Summary of Report:
Spill Response in the Arctic Offshore
Prepared for the American Petroleum Institute and the
Joint Industry Programme on Oil Spill Recovery in Ice
Oil Spill Response in the Arctic
Introduction
Spill Response in the Arctic Offshore
during the spring thaw and then
behaves similarly to oil spilled in
the open ocean. Key weathering
processes in the Arctic include
evaporation dispersion dissolution,
and biodegradation.
Detection and Tracking:
Detection and tracking of oil is
essential for determining the
location, transport, and behavior
of a spill. Detecting and confirming
where a spill is located, either
through remote sensing or direct
observation, play a critical role in
guiding response efforts.
Containment and Recovery:
As attention turns to the Arctic as an important source of
oil and natural gas, the industry is taking proactive steps to
develop modern tools and technology to ensure effective
solutions are available to handle a potential spill. The region
presents unique challenges and it is important to continue to
establish best practices for exploration and production.
Responding to an oil spill is challenging under any
circumstance, but arctic conditions require additional
environmental considerations. This series of fact sheets
discusses the challenges posed by handling a spill in arctic
conditions and the technologies being developed to respond
to such an event. In some cases, techniques have been
modified from standard response techniques for marine
conditions based on years of research. Others have been
recently developed.
CHALLENGES OF ARCTIC
SPILL RESPONSE
Perhaps the most significant
challenge posed by an arctic spill
is dealing with spilled oil in the
presence of ice. Ice can make it more
difficult to find a spill, reach it and
deploy equipment and personnel
to respond. Despite this, there
are some conditions where Arctic
conditions may assist spill response.
For example, ice can act as a
natural barrier and prevent oil from
spreading. Cooler temperatures and
waves dampened by the ice
2
can also slow the breakdown or
“weathering” process of oil. This can
increase the window of opportumity
for recovery, dispersants and in-situ
burning.
Fate and Behaviour of Oil in Ice:
Generally spills under sea ice move
with the ice. In winter, currents
under the ice in most arctic areas
are insufficient to move spilled oil
any significant distance from where
it contacts the ice undersurface.
Spilled oil can be encapsulated in ice
through the winter. Typically, the oil
is re-exposed in a fresh state
Effective mechanical recovery of
spills in open drift ice is possible,
using conventional boom and
skimmer systems modified for
cold weather operations. In more
closely packed ice, over-the-side
and recently developed selfpropelled skimmers can access
isolated trapped pools of oil.
ARCTIC SPILL RESPONSE
AT A GLANCE
• Detection and tracking of
oil is essential for determining
the location, transport, and
behavior of a spill.
• Arctic spill response capability
should be flexible and benefit
from the use of as many tools
and technologies as possible.
Dispersants:
Dispersants are an effective tool in
responding to Arctic spills in ice.
Research confirms that dispersants
can minimize the impact of a spill
by rapidly lowering hydrocarbon
concentrations in the marine
environment, minimizing the
persistence of surface slicks,
reducing or eliminating shoreline
oiling, and protecting wildlife.
In-Situ Burning:
In-situ Burning (ISB) is a safe,
efficient, and proven response
technique in the Arctic. This
method can rapidly eliminate more
than 90 percent of spilled oil that is
encountered. Compared to other
response options, fewer equipment
and personnel requirements make
ISB a more practical response
method in Arctic environments.
Protecting and Cleaning the Shore:
Established methods for shoreline
protection and cleaning are
generally applicable in the Arctic
with modifications to cope with
unique conditions such as ice rich
tundra cliffs. Challenges include
supporting personnel in remote
locations, establishing approved
disposal sites for oily debris and
the short summer season.
CONTINUING RESEARCH
ABOUT
• In January 2012, members
of the international oil and
gas industry launched a
collaborative effort to enhance
arctic oil spill capabilities. This
collaboration, called the Arctic
Oil Spill Response Technology
Joint Industry Programme (JIP),
will expand industry knowledge
of, and proficiencies in Arctic
oil spill response.
• This series of fact sheets is
derived from the OGP/IPIECA
report “Spill Response in the
Arctic Offshore” published in
February 2012.
To read the full report, visit:
http://www.api.org/~/media/
Files/EHS/Clean_Water/
Oil_Spill_Prevention/SpillResponse-in-the-ArcticOffshore.ashx
The oil and gas industry
recognizes the ongoing need to
build on existing research and
improve the technologies and
methodologies for Arctic spill
response. There are currently seven
key areas of research managed
by the International Oil and Gas
Producers Association, Joint
Industry Programme: Dispersants,
Environmental Effects, Trajectory
Modeling, Remote Sensing,
Mechanical Recovery, In- Situ
Burning and Field Research.
• The oil and gas industry
recognizes the need for
ongoing improvements and is
committed to advancing arctic
spill response technologies.
Images
Vessel supporting research in the
Arctic. Photo: JIP Oil in Ice, 2009.
(Opposite page)
Scientists measure acoustic
properties of ice in an effort to
detect trapped oil at Svalbard,
Norway. Photo: D. Dickins, 2006.
3
Oil Spill Response in the Arctic
Fate and Behaviour of Oil in Arctic Conditions
SEASONAL CHANGES
When responding to a spill in the Arctic, it is critical
to understand how the oil will behave in these unique
conditions. Spill response in this region requires extensive
environmental knowledge and poses challenges and
opportunities that must be taken into consideration.
MOVEMENT OF OIL
The spreading of oil on ice is
similar to the spreading of oil
on land. The rate of spread is
controlled mainly by oil viscosity,
so cold temperatures tend to slow
spreading. Oil spilled on rough
ice surfaces may be contained in
a thick pool bounded by natural
ridges and blocks on the ice
surface. As a result, slicks on
ice tend to be much thicker and
smaller than equivalent slicks
on water. Additionally, snow will
4
absorb spilled oil, further reducing
its spread of oil. Even large spills
of crude oil beneath solid or
continuous ice cover will usually
be confined within relatively short
distances from the spill source.
Generally, spills on sea ice
will move with the ice. If the ice
drifts, oil drifts with it. In winter,
currents under the ice in most
arctic areas are insufficient to move
spilled oil any significant distance
from where it contacts the ice
undersurface.
BEHAVIOUR OF OIL IN
ARCTIC CONDITIONS AT
A GLANCE
• Ice, snow and cold
temperatures can greatly
reduce spread of spilled oil.
• Oil biodegrades in all marine
environments, including icefilled waters.
• Oil trapped within ice in the
winter typically emerges at the
surface during spring thaw.
• Encapsulated oil released
due to spring thaws acts
similarly to oil spilled in open
water.
Seasonal changes and ice
formation can significantly impact
the behaviour of oil in arctic
waters. First-year, growing sea
ice will completely encapsulate
oil released beneath it. This
process takes a few hours to a few
days, depending on time of year.
However, after oil is encapsulated,
it remains trapped until the spring
thaw, when oil migrates through
“melt channels” to the ice surface.
Once oil reaches the ice surface, it
floats on melt pools or remains in
patches on the melting ice surface.
Oil spilled under older ice
will remain in place as it would
under first-year ice. Oil spilled
under multi-year ice may appear
on melt pools at the surface, but
likely much later in the melt season
than for first-year ice.
When ice sheets thaw and
break up, oil remaining in melt
pools on the surface will flow into
water in a thin sheen trailing from
the drifting ice. Once exposed
to significant wave action, fluid
oil mixed with water and may
naturally disperse. Viscous oils
that have gelled in the cold may
be discharged as thicker, non-
spreading mats or droplets. Gelled
oil forms are more resistant to
mixing and dispersion and require
a different response tactic.
TEMPERATURE’S ROLE
Temperatures can significantly
impact the natural weathering
processes of oil.
Evaporation typically plays
a significant role in the natural
weathering of spilled oil and oil
products. Following discharge, most
crude oils and light products such
as diesel and gasoline experience
significant evaporation relative to
heavier, more viscous oils, including
bunker fuel and emulsified oils. In
spite of slower rates, given sufficient
time, evaporation is still an important
process in significantly reducing the
spill volume for oil on the water or
ice surface under arctic conditions.
Dissolution is a relatively
minor weathering process (few per
cent by volume) where the light
ends of fresh oil can dissolve into sea
water.
Oil is naturally dispersed into
the water column where wind and
waves are strong enough to break
an oil slick into micron-sized droplets
that disperse and dilute in the
water column. The extent to which
dispersion occurs depends on the
oil type and the amount of ‘mixing
energy’ provided by the wind and
waves. This process is less prevalent
in the Arctic due to the presence of
ice which can reduce or block waves.
Dispersed oil readily
degrades in marine environments.
Studies have shown that naturally
occurring oil-degrading microbes
begin to grow on dispersed oil
droplets in a few days. Microbial
communities in the Arctic
waters have adapted to the low
temperatures of their environment
and rapidly adapt to and consume
dispersed oil.
Images
Researching the behaviour
of oil in ice. Photo: JIP Oil in Ice,
2009.
(Opposite page)
Figure 1
Scenarios demonstrating the
behaviour of oil spilled in arctic fast
ice. Figure: A.A. Allen ABSORB Oil
Spill Contingency Plan, 1980.
5
Oil Spill Response in the Arctic
Detection, Monitoring and Tracking
of Spilled Oil in Artic Conditions
Airborne Remote Sensing:
Multispectral airborne remote
sensing supplemented by visual
observations by trained observers
remains the most effective method
for identifying and mapping the
presence of oil on water. Modern
pollution surveillance aircraft
operated by nations such as
Canada and Sweden employ a mix
of sensors such as Side Looking
Airborne Radar, and Forward
Looking Infrared together with
conventional digital cameras. Visible
sensors are constrained by darkness,
fog and cloud cover.
Satellite Radar Systems:
The advent of Synthetic Aperture
Radar (SAR) satellites in the 1990’s
represented a quantum leap in our
ability to monitor arctic sea ice under
all weather conditions and through
periods of winter darkness. SAR has
proven effective in mapping large oil
slicks on the open ocean and could
be effective in open ice conditions.
Ground-Penetrating Radar (GPR):
In the case of a spill, the detection, monitoring,
and tracking of oil in arctic conditions is critical in
determining what resources are required to quickly
mitigate impact. Spill response must include flexibility
and access to all available tools and strategies to stop
the discharge, contain the spill and remove or recover
the oil from the environment.
Detection, monitoring and tracking are activities
that depend on an integrated feedback loop using realtime data provided from many different sources, for
example satellite imagery, airborne sensors, underwater
vehicles and forecast modelers.
DETECTING OIL
Years of research on detection,
monitoring and tracking
technologies clearly indicate
that no single sensor system,
on its own, meets the needs of
predicting the movement of oil in
the Arctic environment. A flexible
6
response strategy combining
airborne, satellite, surface and
sub-surface-based technologies
provides the best data for
accurately directing the activities of
an oil spill response. The following
technologies are in use today:
DETECTION,
MONITORING AND
TRACKING AT A
GLANCE
• Detection and tracking of
oil is essential for determining
the location, transport, and
behavior of a spill.
• Arctic spill response capability
should be flexible and benefit
from the use of as many tools
and technologies as possible.
• The oil and gas industry
recognizes the need for
ongoing improvements in
this field and is committed to
advancing arctic spill response
technologies
EMERGING TECHNOLOGIES
New technologies being
developed through laboratory
and tank testing could improve
our ability to detect and map
oil trapped under ice in the
near future. Examples include
Frequency Modulated Continuous
Wave (FMCW) airborne radar,
Nuclear Magnetic Resonance
(NMR) and upward looking
sonar mounted on autonomous
underwater vehicles. Unmanned
Air Systems (Drones) could provide
long-endurance aerial surveillance
over a spill site.
TRACKING AND
MODELLING SPILLED
OIL IN ICE
Predicting the future position of
spilled oil provides information
that can be used to direct both
airborne and marine resources,
a crucial tactic in containing
potential spills. Sources of tracking
information include:
• High-resolution satellite imagery;
• The national ice services of a
coalition of countries including
Canada, Russia, United States,
Denmark and Norway;
• Oceanographic and
meteorological services;
• Surveillance aircraft;
• Commercially available satellite
tracking beacons; and
• Environmental monitoring and
tracking buoy data.
Images
Test and Evaluation of Ground
Penetrating Radar at Svalbard
Norway. Photo: D. Dickins, 2006.
(Opposite page)
Environmental data monitoring
and tracking buoy. Photo: JIP Oil
in Ice, 2009.
GPR has been successfully used
to detect oil under ice and within
ice. Readily available, commercial
GPR systems can also be deployed
and used to detect crude oil spills
under snow cover. GPR is currently
being developed for aerial
deployment, but this is not yet an
operational tool.
Integrated Systems:
Integrated shipboard systems
can utilize a combination of high
speed marine radar, long range
thermal imaging cameras (FLIR),
low light video and GPS tracking
buoys. Integrated airborne systems
“fuse” data from a mix of sensors
into a series of products that
display different aspects of the
spill to responders, for example
differentiating between thick and
thin areas.
Trained Dogs:
Dogs can be used to detect oil spills
covered with snow and ice. Tests in
Norway with trained dogs carrying
GPS transmitters have found they
can determine the bearing of an oil
spill at a distance of 5km.
7
Oil Spill Response in the Arctic
Containment and Recovery of Oil
Oleophilic Systems:
In oleophilic skimming systems,
oil adheres to a drum, belt, brush,
disc or “mop” that is rotated
at the water’s surface. The oil is
then scraped off into a storage
chamber or reservoir. These
devices are efficient and it is
common for them to result in a
high recovered oil-to-water ratio.
Light to medium-viscosity oils
are most suited to these systems
though very high viscosity oils can
be handled using certain fittings.
Weir Skimmers:
A weir skimmer collects liquid at
the surface of the water. Round
floats hold a collection bucket at
a level that allows oil to slip over
the edge and into a collector.
These units are less efficient than
oleophilic skimmers and collect
a significant amount of water
with the oil, requiring additional
storage capacity. A benefit of weir
skimmers, however, is their ability
to handle both light and heavier
oil products.
Mechanical containment and recovery is considered the
primary or preferred response strategy in many regions
of the world. Containment booms are normally used
in combination with a skimmer to remove oil from the
water’s surface where it is temporarily stored before
being processed and disposed of. Environmental and
oceanographic conditions and spilled oil’s physical
properties are used to determine the type of mechanical
equipment best suited for oil recovery. Oil spreads less
and remains concentrated in greater thicknesses in broken
ice compared to open water. Most mechanical recovery
systems are technologies developed for open water;
however, several types of skimmers have been developed
specifically for recovering oil in ice. Depending on the time
of year, responders can be facing a spill in open water and
with varying amounts of ice cover.
Mechanical Recovery
of Oil In Open Water
Oil spilled on open water will
quickly spread to form a thin
slick. As a result, some form of
containment is generally required
for effective recovery and removal.
This is typically done with an oil
containment boom towed at low
speed by vessels, a technique that
8
becomes less effective as time
passes and the slick continues to
spread. Once oil is contained and
concentrated to a thicker slick,
various oil recovery devices can be
used to remove it from the water
surface.
There are currently four
main types of skimmers used for
this purpose:
Containment and
Recovery At a Glance
Several types of skimmers have
been developed specifically for
recovering oil in ice-covered
regions. These skimmers are
often brush belts or drums
rotating through the slick and
capable of recovering oil while
processing small ice pieces.
Some skimming units are
equipped with heating systems,
ice deflection frames, and
advanced systems for pumping
viscous oil/water/ice mixtures.
• Containment booms, ice, and
snow provide barriers against
the spread of oil and result in a
thicker layer of oil available for
recovery.
•Environmental and
oceanographic conditions and
the oil’s physical properties
should be taken into account
when determining what type of
mechanical recovery instrument
is best suited for oil recovery in
the Arctic.
Vacuum Skimmers:
These skimmers use vacuum to lift
oil from the surface of the water
or the shore. Vacuum systems
are versatile and can be used on
a variety of oil types, with the
exception of heavy oil and volatile
products. A disadvantage is that
they can be inefficient, recovering
more water than oil.
collecting large volumes of water
relative to oil and can rapidly fill
storage containers, barges, and
tanks.
The nature of the
recovered product plays an
important role in determining
transfer and storage requirements.
Heavy oils can be difficult to
handle, particularly in cold
temperatures. Specialized pumps
may be required and storage
tanks may require heating coils to
allow the recovered product to be
removed. The separation of water
from recovered oil, also known
as decanting, into a temporary
storage system for retreatment
is important to extending the
operating capability of individual
skimming systems.
floes and operate in higher ice
concentrations than vessels towing
independent booms. As ice
concentrations increase beyond 60
percent, ice can provide a natural
barrier against the spread of oil.
This natural containment can
provide an advantage for recovery
operations in responding to small
spills, using skimmers deployed
directly from the side of a vessel.
Several types of skimmers have
been developed specifically to
recover oil in ice-filled water.
Mechanical recovery
of oil in ice
In open water booms are usually
required to contain and thicken
spills for mechanical recovery. A
conventional booming strategy
is most effective in open water
with ice concentrations below 30
percent. Any mechanical recovery
system working in ice-covered
waters needs to deflect the ice
in order to gain access to the oil
and effectively remove it. Single
vessels with built-in skimming or
over-the-side-skimming systems
using short sections of boom
can maneuver between large ice
Images
Desmi Polar Bear Ice Skimmer.
Photo: SINTEF, 2008.
(Opposite page)
M/V Nanuq, a 301-foot arctic
A-1 Class Oil Recovery Platform
Service Vessel. Photo: U.S.
Coast Guard, 2007.
Mechanical Skimmers:
These systems physically lift oil
from the surface and include
various mechanisms from conveyor
belts to grab buckets to contain it.
These types of skimmers are more
suited to very viscous oils.
Storing and
separating
An important factor for an
effective containment and
recovery operation is the
availability of storage on a
skimming vessel. The storage
volume relative to the recovery
capability of the skimming system
being used is critical. For example,
weir skimmers are prone to
9
Oil Spill Response in the Arctic
Chemical and Mineral Dispersion of Spilled Oil
low toxicity to marine life and they
are rapidly diluted;
• Dispersants do not increase the
toxicity of oil;
• Arctic organisms are no more
sensitive to dispersed oil than
temperate organisms;
• Dispersed oil can cause
temporary impacts to sensitive
marine species but these are
limited to the immediate spill
vicinity and for a short period of
time; and,
• Rapid dilution and
biodegradation limit impact to the
ecosystem from both dispersants
and dispersed oil.
Dispersion of oil using either chemical or mineral
additives can be an effective way to enhance the natural
biodegradation process for removing oil from the
environment in the case of a spill. Research has shown that
dispersants are an effective solution in arctic environments.
Oil is naturally dispersed in water when waves and
wind are strong enough to break an oil slick into tiny
droplets that mix into the water below. The extent to
which this dispersion occurs depends on the type of oil
and the amount of “mixing energy” provided by wind and
waves. Chemical and mineral products, called dispersants,
can enhance this natural process to help reduce the
effects of spills. The decision to use dispersants for oil
spill response is determined through a Net Environmental
Benefit Analysis (NEBA). A NEBA helps decision-makers
determine which response strategy — for example
mechanical recovery, dispersants, or in-situ burning [ISB]
— will minimize environmental harm. The NEBA process is
important in an arctic environment, and it is a critical aspect
of any contingency plan.
The basics of
Dispersants
Dispersants are a mixture of
chemicals, similar to common
dish soap, that quickly dilute and
biodegrade in water. Dispersants
are most effective when applied
10
to fresh oil but can work well on
weathered oil depending on the oil
type and ambient conditions. They
are typically applied using boat,
plane or helicopter spray systems
or by subsea injection. Dispersants
are used to remove oil from the
environment by enhancing natural
biodegradation. This is achieved by
Dispersants At a
Glance
• Oil biodegrades in
temperatures found in arctic
waters.
• Arctic organisms are no more
sensitive to dispersants or
dispersed oil than temperate
organisms.
• In open drift ice conditions,
waves may be strong enough
to initiate the dispersion of
treated oil. In more dense
ice conditions, the energy
provided by a storm or from
the propeller wash of a ship will
be adequate.
• Dispersants can minimize the
impacts of an oil spill by:
Enhancing removal of oil
from the environment
through biodegradation;
Minimizing the impact of
surface slicks on marine
mammals and birds; and,
Preventing oil from
reaching sensitive
shorelines.
converting an oil slick to micronsized droplets that disperse and
dilute in the water.
Although dispersants may
increase the amount of oil in an
area of water in the short term, the
rapid dilution of dispersed oil in
the water column quickly reduces
potential impacts on sealife in the
immediate spill area while removal
of oil from the surface minimizes
the potential harm to marine
mammals and birds and prevents
oil from reaching the shore.
Dispersants have an advantage
over other response options not
only because they can treat large
areas very rapidly, but also because
they can be applied over a greater
range of wind and wave conditions
than other response options.
Another advantage of dispersants
is they can be remotely applied
using aircraft. This increases
responder safety by minimizing
the need to put personnel on the
water surface and also increases
the speed of the response
compared to boat-based options.
Dispersants in Cold Water and Ice:
Dispersants have been proven
to be effective when applied
at freezing and near-freezing
temperatures where spilled oil
has not gelled. Water partially
covered with ice can increase the
time a dispersant is effective by up
to one week, as ice can prevent
oil from becoming weathered
and emulsified. Research has
also shown that ice can enhance
dispersion, since ice motion can
increase the surface turbulence,
or mixing energy, needed for
the process. Further, in marine
situations where there are
inadequate waves, the propeller
wash from a ship can be used to
enhance the necessary mixing
energy.
Dispersants in Brackish Water:
Marine dispersants are most
effective in salt water. However,
fresh and brackish water
dispersants have also been
developed. The most effective
dispersant will have to be
determined during oil spill
contingency planning, considering
the conditions for specific spill
scenarios.
Ongoing research
A recent study has shown that
natural mineral fines combine with
oil slicks or oil on shorelines to
disperse oil in water by forming
Oil-Mineral Aggregates (OMA).
OMAs increase the rate of
natural biodegradation, similar to
chemically dispersed oil droplets.
Studies indicate that the use of
minerals combined with the wash
of a ship’s propeller speeds up
the rate of biodegradation even
further.
Dispersed Oil in Arctic Habitats:
Dispersed oil readily biodegrades
in marine environments, all
of which contain petroleum
degrading bacteria. Laboratory
studies have shown that naturally
occurring oil-degrading microbes
begin to grow on dispersed oil
droplets within a few days. The
microbial communities in arctic
waters have adapted to the low
temperatures of their environment
and rapidly adapt to and consume
dispersed oil, removing the
spilled oil from the environment.
Modern dispersants are made
of low toxicity, biodegradable
components and ingredients found
in many household products.
Research indicates that:
• Dispersants themselves are of
Images
Crew of Basler BT-67 fixed wing aircraft releases dispersant over an oil
slick from the Deepwater Horizon,
off the shore of Louisiana on May
5, 2010. Photo: U.S. Coast Guard
by Petty Officer 3rd Class Stephen
Lehmann, 2010.
(Opposite page)
Chemical Dispersion Process.
Photo: ExxonMobil.
11
Oil Spill Response in the Arctic
Controlled Burning of Spilled Oil
Controlled, in-situ burning is a response option that has
proven safe and effective for removing oil in the case of
an oil spill. As attention turns to oil and gas exploration
in the Arctic, research continues to advance the use of
this technique in the region.
In-situ burning (ISB) is a process that transforms
oil into its primary combustion products of water and
carbon dioxide. The method has been used as an
effective tool in the removal of oil since 1958. ISB is
less labour intensive than other recovery techniques
and requires minimal equipment. It has the advantage
of being more versatile in its application, as it can be
applied in regions where there is a lack of infrastructure
or where habitats are particularly sensitive.
Since ISB removes oil from land or water surfaces,
the need for physical collection, storage, and transport
of recovered oil is also greatly reduced.
The Arctic environment helps with the efficiency of
ISB as the presence of ice reduces the spread of spilled
oil and reduces the size of waves. These conditions yield
thicker oil slicks, which increases the effectiveness of
ISB as a solution, while the cooler temperatures slow
evaporation and extend the window of opportunity to
conduct ISB activity.
THE BASICS OF IN-SITU
BURNING
In order for ISB to be effective,
three elements must be present:
fuel, oxygen, and a source of
ignition. The following conditions
need to be considered for ISB to
be a practical option:
Slick Thickness:
Depending on the fuel type and
its evaporation rate, the minimum
oil thickness for ISB ranges from
one millimeter to 10mm.
Wind Speed:
ISB is most effective in low
to moderate wind conditions
so air above a slick retains an
ignitable concentration of vapour.
The maximum wind speed for
successful ignition is about 10 – 12
12
metres per second (20 - 25 knots).
In greater wind speeds, vapour
concentrations decline and cannot
sustain a burn.
Wave Height:
When used on a water surface,
ISB is most effective in low to
moderate wave conditions.
The maximum wave height for
effective ISB is about 1.2 metres
(4 feet). Fire resistant booms can
withstand some wave activity,
but at higher wave heights its
effectiveness declines. Sea ice can
be effective in containing oil by
acting as a natural barrier while
also reducing wave activity.
Emulsions:
Water may mix with spilled oil
and form a foamy, pudding-like
emulsion, often called “mousse.”
For most oils, 25 percent water
IN-SITU BURNING AT A
GLANCE
• ISB is a safe, efficient, and
proven response technique
that can rapidly eliminate
more than 90 percent of
encountered oil.
• The presence of colder
temperatures and calmer
conditions may increase the
window of opportunity for the
effective use of ISB.
• Different oil-in-ice
concentrations will influence
the efficiency of ISB.
• ISB emissions are short
lived and not likely to cause
significant environmental
effects or human health
issues. Safety regulations
and air quality monitoring
requirements are in place for
ISB to ensure the ongoing
safety of its use.
• Compared to other response
methods, fewer equipment and
personnel requirements make
ISB a more practical response
method in arctic environments.
Image: In-Situ Burning of Oil Process. Photo: SL Ross.
is viewed as an upper limit for
emulsions that can be burned.
However, there are some crude
oils that can be easily ignited with
a higher percentage of water.
and requires fewer resources
than traditional booming and
skimming.
Igniters:
ISB has proven effective in drifting
offshore pack ice conditions, but
effectiveness varies based on ice
conditions.
In open water, fireresistant booms can be towed
by vessels to thicken slicks for
burning.
In a case where oil is
spread across an area where there
is 40 to 60 percent ice cover, sea
ice will reduce slick spreading,
but cannot completely constrain
it. The deployment of booms and
towing vessels is risky and there is
an increased likelihood of boom
failure due to interference by ice.
Greater ice concentrations
can serve as a natural boom
to effectively contain a slick.
The primary concern in these
conditions is how to reach the
slick to ignite it.
A variety of igniters are available
to deploy from surface (land and
vessel) and aerial platforms to
ignite an oil slick. They include
simple devices such as flares,
propane torches, and plastic bags
of gelled fuel. Other devices have
been designed or modified for
ISB, such as the helitorch and
ejectable igniters.
Fire-Resistant Containment
Booms:
Several types of fire-resistant
booms have been developed.
Some are constructed of steel
and some are water-cooled, while
others are constructed of heat
resistant fabric.
IN-SITU BURNING UNDER
VARIOUS CONDITIONS
On Open Water:
The practice of intentional
burning of oils slicks on open
water has been in place since the
early 1980s, when fire-resistant
booms were first developed. The
use of fire-resistant booms to
conduct ISB is often more efficient
than other response methods
In Broken Ice:
On Solid Ice:
ISB is the method of choice when
removing oil pools on ice, whether
on land or at sea. Based on
field studies, ISB can remove on
average between 60 to 70 percent
of spilled oil on a solid surface.
In Snow:
Oil that is mixed with snow can be
successfully burned when pushed
into cone-shaped piles. When a
limited amount of oil is found in
snow, a fire starter, such as diesel
fuel or gelled gasoline, may be
necessary to start a burn. Snow
mixed with as little as three to
four percent oil can be burned,
removing up to 90 percent of the
oil even two weeks after a spill.
EMISSIONS FROM IN-SITU
BURNING
Burning oil produces a smoke
plume of particulates and gases.
Combustion of crude oil is
estimated to produce 75 percent
carbon dioxide and 12 percent
water. The remaining smoke
constituents are from oil, which
is converted to carbon monoxide
and soot. Real-time monitoring
of the burn plume is important to
ensuring smoke concentrations do
not exceed air quality standards
so as to avoid any impact to
human (or animal) health.
Residue from incomplete
combustion will remain. When
on land such residues can be
collected. Should they sink in a
water column before recovery,
they may affect bottom dwelling
plants and animals by localized
smothering. Sunken residue
concentrations are likely to be
sparse and/or small in extent.
Knowing the oil properties, it
is possible to predict whether
residue sinking is a concern.
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Oil Spill Response in the Arctic
Shoreline Protection and Recovery
In the event of an oil spill, it is vital to protect the Arctic
shoreline from contamination whenever possible.
The industry continues to develop best practices and
technologies that enhance the ability to protect sensitive
shorelines.
To a large extent, the shorelines of the Arctic
are similar to those of ice- and snow-free environments.
Some specific shore types are unique to the Arctic
though, including:
• Tundra and tundra cliffs;
Shoreline
Protection at a
glance
• Since ice is impermeable,
oil remains on the surface of
shoreline ice unless new ice is
forming.
• Ice in water can prevent oil
from reaching the shore.
• Boulder barricades and sediment ridges created by
rafting or ice pressure; and,
• Pre-planning protection
priorities requires
communication and
collaboration at regional and
local levels.
• Ridges and scarred shores on coasts with fine-grained
sediments (sands, silts and clays) located in sheltered bays.
• Cleaning an oiled arctic shore
must account for sensitive
environments.
Shoreline protection
protocols
Many arctic regions have welldefined human and animal habitats
that can be easily identified and
mapped. Setting response priorities
involves communication with
regional and local communities to
identify important sites as well as
areas of economic and recreational
value.
The primary response
strategy in all oil spills is to contain,
recover or eliminate oil on water as
close to the source as possible. If oil
cannot be prevented from reaching
the shore, the key priority is to
minimize impacts to the shoreline
environment. In Arctic or other
cold climate habitats, the timing of
response operations will vary based
on the season and the presence of
ice and snow.
Effects of Ice on Oil:
When ice is present in the shore
zone prior to offshore winter freeze,
it can protect the shoreline from
approaching oil by forming a natural,
impermeable barrier. The presence
of shore ice can also modify the
behaviour of oil spilled close to the
shoreline in the following ways:
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• Oil spilled into ice cracks may
be carried or trapped under the
floating ice through tidal action;
• Oil stranded after break-up may
become mixed among remaining
grounded floes, coating the floes
and shoreline;
• Oil moving onshore after freezeup
along the coast can become
incorporated within the expanding
ice zone or covered by newly
formed ice at the advancing ice
edge; and,
• The penetration of oil deposited
on a beach that is free of ice in
the summer may be limited by the
presence of subsurface ice (ice
lenses) throughout the year.
Effects of Snow on Oil:
Typically, fresh snow acts as a
sponge for spilled oil, reducing
surface spreading. While oil
covered by snow will continue
to undergo evaporation, it does
so at a much lower rate than oil
directly exposed to the air. With
the arrival of summer, the remaining
oil will eventually evaporate at
approximately the same rate as it
would if spilled on water in summer.
• Washing or manual removal
techniques are labour
intensive.
• Mechanical removal is faster
but generates more waste,
whereas in-situ treatment
minimizes waste.
Image: US Coast Guard Pollution Investigator at Cosco Busan oil spill. Photo: U.S. Coast Guard, 2007.
Detection of Oil in Ice and Snow
on the Shore:
Shoreline Cleanup Assessment
Technique (SCAT) is commonly used
as a method to detect and outline
the location of oil on shore. SCAT
has been adapted for use in cold
climates and on shorelines covered
in ice or snow. This technique
is based on a systematic survey
of surface and subsurface oil to
create an information base for the
response team to use in decisionmaking.
Shoreline cleanup
Any cleanup decision process must
balance environmental concerns,
needs of local communities,
operational practicality, and
safety. The Net Environmental
Benefit Analysis (NEBA) process
is particularly important in arctic
environments where recovery would
be expected to be slower and where
tundra or wetland shorelines are
susceptible to disturbance by human
or vehicle traffic.
To a large extent, the same
strategies and tactics typically used
in warmer environments apply to
Arctic and cold-climate shorelines.
However, the selection of cleanup
options depends on the character
of the shore zone and the presence
of ice and snow. The tactics that can
be used to treat or clean shorelines
can be grouped into three basic
response strategies.
Natural Recovery:
Allowing shorelines to recover
naturally is often the least damaging
alternative for light and moderate
spills, particularly where access is
limited or difficult. This strategy may
be appropriate when:
• Treating or cleaning spilled oil
may cause unacceptable levels of
environmental damage;
• Response techniques would not be
able to accelerate natural recovery; or,
• Response personnel would be put
in danger.
Physical Removal:
One tactic for removing oil from
shore is flooding and washing
stranded oil into adjacent water
where it can be contained and
collected. Manual removal may also
include collecting oil using shovels
and rakes, cutting oiled vegetation
and using passive sorbents; these
strategies are slow and labor
intensive and recover moderate
amounts of oil. Mechanical removal
techniques use equipment designed
for earth-moving or construction
projects. Although the cleanup rates
are less labor intensive and often
quicker than manual removal, there
is a possibility of significant waste
generation that must be addressed
by the response team.
In-Situ Treatment:
These options involve treatments
that are conducted on-site and
minimize the amount of spilled oil.
In-situ treatment is particularly suited
for remote areas where logistics
are a major factor in operational
practicality and safety.
Tactics include:
• Mechanical mixing of oiled
sediments through agitation either
in the absence of water (“dry”
mixing) or in water (“wet” mixing)
to create a sediment-oil mixture that
increases weathering and reduces
the potential for wildlife impacts;
• Sediment transfer involving
relocating oiled sediments to
another location with higher wave
energy levels; and,
• Chemical or biological tactics that
involve the addition of agents to
facilitate removal of oil or accelerate
natural, in-situ oil degradation.
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