Ch. 3 Land - Environment Yukon

Reclamation and Abandonment
When the ore body is exhausted, and a
mining company wishes to abandon
its site, the ultimate goal is to reclaim
the area and return it to a natural state.
All buildings, infrastructure and
equipment must be removed;
recontouring of land, capping or
flooding of tailings, and revegetation
is carried out, depending on the site
requirements and configurations. The
preferred solution is a ‘walk away’
scenario, where the land is revegetated
and no further maintenance is required.
This will not always be possible, and
some mines in the Yukon will require
perpetual treatment of waste waters
prior to their release to the receiving
environment. The fragility of the
northern environment makes mining
and reclamation an even more
challenging aspect of mine planning
in the Yukon. Proven southern
procedures may not necessarily be a
panacea in the north.
One concern over the past few years is
the lack of a process that ensures
mining reclamation will take place. If a
mine is in production for a number of
years, a reclamation fund is to be
created to clean up and rehabilitate
the site following a mine closure or
temporary shutdown. Under the old
Northern Inland Waters Act, a company
was to set aside a percentage of their
total capital cost per year for
reclamation purposes.
In recent years there have been
changes to regulations that deal with
the environmental impact of mining in
Ketza River Project 1998
the Yukon. Now companies must
provide plans and financial guarantees
that ensure reclamation work and mine
abandonment will take place in a
satisfactory manner. If abandonment
is taken into consideration right from
the start, reclamation objectives can
be incorporated into their daily
operations. Overburden, waste rock,
tailings and structures are dealt with
in such a way that their final disposition
is feasible and affordable.
Reclaimed mining areas may be
developed for other land uses. For
example, the City of Whitehorse used
an abandoned open pit from the old
Whitehorse Copper Mine as a solid
waste disposal site for a number of
years. Other feasible post-mining land
use options include improved wildlife
habitats, recreational opportunities, or
other new industrial uses.
While under the Yukon Waters Act,
the Water Board may require a reclamation
fund to be established, the
provisions under the Act and Regulations
are discretionary, not mandatory
requirements. In some cases, the
funds accumulated are inadequate to
cover the reclamation costs at the
time of mine closer, as was the case
with the Faro and Mt. Nansen mines.
Hard Rock Mining Properties –
Active Mines
Brewery Creek
Viceroy Resources Corporation’s
Brewery Creek year-round heap leach
gold operation (the first and only heap
leach operation in the Yukon) is the
only operating mine in the Yukon
(1999). The first bar of gold was poured
on November 15, 1996 and the mine
reached full production in May 1997.
Seasonal open-pit mining produces
11,000 tonnes of ore per day between
April and October annually. Eight oxide
deposits were originally delineated at
Brewery Creek with Upper Fosters and
Canadian deposits now mined out.
Five new zones have been explored,
drilled and trenched, expanding the
reserves.
The reclamation of waste rock, minedout
pits and used ore is an ongoing
process at the Brewery Creek mine.
It is easier for reclamation to progress
because ore deposits are mined from a
series of relatively small pits, instead
of from one large area. As each pit is
mined out, it is reclaimed with waste
rock from the next reserve. Backfilling
is the preferred method as it causes
less site disturbance and the pit walls
end up re-contoured, allowing the area
to blend into the original landscape.
In May 1996, an aggressive revegetation
program was initiated in the Canadian
mine area and the clearing below
the leach pad and ponds, using an
agronomic mix called Klondike Valley
seed mix, covering an estimated area of
11 hectares 2. In 1997 reclamation
work was performed on approximately
20 hectares of disturbed land, including
seeding and fertilizing various locations
throughout the site, and recontouring
and re-vegetating the Canadian waste
dump and the West Canadian pit.
Efforts were made to increase the use
of native seed species (Brewery Creek
seed mix) rather than the agronomic
counterparts 3. In 1998 approximately
six hectares of disturbed land in the
mine, leach pad, and access road were
revegetated. Efforts to procure a native
seed mix were continued. Research
We need to get involved with the
mining companies to explain how
we used the land before. After
they finished (with the mine), see
that they put everything back in
place. Not to leave cyanide
behind; that they clean up before
they go away again.
–Roddy Blackjack,
Little Salmon Carmacks First
Nation Elder.
C H A P T E R 3 L A N D ❧ 4 7