Post-mining Land Research Articles

Adverse effects of coal mine waste dumps on the environment and their management

Waste dumps generated from mining that exposes sulfur-bearing overburden can be active sources of acid generation with the potential to severely contaminate soils, surface and groundwater, and endanger both local and downstream ecosystems. A waste rock management strategy ensure that disposal of such material is inert or at least stable and contained, and minimizes the surface footprint of the wastes, and explores options for alternate uses. Reclamation of waste dumps is another or parallel alternative to decrease the potential for adverse effects. At the coal mining area of Karmozd in Iran, large volumes of wastes have been produced and disposed of without any specific care for the environment. In this paper, the impacts of waste dumps on the environment were identified and this was followed by a research program to determine the characteristics of the wastes, their acid generation potential, the availability of hazardous contaminants, and a prediction of their environmental impacts on the site. Data was collected from the target site and by comparing several reclamation alternatives using a Multi-Attribute Decision-Making technique, forestry was selected as the post-mining land use for the waste dumps. Preliminary evaluations indicated that Zelkava could be a useful tree species for this region.

Optimal hardwood tree planting and forest reclamation policy on reclaimed surface mine lands in the Appalachian coal region

We study the optimal hardwood tree planting decision on reclaimed surface coal mines in the Appalachian region using a mine operator-focused, expected cost model that recognizes costs of preparing the site for tree planting, unit costs of planting seedlings, and opportunity costs of reforestation treatments and the performance bond. We also consider the possibility of failed initial attempts by incorporating the probability of reforestation success, based on empirical seedling ,survival rates and regulated tree survival standards, as well as fixed and unit costs of returning for additional planting. Optimal planting levels from 319 to 780 trees per acre and expected costs from $1049 to $2338 were found using simulations over a range of unit planting costs, fixed costs of replanting, tree survival standards, and interest rates. Further simulations compared optimal planting across un-weathered gray sandstone and weathered brown sandstone substrate materials, finding gray sandstone to be associated with lower expected costs. We conclude that optimal planting density and expected reforestation cost are sensitive to economic parameters, regulations, and planting substrate materials; and those policies influencing these factors may have substantial impact on reforestation outcomes and the choice of post-mining land use by mine operators. Our study provides a framework for understanding forest reclamation decisions that incorporates incentives faced by the mine operators who develop and implement the plans for mine reclamation, including forestry.

Examining the Australian context for post-mined land rehabilitation: Reconciling a paradigm for the development of natural and novel ecosystems among post-disturbance landscapes

This analysis attempts to reconcile existing rehabilitation planning goals and implementation constraints in the form of a paradigm that considers potential and pragmatic ecosystem transformation pathways using the Australian post-mined landscape as a contextual backdrop for investigation. A feature of the framework is that ‘novel’ ecosystems and agro-ecosystems possessing a range of commercial and societal values could bridge the conceptual divide separating the ecological function of under-rehabilitated (e.g., derelict sites) versus re-instated ‘natural’ landscapes. Landscape suitability analyses are incorporated in an operative framework to emphasise the influence of regional landscape and climate in the implementation of such management strategies. Altogether, the paradigm could facilitate the identification of widely pertinent rehabilitation goals and assessment criteria with direct implications at the regional scale of post-industrial land rehabilitation.

Optimizing post-mining land use for pit area in open-pit mining using fuzzy decision making method

Open-pit mining method has severe environmental impacts which should be prevented, monitored, controlled, and reduced by mined-land reclamation process. After mine closure, a permanent post-mining land use should be implemented as an appropriate choice for using different sections of mined land. The most appropriate alternative of post-mining land use for each section of mined land is presented as the optimum post-mining land use. Pit area among different sections of mined land has more significant effects on the environment and also on defining the optimum post-mining land use for other sections of mined land. Though there are several alternatives and criteria for defining the optimum post-mining land use, the multi-attribute decision-making methods can be efficient techniques in this regard. The nature of the effective parameters used for defining the optimum post-mining land use is the same as Fuzzy numbers including incremental changes without definite limits. Thus, application of the Fuzzy multi-attribute decision-making modeling can produce more reliable results than that of other techniques. As well, pair-wise comparisons and judgments through Fuzzy numbers have proper consistency with the nature of the effective parameters; therefore, a model is developed to attain the optimum post-mining land use for pit area through Fuzzy analytical hierarchy processing. As a case study, the model was implemented in Sungun copper mine in the Northwest of Iran. Forestry–lumber production was defined as the optimum post-mining land use containing the greatest relative importance coefficient 3.019 for the pit area in this mine.

Grazing as a post-mining land use: A conceptual model of the risk factors

Driven principally by government regulation and societal expectations, mining companies around the world are seeking to mitigate the environmental impacts of mining through mined land rehabilitation programs. The ultimate goal of rehabilitation is to establish an acceptable and sustainable post-mining land use. Mining companies worldwide face the challenge of specifying just what a sustainable post-mining land use will be. The problem is that while regulations require mining companies to assess post-mining land use sustainability, the mechanism for doing so and the factors that should be considered are not specified. We propose a risk-based approach to post-mining land use assessment with the aim of reducing the uncertainty of mine closure and the potential cost of repair of land degradation caused by inappropriate post-mining land use.Grazing is a commonly suggested post-mining land use, particularly in Australia where most mining activities occur on land previously used for cattle grazing. Grazing is also seen as a use suited to rehabilitated mined land because of the lower land productivity required compared to cropping. In this paper we develop a conceptual model of the factors influencing the land degradation risk posed by grazing on rehabilitated mined land. This was done through a literature review to identify potentially important risk factors, followed by a survey of graziers surrounding six open cut mines within the Bowen Basin Region of Queensland, Australia. The survey results were used to develop a profile of the risk factors likely to influence the land management behaviour of graziers within the Bowen Basin.The results of the research highlight that there are three main sets of factors that affect grazing risk on rehabilitated mined land. These are site biophysical characteristics that influence land productivity and commercial grazing viability, factors that influence the land management style of a grazier (principally stocking rate decisions), and factors that influence the commitment of a grazier to comply with any caveats placed on the management of the land. The profile of risk factors obtained for Bowen Basin graziers showed that grazing is likely to be a low risk post-mining land use where land productivity is high enough to support commercial cattle grazing and where land is managed by local graziers. Both the conceptual model and the profile of risk factors described in this paper are precursors to the development of a predictive risk assessment model.

GIS Database Template for Environmental Management of Mining in Indonesia

Mining sector in Indonesia faces many challenges including needed to support national economy, compliance to central and local government regulations, local community empowerment and environmental impact management. Mining companies are mandatory to perform the environmental management efforts to minimize the negative impact to the environment and pursue sustainability of post-mining land use and as much as possible to restore land to the initial conditions. There are many challenges on management multi parameter and multi temporal spatial data of environmental management. The aim of this research is to design the GIS database template for environmental management in Indonesia’s mining operation. This GIS database is designed using ArcCatalog ArcGIS 9.3 software, through following steps: inventory and assessment government regulations, inventory and assessment environmental quality standards, sorting and grouping parameters, design feature class and attribute, create GIS database, create GIS database dictionary. According to research result, GIS database template has many advantages for environmental management include integrated into a single database, avoid redundancy data, reduce volume data, uniformity data, easy to find and track data, integrated spatial and attribute data, can be used as an input for GIS analysis for decision-making and development strategies.

Soil and Sand Mining: Causes, Consequences and Management

Sand is not only a precious mineral but also protecting the environment, buffer against strong tidal waves and storm, habitat for crustacean species and marine organisms, used for making concrete, filling roads, building sites, brick-making, making glass, sandpapers, reclamations, and in our tourism industry in beach attractions. Sand mining is the process of removal of sand and gravel where this practice is becoming an environmental issue as the demand for sand increases in industry and construction. Topsoil is an essential component in abandoned mines for growth of vegetation and has to be preserved for post-mining land reclamation. Physico-chemical parameters and concentration of heavy metals Pb 2+ , Zn 2+ , Ni 2+ , Co 2+ , As 3+ , Cu 2+ , Fe 2+ , Mn 2+ and Sn 2+ were analyzed in mined soil areas and found that most parameters and metals concentration exceeds the permissible limit and that ex-mining catchment has a high pollution potential. Reclamation strategies of tree planting, amendments like tank silt, poultry litters and growing bio fuel crops are recognised for its ability to restore the soil fertility, build the eco-system and arrest soil erosion. Scientific mining operations accompanied by ecological restoration and regeneration of mined wastelands and judicious use of geological resources, with search for eco-friendly substitutes and alternatives must provide sensational revelation to the impact of mining on human ecosystem.

Evaluation of plant growth on degraded mine soils amended with class F fly ash and animal manures

The coal power generation, livestock production and coal mining industries are three of the largest roleplayers in South Africa’s economy and environment. These industries respectively produce huge volumes of fly ash, organic wastes and degraded land, resulting in both financial and ecological impacts. The need, therefore, exists to explore the recycling potential of fly ash, and combinations of fly ash with cattle and chicken manure. The aim of this study is to determine whether class F fly ash and combinations of class F fly ash with cattle and chicken manure can serve as alternative soil amendments to establish a more sustainable plant production system on degraded soils. Phytotron pot trials simulating the post-mining land capability class for pastures and fodder crop production, were planted with winter rye (Secale cereale), Japanese millet (Echinochloa frumentacea) and forage sorghum (Sorgum vulgare). Two soils, cover soil and acid mine drainage impacted soil (AMD), were amended with twelve treatment combinations at two different levels, optimum and 2X optimum. Treatments included combinations of agricultural lime, fertiliser, chicken manure, cattle manure, and class F fly ash.

English

The Forestry Reclamation Approach is a five-step system for reclaiming mined lands to forests. Step 1 of the FRA involves creating a suitable rooting medium for good tree growth using topsoil, weathered sandstone and/or the material. Several types of overburden types can be selected to place on the surface as growth media. These spoil types include weathered brown sandstone and unweathered rock materials including sandstones, siltstones, shales, and mixtures of these materials. When sufficient topsoil is not salvageable, reclamation scientists often recommend that, when available, weathered sandstone should be considered as the best available topsoil substitute material. Here, we review the scientific evidence that supports such recommendations. Several studies have shown that tree survival was not significantly different among spoil types. Weathered brown sandstone, unweathered gray sandstone, siltstone and shale materials all produced good tree survival (>70%) when compaction and competitive ground covers were reduced. However, growth for most trees (as measured by height, diameter, and volume) was usually significantly greater in weathered brown materials than in unweathered sandstones, siltstones, shales, and mixed spoils. At one site in West Virginia five years after planting, a 10-fold difference in tree volume was found between these two spoil types. Similar results have been found with other studies across Appalachian surface mines. Based on the results of studies summarized herein, the use of weathered brown sandstone is generally recommended, along with topsoil materials when available, to be placed on the surface on sites where hardwood tree species are being planted for forestry post-mining land uses. Weathered brown sandstone spoil materials have a pH, soluble salt content, fine earth content well suited for trees, and sufficient nutrient supplying and water holding capacity that results in superior tree growth compared to other spoil types. The brown sandstone material more closely resembles the native forest soil than the unweathered gray materials.

KARAKTERISTIK PEDOLOGI DAN PENGELOLAAN REVEGETASI LAHAN BEKAS TAMBANG NIKEL: STUDI KASUS LAHAN BEKAS TAMBANG NIKEL POMALAA, SULAWESI TENGGARA

<p>Post-mining land management needs to be done by taking into account a holistic approach concerning the improvement of physical, chemical and biological properties of soil as growth media, in order to support the rehabilitation plans. The objective of this study were: (i) to conduct quantitative and comprehensive an inventory of pedological properties of nickel post mining land, (ii) to analyze the potential and limitations of post mined land, (iii) act designed environmental management, based on the characteristics of the revegetation of the land and the environment. The results showed that the soil in Pomalaa could be classified in Typic Hapludox, clayey, mixed, isohypertermic (P1) dan Typic Hapludalfs, loamy, mixed, isohypertermic (P2), while the material in ex mining area are overburden or parent material. The soil has developed from peridotite and peridotite-serpentinite ultramafic material. This soil has low natural fertility and require efforts to improve the physical properties. Ex-mining area has a high rate of erosion. Poor tree growth in revegetation area has been determined caused by a deficiency of Ca, Fe, Cu, or Mn. The possibility of Ni and Cr toxicity in plants needs to be further investigated. Local resources in the form of slag can be used for revegetation, especially converter slag. The results obtained from this study can be used to give the advice of post-nickel mining land management, based on land characteristics. A better management advice covers two issues, namely improvements of the management action actually implemented and improvements in technical rehabilitation.<br />Keywords: Pedological processes, post nickel mining land, revegetation</p>

A PROPOSAL TO ENHANCE THE EFFECT FOR POST-MINING LAND USE TAN DONG HIEP, NUI NHO AND BINH THUNG QUARRIES IN DI AN, BINH DUONG PROVINCE

According to Mining Regulation, quarry reclamation after mining has to be proposed in EIA. In reality, due to many reasons, a lot of quarries being extracted or closed quarries have not had detailed reclamation plan yet. This lead to waste land resource and cause many environmental problems. In order to enhance mining effect and mitigate negative impacts for Tan Dong Hiep, Nui Nho (are being mined) and Binh Thung (closed quarry) rock quarries in Di An, Binh Duong, several post-mining land use approaches that based on regulations, natural features, land use planning of local government will be proposed.

Private and Social Costs of Surface Mine Reforestation Performance Criteria

We study the potentially unnecessary costs imposed by strict performance standards for forest restoration of surface coal mines in the Appalachian region under the Surface Mining Control and Reclamation Act of 1977 (SMCRA) that can vary widely across states. Both the unnecessary private costs to the mine operator and costs to society (social costs) are reported for two performance standards, a ground cover requirement, and a seedling survival target. These standards are examined using numerical analyses under a range of site productivity class and market conditions. We show that a strict (90%) ground cover standard may produce an unnecessary private cost of more than $700/ha and a social cost ranging from $428/ha to $710/ha, as compared with a 70% standard. A strict tree survival standard of 1235 trees/ha, as compared with the more typical 1087 trees/ha standard, may produce an unnecessary private cost of approximately $200/ha, and a social cost in the range of $120 to $208/ha. We conclude that strict performance standards may impose substantial unnecessary private costs and social costs, that strict performance standards may be discouraging the choice of forestry as a post-mining land use, and that opportunities exist for reform of reforestation performance standards. Our study provides a basis for evaluating tradeoffs between regulatory efficiency and optimal reforestation effort.

Hardwood Tree Survival in Heavy Ground Cover on Reclaimed Land in West Virginia: Mowing and Ripping Effects

Current West Virginia coal mining regulations emphasize reforestation as a preferred postmining land use on surface mined areas. Some mined sites reclaimed to pasture are being converted to forests. In the spring of 2001, we compared the establishment and growth of five hardwood tree species on a reclaimed West Virginaia surface mine with compacted soils and a heavy grass groundcover. We planted 1-yr-old seedlings of five species (black cherry [Prunus serotina Ehrh.], red oak [Quercus rubra L.], yellow poplar [Liriodendron tulipifera L.], black walnut [Juglans nigra L.], and white ash [Fraxinus americana L.]) into sites that were mowed and unmowed on north- and south-facing aspects. We applied a ripping treatment, which loosened the compacted soils and disturbed the heavy ground cover. First year results showed >80% survival for all species. After 7 yr black cherry survival averaged 36%, red oak 47%, yellow poplar 66%, black walnut 80%, and white ash 98% across all sites and treatments. Seedling survival was best on north, unmowed, and ripped areas. Average growth (height x diameter(2)) of trees after 7 yr was greatest with white ash (434 cm(3)), followed by yellow poplar (256 cm(3)) and black walnut (138 cm(3)), then by black cherry (31 cm(3)) and red oak (27 cm(3)). Browsing by wildlife had a negative impact on tree growth especially on south aspect sites. Overall, mowing reduced survival of black cherry, red oak, and yellow poplar, but not for black walnut and white ash. Ripping increased survival of black cherry, red oak, and yellow poplar. Growth of all species was improved with ripping. Using inverse linear-quadratic plateau models, the time required for tree survival to stabilize varied from 1 yr for white ash to 6 to 9 yr for the other species.

English

Past open pit mining operations at the Chevron Mining Inc. (CMI) Questa Mine in Questa, New Mexico, resulted in several large overburden rock piles. The rock piles are generally steep, angle of repose (2:1 and steeper), acidic (pH 2.5 - 7.0) and composed of a variety of igneous rock types. Pre-mining and currently undisturbed vegetation in the area of the mine site is dominated by mixed conifer forests. Forestry is the approved post-mining land use for this mine. Since the early 1990's studies have been conducted examining the potential for establishing the forest vegetation directly on the overburden rock piles. In the fall of 1996 and spring of 1997 two operational scale plantings at two locations on the mine rock piles were conducted to examine both the logistics associated with planting trees and shrubs directly on angle of repose slopes and the subsequent survival and growth performance of the transplanted vegetation. Short-term (three year) overall survival averaged 81%. There were survival differences between the two planting sites and among the three types of plants being transplanted with crop trees (conifers) averaging 87%, nurse trees (deciduous) averaging 63% and shrubs averaging 92%. Long-term (twelve year) survival averaged 43% and differed between planting sites with the lower elevation (2,500 m) planting site averaging 45% and the higher elevation (3,000 m) site averaging 41% overall survival. The resulting vegetative communities differed between the two planting sites with the higher elevation site having a higher proportion of crop trees compared to the lower site that had comparatively a higher proportion of shrub species. Implications of the results relative to future reclamation plantings are discussed.

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Modern mining methods can drastically change landforms in the project area. Traditional reclamation grading methods often do not address all the criteria that must be met for the desired post-mining land use including water quality standards, in-stream uses, vegetation diversity and other reclamation criteria. Inability to meet or mitigate for these changes caused by the proposed reclamation landform can even stop mining activity from proceeding. A new, natural approach to landform grading called GeoFluv TM (Bugosh, 2003) offers a cost-effective alternative for sustainable mineral development than can satisfy the reclamation criteria and is the heart of the Natural Regrade computer software module (Bugosh, 2006). Monitoring results of land surfaces and storm water discharge quality, including runoff that meets NPDES discharge limits before reaching sediment treatment ponds, at constructed projects strongly support the effectiveness of the GeoFluv design method at meeting the reclamation criteria (NMED, 2007). The objective of this paper is to summarize subjective observations of reclamation landforms constructed according to the GeoFluv design and the related objective data from large projects over approximately a seven year period to provide a status report of the effectiveness of the method for minimizing erosion and meeting water quality goals. Additional Keywords: fluvial geomorphic, GeoFluv, sustainable, landform, erosion, water quality, vegetation diversity, invasive species

English

Fine-grinding of ores for the liberation of metal- or other valuable concentrates most often results in acreage dedicated to tailings impoundments. A determination of the post-mining land use of such acreage is then required. Tailings impoundments can be suitably utilized as sites for installation of solar photovoltaic (PV) panels. The electrical energy produced can be used initially for mining and concentrating operations, and subsequently for the utility grid after mine closure is complete. Since the extraction, processing and transport of minerals is energy-intensive, most mines already have a substantial electrical transmission-line infrastructure. This eliminates one of the major costs associated with PV energy farms. In this paper, we analyze the long-term economic benefit (i.e. payback period) of PV installation and energy production at mine sites. We also discuss integrating PV systems with erosion control and revegetation measures.

English

Reforestation of mined lands has become a preferred post-mining land use in some parts of Appalachia since the Appalachian Regional Reforestation Initiative began. With this new emphasis, attention has been focused on replanting the American chestnut on these areas, which was decimated by Chestnut blight during the last century. The American Chestnut Foundation has developed potential blight-resistant hybrids through a series of backcrosses between American and Chinese chestnut. Therefore, the objective of this study was to evaluate the survival and growth of five seed types of chestnut (100% American, 100% Chinese, and three hybrids (B1F3, B2F3, and B3F2)) into loosely-graded minesoils at the Glory surface mine in Boone County, West Virginia. The five seeds types were randomly planted in eight blocks (four with tree shelters and four without shelters) and each block was split into randomly assigned peat or no peat treatments. Average seedling survival from seeds after the first growing season was 72% across all treatments, with survival of Chinese 82%, American 67%, and the hybrids at between 69 and 74%. Seeds with tree shelters showed a significantly higher survival at 81% compared to non-sheltered seeds at 63%. Peat treatment generally reduced seed survival but especially so on the non-sheltered seeds. Height growth of trees showed similar results as that of survival, with Chinese seeds and sheltered trees being greatest in height. Additional plantings of seeds and seedlings will be conducted in spring 2009 in West Virginia. Additional Keywords: chestnut hybrids, Forestry Reclamation Approach, minesoils, tree seedlings, tree seeds

An analytical approach with a reliable logic and a ranking policy for post-mining land-use determination

Because it is the post-mining land-use that prescribes the methods, the measures and the costs of mine reclamation, a major implicit goal of mine reclamation is to determine an after-use option. Therefore, there should be an analytical approach to optimize the determination of post-mining land-use. A Mined Land Suitability Analysis (MLSA) framework, which had been previously derived from reclamation practice reports of mines and other disturbed lands, is used in combination with two Multi-Attribute Decision-Making (MADM) techniques to provide the required analytical approach. In the proposed approach the decision makers consist of the most related experts and the identified stakeholders. The Analytical Hierarchy Process (AHP) method is used to determine global weights of MLSA framework attributes via pair-wise comparison matrixes composed by each individual expert. Once the global weight vector of the attributes is calculated using AHP, they are incorporated into the decision matrices composed by stakeholders and passed to the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), which is a distance-based MADM technique and is used to determine preference order of post-mining land uses.

Impact of post-mining subsidence on nitrogen transformation in southern tropical dry deciduous forest, India

The goal of our research was to assess the impact of post-mining land subsidence, caused due to underground coal mining operations, on fine root biomass and root tips count; plant available nutrient status, microbial biomass N (MBN) and N-mineralization rates of a Southern tropical dry deciduous forest of Singareni Coalfields of India. The changes were quantified in all the three (rainy, winter and summer) seasons, in slope and depression microsites of the subsided land and an adjacent undamaged forest microsite. Physico-chemical characteristics were found to be altered after subsidence, showing a positive impact of subsidence on soil moisture, bulk density, water holding capacity, organic carbon content, total N and total P. The increase in all the parameters was found in depression microsites, while in slope microsites, the values were lower. Fine root biomass and root tips count increased in the subsided depression microsites, as demonstrated by increases of 62% and 45%, respectively. Soil nitrate-N and phosphate-P concentrations were also found to be higher in depression microsite, showing an increase of 35.68% and 24.74%, respectively. Depression microsite has also shown the higher MBN value with an increase over control. Net nitrification, net N-mineralization and MBN were increased in depression microsite by 29.77%, 25.72% and 34%, respectively. There was a positive relation of microbial N with organic C, fine root biomass and root tips.

Achieving to some outranking relationships between post mining land uses through mined land suitability analysis

Adoption of most suitable post mining land use is a problem with multi-dimensional nature. There are so many factors in this problem which seriously influence on the decision judgments. Therefore, in this study a fifty- attribute framework for mined land suitability analysis including fifty numbers of economical, social, technical and mine site factors developed to be a foundation for this decision making problem. Analysis by an outranking multi- attribute decision-making technique, called elimination et choix traduisant la realite method, was taken into consideration because of its clear advantages on the field of mined land suitability analysis as compared with multi-attribute decision- making ranking techniques. Analytical hierarchy process method applied to calculate global weights of the attributes through pair wise comparison matrixes. The weights then passed to the elimination et choix traduisant la realit method so that the most efficient post mining land uses could be appointed through comparisons of pair-wise dominance relationships between alternatives. This approach applied to an illustrative example where, final results showed that, there were two non-dominated land-uses for the considered example; industrial and pasture. However by increasing indifference threshold limit, the non-dominated set reduced to a single alternative that was pasture land-use.