TABLE OF CONTENTS May 2010 - 1 comment

Coal mine fits right in with the community

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By: Russell Noble
2010-05-01

"Closed for the Season" is the kind of sign you'd expect to see at a roadside fruit or vegetable stand. It speaks for itself by clearly telling passers-by that everything is gone; there's nothing left for sale, the season is over!

Plain and simple, no question about it, but when you see a sign like that posted at the gate of a coal mine, you really start to wonder.

How can 'coal' go "out of season?"

In almost all cases, it doesn't but at Pioneer Coal Limited in Stellarton, Nova Scotia, coal is, in fact, "out of season" during July and August because that's when John Chisholm, president of the company, shuts down part of his coal mining operations for two months so that his neighbours can enjoy the outdoors a little more during the summer months.

It's an agreement he made with the community, and the local government, and he keeps his word every July and August.

As Chisholm says, "it is a producing coal mine and like all open-pit mines, there is a certain amount of noise and dust associated with it. Not a whole lot in our case, mind you, because there's no blasting on the site and most of the drilling and digging is now deep within the mine and out of sight and earshot of the surface. But there still is some."

Chisholm points out that many neighbour-friendly components have been designed into the mine, including an extensive conveyor system that has been installed so that coal is stockpiled far away from the boundary of the property.

Haul roads have also been routed away from public areas and are watered constantly to help ensure that dust is kept under the best possible control.

Haulers also limit the use of transmission brakes whenever possible to further reduce noise.

When it comes to crushing and processing coal, Pioneer has a fully enclosed primary and secondary crusher system built into a vented structure. All crushed coal is also blended and transferred from an enclosed building to a computerized feeder that loads more than 900 tonnes of coal a day to trucks for shipping to Nova Scotia Power's Trenton Generating Station, located about 13 km away.

To ensure that NSP gets a year-round supply of coal from the mine, Pioneer stockpiles thousands of tonnes near the crusher during the 'mining months' before the July-August shutdown and by doing so, only the enclosed crushing, blending and load outs are operational.

It's business as usual but without the drilling and digging.

As mentioned at the outset, the Pioneer Mine in Stellarton looks like a low-key operation but upon closer look, the mine is still one of the more active productive facilities operating in the region operating in close proximity to residences since 1996 with relatively few complaints from the neighbours.

From its five main, steeply-dipping seams; Foord (10.7 m), Cage (5.3 m), Flemming & MacGregor (4.0), Third (3.3 m) and New (1.5 m), Pioneer Coal has approximately 1.1 million tonnes of coal resource available. The numbers in brackets represent the thickness of the coal seams.

Through a conscientious rehabilitation program, the five seams are being mined in an east-west direction with the overburden volumes from the second pit being placed directly into the pit excavation to the east.

This sequence moves westerly with the final excavation being filled with overburden material from the first excavation. This progressive reclamation approach limits stockpile sizes and enables Pioneer Coal to complete final reclamation closely behind its mining operations.

As with all mining operations, potential contamination to surface runoff is always a major concern and to handle its water management issues, Pioneer Coal has gone to great lengths to help ensure that suspended solids from construction and mining activities and from storage of waste rock, topsoil and overburden go through a drainage system designed to collect surface runoff from active areas within the site for removal of suspended solids by gravity sedimentation.

Runoff is collected in ponds formed in low points of exhausted pits located toward the east end of the coal seams. It is pumped into an east transfer pond for initial setting and from there into sedimentation ponds.

The sedimentation ponds have a total surface area of approximately 7400 m2 and a volume of about 15,000 m3; therefore, highly conservative sedimentation conditions are provided at a maximum flow rate through the ponds of 1540 m3/h.

Only treated effluent is discharged from the site and the various holding and treatment ponds provide substantial containment capacity for storm runoff or for any other emergency situations that require holding water prior to treatment.

In addition to ensuring that the entire Stellarton site is safe from water contamination, Pioneer Coal has also developed plans with the local community to improve the condition of the landscape which had been marred by past underground mining activities. The overall reclamation of the site requires backfilling and contouring pits and covering the recovered areas with topsoil and vegetation. However, by coordinating the reclamation efforts with the community, the host community is saving.

Spending millions of dollars by having Pioneer Coal build a massive sports'complex for the community (complete with playing field, track, and bleachers and lighting) all on top of what was once a coal pit. Pioneer also built a "pad" for a large community water storage tower which is now in service while mining continues on the site.

As stated at the outset, Pioneer Coal Limited believes it is good practice to be is a good neighbour to the people of Stellarton but its work goes well beyond that town and spreads to other parts of the province where it's also active in coal mining.

Dan Khan, a Planning and Development Officer with the Nova Scotia Department of Natural Resources, Mineral Resources Branch, wrote a paper entitled: A study of concurrent reclamation practices at the Point Aconi Surface Mine, and in it he tells more about why Pioneer Coal Limited deserves recognition for its efforts in coal mining, and in particular rehabilitation because of the responsible manner in which it conducts business.

Khan says "Pioneer Coal Limited has operated several surface coal mines in Nova Scotia during the past three decades. The most recent mine, the Point Aconi Reclamation Mining Project, began in 2006. Near-surface coal resources at Point Aconi are being recovered following the 2001 closure of the underground Prince Mine.

A representative from Pioneer Coal Limited participated in the Surface Coal Mine Reclamation Enhancement Initiative and some of the ideas and methods developed through the initiative are now being applied at the Pioneer Coal project at Point Aconi, Cape Breton County, after positive results from vegetation test plots installed at Little Pond, Cape Breton County in 2007 by DNR.

Last year the Department of Natural Resources and Pioneer Coal began collaborating by documenting procedures being employed at the mine.

Pioneer Coal has allowed access to the mine site to document the reclamation practices employed and to conduct vegetation surveys of pre-existing conditions and post-reclamation conditions.

The mine operator has used three main approaches to utilize existing on-site vegetation during final reclamation at the mine site. Forest-floor grubbing and transplanting, shrub-clump transplanting and shrub-clump plantation methods were all applied last year.

Preparations for removing and transplanting the existing vegetation consisted of clearing existing trees from the forest by using a tree shredder/ chipper. All larger trees were felled and chipped in place to conserve the organic matter available for reclamation.

Following tree clearing, the forest floor (organic layer) was grubbed off with an excavator and loaded into dump trucks. Loaded dump trucks travelled to areas previously prepared for reclamation and discharged their loads. The materials were then spread with another excavator and a ground-cover depth of over 30 cm was generally achieved. The excavator operator attempted to place stumps in an upright position while covering the previously graded surfaces to encourage new tree growth. The work was conducted in winter months when plants were dormant. This approach was similar to the test plot conducted at Little Pond in 2007 and 2008 but at a much larger scale.

The second method used at the site was to remove large 'shrub-clumps' and transport them to a reclamation area immediately following excavation.

This process was accomplished using a loader equipped with a large pan-shaped bucket approximately 3 m by 4.45 m.

Shrub clumps were transported using the loader and placed on the surface in a relatively intact condition without disturbing roots and surface soil structure.

The clumps were placed tightly together to essentially cover all the ground. This work was done last summer.

The third method used at the site was a variation of the shrub-clump transplanting technique.

The primary change was that the shrub-clumps were not placed tightly together; instead the clumps were placed in a plantation pattern with areas remaining between the clumps.

The plantation approach allows larger reclamation areas to be treated with 'islands' of native vegetation, with the expectation that the vegetation will spread from the transplanted vegetation clumps. This work was done last fall.

Between the mining and reclamation work at Stellarton and the rehabilitation efforts underway at Point Aconi, Pioneer Coal Limited of Antigonish, Nova Scotia, certainly has a lot on its plate and CMJ salutes the company for providing innovative solutions to long-standing challenging environmental problems faced by many communities in Nova Scotia. CMJ

Photos

Aerial photo of Pioneer's Stellarton mine shows it in proximity to surrounding community.
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Caption: Aerial photo of Pioneer's Stellarton mine shows it in p...
A closer look shows some of the seams being worked at the mine.
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Caption: A closer look shows some of the seams being worked at t...
Pioneer President John Chisholm (far right) is joined by Diane Webber, Liaison Geologist, Nova Scotia Natural Resources (Mineral Resources Division), during a recent tour of the Stellarton Coal Mine.
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Caption: Pioneer President John Chisholm (far right) is joined b...
Steep-wall drilling deep within the Stellarton mine involves the use of customized drilling equipment.
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Caption: Steep-wall drilling deep within the Stellarton mine inv...
Conventional loaders to move the coal for processing.
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Caption: Conventional loaders to move the coal for processing.
Mine reclamation involves using a large pan-shaped attachment on a loader to move shrub-clumps into a 'plantation pattern' with areas left between the clumps to encourage extending growth.
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Caption: Mine reclamation involves using a large pan-shaped atta...
Technicians monitor new growth at every reclamation site.
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Caption: Technicians monitor new growth at every reclamation sit...
Overall view of Stellarton mine shows working pits in background and reclaimed land in foreground. Of particular interest in this photo are: the dome-shaped structure at two o'clock. (a water tower backfilled to blend with the rolling landscape and to provide a slope for winter activities); the rectangular-shaped impression in the middle (a track and sports field in early stage of construction) and three sedimentation ponds in the foreground to handle surface runoff.
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Caption: Overall view of Stellarton mine shows working pits in b...
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Reader Comments

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javier sanchez

Very nice to read this and to know that I work an a mine where we do the same as yo do there. I want to know more about this mine.

Posted September 5, 2014 07:23 PM


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