the nature of the analyzer. The instrument required a
considerable degree of technique for its successful operation and was sub-
ject to error unless precautions were constantly observed. Since reproduci-
bility was difficult to achieve in many instances, particularly for values
less than about 50 ppm, it is believed that heavy reliance should not be
placed on absolute values from the Esso' Analyzer. The trends, however, ap-
pear to be significant and support other evidence that indicates that past
products separated quite completely and accumulated on the water surface.
An attempt was made to correlate the accumulation of oil in the
surface layer (assumed to be 1") with calculated values based on the re-
sults of the previous fuel wastage studies. The method of calculation is
31
-------
included along with the calculated values (Table 7). A comparison of
calculated cumulative oil concentrations and actual oil concentrations
in the surface layer is presented in Table 8. While obvious dis-
crepancies occur, some interesting observations may be made. At the end
of run 2, which was run in descending order of engine rpm, the actual
concentration was well below the calculated concentrations. However,
four days later the actual concentration had risen to over one-half of
the calculated value. At the end of run 3, which was run in ascending
order of engine rpm, the actual concentration was very close to the cal-
culated concentration. This eventually dropped off after six days to one
similar to those obtained from the surface of a "clean pool". These com-
parisons bear out hypothesis that most of the waste oil discharged into
the water accumulates in the surface layer (at least the top one inch) and
reinforces other results obtained in the study.
The oil test papers were useful in determining, qualitatively,
relative amounts of oil present. At first they were employed for surface
wipes and they seemed to give sound basis for comparison from one point
in time to another. But, by far, their most important use in this study
was in determining the distribution of oil with depth. This distribution
could be found at any one point in time or the test papers- could be left
in the water at the desired depth for any length of time, thus giving the
cumulative effect of the oil movement (if any) during that time. As previ-
ously mentioned, these papers were placed at various depths within the pool
during a 1000, 2000, 3000 rpm series run to obtain the cumulative effect of
waste discharge. Although the papers below the surface show a slight pres-
ence of oil, the paper placed at the surface clearly indicates that most of
the oil accumulated there. A number of tests show this situation remains
relatively unchanged for at least four days afterward.
In the biodegradability studies measurements of raicrobial activity
were made by assessing the numbers of viable cells as a function of time.
Other common methods such as turbidity are precluded due to the emulsion
that results in the oil-water system and the adherence of the microbial
cells to the oil droplets. Insufficient cell mass was obtained in these
studies for reliable dry weight or protein estimation. Pure cultures of
Pseudomonas fluorescens and Pseudomonas pleovorans, as well as controlled
mixed cultures of Ps. fluorescens and Ps. oleovorans, and random mixed cul-
tures are employed. Ps. fluorescens is a common soil and water organism
which is known to oxidize a wide range of compounds. Ps. oleovorans has
been isolated from oils used in cutting compounds.(13)
The data shown in Table 4- show that the exhaust products alone
contained adequate accessory nutrients to support the degree of microbial
growth observed under these conditions. The degree of growth, however,
was not as much as expected if complete utilization of these products oc-
curred. Stepwise growth on spent fuel (including volatile) was observed.
Growth on fresh motor oil was less, suggesting the presence of gasoline
residues or partial degradation products in the spent fuel, yielding a
more biodegradable product.
-------
Table 7
Calculated Oil Concentrations in Top 1"
RPM
1000
1000
2000
2000
2500
3000
Fuel Wasted
ml
680
515
245
180
370
125
Calculated
ppin in Top 1"
793
600
286
210
432
14-6
Sample Calculation
RPM = 1000 Fuel Wasted = 680
Density of waste fuel = 0.7 gm/ral
mg/1 waste in top 1" =
680 x 0.7 x 1000
TT x (18/2) x (1/12) x 28.32
= 793 mg/1
-------
Table 8
Cumulative Oil Concentration in Top 1" of Water
Run RPM
1000
3000
2000
1000
4 days later
1000
2000
3000
2 days later
4 days later
6 days later
Calculated ppm
600
146
356
956
956
600
810
956
956
956
956
Actual ppm
181.50
168.75
182.62
163.12
580.00
58.60
57.87
997.60
502.50
787.50
180.00
-------
Growth under the conditions of all of these experiments is only
about 1 percent of that anticipated considering the chemical nature of
the fuel. Greater than 90 percent conversion of highly reduced carbon
compounds to cells can be expected under the proper oxidative conditions.
Therefore, the effect of increasing the oxygen transfer capability of the
growth system was investigated.
A sulfite value determination(2) showed that the oxygen transfer
capability of the shaker was increased both by reducing the volume of
liquid in the shake flask and by operating the shaker at a greater number
of reciprocations per minute as shown in Table 5.
Consequently, duplicate flasks were prepared and the cell yield
determined in flasks containing 100 ml of medium at low and at high speed.
The nutrient conditions for the experiment reported in Table 6 are 1600 mg
C/l of waste fuel from an engine operating at 2000 rpm and 0 percent or
10 percent N as (NH.,)QPO .
*t o H1
These results indicate that approximately a two-fold increase in
cell number is achieved by operating at high speed. The oxygen transfer
capacity at high speed is about twice that of low speed. According to
these results, oxygen seems to be the limiting factor under these condi-
tions of growth. Increasing levels of oxygen transfer capacity are being
studied currently to determine the degree of fuel utilization possible
by microbial activity when oxygen is not limiting. These current studies
include a kinetic investigation of the pattern of degradation of the vari-
ous components of fuel and exhaust products from outboard engines by both
pure and mixed cultures.
35
-------
SECTION IX - REFERENCES
1. The Boating Business 1969, The Boating Industry.
2. Cooper, C. M., Fernstroro, G. A. and Miller, S. A., Ind. Eng. Chem.
36, 504, 1944.
3. The Cost of Clean Hater, U. S. Dept. of the Interior, FWPCA, Jan.
10, 1968.
4. Dietrick, K. R., "Investigation Into the Pollution of Water by Two-
Stroke Outboard Motors", Gesundheitsingeniew, 1964, 85, 342-347.
5. Drinking Water Standards (New York State).
6. English, J. N., "What Does Outboard Motor Exhaust Contribute to
Water?", Robert A. Taft Sanitary Engineering Services, Cincinnati,
Ohio, Jan. 17, 1961.
7. English, J. N., "Pollutional Effects of Outboard Motor Exhaust-
Laboratory Studies", p. 923, JWPCF, July 1963.
8. English, J. N., "Pollutional Effects of Outboard Motor Exhaust-
Field Studies", p. 1121, JWPCF, Sept. 1963.
9. Galtsoff, P. S., "Effects of Crude Oil Pollution on Oysters in
Louisiana Waters", Bull. U. S. Bureau of Fisheries 48:143, 1936.
10. Goggi Corporation, "Pollution from Outboard Motors Can Be Stopped".
11. International Standards for Drinking Water, The World Health
Organization, Geneva, 1963.
12. Kempf, Ludemann, Pflaum, "Pollution of Waters by Motorized Operations",
Water Pollution Abstracts 1968:316, p. 85.
13. Lee, M. and Chandler, A. C., J. Bacteriol. 41, 373, 1941.
14, Ludzaek, F. L., "Persistence of Oily Waters in Polluted Water Under
Aerobic Conditions", Ind. and Eng. Chem. p. 263, Feb. 1956.
15. McCauley, R. N., "The Biological Effects of Oil Pollution in a
River", Dissertation Abstracts 1965, 25, 4373.
16. Milwaukee Journal, "Kiekhaefer Denies Lake Pollution", Sept. 6, 1969.
17. Muratori, Alex, Jr., "How Outboards Contribute to Water Pollution",
The Conservationist, June-July 1968.
18. New York Times, "It Keeps Oil Off Troubled Waters", Feb. 9, 1968.
19. Oil Pollution Act (PL 89-753).
20. Oil Pollution - A Report to the President, U. S. Dept. of the
Interior, U. S. Dept. of Transportation, Feb. 1968.
21. Orlando Sentinel, "Marine Engines Said Not Guilty of Pollution", Sept.
10, 1969.
22. Putnam, H. D., "Analysis of Findings by Environmental Engineering, Inc.",
23. Shelford, V. E., "An Experimental Study of the Effects of Gas Waste
Upon Fishes", Bull. 111. State Lab. Nat. Hist., 11, 1917.
24. Smith, E., "Oil Sumps, Death Traps for Wildlife", North Dakota Outdoors,
Vol. 30, No. 1, July 1967.'
25. Snell, Foster D., Inc., "Outboard Motor Tests Using Petro Save and
Kleen Zaust Devices", Sept. 20, 1965.
26. Stewart, R. , "Outboard Motor Fuel Discharge", Presented at the Univ.
of Wisconsin Engine Exhaust Inst., Oct. 20, 1967.
27. Stewart, R. , "Water Pollution by Outboard Motors", The Conservationist,
June-July 1968.
28. Stillwell and Gladding, Inc., "Pollution Factors of Two-Cycle Outboard
Marine Engines", Oct. 20, 1969.
29. The Sunday Bulletin, "Device Drains Unburned Fuel", Philadelphia,
July 2, 1967.
37
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30. The Sunday Star-Ledger, "Tests Show Outboards Don't Cause Pollution",
Sept. 14, 1969.
31. The Water Skier, "Pollution from Outboard Exhausts? Not So.", Oct.-
Nov. 1969.
32. Wiebe, A. H., "The Effects of Crude Oil on Fresh Water Fish", Trans.
of the Am. Fisheries Soc., Vol. 20, pp. 324-350.
38
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
4. Title
2.
CONTROL OF POILUTION FROM OUTBOARD EN§IHB
EXHAUSTS: A RECONNAISSANCE STUDY,
7. Author(s) Shuster, W0W.
9. Organization
Renaselaer Polytechnic Institute, Troy, Bio-Environ
mental Engineering Division
3. Accession No.
w
5. Report Date
6.
8. Performing Organization
Report No.
W. Project No.
12. Sponsoring Orgtaitttion
15. Supplementary Notes
11. Contract I Grant No.
EPA 15020 ENN
13. Type of Report and
Period Covered
16. Abstract
A reconnaissance study has been made to determine the extent of pollution which results
from the operation of a two-cycle outboard engine. Comparisons have been made of
engine operation with and without a pollution control device attached. Studies have
also been made of the biodegradability of the fuel and exhaust products.
Tests made in a swimming tank with an untuned engine have shown that the quantity of
fuel wasted as exhaust varied from about 7 percent of the volume of fuel used at
high speeds, to over 30 percent at low speeds. For a recently tuned engine, the
quantity of fuel discharged ranged from about 3 percent at high speeds to about
26 percent at low speeds. When the Goggi pollution control device was installed, these
quantities were intercepted and collected rather than discharged with the exhaust.
Analysis at various depths indicated that nearly all, products separated from the water
in a short time and collected on the surface. Very little dissolved or emulsified oil
was noted. Various analytical techniques were studied.
It appears that both fuel and exhaust products are capable of supporting microbial
growth. Growth rates, however, appear to be limited by available oxygen.
17a. Descriptors
^Recreation wastes, ^Boating, *Water pollution sources, Pollutant identification,
Water quality, Analytical techniques, Water pollution control
17b. Identifiers
*Watercraft pollution, ^Outboard engine exhaust, Two-cycle engines, Biodegradability
of exhaust products.
17c. COWRR Field & Group Q5B
18. Availability
19. Security Class.
(Report)
20. Security Class.
(Page)
21. No. of
Pages
22. Price
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTM ENT OF THE INTERIOR
WASHINGTON. D. C. 20240
Abstractor W.W0 Shuster
I institution Rensselaer Polytechnic Institute
WRSIC 102 (REV JUNE 197l)
GP O 91 3.261
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