Taseko Mines Ltd. vows it can preserve and protect Fish Lake in its entirety if the New Prosperity Mine goes ahead.
Speaking to 93 people at the Williams Lake & District Chamber of Commerce’s monthly luncheon on March 29, Taseko’s vice president of corporate affairs Brian Battison said the tailings facility will be moved two kilometres upstream and away from Fish Lake.
In addition, a new location will be found to store the waste rock and the overburden required for reclamation.
“Fish Lake, and the environment completely surrounding it on which it depends, can be preserved and secure,” Battison said. He said the deposit at the site contains the world’s seventh largest gold/copper reserve, measuring approximately 1,500 metres by 800 metres and extending to a depth of 880 metres.
It is located within the Fish Creek watershed, which contains Fish Lake, Little Fish Lake and Fish Creek. The original plan for the mine called for the draining of Fish Lake. That is no longer the plan.
Battison shared a short video, prepared by Taseko, that outlines how the company believes the lake and its watershed can be saved. The company plans to spend $300 million more than its last proposal to save the lake.
Highlights from the video are listed here:
During the four-phase, 20-year-mine life, it is estimated the open pit will grow up to 1,600 metres in diameter of the pit rim and that the rim of the pit will be approximately 500 metres from the lake.
Waste rock will be stock piled north of the pit, and lower grade ore will be stored northeast of the pit for processing later in the life of the mine. Over time the tailings facility will increase in size, keeping pace with the rate of mining taking place in the pit. Some of the waste rock will contain naturally occurring sulphites, which must be kept submerged in the tailings pond to prevent oxidation and potential acid rock drainage.
The aim is to ensure that all mining activity and disturbance occurs in a single watershed upstream of the pit.
Currently rain and snow melt are the only sources of water within the Fish Creek watershed. Upper Fish Creek flows to the northwest and discharges into Fish Lake, which drains into lower Fish Creek, which then drains into the Taseko River.
During mining operations, the project will impede the natural water flows in the watershed; specifically the tailings facility will cut off and limit the flows into Fish Lake, while the open pit will cut off the outflow from Fish Lake.
However, the company will implement a number of mitigation measures, including the preservation of the lake and the viability of its trout population.
To maximize the contribution of non-contact water to Fish Lake, surface water from the upland area east of the project will be intercepted and directed to the lake.
In an effort to maintain appropriate water levels and flows into Fish Lake, the water draining out of Fish Lake will be recirculated back to feed Fish Creek’s spawning and rearing habitat, and ultimately Fish Lake itself.
Any excess water not required to maintain Fish Lake will be pumped to the tailings pond, while rainfall and groundwater, in and around the pit, will be pumped directly to the concentrator for use in the milling process and then pumped up to the tailings pond.
Ditches around the ore and waste stock piles will also collect water to be pumped to the concentrator.
To ensure water from the tailings pond is contained and restricted from impacting the water quality of Fish Lake, it will be collected in seepage ponds and pumped back into the tailings facility.
Deep watering wells will be installed in the area of the pit to increase the stability of the pit walls. The wells will temporarily lower the ground table in the immediate area.
The tailings pond will sit on low, permeability, clay-like glacial till, which the company suggests will be ideal for limiting seepage.
Additional monitoring wells will be installed downstream of the tailings embankments to monitor ground water quality and determine rates of the water’s movement.
If the monitoring suggests an undesirable deterioration of water quality, then this water will be collected and pumped back into the tailings pond.
Reclamation plans for the mine after operations discontinue include restoration of the natural drainage pattern of the watershed.
It is assumed the pit will naturally fill up with rain and water — a process, the company estimates, will take about 40 years.
At the end of the mine life, the crushers, mills, conveyors and all mining facilities will be removed from the site and disposed of.
The waste rock stockpile will be re-sloped and, along with the tailings, embankments and beaches, covered with soil, seeded and planted to establish wildlife and waterfowl habitat.
Once the pit is filled with water, and provided the water quality meets the expectations and guidelines of the day, the natural drainage course for the entire watershed will be re-established. The site will continue to be monitored to ensure that two new lakes will become successful components of the Fish Creek watershed.
Battison said in the 22-year construction and operating life of the mine, the company anticipates that it will increase annual employment by 3,000, increase federal government revenues by $4.3 billion and provincial government revenues by $5.5 billion, and increase consumer spending by $9 billion.
“At a time when the economy in our province and indeed the country is struggling, unemployment is too high and government revenues are falling and deficits are climbing, there’s an opportunity for Williams Lake and this region for an infusion of billions of private sector investment that will last for 22 years.”
When asked about copper prices dropping and stockpiles increasing around the world due to the slow down of the economy in China and whether that’s causing Taseko concern, Battison responded it’s a concern to everybody.
“The price of copper, in relation to those reports, only dropped five to 10 cents. So whether the economic growth of China is 14 per cent or whether it’s growing at six per cent or eight per cent there is a huge demand for copper around the world and we expect that to continue,” he said.
Mayor Kerry Cook asked Battison to clarify the accommodation and shift schedule with the new project proposal.
“When we took over Gibraltar Mine it was a seven-seven shift and a number of employees actually lived in other communities, but our president, who is a small-town British Columbia type of guy, says if you’re going to build a mine in a community you have to make that community strong and direct the spending in that community.”
He changed the shift to four and four and as much as 40 per cent of the workforce quit.
“We had to find all new people because those people did work in other communities. We found those people and they are living here and some of them are in the room today,” Battison added.