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Executive Summary On October 11, 2000, near Inez, Kentucky, a breakthrough occurred in which a 72-acre surface impoundment of waste materials of the Martin County Coal Corporation released approximately 250 million gallons of slurry into a nearby underground coal mine. The slurry flowed through the mine and into nearby creeks and rivers, flooding stream banks to a depth of 5 feet. Although the spill caused no loss of human life, environmental damage was significant, and local water supplies, taken from the rivers, were disrupted for days. This incident caused Congress to request the National Research Council to examine ways to reduce the potential for similar accidents in the future. To conduct this study, the National Research Council appointed the Committee on Coal Waste Impoundments. The committee held a total of 10 meetings between March and July 2001, eight of which included a town meeting to gain input Mom citizens of local communities. The charge to the committee includes three major components. First, the committee was to examine engineering practices and standards currently being applied to coal waste impoundments and to consider options for evaluating, improving, and monitoring the bamers that retain coal waste impoundments. Second, the committee was charged with evaluating the accuracy of mine maps and exploring ways to improve surveying and map- ping of underground mines to delineate more accurately how underground mines relate to current or planned slurry impoundments. The third task was to evaluate alternative technologies that could reduce the amount of coal waste generated or allow productive use of the waste. The committee also examined alternative disposal options for coal slurry. It is important to recognize that this charge specifically directs the committee to focus its analysis on the engineering and characterization of coal waste impoundments. The committee was not asked to consider other factors that are related to potential impacts of disposing of coal waste in an impoundment, or any other disposal option. For example, these factors might include potential long-term effects on water quality; land-use issues,
2 COAL WASTEIMPOUNDMENTS including long-term stewardship of closed impoundments; and economic and cost-benefit analyses of alternatives. The committee also was not asked to evaluate the risks of individual impoundments, examine the qualifications and training of inspectors, or comment on coal mining policy issues not directly related to impoundments. Although important, such issues are well beyond the charge to this committee. Furthermore, a comprehensive analysis of these issues would require considerably more time than was available for the present study. Advances in mining technology have increased productivity at the expense of quality of the run-of-the-mine product, both in terms of included impurities and a greater proportion of fine-grained coal. This is particularly true for the coal from eastern coal fields, and upgrading of the product to meet requirements of power plants and other users is now a common practice. The treatment of the raw coal can produce as much as 50 percent waste as coarse included rock and as fine-grained coal and mineral matter. Coal waste slurry is one of the refuse streams and is composed mainly of fine coal, small particles of rock, and clay suspended in water. Coal waste slurry is usually disposed of by pumping it into an impoundment, where particles are allowed to settle. Most impoundments in Appalachia utilize the natural topography to form the storage basin that will contain the slurry. This is often accomplished by constructing an embankment in a valley or water- shed to complete the basin structure used for storage. Impoundments are often located in steeply sloping valleys. Coal waste slurry facilities have been involved in several accidents since the 1972 Buffalo Creek incident, where a coal waste impounding structure collapsed, killing 125 people, injuring 1,100, and leaving more than 4,000 homeless. The majority of the incidents involve failure in the basin area. Inaccurate mine maps and inadequate characterization of the basin area most likely contributed to at least some of these incidents. This report, in an effort to identify potential causes of failure, evaluates current practice in site characterization, basin placement, and embankment construction, mainten- ance, and monitoring. It concludes with a discussion of alternative methods of coal use and waste disposal. Technical terms used in the text are defined in the glossary (Appendix C). ENGINEERING STANDARDS, BARRIER STABILITY AND MONITORING The Mining Enforcement and Safety Administration developed standards for impoundments and refuse piles after the 1972 Buffalo Creek =
EXECUTIVE SUMMARY 3 incident. One of the purposes of the Federal Mine Safety and Health Act of 1977 was to establish mandatory standards to protect the health and safety of miners. This charge is important in assessing the Mine Safety and Health Administration's (MSHA's) regulatory responsibility and authority associ- ated with potential impoundment breakthroughs and failures that do not directly affect the health and safety of miners but may affect persons, communities, or ecosystems downstream. On the other hand, the Office of Surface Mining's (OSM's) legislative and regulatory direction under the Surface Mining Control and Reclamation Act of 1977 (SMRCA) to protect society and the environment from the adverse effects of surface coal mining operations, complements the intent of the Federal Mine Safety and Health Act. The committee examined the regulations by MSHA and OSM and its state delegate programs that directly relate to the design, construction, operation, and closure of refuse impoundments, as well as to alternative refuse disposal techniques. The committee also examined other federal statutes that may relate to refuse impoun~nents or alternatives (e.g., the Clean Water Act). The regulatory structure that covers many aspects of the design, construction, and operation of coal waste impoundments is exten- sive. The MSHA and OSM regulatory language addresses in detail the engineering and stability aspects of the embankment; however, there is little reference either to the basin area or to requirements of the engineering design for other areas of the facility. The impoundment operator and professional engineer are responsible for providing information about under- ground mine workings, including the depth and extent of the workings. However, no regulation or standard industry practice instructs or guides the engineer in this task, and there is no procedure for an independent verification of the information submitted. In addition, there is no regulation requiring an evaluation of the breakthrough potential of impoundments. However, in practice, MSHA and OSM appear to have the jurisdiction to require an evaluation of breakthrough potential through indirect regulatory language. The committee concludes that while the regulatory review of a proposed impoundment is detailed with respect to the embankment, the regulatory review of the impoundment basin has been less rigorous. The authority for review of the basin characterization and design appears to be covered only in general language authorizing investigation of all relevant issues with respect to the impoundment. The committee recommends that MSHA and OSM should have clear authority to review basin design. It is not evident to the committee whether specific legislation to authorize more detailed examination of basin issues is required, or whether these issues can be handled by additional rulemaking under existing authority.
4 COAL WASTEIMPOUNDMENTS The committee examined in particular the elements of design, operation, and reclamation of coal refuse impoundment systems in the Appalachian coal region. The principles that govern the design of structures, which were promulgated in response to the Buffalo Creek disaster, are well understood and fully documented. An embankment built to contain coal mine waste is similar to an embanianent built to contain mine waste from other extractive industries. Reviews of failure modes in other extractive industries are relevant to identifying potential failure modes of coal waste impoundments. Given the fact that some modern dams in other extractive industries have failed, the committee concludes that it is essential that MSHA and OSM stay current by ensuring that design criteria reflect the latest experience from all segments of the mining industry. Although the committee has not identified any deficiencies, it is a matter of due diligence that MSHA and OSM and industry employ the best available current technology. The committee recommends that MSHA and OSM continue to adopt and promote the best available technology and practices with regard to the site evalu- ation, design, construction, and operation of impoundments. For example, MSHA and OSM should commission periodic reviews of existing technical procedures and practices, with particular attention to the basin. Results of the reviews should be disseminated to industry. Based on the outcome, MSHA and OSM may need to revise guidelines to establish minimum expectations and levels of investigation for site characterization, design, construction, operation, and closure of coal refuse impoundments. Embankments can fad! in a variety of ways, including slope instability, liquefaction, and foundation failure. Seepage through embankments can lead to failure by internal erosion. Overtopping of an embankment can cause substantial erosion of the crest, which, if left uncontrolled, will work pro- gressively downward, releasing water and coal refuse downstream. While continued vigilance concerning design, construction, and operation of embankments is clearly warranted, the committee concludes that the largest uncertainties remain in the characterization of the basin area and, therefore, in the mitigation of risks associated with the breakthrough potential. The potential for underground coal mine workings to be near an impoun~nent is a factor in the design of new and in modifications to existing coal waste impoundments in Appalachia. The relative elevations of local drainage and slurry height, with respect to underground mines, can be a critical design issue. The stream channel at the base of the impoundment basin defines the approximate level of local drainage. Coal seams and mines that do not crop out above the level of the stream channel are termed below-drainage; whereas, those that crop out along the valley wall above the stream channel are termed above-drainage. Existing impoundments with above-drainage =
EXECUTIVE SUMMARY mine workings, where the slurry elevation does not exceed the level of the coal mine workings, can relatively easily incorporate mitigative measures for these workings in their design. Above-drainage coal mine workings in existing impoundments, where the slurry elevation exceeds the level of the mine workings, are the most challenging in the design and operation of a facility. If the outcrop coal barrier is of insufficient width, or the overburden above the mined area is too thin, impounded water can break into a mine. Conversely, an inundated mine under high hydraulic head can introduce a large volume of water into the impoundment. Should a blow-out occur elsewhere in the watershed, above the pool level, an inflow of substantial amounts of water into the impoundment can result. This, in turn, may result in overtopping of the embankment or damage to the principal and emer- gency spillways. Synergistic reactions among geologic and hydrogeologic conditions can compound the instabilities created by any one of the failure modes. Currently, no federal regulations address the width of outcrop barrier that should be left during underground coal mining. OSM has studied the problem of outcrop barriers but has released no conclusions to date. The committee recommends that MSHA and OSM jointly pursue the issue of outcrop coal barrier width and overburden thickness and its competence and develop minimum standards for them. If slurry Tom an impoundment leaks into active or abandoned mine workings or may do so, bulkheads or seals may be constructed to preclude the water from escaping into the outside environment. Many mitigative measures can be designed using established procedures; however, bulkheads designed to support high hydrostatic pressure present a different kind of problem. The committee recommends that MSHA review its current practice and develop guidelines for the design of bulkheads intended to withstand hydraulic heads associated with slurry impoundments. The bulkhead should be constructed from material that can withstand water action without deterioration in the presence of the various chemicals in the impoundment water. Furthermore, the bulkhead should be suitably anchored in competent, unfractured strata. If such an area is not available, pressure grouting may be needed. Deterioration of the anchoring strata can be a major structural problem where the bulkhead is keyed into water-sensitive, clay- bearing strata. The size, integrity, and s~eng~ of the surrounding coal pillars, roof, and floor are critical to successful sealing. Generally, seals constructed for ventilation cannot withstand water pressure. The committee concludes that selecting the appropriate mitigative measures relies strongly on reliable basin characterization. The committee recommends that MSHA and OSM develop and promulgate guidelines
6 COAL WASTEIMPOUNDMENTS for the site evaluation, design, construction, and operation of basins. They should be comparable in scope to the guidelines used in embankment design. Monitoring is a critical component in the construction and operation of coal slurry impoundments. Measurements are commonly made to detect surface displacements, internal movement, pore pressure, groundwater level, surface water discharge, and subsurface movement. Procedures in place for monitoring the embankment, which include visual inspection and instru- mentation, appear to be performing as envisioned in the regulations MSHA implemented. For monitoring to be successful, it should be applied to all potential failure modes. The committee believes that there are opportunities for additional continuous monitoring that may offer timely warning in case of impending failure of an embankment or basin. The committee recom- mends that MSHA and OSM consider requiring additional continuous monitoring in specific instances and evaluate automation of monitoring instruments. SITE CHARACTERIZATION Key to assessing the potential for breakthrough of coal slurry into underground mine workings is knowing the extent of those workings with respect to the ground surface in the impoundment basin area. The committee examined several aspects of the topic of site characterization, including geology, hydrogeology, the accuracy of surface and mine maps, and methods for delineating the extent of underground mine workings in situations where maps are nonexistent or inaccurate. A particular problem is old surveys and maps, some of which have been lost or destroyed. If unknown mine workings are present, the impoundment could suffer unexpected structural failure. In areas where impoundments are constructed near known or suspected under- ground mines, vertical and horizontal bamer distances between the mined area and the impoundment may not be accurate. Current regulations require closed-loop mine surveys, but surveys for many older mines were not closed. Furthermore, underground mine surveys may have been based on a foreman's notes or sketches that lack a reference point or a recognized coordinate system that would allow accurate location. These shortcomings are more common in small mines or room-and-pillar mines where a number of short panels were driven and extracted. Therefore, the committee recommends that MSHA work with OSM and state agencies to establish standards for mine surveying and mapping. These should include the following: =
EXECUTIVE SUMMARY . 7 Determining surface coal outcrop locations by aerial topographic measurements, where adjacent to existing or proposed refuse impoundments, · Implementing a coordinated and assertive approach to collecting and archiving mine maps, Scanning paper copies of mine maps into electronic data files upon receipt, · Setting standards for minimum closure error for all under- ground closed-loop surveys and that a closed-loop survey be maintained within a standard distance (to be determined by MSHA), · Recording the depth of the last cut taken to a level of accuracy to be determined by MSHA, Using state plane coordinates or latitude and longitude, and bottom-of-seam elevations as the map base reference, Listing appropriate coordinate transformation eauation(s) on the mine map, Adding a qualifying statement to accompany any coordinate transformation that is based upon the alignment of surface features, Improving and maintaining the location of surface controls, Determining which mine permit documents should be retained, in what form, and for how long, Avoiding the use of coal seam names as the sole basis for deter- mining the vertical location of an abandoned mine. . %, When no mine maps can be found or there is reason to doubt their accuracy, additional investigation to locate underground Nine workings is warranted. This can be expensive and time consuming. Because of the time and expense and remaining inherent uncertainty associated with extensive drilling, remote sensing and geophysical methods have been employed to search for abandoned coal mines. The objective of geophysical surveys is to determine the physical characteristics of a three-dimensional volume of earth material, including the presence of voids. Since no geophysical technique is capable of performing optimally under all geologic and topographic condi- tions, multiple geophysical techniques may be necessary to reduce the probability for error to an acceptable level. Drilling is still necessary to confirm and calibrate interpretations of geophysical and remote sensing data. The absence of evidence of a mine is not evidence of absence of a mine, and there are many opportunities for error in the modeling and geophysics surveys needed to detect voids. The committee concludes that geophysical
8 COAL WASTEIMPOUNDMENTS techniques can be useful in coal mine void detection, especially the use of seismic surface waves, seismic reflection, ground-penetrating radar, and electrical resistivity methods. The committee also concludes that geophysical techniques have been underutilized in the coal-mining industry and could benefit from additional research. The committee recommends that demon- stration projects using modern geophysical techniques be funded, and that the results be widely conveyed to the mining industry and to government regulatory personnel through workshops and continuing education. Continuing education could include the opportunity to attend short courses and seminars that present the latest technology along with case histories to support its use. ALTERNATIVE TECHNOLOGIES Coal waste impoundments are one of the waste disposal options of the present system of mining and preparing coal for energy production. To assess thoroughly other alternatives, the entire system of mining, prepara- tion, refuse disposal, transportation, and power generation should be explored through an in-depth life-cycle assessment, including cost assessment, with the goal of optimizing the system to generate less fine coal waste while maintaining the performance and economics of the system. However, benefits may be difficult to realize because of differences in interests and perceptions between the mining industry and the utility industry, and because of the resistance to change embedded in these mature industries. The committee recommends that the total system of mining, prepara- tion, transportation, and utilization of coal and the associated environ- mental and economic issues be studied in a comprehensive manner to identify the appropriate technologies for each component that will eliminate or reduce the need for slurry impoundments while optimizing the performance objectives of the system. The committee concludes that a similar analysis of the waste use and disposal technologies that malice up the coal system would have value. The committee recommends incorporating life-cycle assessment of the costs and environmental impacts of the alternatives to evaluate them on a more objective, comprehensive basis. In addition, a detailed analysis of the economic and environmental impact of the various policy alternatives should be performed. The opportunities for reducing slurry volume include mining alterna- tives and coal processing alternatives. However, modern methods of surface and underground coal mining offer a limited possibility for quality control during mining. Slurry volume can be reduced by improving fine coal =
EXECUTIVE SUMMARY 9 recovery, minimizing the mass of solids for disposal, and dewatering. Many dewatering technologies are currently available for specific applications, though none is likely to be universally applicable. The committee believes that equipment vendors' current research and development will lead to improvements in these technologies and that operators of coal waste im- poundments should monitor them carefully. Slurry refuse can be used directly for power generation, either in con- ventional boilers or in advanced combustion and gasification technologies. Some of these technologies can reduce cleaning requirements for coal. However, the use of low quality coal feed will increase the amount of waste generated at the power plant. The committee concludes that technologies for utilization of fine coal waste for electricity generation in conventional coal- f~red power plants are available. These technologies offer near-term oppor- tunities for the reduction of fine coal waste disposed of in impoundments. However, the coal produced is more expensive than cleaned coal, as a result of capital and operating costs of additional equipment, and, in the case of coal water slurry, the additional cost of transportation. To compare tech- nologies fully, the avoided costs of slurry impoundments must be included in the analysis. Fluidized-bed combustion and gasification show promise for recovering the heat content of fine coal waste while avoiding some of the operational problems that limit use of coal fines in conventional pulverized coal-fired boilers. The committee concludes that the burning of fine coal waste in advanced combustion technologies, such as fluidized-bed combustion and gasification, is an alternative that shows considerable long-te~m promise. Atmospheric fluidized-bed units are already in use for combustion of fine coal waste slurries from both preparation plants and old slurry impound- ments, but they have not gained wide usage. Pressurized fluidized-bed technologies offer improved efficiency over atmospheric technologies but have not been utilized in full-scale applications for burning fine coal waste. Gasification technologies are also promising for coal water slurries, because they operate more efficiently, and because emerging technologies can utilize the water from the slurry as a steam source required for the gasifies. Further research is needed on the use of fine coal waste slurries as feeds, and incentives may be useful if these technologies are to be widely incorporated for fine coal waste combustion. Even though coal combustion wastes from power plants are already being used for a number of purposes, safe handling of coal combustion waste from these advanced combustion technologies should be studied further. Methods are available for the disposal of coal slurry other than in impoundments, including both surface and underground options. Alternative
10 COAL WASTEIMPOUNDMENTS surface methods include incised ponds, slurry cells, combined refuse piles, and co-disposal of fine and coarse refuse. In many instances, these methods are influenced by topography, geology, and mining and coal preparation characteristics, and, therefore, their application is site specific. Incised ponds, which are similar to slurry impoundments but without an embankment, are designed to accept any form of coal waste including slurry. This method of surface disposal is most common in the Midwest where area surface mining is practiced on flat topography. Area surface mining produces long end-cuts and inclines' which are usually allowed to fill with water to form a permanent lake. These excavations are at or below the level of sur- face drainage and do not present a danger of sudden failure if used for slurry disposal. Slurry cells are designed to impound less than 20 acre-feet of slurry. The advantage of this method over conventional cross-valley impoundments is that each cell is small and self-contained and can be designed according to the strength properties of the coarse refuse. The main disadvantage in steep terrain is the limited availability of flat land to construct the cells. Another disadvantage is that slurry cell operations are not compatible with a high coal preparation production rate. Combined refuse piles consist of fine refuse from a static thickener that has been mechanically dewatered and combined with coarse refuse. Mechanical dewatering to yield the required moisture level is frequently a problem. In addition, the dewatered material is difficult to handle and compact. Combined refuse is expensive because of Me high cost of mechanical dewatering and the potential need for chemical additives to stabilize the combined refuse. This method is best suited to flat land. Co-disposal involves the combination of fine refilse from the static thickener with coarse refuse. This method requires less total storage volume than separate fine and coarse disposal methods, and the refuse stabilizes more quickly than typical slurry. Co-disposal has been used primarily in sparsely populated areas with low annual rainfall. Questions remain about its suitability for steep hills with high annual rainfall. If an effective dewatering approach, such as paste thickening, is used, the resulting waste can be disposed of by thickened high-density residue stacking. Although used in other extractive industries, this process has seen limited use in the coal industry for the disposal of fine coal refuse. Three considerations land availability, steep terrain, and cost hamper applying unsupported thickened high-density residue stacking to fine coal refuse disposal. This method is best suited to areas where the slope of the land is less than 5 percent. The lower throughput rate of deep cone thickeners =
EXECUTIVE SUMMARY 11 compared with that of standard thickeners may significantly affect the economic feasibility of the method. For the underground options, two primary methods for injecting fine coal refuse into underground mines are controlled flushing, where the underground workings are accessible, and blind or uncontrolled flushing, where the underground workings have been abandoned or have caved in. However, several issues are both important and independent of the method of slurry injection. For example, it is essential to have an adequate supply of water. This is especially true when water is not being recaptured from the underground workings. Additional issues include surface ownership, permits, surface layout, and surface drainage. Filling above-drainage mine workings with slurry may increase hydraulic head on the coal barriers and result in a blow-out, making evaluation of mine workings above a surrounding stream valley critical. The accuracy of mine maps must be ascertained, and the underground barriers must be assessed for adequacy to contain the slurry. Mines below the surrounding natural drainage level offer more secure under- ground disposal sites. The committee concludes that although there are alternatives to disposing of coal waste in impoundments, no specific alternative can be recommended in all cases. Acceptable alternatives are highly dependent upon regional and site-specific conditions. Also, the alternatives that have been identified are in varying stages of technological development and implementation. One of the factors lifting implementation to this point has been the costs associated with the various alternatives. Additional research is needed to develop these altematives fiercer and to evaluate the economics of these processes. The committee recommends that a screening study be conducted that (1) establishes ranges of costs applicable to alternative disposal options, (2) identifies best candidates for demonstration of alternative technologies for coal waste impoundments, and (3) identifies specific technologies for which research is warranted. Input from MSHA and OSM regarding regulatory issues will be valuable to such a study. The committee recommends that the use of economic incentives be explored as a way of encouraging the development and implementation of alter- natives to slurry impoundments. The development of incentives should be based on the full range of the portfolio of technologies as well as the economics of the technologies. The incentives should be linked directly to the reduction in slurry production or the utilization of slurry. One method for reducing the volume of material in older slurry impoundments is to recover or remine the fine coal. Older impoundments contain significant amounts of coal refuse with recoverable energy value. However, as processing technologies and the capacity of dewatering
12 COAL WASTEIMPOUNDMENTS equipment have improved, the proportion of coal with high energy value being deposited in slurry impoundments has decreased. In many cases, the finer slurry materials being disposed of today with less recoverable and marketable coal are placed over the more amenable, profitable, and recover- able slurry. Typically, if an impoundment contains at least 1 million tons of in-situ slurry, a recovery rate of at least 30 percent of a marketable fine coal product (300,000 tons) from the slurry could prove to be a profitable venture. The committee concludes that as advances are made in the use of low value coal or coal water slurry, remining of slurry impoundments can be an attractive source for fuel supply. ADDITIONAL RECOMMENDATIONS In its deliberations, the committee identified several issues that cut across elements of the statement of task and some related issues that warrant additional study. MSHA currently uses two systems to classify coal waste impoundments. One system classifies impoundments as high, medium, or low hazard, based upon the magnitude of the potential consequences of failure of the embank- ment structure. If communities and structures are immediately downstream, the embankment would be classified as high hazard, regardless of its likeli- hood to fail. A second system addresses the potential for the unintentional release of water or SlU~Ty from impoundments into active or abandoned mines. These ranking systems are based on the proximity of the basin to underground workings as well as the potential downstream impacts if a basin were to fail. The second classification comes closer to the standard definition of risk as the product of hazard (the likelihood of failure) and consequences (such as loss of life, environmental damage). The committee concludes that using different hazard classification methodologies for embankments and basins is inappropriate. Therefore, the committee recommends that: (1) MSHA and OSM review activities related to risk assessment for existing impoundments (including both embankments and basins) to ensure that they are consistent and that they distinguish appropriately between hazard and consequence assessment in the methodologies adopted; and (2) MSHA and OSM establish a single, consistent system, which should be used to assign both embankments and basins to risk categories. The ranking should be based on the appropriate combination of hazards and consequences. The committee believes that this can be accomplished using qualitative risk assessment techniques.
EXECUTIVE SUMMARY 13 A consistent risk assessment system would allow decisions to be based on their relative risks. The committee recommends that MSHA and OSM oversee a thorough assessment of potential mitigation measures for those impoundments that fall in the highest risk category and should deter- mine which mitigation measures should be applied to reduce this risk to an acceptable level. The committee also concludes that the design process for impoundments would be improved by a more formal risk analysis. Proposed new impound- ments should also be assigned to risk categories, based on a combination of hazards and consequences, as was suggested for existing impoundments. To maximize the potential for risk reduction, the committee recommends that all impoundment designs be accompanied by a risk analysis utilizing qualitative methods. Examples of such methods include Potential Problem Analysis and Failure Modes and Effects Analysis. The committee believes there is a limit to risk tolerance, for both existing and new impoundments. When risk is high, and when mitigation, either through more reliable characterization or barrier construction is impossible, of limited precedent, or so expensive that it is infeasible, then a substantial change in operation of the impoundment is warranted. This may range from minimizing slurry fluidity to ceasing operations. If an impoundment fails risk-assessment criteria and if risk cannot be mitigated it should be phased out or alternatives considered. In collecting information concerning the design of impoundments and the process by which the design is reviewed by regulatory authorities, the committee heard reports that the review process is undesirably lengthy, commonly exceeding 2 years. In addition, it appears that review times have lengthened considerably in recent years. The committee concludes that timely review is an essential component of an effective regulatory process. An efficient and coordinated regulatory review process can be of substantial benefit to both the applicant and the jurisdictional agencies. A well- coordinated technical review process can ensure that the health and safety of both the miners and the public, and the protection of the environment are ensured in a sensible and streamlined way. Therefore, the committee recommends that the review process for both new permits and existing permits be overhauled to include the following elements: · ~ formal joint process that would coordinate the currently frag- mented and inefficient collection of reviews into a single process.
14 COAL WASTEIMPOUNDMENTS . Sufficient staff for engineering and other reviews in the agencies that participate in the joint process so that the time required to complete the review can be reduced significantly. In its review of information about the impacts of uncontrolled releases of water and slurry from impoundments, the committee found that only very limited information was available concerning the quantities of trace elements present in the slurry and associated water. A common theme at the town meetings was the concern about the quality of ground and surface water. While a detailed review of the environmental impacts of coal waste impoundments was beyond the scope of this study, the committee identified this area as one needing further study. As a result, the committee recom- mends that research be performed to identify the chemical constituents contained in the liquid and solid fractions of coal waste, and to charac- ter~ze the hydrogeologic conditions around impoundments. Public concern regarding emergency response and evacuation plans was another recurring theme in public comments made to the committee. Some residents were unaware of emergency evacuation plans; others had seen evacuation plans but disagreed with the logic behind the evacuation routes and would not have used the plan in the event of an emergency. Conversely, coal industry and regulatory agency representatives stated that these plans are being developed and shared with the public through the various community contacts (e.g., local fire departments, police, health care pro- viders). The lack of realistic communication constitutes a fundamental barrier to the industry's ability to make stakeholders aware of the risk associated with coal refuse impoundment construction, operation, and closure and of steps taken to mitigate that risk. The committee concludes that communication concerning coal refuse impoundment risk and emer- gency response between the industry and the local communities could be improved substantially. The committee suggests that the industry take steps through the appropriate emergency response agencies to address these problems. SUMMARY The conclusions and recommendations offered above reflect the committee's judgments concerning ways to improve the design process for coal waste impoundments, ways to improve mapping of mines and the characterization of sites of existing and future impoundments, ways to improve the assessment and mitigation of risks associated with impound- =
EXECUTIVE SUMMARY 15 meets, and ways to assess options for coal waste slurry. The committee believes that implementation of the recommendations will substantially reduce the potential for uncontrolled release of coal slurry from impound- ments, particularly through the mechanism of breakthrough into nearby underground mine workings. In addition, the committee believes that viewing the designs of embankment and basins as well as the entire process of handling and burning coal as systems of interlinked components that operate together is an appropriate way to balance alternatives for creating, handling, and disposing of wastes and to understand and mitigate the impacts of failure of any element in these systems. The safe operation of these systems is a shared responsibility of government and industry that depends on effective engineering design, construction, and operation in addition to appropriate monitoring. With the recommended improvements in each of these areas, the potential for incidents like that in October 2000 at Inez, Kentucky, can be reduced. 1
16 COAL WASTE IMPOUNDMENTS Some residents were unaware of emergency evacuation plans; others had seen evacuation plans but disagreed with the logic behind the evacuation routes and would not have used the plan in the event of an emergency. Conversely, coal industry and regulatory agency representatives stated that these plans are being developed and shared with the public through the various community contacts (e.g., local fire departments, police, health care providers). The lack of realistic communication constitutes a funcia- mental barrier to the industry's ability to make stakeholders aware of the risk associated with coal refuse impoundment construction, operation, and closure and of steps taken to mitigate that risk. The committee concludes that communication concerning coal refuse impoundment risk and emer- gency response between the industry and the local communities could be improved substantially. The committee suggests that the industry take steps through the appropriate emergency response agencies to address these problems. SUMMARY The conclusions and recommendations offered above reflect the committee's judgments concerning ways to improve the design process for coal waste impoundments, ways to improve mapping of mines and the characterization of sites of existing and fixture impoundments, ways to improve the assessment and mitigation of risks associated with impoundments, anal ways to assess options for coal waste slurry. The committee believes that implementation of the recommendations will substantially reduce the potential for uncontrolled release of coal slurry from impoundments, particularly through the mechanism of breakthrough into nearby underground mine workings. In addition, the committee believes that viewing the designs of embankment and basins as well as the entire process of handling and burning coal as systems of interlinked components that operate together is an appropriate way to balance alternatives for creating, handling, and disposing of wastes and to understand and mitigate the impacts of failure of any element in these systems. The safe operation of these systems is a shared responsibility of government and industry that depends on effective engineering design, construction, ant! operation in addition to appropriate monitoring. With the recommended improvements in each of these areas, the potential for incidents like that in October, 2000 at Inez, Kentucky, can be reduced. Prepublication Version - Subject to Further Editorial Correction