Ch. 3 Land - Environment Yukon

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Figure 3.12 shows the location of some of the active mines, development projects and exploration projects in the Yukon in 1998. Production occurred at Brewery Creek and Mount Nansen in 1998. During 1999, only Brewery Creek Mine operated. Placer Mining Placer deposits occur throughout the Yukon, though historically, most of the mining has taken place in the Klondike gold fields near Dawson City. This area is particularly favourable for placer Early Placer Miners The first placer miners in the Yukon were First Nation people who recovered native copper nuggets from the White River area in the southwestern part of the Yukon Territory. After 1850, prospectors and explorers began to report fine gold on river bars and coarse gold in the Fortymile and Sixtymile rivers. On August 17, 1896, the discovery of nugget gold by George Carmack and Skookum Jim on Bonanza Creek set off the Klondike gold rush. Emeralds In 1999, Expatriate Resources announced that emeralds had been discovered on one of its exploration properties near Finlayson Lake. The company has commissioned a team of gem experts to evaluate the find. Gem quality emeralds are extremely rare and much work is needed to recover and appraise the rough gems. The wintering range of the Finlayson Woodland Caribou herd is located in this area. deposits because it lies in the unglaciated part of the Yukon. Approximately 80 per cent of the Yukon’s placer gold is currently mined from the Klondike and other unglaciated parts of the territory. Placer deposits consist of loose material (gravel, sand and clay) formed by the weathering of mineralized bedrock. As the bedrock breaks down, heavy minerals like gold, silver, platinum, tin, copper, tungsten and some gemstones are released. These minerals concentrate in layers because their relative weight (specific gravity) allows gravity and the natural flow of water to sink them to the bottom of creeks or a ‘hardpan’ layer where they accumulate through time. Water is usually used as the transporting or washing agent to remove gold from sand and gravel. Minto Mt. Nansen Brewery Creek Dublin Gulch Carmacks Copper The water is often pumped from a stream into an elaborate system of pumps and settling ponds and is later returned once the fine sediments have settled. Water quality standards for Yukon placer mining streams are set by the Yukon Placer Authorization which establishes the allowable sediment that may be discharged into streams, based on fish habitat. Low gold prices continued to daunt the Yukon’s placer industry in 1998 and 1999, resulting in a decrease in both production and employment; however, placer mining is still an important sector in the Yukon’s economy. In 1998, 90,288 ounces of placer gold, valued at $31 million (Cdn), were produced from 161 placer mines employing approximately 600 people. This represents an approximate 22 per cent drop in production from 1997. 4 6 ❧ Y U K O N S T A T E O F T H E E N V I R O N M E N T R E P O R T 1999 Keno Hill Faro Marlin Tea Kudz Ze Kayah Active Mines Past Producing and Developing Hardrock Mines Exploration Projects Tintina Trench Sa Dena Hes 100 Km Figure 3.12 1998 Yukon Mining, Development and Exploration By 1999, Brewery Creek was the only active mine operating in the 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
Page 1 and 2: The Yukon is situated in the northw
Page 3 and 4: number of humans is immense. As cou
Page 5 and 6: Different data sources for 1999 tha
Page 7 and 8: ■ protecting core areas within ea
Page 9 and 10: within the study area in February 1
Page 11 and 12: 3.4 Mining Mining has been an impor
Page 13: An environmental review committee,
Page 17 and 18: first bar of gold on November 23, 1
Page 19 and 20: This creates uncertainty and delays
Page 21 and 22: every year in the Yukon, but the an
Page 23 and 24: Direct Costs: ■ Picking up Whiteh
Page 25 and 26: The Yukon’s beverage container re
Page 27 and 28: Contaminant? In Carcross, the recen
Page 29 and 30: PROGRESS & CHALLENGES Since the 199
Page 31 and 32: with the objective of import replac
Page 33 and 34: still exist along the old trails an
Page 35 and 36: 3.8 Tourism Tourism is gaining impo

Ch. 3 Land - Environment Yukon

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