Post-mining Conditions Research Articles

Sustainable Afforestation Strategies: Hybrid Multi-Criteria Decision-Making Model in Post-Mining Rehabilitation

This article describes an effective approach for selecting suitable plant species for afforestation in post-mining rehabilitation. The research was conducted in the Western Black Sea region of Turkey. The aim of the research is to perform accurate criteria weighting and species prioritization for afforestation in post-mining degraded areas. This helps to ensure consistent conditions for the future use of the site as a forest, sustainability of nature, and selection of appropriate species adapted to the difficult post-mining conditions. In this study, which is a multi-criteria decision-making problem (MCDM), the weights of the criteria were determined by stepwise weight assessment ratio analysis (SWARA), and the priority ranking of the species was determined by the analytic hierarchy process (AHP). Analyses were carried out with 10 afforestation criteria and five tree species. According to the analysis, the top three ranked criteria are Economic Efficiency > Carbon Stock and Credit > Reducing Afforestation Cost. The five species’ priority ranking is Robinia pseudoacacia L. (0.456) > Alnus glutinosa subsp. glutinosa (0.248) > Populus nigra subsp. nigra (0.146) > Salix alba L. (0.103) > Quercus robur subs. robur (0.048). The hybrid approach is expected to increase the effectiveness of post-mining rehabilitation works.

Strengthening Reclamation Obligation through Mining Law Reform: Indonesian Experience

Reclamation can produce more value for the environment and create a far better situation than post-mining conditions. While the reclamation obligation policy is a great way to introduce a restorative approach to the environment, the main problem is the disobedience of the mining companies in their reclamation obligation. Therefore, we focused on conceptualizing the strengthening of the reclamation obligation policy in the Mining Act based on the understanding of preventing environmental and social damage. This research is conducted in doctrinal legal studies to create a prescriptive result. Despite the 2020 Mining Act Revision, Indonesia is still facing the previous legal issue due to blind spots in the regulatory framework. Ranging from the continuous conflicts between the mining company and the local community to the problem of non-compliance with the reclamation policy, which has resulted in excavation holes that were left untreated and abandoned, which has created casualties over the years. We offer two major reforms in formulation to strengthen the reclamation obligation. First, is the need to reinforce the essence of “obligation” for IUP and IUPK holders to perform reclamation and post-mining with supervision, as in the Environmental Act. With this formulation, the placement of the reclamation fund by the company does not eliminate the company’s obligation to carry out reclamation and post-mining activities. Second, for the company to comply with placing reclamation and post-mining funds, it is crucial to implement a mandatory condition, whereby the placing of a reclamation guarantees fund is a requirement for approval of the mining plans and budgets (the RKAB), and Clean and Clear (CnC) Certification. Therefore, the reform will cause a shift and strengthen the values of obligation in post-mining reclamations.

Assessment of hydrochemistry and heavy metals pollution in the groundwater of Ardestan mineral exploration area, Iran

The aim of this research is to determine the effective factors on the hydrogeochemistry and assessment of heavy metals pollution indices in the groundwater of Ardestan copper exploration area, Iran. In this study, in total, 111 groundwater samples from one well and several qanats and springs were collected. Piper and Stiff diagrams and statistical methods and quality indices were applied to hydrochemical data. Afterward, the water samples were classified into four groups, namely CaHCO3, CaCl, NaCl, and NaHCO3. According to evaluation indices, considering the fact that only a few points are in the high risk level, the groundwater of the study area has a low level of pollution. On the other hand, the pH of the groundwater of the region was mostly neutral and acid mine drainage was not found. Since the condition of the area is in pre-mining process, two factors are possibly influential: (1) rocks or minerals having sulfides are not exposed to an atmosphere (normally below groundwater) and H+ release does not occur and (2) the existence of minerals containing silicate and carbonate that can rapidly reduce acidification of water. Finally, it seems that during mining and in post-mining conditions, acid rock drainage which results from the oxidation of sulfides will probably influence the quality of water resources in Ardestan city. This is because the groundwater flow direction is from the mine toward Ardestan plain.

Groundwater system for the periods of pre- and post-longwall mining over thin overburden

The groundwater loss is one of the primary issues for environmental destruction. Underground longwall mining methods can cause rapid subsidence of the overburden strata. Especially in shallow coal seam mining. Since the subsidence through the overburden to ground surface, the groundwater may be affected and drawdown into the lower levels above the longwall panels. This paper analysed the potential impact of longwall mining on groundwater over thin overburden. Four water wells were drilled down to the proposed deformation zone above two longwall panels to record the different water levels’ variations throughout the mining period. A numerical groundwater flow model (GGU-SS-FLOW3D) was performed to predict the water levels in the periods of pre- and post-mining conditions. To set-up model, local mining conditions and regional geology characteristics were ascertained in this study. The measurement data from the four water wells were adopted to calibrate the flow3D model. The field measurement and GGU-SS-FLOW3D model can help to better understand the variation of the groundwater system related to the ground subsidence from longwall mining over thin overburden.

Impact of longwall mining on groundwater above the longwall panel in shallow coal seams

Since longwall mining causes subsidence through the overlying strata to the ground surface, the surface water and groundwater above the longwall panels may be affected and drained into the lower levels. Therefore, loss or interruption of streams and overburden aquifers is a common concern in coal industry. This paper analyzed the potential effects of longwall mining on subsurface water system in shallow coal seam. In order to monitor different water level fluctuations throughout the mining period, three water wells were drilled down to the proposed deformation zone above the longwall panel. A GGU-SS-FLOW3D model was used to predict water table contours for the periods of pre- and post-mining conditions. The field data from the three water wells were utilized to calibrate the model. The field test and numerical model can help to better understand the dewatering of shallow aquifers and surface waters related to ground subsidence from longwall mining in shallow coal seam.

Post-mining policies and practices in the Eastern USA coal region

Surface coal mines prior to 1950 in the USA were generally left without any reclamation. As government regulations advanced since then, mine operators were required to backfill the area and plant grasses or trees. After the federal Surface Mining Control and Reclamation Act (SMCRA) was passed in 1977 in the USA, mine operators were required to conduct pre-mining analyses of the site and to designate a land use that could be achieved after mining. Successful reclamation, as needed to satisfy today’s societal demands, requires engineering, design, and purposeful reconstruction of the full mining disturbance, not just its surface, and control of waters leaving the mine site. Effective reclamation on modern American coal mines is fully integrated with the mining operation. A suitable and effective post-mining land use that is sustainable for future generations is crucial to the long-term success and profitability of the mining business and to the future economic benefits of the landowner. Accepted post-mining land uses in the USA are: (1) prime farmland, (2) hay land and pasture, (3) biofuel crops, (4) forestry, (5) wildlife habitat, and (6) building site development. Policies and regulations for each post-mining land use were developed and practices to achieve successful and sustainable land uses were established. Post-mining conditions should provide ecosystem services and produce lands capable of supporting societal needs in the future.

Simulating Direct and Indirect Damages to Commercial Fisheries from Marine Sand Mining: A Case Study in Korea

Rapid growth in marine sand mining for construction and other uses poses environmental challenges to coastal nations virtually worldwide. Yet the development of management policies, such as a system of fees imposed on operators for damage caused by mining, has been frustrated by a lack of studies to support such measures. Adapting a Beverton-Holt bioeconomic model, this paper attempts to contribute to the estimation of external costs to commercial fisheries due to marine mining. Using the major mining area of Ongjin in Korea as a case study, we estimate economic losses in use value of commercial fisheries through the time to recovery of the injured resource stocks. Present value of lost catch over a 1-year period from mining to resource recovery is estimated at $38,851 for a single "prototype" mining site. Estimated cumulative damages due to recurring mining for 5 and 10 years are $1.5 million and $2.2 million, respectively, at 20 mining sites. Sensitivity analyses are used to examine the effects of alternative assumptions to assess the many sources of uncertainty. Using a form of meta-analysis, dose-response information is used to assess the excess mortality the mining sediment plume has on eggs and larvae and, ultimately, on the value of lost catch ($841). Also addressed is the importance of specifying the appropriate "premining" conditions against which to assess environmental losses at the mining site. Damages estimated with premining fish populations are $23,066 higher than is the case using postmining conditions. Overall, the illustrative results suggest the variety of complex conditions which influence damage to fisheries from mining and which can benefit from further study to improve management guidelines.

English

The goal of returning diverse life to lands surface-mined for coal has followed the passage of the Surface Mine Control and Reclamation Act of 1977 (SMCRA) into State mining reclamation acts and regulations promulgated therefrom. Expectations for the level of plant species diversity that should exist on lands revegetated under SMCRA has taken the form of a variety of performance standards that reflect the prevailing attitude that species diversity is an attribute that can be “made to happen.” Over 25 years of monitoring data from revegetated lands suggest that species diversity is not “made to happen” but rather “allowed to happen.” For sites with at least moderately favorable soils and climate, a recurring conclusion based on long-term monitoring data is that grasses (typically abundantly represented in revegetation seed mixes) are highly competitive in post-mining conditions. SMCRA and similar state requirements for unbroken post-mining surface configuration covered by substantial depths of agriculturally suitable soil have provided the ideal environment for the widespreading and dense root systems that grasses possess. As a result, the occurrence of non-grass plant species has typically been limited. It is posited that the longterm status of plant species diversity will be related to occasional interruptions of the overwhelming ecological dominance that grasses most often presently hold. As a consequence, the accretion of plant species richness at any particular location will be slow and to some degree unpredictable. Given, thus, that species diversity after 10 years or even 20 years may still be competitively suppressed, quantitative approaches are set forth for “looking into the future” to evaluate the availability of the less-competitive plant species to respond to eventual opportunities that would allow them to proliferate in the revegetated plant communities. Central to these approaches is the need to avoid direct matching of species’ abundance between reclaimed and reference areas. Instead, alternatives in the form of species presence, life-form similarity, and scale-corrected species density evaluations are described. Ecological reasoning underlying the approaches is examined. ___________________ 1 Paper was presented at the 2006 Billings Land Reclamation Symposium, June 4-8, 2006, Billings MT and jointly published by BLRS and ASMR, R.I. Barnhisel (ed.) 3134 Montavesta Rd., Lexington, KY 40502. 2 David L. Buckner, Ph.D. Senior Plant Ecologist, ESCO Associates Inc., P.O. Box 18775, Boulder, CO 80308 (303 499 4277) e-mail: escassoc@mindspring.com Proceedings America Society of Mining and Reclamation, 2006 pp 143DOI: 10.21000/JASMR06010143

Impacts of surface mine valley fills on headwater floods in eastern Kentucky

The potential impacts of valley fills associated with mountaintop removal/valley fill (MTR/VF) coal mining on downstream flooding in the coalfields of eastern Kentucky and adjacent states are a subject of public debate and scientific uncertainty. This study explored two aspects of this issue. First, hydrologic indices of relative runoff production and surface and subsurface flow detention were applied to conditions typical of headwater and low-order drainage basins in eastern Kentucky. Results show that there is a clear risk of increased flooding (greater runoff production and less surface flow detention) following MTR/VF operations, and suggest that, on balance, valley fills are more likely to increase rather than decrease flood potential. However, there is a wide range of outcomes, qualitatively and quantitatively. Flood risks can be increased or decreased, and the degree of either may vary markedly. The effects of MTR/VF mining on downstream peak flows are highly contingent on local pre- and post-mining conditions, and it would be unwise to apply generalizations to specific sites. Second, the occurrence of flash floods downstream of MTR/VF operations when nearby unmined areas did not flood or had less severe floods has frequently been explained (without supporting data) in terms of locally greater precipitation. The likelihood of such short-range variability of storm precipitation is evaluated by applying the state probability function to NEXRAD radar estimates of precipitation for two 2001 storms which produced flash floods in eastern Kentucky. The spatial structure of the storm precipitation indicates that at the scale of the analysis (pixel size of approximately 2 km) large local variations in storm precipitation are unlikely—that is, the probability of nearby hollows or low-order drainage basins receiving substantially different storm precipitation totals is low.

A Quarter Century of Coal Mining and Hydrogeologic Research in Southeastern Montana

Two valuable natural resources coexist in eastern Montana--coal and ground water. Water related issues are the major concerns during coal mine permit decisions. Due to the concerns about mining related impacts, ground water in the vicinity of coal mines has been continuously monitored since 1970. The continuity and duration of the Montana Bureau of Mines and Geology monitoring program under a variety of geologic, mining, and post-mining conditions have provided a fundamental knowledge on impacts to water levels and water quality. Coal beds are among the most dependable and utilized aquifers in eastern Montana, due to their lateral continuity and fracture-related transmissivity. In response to coal strip mining, water levels in coal-bed aquifers have dropped at distances as far as 2 miles away from mines near Colstrip, and as far as 15 miles from mines near Decker. Water levels typically return to pre-mining levels within several years after pits are backfilled. Mining-induced drawdown in stratigraphically deeper aquifers exceed those in mined aquifers in some areas, and relate to inadequately plugged boreholes from older exploration drilling programs. Dissolved-solids concentrations of water in the spoils aquifers have increased by 50 to 200% due to the dissolution of newly available salts of calcium,more » magnesium, sodium and sulfate. However, in some sites freshening of the water appears to be occurring as initial salt loads are flushed through the systems. Water-quality impacts are expected in off-site and deeper aquifers due to normal ground-water flow, and in deeper aquifers due to poorly plugged exploration drill holes. However, downgradient impacts to water quality are rarely observed. Future ground-water monitoring should document stable water levels and improving water quality as spoils aquifers reach equilibrium with local undisturbed hydrologic systems.« less

CUMULATIVE HYDROLOGIC IMPACT ASSESSMENTS ON SURFACE-WATER IN NORTHEASTERN WYOMING USING HEC-1; A PILOT STUDY

The Surface Mining Control and Reclamation Act of 1977 requires that areas in which multiple mines will affect one watershed be analyzed and the cumulative impacts of all mining on the watershed be assessed. The purpose of the subject study was to conduct a cumulative hydrologic impact assessment (CHIA) for surface-water on a watershed in northeastern Wyoming that is currently being impacted by three mines. An assessment of the mining impact`s affect on the total discharge of the watershed is required to determine whether or not material damage to downstream water rights is likely to occur as a result of surface mining and reclamation. The surface-water model HEC-1 was used to model four separate rainfall-runoff events that occurred in the study basin over three years (1978-1980). Although these storms were used to represent pre-mining conditions, they occurred during the early stages of mining and the models were adjusted accordingly. The events were selected for completeness of record and antecedent moisture conditions (AMC). Models were calibrated to the study events and model inputs were altered to reflect post-mining conditions. The same events were then analyzed with the new model inputs. The results were compared with the pre-mining calibration. Peak flow, totalmore » discharge and timing of flows were compared for pre-mining and post-mining models. Data were turned over to the State of Wyoming for assessment of whether material damage to downstream water rights is likely to occur.« less