August 2007

Engineering Exchange

Mining experts from concept to closure

By H. Weldon

Wildlife at Campo Morado

Knight Piésold Consultants first put down roots in South Africa in 1921. They now have offices around the globe including Vancouver, which opened its doors in 1975, and North Bay, opened in 1994. With 500 employees worldwide, including 140 in Canada, Knight Piésold remains a comparatively small, but specialized international company, with a reputation for high quality engineering and environmental services and maintaining long-term relationships with their clients.

According to Jeremy Haile, president of Canadian operations, 60 per cent of Knight Piésold’s work is in geotechnical, environmental, and water-related projects for mining clients with a sub-speciality in renewable energy, namely, hydropower and wind. Because of their keen interest in the environment, “Knight Piésold is at the leading edge of applying renewable energy to mining operations,” Haile stated.

Haile is enthusiastic about the strong mining economy. “We’ve been very busy,” he admitted, “with a significant increase in workload over the last three or four years.” Knight Piésold is mostly made up of young, energetic, and highly skilled members. “We offer a lot of training and professional development programs and we’ve been fortunate in attracting the right talent to come and join us,” Haile proudly said. Haile himself is one of the old-timers; he began working for Knight Piésold in Zambia, in 1972.

Knight Piésold carries out work for mining clients all over the world, and is involved in all stages of the mining life cycle, from baseline studies for early development projects, through detailed design and construction, on-going operations, and closure. What follows are examples of typical projects being undertaken by the Canadian offices at different stages of development, and in different geographic settings, including Canada, Mexico, and Greenland.


Knight Piésold’s first foray into Greenland began in 2005 with the Malmbjerg project. This future molybdenum mine is still in its infancy. Knight Piésold’s involvement includes geomechanical and geotechnical design, and tailings and water management as part of the pre-feasibility study.

Malmbjerg is located in eastern Greenland, near the coast. Working that far north can leave even the most seasoned engineer scratching his head in dismay. Ken Embree, managing director of the North Bay office, has been with the project since the beginning. He and his team have met the challenges head on, and remain unfazed. “The logistics associated with the far north pose certain challenges,” Embree noted. “Malmbjerg will be a fly-in/fly-out camp. Its Arctic location means continuous permafrost, which factors into all design aspects, and the dry climate and steep mountainous glacial terrain add to the challenge of water management.”

As part of the waste management design, Knight Piésold is currently undertaking a laboratory testing program on tailings and rock samples, which play an important role in the environmental baseline studies. “We are currently looking at different options for tailings and waste management,” Embree stated. Conventional slurry, thickened paste, and dry stacked tailings are all possible, and through research and testing, Knight Piésold will determine which method is best suited to the site.

Other challenges for Malmbjerg are due to its remote location and pristine environment. There is only a three- to four-month shipping window, and as the nearest town is 200 kilometres away, finding an adequate labour pool of locals will be difficult. There is also a limit on geographical areas where work is to be done. For example, work plans will have to consider times when native animals are in more fragile states, such as when the geese are moulting, or when the musk ox are travelling through the area.

The days of 24-hour sunlight can be an adjustment too. “One of the guys was very proud to announce that he got sunburned … while working night shift!” Embree chuckled.

Campo Morado

Farallon Resources are currently developing the G-9 mine on the Campo Morado property located in Guerrero State, Mexico. It is a historic mining property that, in 1997, was acquired by Hunter Dickinson. Knight Piésold is assisting with environmental permitting, water and waste management, and all geotechnical aspects of the project. Permits were awarded to develop the mine in June of this year and Knight Piésold’s team is flat out on this fast track development. Their scope of work includes the design and construction of a zero discharge, sophisticated water and waste management system, which includes stream diversions and a membrane-lined, earth-rock fill embankment dam.

Challenges specific to the site include the remediation of the historic mining discharge, rugged terrain, and seasonal heavy rains. Knight Piésold is also involved in designing an access road and the building of a large platform for the mill. With assistance from its Lima office, Knight Piésold’s Vancouver staff will provide construction supervision services for the initial mine construction, and ongoing services for water and waste management, and geotechnical design for the underground mining.

Mount Polley

Closer to home, Knight Piésold has been involved with the Mount Polley mine in central British Columbia, near Williams Lake. Knight Piésold got involved in 1989 when Mt. Polley was in the feasibility stage. Les Galbraith, senior engineer, became involved in 1996 when construction of the initial phase of the tailings facility began. Knight Piésold has provided all the detailed design and construction QA/QC for the multiple tailings dam raises since that time, completed annual inspections of the tailings facility, and in 2006 provided the design and QA/QC services for a heap leach pad.

Mount Polley Mine started production in 1997 and had milled approximately 27.5 million tonnes of ore prior to stopping production in October 2001. Mount Polley Mine re-opened in March 2005 after managing the facilities for care and maintenance activities since October 2001. MPMC is currently mining and milling ore from the Bell pit and the Wight pit with the non-reactive tailings being deposited as slurry into the tailings storage facility. The tailings facility consists of filter-graded earthfill embankments with a low permeability core zone that is constructed with local glacial till materials that extend throughout the basin. Process water is collected and recycled back to the mill for recycle in the milling process.

Mt. Polley operates the mill concentrator at nominal 20,000 tonnes per day. The Cariboo pit has been mined out, the Wight and Bell pits are currently being mined, with the Springer pit and the South East Zone expected to come on line within the year. Water management is important as the mine site is currently operating under water surplus conditions, with the water being stored in the tailings facility. Knight Piésold engineers are working with Mount Polley mine personnel to adapt the site water management plan so that it accom­modates the ongoing expansion of the mine.

The current mine plan extends through 2015, although further exploration is ongoing. Although mine closure is at least eight years away, the closure plans are reviewed during each expansion stage of the tailings facility by Knight Piésold to ensure that the design is consistent with the long-term closure and reclamation plans. Knight Piésold has been involved with Mount Polley mine for 18 years and plans on seeing the mine through to its closure and reclamation stage.

Knight Piésold is firmly committed to seeing projects through from beginning to end. Many of their clients are companies they have consulted for in the past. A large proportion of their contracts are long term, such as the Montana Tunnels Mine in Montana, where Knight Piésold started investigations in 1985. Twenty-three years later and they’re still there. In the mining industry, that’s a lifetime indeed.

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