Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation MINE DEVELOPMENT: AN INTEGRATED APPROACH by Malcolm K. Ross and W. Stuart Hunter Good morning ladies and.gentlemen. When Jim Lant, your persudsive pro- gram chairman, invited Malcolm and I to present a paper to you today, we accepted with the proviso that we would not restr ict the paper to a part icular facet of recla- mation. Rather we would like to describe, as an example, reclamation as a single facet of overall mine development and operations. Before defining the framework and ob- jectives of the integrated approach to devel- opment, I would like to il lustrate the evolu- tion of project planning as we see it in Crows Nest. I must admit that the concept of the various stages of evolution and the "bubble" diagrams (which you will see) did not origin- ate with us. Credit is due to Bert Webber of the Western Washington State University who has included them in a soon-to-be-published book on coal transportation. However, I have mod i f ied and added to the t i t les in the bubbles to reflect my understanding and, per- haps, biases (Figure I). Stage I, then, describes the structure of project planning up to around the 1950's and early sixties. This stage could be equally well characterized by reversing the order of the "bubbles." It is also significant that this era was one in which large projects of a more polit ical nature were committed for motives of national prestige, sometimes only having a tenuous link to economics, markets or the technical disciplines. Stage Il developed during the 1960's, partially due to the need to more efficiently manage the megaprojects. As a result of the impacts of large projects speci f ical ly and the developed nat ion's increasing industr ia l act iv i t ies, concern for the environment did begin to factor in project planning by the early 1970's but still more as a cosmetic afterthought and usually in operations (Stage III). Stage IV (Figure 2) shows the process in vogue during the late 1970’s, with the addi- t ion of publ ic involvement ref lect ing in- creasing public pressure to have some say in projects impinging on their l i festyle. How- ever, the process is still sequential. Lastly, Stage V represents the process towards which we are evolving in the 1980's with all com- ponents ful ly integrated from the earl iest stages of the development process. The interlocking of the three bubbles also implies that the project group is an interdisciplinary team of specialists who un- derstand and "buy-in" to the concept of inte- grated mine development. This team must serve two masters. The first is the company executive who must be convinced that, in the uncertain world of mining and selling coal, the project is soundly conceived and that future risks have been sufficiently accounted for to provide the de- gree of confidence that a decision can be made. The second master is government who must also have sufficient information to as- sess the project and decide whether or not, on the basis of aggregate benefits and costs, society in general will benefit if the project proceeds. Integrated development planning, then, is the task of identifying, measuring and understanding all of the resources, their con- straints and interdependences. The object- ives are to provide a rational and consistent framework for decision making and, in the successful cases, a basis for ongoing oper- ational design. Reclamation, incorporating elements of environment, engineering, geology, econom- ics and public perceptions as to end use is an excel lent example of how th is approach works in practice. So I ' l l turn the presen- tat ion over to Malcolm Ross who wil l de- scribe reclamation planning and activit ies which CNRL has carr ied out to date at our 7 Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation Telkwa property near Smithers. The concept of integrated development has been explained. Implicit in this concept is an understanding and committment by all members of the Planning and Development Team that they are coal miners. I am a coal miner with particular disciplinary skills which enable me to supervise, on behalf of the company, those aspects of coal mine develop- ment which are environmental in nature. This does not diminish my committment to the environment. On the contrary, it ensures that environmental matters are fully accounted for. Let us then consider, as a practical example of integrated development, part of the 1983 development program on Crows Nest Resources Limited's Telkwa property. Since exploration commenced on this pro- perty in 1979, the successful reclamation of roads, trenches and drill sites has been well- documented, and considerable practical re- clamation experience has been gained as a result. The development program included a bulk sample component as well as conven- tional exploration, environmental and socio- economic studies and community liaison. In the bulk sample sub-program, multi-seam coal samples were taken from two test pits which were excavated in a cleared area ap- proximately 1,000 x 70 m. The objectives of this program were to obtain coal samples for analyses for essential data on processing and utilization, and to maximize operational information on geology, mining and reclamation. This, as indicated earlier, will contribute to a more accurate assessment of conditions and facili- tate more efficient planning of the proposed coal mine. The area was cleared in June of 1983 and the predominently poplar vegetation cover removed. Topsoil from the cleared area was then removed and stockpiled. The de- cision to proceed with the two pit con- figuration instead of one large pit was made as a result of the structure of the sub-crop and as a method of reducing the overall surface disturbance and consequential cost reduction. The smaller, shallower east pit and the larger west pit were excavated se- quentially from east to the west. Not all of the initial objectives of the program were able to be met. For example, in keeping with Crows Nest Resources Limited's desire to maximize operational in- formation from the bulk sample pit, it had been proposed to leave part of a pit open for a predetermined period of time to determine the geotechnical stability of the highwall. This was contingent on the highwall being suitable for such studies. This did not event- uate, and both pits were completely back- filled following coal removal. Poor weather conditions enabled an assessment of equip- ment capability under all conditions. While the pits were open, every opportunity was taken to collect operational information. The waste materials produced from such a bulk sample extraction are similar to those which would be produced during actual mining. In- formation was collected on the swell factor of overburden materials, and samples were taken at intervals along the pit walls for chemical characterization. Channel samples also were taken from the footwall and hanging wall of each seam. These latter samples in particular were collected for analyses for potential acid mine water pro- duction. Pit water was pumped to a settling pond and sampled for quality. Coal samples were taken sequentially from the higher to the lower seams and sampling was followed by progressive back- filling. The deeper west pit was still open when the shallower east pit had been back- filled. Backfilling of the west pit then com- menced from the eastern end. At the eastern end of the western, deeper pit, that is, roughly in the centre of the bulk sample site, the backfilled spoil was levelled at approxi- mately I meter below the original surface level. This area, 12Om x 20 m, was used as the location to construct a series of repli- cated treatments investigating the growth capabilities of various combinations of spoil and overburden material (Figure 3). These investigations were designed to contribute to the development of the most appropriate materials-handling methods to 8 Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation Figure I EVOLUTION OF INTEGRATED DEVELOPMENT PLANNING Source: Webber et al. 9 Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation Figure 2 EVOLUTION OF INTEGRATED DEVELOPMENT PLANNING Source: Webber et al. Figure 3 TELKWA RECLAMATION PLOTS IO Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation Figure 4 RECLAMATION PLOT DESIGN 11 Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation ensure operational reclamation success, not to provide a definitive method. It is import- ant to grasp the conceptual difference be- tween theoretical and applied, or operational, reclamation research. Operational research does not, and should not, investigate the relative performance of new species or culti- vars or different modes of propagation of these species. The vegetative species to be used in mine reclamation are qualified in the operational objectives of the reclamation plan by the pre-determined post mining land uses. These land uses may be forestry, agri- culture, wildlife habitat, watershed manage- ment or other specified uses either singly, or in combination. The most successful, and most appropriate species to meet the opera- tional reclamation objectives are known on a site specific basis: they are the species which are present already, the local ecotypes, pro- venances and cultivars. The problem, then, is how to provide the best possible growth medium, or seedbed, for the establishment, survival, and self-sustaining productivity of these species. Three replicates of each treatment were included (Figure 4). The four treat- ments, each 20 x 10m, were subsoil manipula- tions, each of which was topsoiled. The treat- ments were: topsoil over till, which in effect was a reconstituted soil profile; topsoil over raw spoil; topsoil over a fluvial material which occurs over a significant portion of the property; and topsoil over a mixture of till and spoil. The latter is the combination of material which is most likely to occur on the surface following mining. As a control, 3 replicate comparison plots were laid down on nearby undisturbed soil, each 20 x 10m. The area cleared for the comparison plots was calculated with an understanding of the need for similar light regimes on treatments and controls. Two scrapers, a large dozer, and a small dozer were used to spread the subsoil treatments. These treatments were deter- mined following discussion with engineering and geology staff, following a 1:5,000 soil survey which was conducted over the project area, and following analyses of overburden and parting quality and quantity. After the subsoil treatments were put in place and levelled, the major construction was com- plete, and the area was ready for topsoil ing. Prior to topsoiling, soil samples were taken from each subsoil treatment down the center line of the plots. As a result of working in a confined area, the excess travel by scrapers compacted the treatments, particularly the raw spoil treatment. As a result, this latter treatment was ripped prior to top soiling. This would not be required in an operational mining sequence. Topsoiling then took place to a predetermined thickness. During and after test plot construction, the rest of the bulk sample area was back- filled and levelled. The surface was surveyed to determine variance from original contour. As well, a drainage line which traversed the site prior to operations was replaced. One-third of each of the treatments was planted to a forage mix which was re- commended by the local district agricultural- ist. The remaining two-thirds of the areas of the reclamation plots will be planted to com- mercial tree species, spruce and pine, in the spring of 1984. Arrangements are being made to obtain local provenances from the district office of the Ministry of Forests. The same forage mix and trees will also occur on the comparison plots. The remainder of the sur- face of the sample site was seeded to the forage mix in the fall of 1983. The completed sample area, on the eastern side, indicates the blending with local topography that is possible with contouring. On the western end, the surface was contoured in a manner that directed surface flow into the surrounding bush and not directly towards Goathorn Creek. These plots will provide information on the crucial stages of establishment and early growth for approximately 8 years prior to their being mined during operations. The completed program produced a site which can be used as a demonstration of the success of integrated development planning to the local community and to the Provincial Government. It must be emphasized that every effort was made to maximize informa- tion available. As a further example, the trees cleared from the area used for 12 Proceedings of the 8th Annual British Columbia Mine Reclamation Symposium in Victoria, BC, 1984. The Technical and Research Committee on Reclamation comparison plots were sectioned and ana- lyzed. From this information a series of site index curves for merchantable tree species were developed. Incremental costs of these plots represented 2 days of machine time plus consultant time. Consideration of all aspects of the bulk sample program allows an early assessment of the relative magnitude of potential envi- ronmental and reclamation problems, both technical and financial. Early identification of potential areas for specialized materials handling methods is one of the numerous advantages which accrues from the integra- tion of geology, engineering and the environ- ment. When all disciplines are incorporated into the mine design and cost studies, an objective, balanced assessment of the tech- nical and financial viability of the project results. This is a real assessment, not a laboratory study, a paper study or a computer simulation. 13