Aboriginal Affairs and Northern Development Canada
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Frequently Asked Questions
We have included some of the most commonly asked questions at public information sessions and community visits. Please don't hesitate to contact us should you not find an answer to your question in this section of the website.
REMEDIATIONHEALTH AND SAFETY
FROZEN BLOCK
ENVIRONMENT
GENERAL QUESTIONS
Arsenic Trioxide
What is arsenic? Is it harmful?
What is arsenic trioxide and does it have a half-life?
How much arsenic trioxide is there at Giant Mine?
How and where is the arsenic trioxide currently stored?
Is there arsenic trioxide in the tailings ponds?
Other
How has public input influenced recent decisions made about Giant Mine?
Why is it important to move forward with any long-term alternative now?
Is the Frozen Block method a "walk-away" solution for Giant Mine?
How does the contamination at Giant Mine compare to other contaminated sites around the world?
Who is paying for the clean-up of Giant Mine?
How can the public get more information on the Giant Mine project and offer their feedback?
REMEDIATION
Why do we need a Remediation Plan? What is the point?
What does the Remediation Plan cover?
Is there anything the Remediation Plan doesn't cover?
Why can't INAC just go ahead with the remediation?
Who is the Remediation Plan being submitted to?
When will remediation of the site be finished?
Will the remediation work remove all traces of arsenic trioxide from the area?
Is the Remediation Plan a "safe" plan?
Where can I get a copy of the Remediation Plan? What does it look like?
How was the Remediation Plan developed? How do you know you've got it right?
What will the mine site look like when the Remediation Plan is finished?
HEALTH AND SAFETY
Is the water in Yellowknife safe to drink?
Is treated water getting into the water supply?
Exactly how safe is the mine site right now?
Do you have a contingency plan in place in case of an emergency at the site?
Are the underground storage chambers really safe?
FROZEN BLOCK
Why is INAC going forward with the Frozen Block method?
How does the Frozen Block method work?
How long will the frozen blocks remain frozen? What if there is a power disruption?
What are thermosyphons and how do they work?
Has Global Warming been factored into the freezing option?
Will the permafrost in the area of Giant Mine re-establish itself?
ENVIRONMENT
Why not just take the arsenic out and send it back where it belongs?
Why is INAC not taking the arsenic trioxide out of the mine and shipping it away?
Why was Baker Creek relocated and what
will it look like after the remediation work is
finished?
Can we fish in Baker Creek? Can we drink the water from Baker Creek?
Will there be any trees or vegetation after the remediation work is finished?
GENERAL
Arsenic Trioxide
Q. What is
arsenic? Is it harmful?
A. Arsenic — like oxygen, copper,
zinc or iron — is an element of the periodic table.
It occurs naturally in the rock throughout the earth, and
is toxic. However the bedrock in the Yellowknife area
contains arsenopyrite, a naturally occurring mineral
composed of iron, sulphur and arsenic. The arsenic that
is found in the arsenopyrite is in a stable form and does
not present a health hazard.
Q. What is
arsenic trioxide and does it have a
half-life?
A. Arsenic — like oxygen, copper,
zinc or iron — is a naturally occurring element.
When the ore taken from the Yellowknife area was roasted
to remove the gold, the arsenic was changed into an
arsenic-rich gas which combined with oxygen to form
arsenic trioxide dust. Arsenic does not have a half-life,
meaning it does not decay over time.
Q. How much
arsenic trioxide is there at Giant Mine?
A. About 237,000 tonnes of arsenic
trioxide dust is stored in 15 underground chambers on the
mine site. The dust stored underground is about 79%
arsenic trioxide and contains other minerals such as
iron, antimony and gold. The roaster at Giant Mine is no
longer in use and no new arsenic trioxide has been
produced since Royal Oak Mines went bankrupt in 1999.
Q. How and
where is the arsenic trioxide currently stored?
A. The arsenic trioxide dust is stored
in 15 mined-out chambers located in solid rock between 80
and 250 feet below the surface. The chambers are all
located near the "C" shaft on the mine site. The arsenic
trioxide is not in barrels, and the chambers are not
under the lake or under the communities of N'Dilo, Dettah
or Yellowknife.
Q. Is there
arsenic trioxide in the tailings ponds?
A. There is very little arsenic trioxide
in the tailings. Most of the arsenic in the tailings is
in stable forms, including arsenopyrite, which is a
natural arsenic-bearing mineral found in the bedrock of
Yellowknife.
Q. Have there
been studies on the extent of arsenic trioxide
contamination on the surface at Giant Mine and in the
nearby area?
A. Yes, there are several completed
studies on arsenic contamination on surface. Studies are
available at the Giant Mine Remediation Project's
Public Registry,
located on the First Floor, Waldron Building, 5103 - 48
Street.
Other
Q. How has
public input influenced recent decisions made about Giant
Mine?
A. INAC's Giant Mine Remediation Project
team has worked diligently to engage the communities of
Yellowknife, N'Dilo and Dettah and listen to their
concerns. When the public told the team it wanted more
information, INAC extended its communications efforts by
four months and participated in 20 additional public
sessions. The majority of residents said they did not
want a "take it out" alternative due to high worker
health and safety risks, among other reasons. The public
is now telling INAC that it is time to move forward with
remediating the site, and INAC has submitted its Remediation Plan for Giant Mine
to the regulatory process.
Q. Why is it
important to move forward with any long-term alternative
now?
A. A long-term management strategy is
needed now to minimize the risk posed by the arsenic
trioxide at Giant Mine. Although the 237,000 tonnes of
arsenic trioxide dust is currently being safely contained
and managed, such a large amount of toxic material
demands a more comprehensive plan to minimize the risk.
INAC has dedicated more than three years of research and
community consultation to finding the most effective
alternative to protect the health and safety of
northerners and the environment. The answers are in and
it is time to move forward with a solid long-term
plan.
Q. Is the
Frozen Block method a "walk-away" solution for Giant
Mine?
A. A total “walk-away”
solution does not exist. The arsenic trioxide dust that
is in the stopes and chambers would be contained in
frozen blocks, but a smaller amount remains distributed
throughout the other underground mine workings. Ongoing
water treatment is likely to be required to ensure this
arsenic does not leave the site. All of the arsenic
trioxide management alternatives would require ongoing
water treatment and monitoring, including those options
that would take the arsenic trioxide out of the stopes
and chambers.
Q. How does the
contamination at Giant Mine compare to other contaminated
sites around the world?
A. It is believed that Giant Mine holds
the largest amount of stored arsenic trioxide dust in the
world. The fact that it is located near a city and on the
shores of a large lake are also significant risk
factors.
Q. Is the
federal government committed to further research and
development now that a Remediation Plan has been
finalized?
A. Indian and Northern Affairs Canada
(INAC) will continue to protect human health and safety,
and the environment, even once the remediation is
complete. The Giant Mine site will be continuously
monitored and inspected. New and relevant information
regarding this project will also continue to be
considered and evaluated.
Q. What if new
technology in the future reveals a better method for
dealing with the arsenic trioxide dust instead of
freezing it? Can the work be reversed?
A. Freezing can always be reversed in
the unlikely event that better cost-effective
technologies for dealing with the arsenic trioxide are
developed.
Q. Who is
paying for the clean-up of Giant Mine?
A. The Government of Canada and the GNWT
will share the costs of remediation at Giant Mine
according to terms laid out in the 2005 Cooperation Agreement.
Q. How can the
public get more information on the Giant Mine project and
offer their feedback?
A. There are several ways to learn more
about the Giant Mine Remediation Project. Information
about the project can be found on this website and at the
Giant Mine Remediation Project's public registry on the 1st
floor of the Waldrun Building in Yellowknife. For more
information, please call the project office at (867)
669-2426.
The Giant Mine Community Alliance is a public advisory group set up to relay public concerns to INAC. For more information, contact one of the GMCA Co-Chairs: Lynda Comerford (867) 873- 4746 or Steve Petersen (867) 873-5192 or email: GMCA-ACMG@inac-ainc.gc.ca.
REMEDIATION
Q. What is a
Remediation Plan?
A. The Remediation Plan for Giant Mine
is the blueprint for cleaning-up the Giant Mine site to
ensure that human health and safety and the environment
are protected for the future.
Q. Why do we
need a Remediation Plan? What is the
point?
A. The current status of Giant Mine is
unacceptable. The site has been impacted by over 50 years
of gold mining and ore processing. Arsenic trioxide
stored underground must be effectively managed to protect
human health and safety and the environment. The
Remediation Plan explains how this will be done and also
describes general site clean-up activities on the surface
of the mine site.
Q. What does
the Remediation Plan cover?
A. The Remediation Plan covers the
clean-up of the entire mine site, including the
management of the 237,000 tonnes of arsenic trioxide dust
currently stored underground, remediation of tailings
ponds, and the demolition of buildings and other surface
structures.
Q. Is there
anything the Remediation Plan doesn't
cover?
A. The Remediation Plan was thoroughly
reviewed by technical advisors and subject matter experts
to ensure it addressed all the issues associated with
cleaning up the mine site. It covers all surface and
underground aspects of Giant Mine. It does not address
future uses of the site after the remediation is
completed.
Q. Why can't
INAC just go ahead with the remediation?
A. We need to apply for a water license
as part of the regulatory process first, and get approval
for our plan before we can begin doing the work.
Q. Who is the
Remediation Plan being submitted to?
A. The Remediation Plan was submitted to
the Mackenzie Valley Land and Water Board
as part of an
application for a water license in accordance with the
regulatory process.
Q. When will
remediation of the site be finished?
A. We expect that the surface
remediation may take up to 10 years to complete, while
the complete freezing of the underground arsenic trioxide
chambers and surrounding areas may take up to 15 years to
complete.
Q. Will the
remediation work remove all traces of arsenic trioxide
from the area?
A. Most of the arsenic trioxide will
stay safely sealed in the underground chambers behind
concrete bulkheads and will be frozen. Any soils on the
surface that are contaminated will be excavated and
disposed of safely at the mine site.
Q. Is the
Remediation Plan a "safe" plan?
A. Yes. The Remediation Plan includes
clean-up methods that have been successfully used at
other contaminated sites across North America. Safety
measures that were developed for other clean-up projects
in North America have been adopted for the remediation of
Giant Mine. Managing the arsenic trioxide dust where it
is currently stored will avoid the potential worker
health and safety risks associated with having to move or
handle the toxic material in the "take out" option.
Q. Where can I
get a copy of the Remediation Plan? What does it look
like?
A. The Remediation Plan is more than 200
pages long, and there are more than 40 supporting
technical documents — maps, diagrams, tables,
spreadsheets, illustrations — making for a pile of
binders more than two feet high. Click here for an
Executive Summary
of the Remediation Plan. All supporting
technical documents — including the complete
Remediation Plan and supporting documents — are
available through our public registry located on
the First Floor, Waldron Building, 5103 - 48 Street.
Q. How was the
Remediation Plan developed? How do you know you've got it
right?
A. INAC and its Technical Advisor spent
the last five years assessing the conditions at Giant
Mine to gather the necessary information for developing
the Remediation Plan. The initial plan for the long-term
management of the underground arsenic trioxide dust was
presented to the public and discussed at two separate
workshops in 2003. Subsequently, the management plan for
the underground arsenic trioxide dust was incorporated
with the plans for the surface clean-up, to form the
Giant Mine Remediation Plan.
Q. What will
the mine site look like when the Remediation Plan is
finished?
A. The goal of the remediation is to
minimize public health and safety issues and
environmental concerns. Best efforts will be made to
return the site to the natural landscape for the
Yellowknife area. However, there will be some small areas
that will need to remain under active management and
monitoring — notably the water treatment plant, and
the ground freezing system.
HEALTH & SAFETY
Q. Is the water
in Yellowknife safe to drink?
A. Yellowknife's water is safe to drink.
It comes from the Yellowknife River and is collected well
upstream of the Giant Mine before the river enters
Yellowknife Bay. Arsenic is a naturally occurring element
that is commonly found in the water of many rivers and
lakes including the Yellowknife River. These trace
amounts of arsenic are well below the Guidelines for
Canadian Drinking Water Quality, similar to levels
found in many other communities such as Gameti, Edmonton
and Toronto.
Q. Is treated
water getting into the water supply?
A. Giant's treated mine water does not
get into Yellowknife's water supply. The treated mine
water is released into Baker Creek. Yellowknife's
drinking water is collected from the Yellowknife River,
well upstream of Giant Mine, before the river enters
Yellowknife Bay. The quality of this water is monitored
by the City of Yellowknife.
Q. Exactly how
safe is the mine site right now?
A. Safety is our first priority at Giant
Mine. The NWT Mine Safety Inspector regularly inspects
the site to observe the working conditions above and
underground for qualified mine workers. These workers are
well-trained in mine safety measures and have years of
experience working in the mining industry. Every
precaution is taken during their shifts and they have a
good understanding of the risks they face. Security
personnel are responsible for ensuring the public does
not go on the site.
Q. Do you have
a contingency plan in place in case of an emergency at
the site?
A. Yes. Deton'Cho Nuna Joint
Venture has a comprehensive Emergency Response Plan
that covers many different situations. For example it was
effectively put into motion when a minor fire was
discovered in a ventilation unit on April 10, 2007.
Q. Are the
underground storage chambers really safe?
A. The current storage of arsenic
trioxide underground at Giant Mine is safe. The
underground storage chambers are contained in bedrock and
sealed with concrete bulkheads. The pumps at Giant Mine
keep the level of groundwater well below the storage
chambers. Any water seepage that comes into contact with
the storage chambers is collected in the mine water
system, pumped to the surface and treated. The mine and
local surface waters are regularly monitored to ensure
that arsenic trioxide does not escape into the
environment. The arsenic trioxide at Giant Mine has been
stored safely underground for decades and will continue
to be safely stored until the Remediation Plan —
and Frozen Block
Method — is fully implemented.
FROZEN BLOCK
Q. Why is INAC
going forward with the Frozen Block method?
A. Freezing the arsenic trioxide in
place is the best long-term management strategy to
protect Northerners and the environment. Of all the
alternatives considered, it offers the least risks,
including low risks to worker health and safety, low risk
of arsenic release during the implementation of the
management method, and low risk of arsenic release over
the long term. Freezing the arsenic trioxide dust and the
surrounding rock will effectively isolate the dust from
the environment. There will be no seepage of water into
or out of the frozen zones, and there will be no release
of arsenic. This decision comes after three years of
extensive scientific and technical research, and
community consultation. Fifty-six management alternatives
were considered; 12 were studied in detail, and finally,
the Frozen Block method was selected for remediating the
arsenic trioxide dust, based on scientific evidence and
community input.
Q. How does the
Frozen Block method work?
A. The 15 underground chambers and
stopes (mined-out cavities), containing arsenic trioxide
dust, will be frozen as solid, impenetrable blocks of
ice. The blocks will be frozen using a cooled liquid
circulated through a series of underground pipes, which
will be attached to a freezing facility on the surface.
The system will be very similar to the system used for
indoor ice rinks. Thermosyphons will be
installed to aid the freezing process and effectively
maintain the frozen area indefinitely. The freezing will
occur in stages over many years to make certain that the
blocks are completely frozen. INAC will ensure that the
site is safely managed throughout the entire process.
More on the Frozen Block Method.
Q. How long
will the frozen blocks remain frozen? What if there is a
power disruption?
A. The frozen blocks should remain
frozen indefinitely, because thermosyphons will be used
to maintain the freezing — if there were no
thermosyphons, the solid ice block would stay frozen for
more than 50 years. Thermosyphons do not require
electricity. Instead, they use the cold air in winter to
cool the ground. As a precaution, thermometers would be
used to monitor the ground and air temperatures. If
thawing were to occur, the active freezing system would
be used to refreeze the ground.
Q. What are
thermosyphons and how do they work?
A. Thermosyphons are tall,
metal tubes that draw and expel heat from the ground.
They are commonly used in the North to keep ground
frozen. For example, thermosyphons are being used to
preserve natural permafrost below the parking lot at the
NWT Legislative Assembly in Yellowknife. Thermosyphons
are self-sustaining and do not rely on an external source
of power.
Q. Water
expands when it freezes. Could the freezing cause
fractures or otherwise affect the stability of the
chambers?
A. Experience elsewhere shows that
cracking of the rock is very unlikely. However, the
detailed design of the freezing system will need to
ensure that the freezing does not create high pressures
within the dust or the surrounding rock. This is one of
the design details that will be addressed prior to
implementation.
Q. Has Global
Warming been factored into the freezing
option?
A. Yes. The calculations completed by
the technical advisor show that the system being
considered for freezing the mine will continue to work
even with an increase of several degrees in the regional
mean temperature. The site will also be continuously
monitored using sophisticated equipment. Adjustments will
be made if necessary to maintain the frozen areas.
Q. Will the
permafrost in the area of Giant Mine re-establish
itself?
A. No, the permafrost will not
re-establish itself naturally. When the decision was made
to store the arsenic trioxide in the chambers
underground, it was considered to be the safest place
because the chambers and stopes were within the
permafrost zone. Over time, mining has caused
deterioration of the permafrost. The selected long-term
management alternative involves actively freezing the
chambers, stopes and surrounding rock into frozen blocks
with the use of a large freezing plant, similar to what
is used to make artificial ice in rinks.
ENVIRONMENT
Q. Why not just
take the arsenic out and send it back where it
belongs?
A. Arsenic doesn't belong anywhere else.
It's from here. The arsenic — just like the gold
— originates from the local rock. After the ore was
mined at Giant Mine, it was roasted to remove the gold.
The arsenic, found in the mineral arsenopyrite, was
transformed into an arsenic-rich gas which combined with
oxygen to form arsenic trioxide dust.
Q. Why is INAC
not taking the arsenic trioxide out of the mine and
shipping it away?
A. This alternative was thoroughly
examined by INAC and its Technical Advisor. It
was rejected for many reasons: First, removing the dust
would pose significant risks for workers, who would be
mining out this highly toxic material. Second,
transporting the material would seriously endanger the
environment. Members of the public have told INAC that
they do not want this level of risk. INAC and its
Technical Advisor also looked at options for removing the
arsenic trioxide dust and placing it in a secure landfill
on the Giant Mine property. That would eliminate the
problem of spills during transport, but it would mean
that a permanent hazardous waste site would need to be
created on the Giant Mine surface. Due to the irregular
nature of the rock surrounding the storage chambers, it
would be impossible to remove all of the dust. Up to
several thousand tonnes of arsenic trioxide dust would
likely remain underground. That would mean there would be
two hazardous waste sites — one above ground, which
would be a surface landfill, and one underground. In the
final analysis, all of the "take-it-out" alternatives
were found to pose more risks to human health and safety,
and the environment, than the Frozen Block
alternative.
Q. Why was
Baker Creek relocated? What will it look like after the
remediation is done?
A. Baker Creek was relocated many times
over the course of Giant Mine's history. The latest
relocation was done to prevent infiltration of creek
water into the mine. Our approach for Baker Creek is one
of environmental restoration. We would like to return the
creek as close as possible to pre-mining conditions.
Q. Can we fish
in Baker Creek? Can we drink the water from Baker
Creek?
A. Baker Creek is catch and release
fishing only. Eating fish from Baker Creek will likely be
discouraged for many years even after the remediation is
complete. It may be possible to drink water from Baker
Creek many years in the future.
Q. Will there
be any trees at the mine site after the remediation is
finished?
A. Yes. There are plans to revegetate
the approximately 95-hectares of tailings, roads and
other areas with native grasses and vegetation. Trees and
other plants are expected to move back into the area with
time.
