NWT Contaminated Sites
Giant Mine
For more detailed information please go directly to the Giant
Mine Remediations Project website.
Yellowknife’s Giant Mine began operations in 1948 and quickly became
one of Canada’s most prolific gold mines. Over its lifespan, Giant
Mine produced more than 7 million ounces of gold. This is one of three
mines that reverted back to the Crown in 1999 when the mines’ owner
at the time, Royal Oak Mines Inc., went into receivership.
Why is it a contaminated site?
The main issue at Giant Mine is the 237,000 tonnes of arsenic trioxide
dust stored underground at the site. The dust was created during the gold
production process. When the mined ore was roasted to release the gold,
the arsenic was also released as arsenic trioxide dust.
The highly toxic arsenic trioxide dust continues to be safely stored
in the 15 stopes and chambers underground at the site. The amount is equivalent
to seven and a half 11-storey office buildings. On site, there are also
tailings ponds, old mine structures and other surface features that require
remediation.
What’s going on at the site?
Giant Mine is currently under care and maintenance. This means the site
is secure and is being monitored. Also, all water pumped from the mine
is being collected and treated on site before being released into Baker
Creek. Numerous on-site studies are also being carried out to gather more
information about the environmental conditions of the site.
Future plans
DIAND’s Giant Mine Remediation Project Team is creating a Remediation
Plan for the site. This will include a plan to freeze the underground
stopes and chambers containing the arsenic trioxide, and the surrounding
rock.
Colomac Mine
Newsletter (Summer
2005)
Colomac Mine was a gold mine in operation from 1989 to 1997, located
222 kilometres northwest of Yellowknife. This is one of three mines that
reverted back to the Crown in 1999 when the mines’ owner at the
time, Royal Oak Mines Inc., went into receivership.
Why is it a contaminated site?
One of the main concerns at Colomac is “tailings water”- contaminated
water produced by the processing of the gold ore. The tailings water is
contaminated with cyanide, a chemical that was used to get the gold out
of the ore, among other substances. Currently, the contaminated water
is safely contained in two areas, the Tailings Containment Area (TCA)
and a mined-out pit known as Zone 2 Pit. At present, both areas contain
approximately 10 million cubic metres of water. However, rainfall and
snowmelt will eventually fill both the TCA and Zone 2 Pit.
What’s going on at the site?
After extensive community consultation, DIAND filed a Remediation Plan
with the Mackenzie Valley Land and Water Board on March 31, 2004. This
plan recommends Enhanced Natural Removal as the best remediation option
for tailings water. This involves adding phosphorus to the contaminated
water, which promotes the growth of algae. The algae breaks down cyanide
and ammonia into non-toxic substances. Measurements over the past three
years have shown that this process successfully reduces contaminants,
including cyanide and ammonia.
A lot of other remediation work continues to be done at the site, including
an eight-kilometre fence installed to prevent caribou and other wildlife
from entering the tailings containment area.
DIAND is working in partnership on the Colomac project with the Tlicho
people, who live in the area. The site operator is Tli Cho Logistics,
a Dogrib company, and the majority of the workforce are Tlicho people.
Future Plans
Once the new water licence and land-use permit are issued, implementation
of the large remediation tasks can begin. Remediation of the entire site
is expected to be completed by 2010. This will be followed by monitoring
for about five years to confirm that the remediation measures are effective.
Tundra Mine
Tundra Mine is a former gold mine, located 240 kilometres northeast of Yellowknife.
Operations began in 1964. This is one of three mines that reverted back
to the Crown in 1999 when the mines’ owner at the time, Royal Oak
Mines Inc., went into receivership.
Why is this a contaminated site?
During the operation of Tundra and nearby Salmita Mines, processed tailings
were deposited in Russell Lake (tailings pond). Elevated metal concentrations
have been measured downstream. The water in the tailings pond has elevated
levels of aluminium, arsenic, chromium, manganese, copper, iron and lead
and is believed to be the source of contamination downstream. Contamination
at the site is associated with the tailings pond, metals leaching from
the waste rock piles and hydrocarbons (fuels and oils) released during
operations at the mine.
The Tundra site includes milling and crushing facilities, a tank farm,
assay laboratory, powerhouse, head frame and many other support buildings.
During the operation of nearby Salmita Mine, ore was trucked from the
mine along a 10–kilometre road to be processed at the Tundra Mill.
Salmita Mine ceased operations and was remediated by Royal Oak in the
1980s.
What’s going on at the site?
Since 1999, the site has been in care and maintenance mode. This has included
dam repairs, geotechnical inspections, securing buildings and posting
signs. Additional work is being done to repair the dams around Russell
Lake and more research is being conducted to develop remediation strategies
for the site.
Future Plans
When all the environmental studies are completed, a Remediation Plan will
be developed and submitted to the Mackenzie Valley Land and Water Board
for approval. Once the required licences are received, remediation on
the site can proceed.
Rayrock Mine
Rayrock Mine was an underground uranium mine that operated for two years,
from 1957 to 1959. It was operated by Rayrock Mines Ltd., which left the
site in 1959. It is located 145 kilometres northwest of Yellowknife and
74 kilometres northwest of Rae.
Why is this a contaminated site?
During the operations at Rayrock Mine, an on-site mill facility processed
approximately 70,000 tonnes of ore yielding 207 tonnes of uranium concentrate.
The site became contaminated with radioactive tailings that were deposited
on land and partly flowed into three small lakes. In 1959, two tailings
basins contained 70,903 tonnes of radioactive tailings that had the potential
to leach metals. Construction of the mine also created a source of potential
radioactive contamination through radon gas emissions from the mine openings
(adit, vent shafts).
What’s going on at the site?
In the early 1980s, buildings were demolished and/or removed from the
site. Tailings remediation began in 1996, with the objective being to
contain contaminants at the site and limit exposure to persons who visit
the area. Remediation activities included sealing mine openings, removing
radioactive material from the dump, disposing of this contaminated material
on the tailings, and capping the tailings piles with a layer of silty
clay, followed by revegetation.
Future plans
Long-term monitoring is ongoing at this site. It is to be conducted annually
for 10 years (2000 to 2009), followed by once every 10 years for a further
100 years. This may change if results warrant adjustment, such as some
minor care and maintenance work completed in summer 2004. Monitoring assesses
the integrity of sealed mine openings, water quality and potential risks
to humans.
Discovery Mine
Discovery Mine is a former gold mine, located on the west shore of Giauque
Lake, approximately 80 kilometres northeast of Yellowknife. It was owned
by Discovery Mines Ltd. and was in operation from 1949 to 1969.
Why is this a contaminated site?
At the time of closure, approximately 1.1 million tonnes of mercury-contaminated
tailings were spread over 32 hectares of land and 3.7 hectares of lake
sediment above the low water level. A tailings beach was created in Giauque
Lake. The majority of the tailings were covered in 1999/2000, although
there remains some residual exposed tailings on site. There also remains
old buildings, mine structures and unsealed mine openings on site that
pose contamination and/or safety risks.
What’s going on at the site?
After extensive assessment, remediation started in 1998. The work involved
the general clean-up of the site, off-site disposal of some hazardous
wastes, and the capping of the tailings using a low permeability clay
cover and waste rock. This work was completed in 2000.
In the fall of 2001, the silty clay borrow pit, which was used as the
clay source for capping the tailings, became full due to precipitation
and runoff. This borrow pit overflowed into Giauque Lake, creating a sediment
plume. This water is not contaminated from tailings, but contains suspended
clay from the pit itself. To fix this situation, vegetation was planted
on the sides of the pit to stabilize the banks and stop erosion. The water
in the pit is also being treated, and once the clay is settled out, the
clean water is pumped out into the environment.
Future plans
A long-term Environment Monitoring Program (EMP) was developed and implemented
to monitor the effectiveness of the initial remediation work. This includes
monitoring the tailings cap, lake water quality, sediments, fish and vegetation.
A long-term Remediation Plan is also being developed to address the borrow
pit and remaining issues on the site, such as the buildings and structures.
Silver Bear Properties
The Silver Bear Properties consist of four former mines; Terra, Northrim,
Smallwood and Norex. They produced silver, copper and bismuth. Mining
began in the area in the 1960s. Terra, Smallwood and Norex mines were
owned by Terra Mining Ltd. and Northrim Mine was owned by Northrim Mines
Ltd. All mining operations ceased by 1985. The sites are located approximately
300 kilometres northwest of Yellowknife, near the southeast corner of
Great Bear Lake.
Why is this a contaminated site?
There are two tailings ponds at the Silver Bear Properties, including
HoHum Lake at Terra Mine and Hermandy Lake at Northrim. There is hazardous
waste on site, including lab chemicals, ore concentrates and waste fuels.
The containers holding these materials have degraded and pose a risk to
the environment. More than 30 buildings on site have not been maintained
and pose safety risks. The first issue that needs to be addressed on site
is sealing the more than 20 openings into the underground mines.
What’s going on at the site?
Studies have been conducted at the sites since the early 1990s to prepare
for remediation. A limited amount of remediation work has been done so
far. This includes placing leaking barrels of fuel and antifreeze into
new containers at Terra Mine in 1999. In 2001, PCBs and lab chemicals
were secured and removed from the site for disposal.
Studies are continuing to develop a remediation plan and offer insight
into the condition of the water quality, tailings, waste rock and soils.
The contents of 900 barrels at Terra Mine were sampled this year to prepare
for incineration.
Future plans
Once studies have been completed, a Remediation Plan will be developed
and submitted to the Sahtu Land and Water Board for approval. The Remediation
Plan will outline how the tailings ponds will be treated, how the mine
openings will be closed and where waste from the site will be placed.
In the meantime, water quality monitoring will continue, chemicals will
be secured and waste oils will be incinerated.
Contact Lake Mine
The Contact Lake Mine is located on Contact Lake, approximately 265 km
east of Déline and 300 km northwest of Yellowknife. It was originally
a silver mine in the 1930s but was mined for uranium from 1949-1950. Mining
operations took place intermittently until 1980. The mine was owned by
Echo Bay/Ulster Peter Ltd.
Why is this a contaminated site?
During the mine's operation, an estimated 29,100 cubic metres of waste
rock and 1,450 cubic metres of processed tailings were deposited downslope
of the mine site towards Contact Lake. The tailings are not contained.
Surface water runs downslope from the waste rock pile, through the tailings
and collects in a settling (tailings) pond. The tailings and surface mine
water have elevated levels of metals including arsenic and uranium. There
is the possibility of metals leaching from the waste rock piles and tailings
to Contact Lake. There are also old buildings, as well as mine structures
and openings, that pose safety hazards.
What's going on at the site?
In 1993, an environmental assessment was conducted. Inventory was taken
of the buildings, waste deposits were surveyed, tailings, waste rock and
surface water were sampled and lake bottom sediments were collected.
In September 2002 and June 2003, more water and soil sampling was conducted
to further quantify and qualify the potential impacts of the mine site
drainage on the surrounding environment.
This year, baseline studies have continued, as well as posting warning
signs, installation of groundwater monitoring wells and additional water
quality sampling. The groundwater wells were installed to investigate
groundwater quality and determine if there is a flow path from the tailings
pond to Contact Lake.
Future Plans
Continued water quality monitoring is planned for Contact Lake. The assessment
will be used to create a Remediation Plan for the site.
Port Radium Mine Site
Port Radium mine site is located on a peninsula along the eastern shore
of Great Bear Lake in the Northwest Territories, 440 kilometres north
of Yellowknife and 265 kilometres east of the Dene community of Déline.
The site was discovered by Gilbert Labine in 1929 and mined for radium
and silver until 1940. In 1942, the Crown-owned Eldorado Mining and Refining
Company mined for uranium until 1960 before leaving the site. In 1964,
Echo Bay Mines took over operations and mined for silver. Echo Bay Mines
ceased mining operations at Port Radium in 1982 after covering most tailings
and garbage with waste rock, moving all valuable equipment to nearby mining
operations and destroying buildings on-site.
Why is this a contaminated site?
Historical and environmental studies done to date determine the following
concerns: status of closed mine openings; remaining scrap materials; exposed
tailings; elevated gamma radiation levels at the former plant site and
spilled tailings areas; elevated metals levels in local surface seeps,
some vegetation, lake sediments and water quality; status and environmental
issues associated with exposed waste rock; suitability of on-land tailing
covers; status of uncapped tailings basin; and if any effects are due
to the unknown quantity of tailings deposited into Great Bear Lake.
What's going on at the site?
In 1999, the Canada-Déline Uranium Table (CDUT) was formed. It
is comprised of representatives from DIAND and Déline residents.
DIAND represents Canada on behalf of Health Canada and Natural Resources
Canada. The CDUT created an Action Plan, to describe, scope and recommend
studies and activities that, when completed, will provide the information
necessary to enable the CDUT to make informed decisions about the long-term
management of the Port Radium site and any ongoing community health requirements
relating to the mine site.
Future Plans
In March 2005 the CDUT will complete the Action Plan final report, which
will include results of the CDUT studies and CDUT recommendations to the
Chief and Council and the Minister of Indian Affairs and Northern Development.
Axe Point Military Site
Axe Point was an airstrip, staging area and camp along the winter road
to Norman Wells for the American military during World War II. The site
supported the construction of the CANOL Project, an oil pipeline between
Norman Wells and Whitehorse. It is believed that the site was also used
for a couple of years in the early 1940s. Axe Point is 60 kilometres west
of Fort Providence, on the shores of the Mackenzie River.
Why is this a contaminated site?
There is very little documented historical information about Axe Point.
Most of the available information is from elders in nearby Fort Providence.
Remaining on site are seven collapsed buildings, metal debris, a boiler,
several old vehicles and old batteries. The site is overgrown with willow,
alder, birch and poplar trees. Investigations have found elevated levels
of hydrocarbons and metals in soils and groundwater on site. Geophysical
surveys have identified buried materials on site.
What’s going on at the site?
In 2001, a general site assessment was done, which included water testing,
assessing old buildings, and gathering information about contaminants
on site. In 2003, more water quality testing was done, including a detailed
study of any impacts on the nearby Mackenzie River. This work was done
in cooperation with the Fort Providence Resource Management Board. Preliminary
results indicate no water is moving from site and there is no impact on
the Mackenzie River.
Future Plans
Further investigations are required to determine the extent of contamination
on site and to determine options for remediating the site. This information
will be used to develop a Remediation Plan which will be submitted to
the Mackenzie Valley Land and Water Board. Once approvals and licences
are obtained remediation can begin at Axe Point.
Kittigazuit Military Site
Kittigazuit was used as a long-range navigation site (LORAN) by the military.
This was a significant LORAN site in the northern region, built in 1947
and operated from 1948 to 1950. The station was code named “Yellow
Beetle”. The site is located near Kittigazuit Bay, located between
Inuvik and Tuktoyaktuk in the Inuvialuit Settlement Region.
Why is this a contaminated site?
After the LORAN project was shut down, a lot of debris remained at the
site, including decaying buildings and equipment. It was then used as
a waste metal depot by DIAND. Through site assessment, it was determined
that there was also DDT and metal contaminated soils, asbestos waste associated
with the buildings, and hydrocarbon-contaminated soils.
What’s going on at the site?
The scope of remediation of this site was developed by DIAND and the Inuvialuit
Regional Corporation/Inuvialuit Land Administration. The buildings and
contaminated soils have been removed and remediation should be complete
by fall 2004.
Future Plans
As an Annex ‘R’ site under the Inuvialuit Final Agreement,
once the remediation is complete, the land will be transferred to the
Inuvialuit.
Atkinson Point Military Site
Atkinson Point, otherwise known as BAR-D was an Intermediate Distant
Early Warning (DEW) Line site located approximately 80 kilometres east
of Tuktoyaktuk by McKinley Bay. This military radar site was constructed
in 1957 and operated until 1963. The land reverted to DIAND in 1965. DIAND
made this site available for scientific use by government and university
groups until 1981. During the 1970s, DIAND leased the land to Imperial
Oil.
Why is this a contaminated site?
Most of the visible debris at Atkinson Point was collected and stockpiled
in 1993. However, there are still several landfills, numerous barrels
and several fuel tanks, as well as buildings contaminated with PCB-amended
paint and asbestos. Several soil samples also showed levels of copper,
lead, zinc and PCBs above guidelines.
What’s going on at the site?
Assessment work is planned for this site after the Kittigazuit Bay military
site has been remediated. The area is still in use by reindeer herders,
the oil and gas industry, as well as hunters and trappers.
Future Plans
Preliminary assessment work at this site was completed in 2000. However,
several new guidelines or standards are now in place, and additional assessment
work is required. Once this is completed, a Remediation Plan will be developed.
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