Summary
Gold is a high-value metal utilized primarily in electrical devices, in jewelry, and for investments. Western states, especially Nevada, have dominated recent gold production in the United States, but as current deposits become depleted and gold prices rise, mining companies are increasingly exploring for lower-grade gold deposits or those that are deeper in the Earth. The Commonwealth of Virginia was one of the first major gold-producing states in the nation, but only intermittent exploration activity and small operations have occurred in the past 70 years. Recently, there has been renewed attention to the potential for gold exploration and mining in Virginia, both at new sites and at historical sites where advances in mining and processing techniques might allow for the profitable production or “remining” of gold from deposits that were previously uneconomic.
The National Academies of Sciences, Engineering, and Medicine’s Committee on Potential Impacts of Gold Mining in Virginia was formed following House Bill 2213, which passed in response to stakeholder concerns regarding gold exploration in central Virginia. The committee’s task focused on the technical aspects of potential gold mining in Virginia—including a review of the geologic characteristics of the main gold deposits and probable modern mining techniques that could be used in such deposits, an evaluation of the potential impacts of those activities, and an assessment of the sufficiency of existing regulations in the Commonwealth to protect air and water quality (see Box 1-3 for the full Statement of Task). A parallel committee (the “state agency committee”) formed by the Virginia Department of Energy, the Virginia Department of Environmental Quality, and the Virginia Department of Health focused on local equity and environmental justice issues and environmental and human health concerns of the local community.
Overall, the committee found that the regulatory framework of Virginia appears to have been designed for operations like crushed stone quarrying and sand and gravel operations, not gold mining. As such, Virginia’s current regulatory framework is not adequate to address the potential impacts of commercial gold mining.1 More specifically, Virginia’s regulatory framework lacks an adequate financial assurance system, which poses a fiscal and environmental risk to the Commonwealth. Additionally, Virginia lacks opportunities for a diverse public to be engaged in permitting processes and a modern system for review of environmental impacts from potential gold mining projects. These and other portions of Virginia’s regulatory framework fell short in comparison to other states, the federal government, and modern best practices.
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1 In this report, commercial gold mines refers to larger and more technologically complex operations than small-scale gold mines. Small-scale gold mines are typically low-tech, labor-intensive mineral extraction and processing carried out mostly by local people (Hilson and Maconachie, 2020).
SOURCE: Modified from Sweet (2007).
GEOLOGIC CHARACTERISTICS AND PROBABLE MINING OPERATIONS
Most known gold occurrences in Virginia are associated with metamorphic and igneous rocks in the Piedmont physiographic province, except for a few small occurrences in the Blue Ridge province (see Figure S-1). These deposits in Virginia occur in lens-shaped, low-sulfide, gold-quartz veins (1–5 percent pyrite) that dip at steep angles, making shallow open pit and underground mining the most likely excavation methods. As demonstrated by the historic London and Virginia, Buckingham, and Williams mines, massive sulfide bodies can occur in close proximity to the low-sulfide, gold-quartz vein deposits in Virginia (see Chapter 2), and could release acid rock drainage (ARD) and metals if disturbed during mining. All available evidence indicates that Virginia gold deposits are generally smaller than those in other gold-producing states, which suggests that it may be more economical for companies to ship ore or pyrite concentrates off-site for the later stages of processing. This is significant because the magnitude of the potential impacts of gold mining can scale with the size of the operations and whether processing occurs on- or off-site.
THE POTENTIAL IMPACTS OF GOLD MINING
The potential human health and ecological impacts identified in this report are based on a review of the impacts of gold mining at U.S. and international sites and on the concerns expressed by community members during the information-gathering activities in this study. Given the statewide focus of the Statement of Task, the committee could not predict site-specific impacts from gold mining. Instead, the committee evaluated the impacts reported at other gold mining sites in the context of the environmental, geologic, and social conditions of the gold-bearing regions of the Commonwealth. The major potential impacts of concern are related to surface water and groundwater contamination, groundwater table drawdown, remobilization of legacy mercury from past uses, rare but catastrophic events such as dam failures and spills, and cumulative health effects due to interacting stressors. All of these factors are likely to affect some communities more than others, particularly those with lower socioeconomic status
and higher proportions of racial and ethnic minorities, which could further exacerbate environmental injustice and health disparities. A robust regulatory framework and modern best practices can significantly reduce many of the impacts associated with gold mining, but the risk of adverse impacts cannot be completely eliminated. The largest potential impacts, and factors that could mitigate or exacerbate those impacts, are discussed below.
Remobilization of Legacy Contaminants
Remobilization of legacy mercury from mining operations that take place at historically mined sites poses a significant risk to human health and the environment. Mercury is no longer used for the processing of gold in the United States, but it was used at historical gold mines in Virginia. As a result, considerable legacy mercury may exist in surface waters, soil, and mine waste at previously mined sites. These areas may still harbor unmined gold deposits and unrecovered gold in historic waste material, and future gold mining operations could remobilize this legacy mercury unless appropriate extraction and processing circuits are implemented to capture the mercury. Because of mercury’s high toxicity, careful characterization for mercury is essential at all potential mine sites in order to protect environmental and human health.
Impacts to Water Quality
ARD is among the most important potential environmental impacts of concern and poses a substantial risk if massive sulfides are disturbed during gold mining operations and if proper engineering controls are not in place. ARD can persist long after mining has ended and can cause acidity, high salinity, and elevated concentrations of toxic metals in surface water and groundwater if appropriate engineering controls are not in place. Many gold deposits in Virginia are not directly associated with large quantities of sulfide-containing minerals, reducing the likelihood of extensive ARD associated with mining. However, if adjacent massive sulfide deposits or sulfide-bearing country rock are disturbed and if appropriate engineering controls are not applied, ARD could adversely impact sensitive freshwater fauna in nearby streams and wetlands, resulting in substantial remediation costs. Site-specific characterization, engineering controls, and monitoring throughout the life cycle of gold mines are important to minimize and mitigate ARD that could negatively impact surface water and ecological communities.
Site-specific geologic conditions determine whether metals could be released from gold mining operations in sufficient quantities to pose human health threats to surrounding communities. The primary elements of concern for human health that could be released from Virginia gold deposits or from nearby rocks disturbed during mining include antimony, arsenic, cadmium, lead, mercury, and thallium. Most Virginia gold deposits occur in low-sulfide, gold-quartz veins and the few reliable geochemical data that are available for these deposits show low concentrations of metals of concern in discharge waters. However, some gold deposits in Virginia are located in close proximity to massive sulfide deposits, which have higher concentrations of pyrite and higher risk of toxic metal discharge, leaving considerable uncertainty in predicting risk across the state. Therefore, any future efforts to mine gold deposits in Virginia should be accompanied by detailed studies to characterize the mineralogy, metal content, and geochemistry of each deposit and its surrounding rock. Site-specific characterization, water quality management, and monitoring throughout the life cycle of gold mines will be important to minimize and mitigate the release of metals that could negatively impact surface water and groundwater quality.
Mining can increase nitrate loading to local waterways, which can contribute to eutrophication of local surface waters. Although best practices for blasting activities can limit nitrogen loading of surface water and groundwater (see Chapter 3), incomplete combustion of ammonium nitrate and fuel oil explosives under wet, nonideal conditions may result in nitrate-laden, mine-influenced water that can exceed water quality criteria. If this water is not appropriately managed and it reaches local surface waters without significant dilution, depleted dissolved oxygen and reduced pH due to eutrophication may result, which can be lethal to invertebrates and fish. Mining could also contribute to the total loading of nitrogen to more distant habitats (e.g., the Chesapeake Bay), although the relative contributions to the total loads are expected to be small. Elevated nitrate in drinking water can also be harmful to human populations, but these higher concentrations
are likely only possible in groundwater in the immediate vicinity of the mine site and can be prevented with best practices for blasting activities.
Open impoundments that contain cyanide pose acute toxicity risks to wildlife unless proper management and deterrents are in place. Wildlife species are attracted to virtually any kind of surface water body, natural or constructed, including waste and treatment impoundments. In the arid western United States, there have been numerous acute toxicity events affecting wildlife (especially birds) at cyanide impoundments in gold mining sites, although there have been fewer reports documenting these toxicity events following the establishment of modern best practices for cyanide management. Although surface water is plentiful in Virginia, the Commonwealth hosts diverse and abundant wildlife species that are dependent on access to open surface water. Unless best practices (e.g., deterrent systems, cyanide destruct systems) or alternative methods (e.g., enclosed tank leaching) are used, wildlife acute toxicity events could occur at open impoundments containing cyanide.
Rare But Catastrophic Events
Catastrophic failures of gold mine tailings dams and cyanide solution containment structures are low-likelihood but high-consequence events that have caused significant impacts where they have occurred. Tailings dam failures can lead to acute danger (e.g., fatalities, injury, destruction of property) as well as long-term ecological effects that are caused by the dispersal of toxic metal-containing mine wastes in rivers and floodplains. The magnitude of the long-term ecological effects depends on the scale of the spill, bioavailability of the contaminants, and effectiveness of cleanup efforts. In contrast, cyanide spill events do not pose long-term risks because cyanide degrades in the surface environment relatively quickly. However, because of cyanide’s high acute toxicity, accidental spills have caused mass mortality events of aquatic life and pose an acute human health risk where water affected by the spill is used as a drinking water supply. If tailings and cyanide containment structures are not designed to accommodate seismic, high-precipitation, and flooding events, then the likelihood of these potential high-consequence events will increase. This is especially pertinent in light of the potential for increased frequency and severity of precipitation events due to climate change.
Impacts to Air Quality
The committee did not find evidence to indicate that gold mining in Virginia would significantly degrade air quality if appropriate engineering controls were in place. Fugitive dust produced from excavation activities, heavy equipment, and mine road traffic can be a nuisance that impacts the quality of life of affected neighbors. In addition, toxic fine particles and gaseous pollutants generated from fuel combustion and gold processing can be hazardous if released, because of their greater respiratory impacts and longer atmospheric transport distance. Given the likely small scale of future commercial gold mining in Virginia that would lead to limited heavy equipment operation and traffic, and the technological advancements in recent decades that allow for effective dust suppression and control of hazardous air pollutants, the impacts of air pollutants on surrounding communities are expected to be limited.
Impacts to Water Quantity
Drawdown of the water table associated with the dewatering of an open pit or underground mine could impact local groundwater users, depending on aquifer conditions and the proximity of wells to the mine site. Unless appropriately mitigated, drawdown of the water table could significantly affect the quality of life and the cost of living for residents near the mine site who rely on groundwater supplies. Rigorous site characterization and modeling is needed to estimate the level and geographic span of groundwater impacts and to evaluate whether alternative sources of water or new wells need to be provided to local citizens. Public engagement and participation during permitting is essential if alternative sources of water or new wells may need to be provided.
Cumulative Risk
Robust analyses of the potential impacts of mining consider cumulative health risks. Human populations are exposed to multiple hazard types, including biological, physical, chemical, psychological, and social (e.g., poverty, discrimination, unemployment, limited access to health care). These hazards can occur through different exposure settings (e.g., environmental, occupational) and multiple media (e.g., air, water, soil). Different hazard types, especially chemical and nonchemical stressors, can interact to affect human health in complex and dynamic ways. These multiple, sometimes synergistic, stressors can lead to asymmetric impacts within and between communities, and historically underresourced and underrepresented populations are often most affected.
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The above conclusions outline the potential impacts of gold mining across the Commonwealth of Virginia, but only robust site- and project-specific analyses can assess the potential impacts of a particular project on human and ecological health.
RECOMMENDATION: To minimize impacts to human health and the environment, the Virginia General Assembly and state agencies should ensure that robust site- and project-specific analyses of impacts are completed prior to the permitting of a gold mining project.
VIRGINIA’S REGULATORY FRAMEWORK
Gold mining has a long history in Virginia, dating from the 1800s. At present, however, there are few metal mining activities in the state and no active commercial gold mines. Given the current lack of metal mining activities in the Commonwealth, it is not surprising that the present regulatory framework appears geared toward projects such as sand and gravel mining and not gold mining. Although most of Virginia’s mineral mining laws and regulations seem suitable for the types of mines now operating in the state, the current regulatory framework is not adequate to address the potential impacts from commercial gold mining. Gold mining raises a number of environmental and public health issues that merit additional attention and suggest a need for changes in laws, regulation, and guidance.
Review of Impacts
Virginia’s current regulatory system lacks an effective and consistent process for review of environmental impacts from potential gold mining projects. As a result, it is unlikely that a robust collection, evaluation, and review of site-specific data regarding potential impacts of gold mining activities and their impact on the public health and welfare of surrounding communities will take place. The National Environmental Policy Act (NEPA) requires federal agencies to consider the potential environmental effects on natural resources, as well as social, cultural, and economic resources, before permitting. Virginia law does not require a NEPA-like review of environmental impacts for private lands, where gold mining is most likely to occur. Additionally, while baseline studies in Virginia appear to be recommended, they are not required. This means that in the absence of a major federal action that triggers the federal NEPA process, there may be limited collection of baseline information and no formal documentation of the regulatory program’s analysis, disclosure of impacts, or decision making for a range of environmental resources or factors. Some states have a state-specific NEPA-like process that allows for a consistent approach to collecting and considering baseline information and other material relevant to environmental impacts (e.g., Montana and California). Other states have regulation, code, and guidance documents that emphasize the importance of baseline studies (e.g., Colorado, Nevada, Montana, California). The protection of air and water quality would be strengthened if Virginia adopted laws and promulgated regulations that required up-front, robust data collection and a NEPA-like analysis that discusses and evaluates reasonable alternatives.
Exemptions
Virginia provides exemptions from regulatory oversight for off-site processing and exploratory drilling which are not commensurate with the potential impacts from those operations.
- Off-site processing: Gold processing facilities in Virginia that are not located on site with active mining or extraction (“toll mills”) would not require a permit from the Mineral Mining Program for the operation and reclamation of the site. Toll mills may look very similar to permitted on-site processing facilities and similar environmental impacts may result from toll mills. In fact, the waste materials at toll mills may contain a broader range of potential contaminants if the source materials come from different locations. While toll mills may be required to obtain permits from other agencies to protect air quality and water quality, the lack of regulatory oversight by the Mineral Mining Program means that site characterization, project plans and designs, and the implementation of best practices for operations, reclamation, and long-term stewardship may not be adequately addressed.
- Exploratory drilling: Virginia’s current laws and regulations exempt exploratory drilling for mineral resources. Impacts on the environment during initial exploration are generally minor, localized, and easily reclaimed. However, advanced exploration methods may be associated with greater impacts (see Chapter 3). While surface impacts including erosion and runoff may be regulated by the Virginia Department of Environmental Quality and the Virginia Department of Conservation and Recreation, there are currently no mineral mining regulations for exploration in Virginia that mandate the plugging of drill holes or the covering of drill cuttings from the hole. If best practices are not utilized for these closure activities, pollution of the local groundwater and surface water could occur. This exemption for exploratory drilling also means that public notice to citizens and local communities is not required. Greater oversight of exploration drilling would ensure community participation starting at the earliest appropriate stage and continuing throughout the life cycle of a potential gold mine, and would lessen the likelihood of these localized impacts, especially in regard to more advanced and intensive drilling programs. This oversight could include requirements to file plans for drilling, closure, and reclamation, and a requirement to provide notice to those around the exploration site.
Underground gold mining without significant surface effects is also currently exempt from regulations under Virginia’s mineral mining codes and regulations. While significant surface effects related to disturbances and facilities would require a permit, the exemption for underground gold mining could cause important aspects of underground mines to be excluded from operations and closure plans of the surface permit. Additionally, the level of technical assessment and oversight for underground gold mines by Virginia Energy is not clear.
Financial Assurance
Virginia’s bonding requirements are insufficient to cover the costs of reclamation and long-term stewardship of gold mining and processing operations, which poses a fiscal and environmental risk to the Commonwealth in the case of the bankruptcy of mining enterprises or abandonment of their mining sites.
- Bonding rates: Virginia’s bonding rates are based solely on disturbed acreage. This type of bond calculation often leads to undercollection of bonds for gold mining and processing operations because it focuses only on aspects of land reclamation and does not account for additional costs like postclosure water management. Additionally, Virginia offers a bond pool, called the Minerals Reclamation Fund, with even lower per-acre rates and pooled risk. The complex reclamation and long-term stewardship activities that might be necessary for some gold mining projects could greatly deplete or potentially exhaust the Minerals Reclamation Fund used by the Commonwealth to guarantee reclamation. The regular recalculation of potential costs using verifiable engineering estimates would constitute an improved model for determining bonding rates. This model would estimate the costs for reclamation and long-term stewardship for all aspects of the operation over the project’s life, including any postclosure water management, treatment, and monitoring
- Exemptions from bonding: Virginia’s exemptions from bonding for underground gold mining (without significant surface effects), small-scale gold mining, and toll mills do not reflect the costs necessary to conduct reclamation and long-term stewardship at those operations. No financial assurance is provided to the Commonwealth for these exempt operations, which poses a fiscal and environmental risk to the Commonwealth and its citizens.
- Bond release: Virginia does not have clear guidance regarding the criteria for bond release for projects that require complex closure and reclamation. To ensure successful mine reclamation, bonds should only be released following the demonstration that performance standards for reclamation have been achieved over a sufficient period of time. These performance standards may include requirements for slope stability, vegetation establishment, water quality, and hydrologic balance. Incremental bond release for areas at which successful reclamation has been demonstrated can encourage the timely completion of reclamation.
that may be required to achieve long-term hydrologic, physical, and chemical stability. The integrity of the Minerals Reclamation Fund could be maintained using a similar bond calculation model, or by establishing membership criteria that are based on the operation’s characteristics and its potential impacts.
Standards and Their Enforcement
To incorporate best practices, build a mutual understanding among permittees and regulators, and better support protection of human health and the environment, Virginia agencies will need to review the regulatory performance standards pertinent to gold mining and update guidance documents. Virginia’s performance-based laws and regulations provide flexibility for the site-specific designs of each project, but do not provide sufficient guidance for operators to achieve objectives and do not offer sufficient metrics for regulators to evaluate during the review of applications and inspection of activities. Fiscal and environmental risks to the Commonwealth would be reduced with improved guidance and performance standards on best practices for the collection of baseline information, geochemical characterization, water management, waste rock management, tailings management, and impoundment design. Specifically, performance standards for impoundment designs could recommend a probabilistic framework for designing for seismic events and a consideration of the predicted increased frequency and magnitude of major storm events due to climate change. Performance standards would also be improved with conservative recommendations for slope angles and safety factors that reflect best geotechnical practices and incorporate the potential for undrained loading and liquefaction in saturated tailings. Additionally, decision makers may want to reconsider the current practice of using incremental damage assessments to calculate design flood requirements for impoundments.
The capacity to regulate is as important as a strong regulatory framework and is a concern for Virginia given the limited experience with the regulation of metal and gold mining. The capacity to regulate requires robust funding of the regulatory entities, as well as diverse and appropriate technical expertise of the regulators, supplemented by periodic reviews of evolving best practices. In addition, effective coordination between multiple regulatory entities is critical for protecting air quality and water quality, particularly when evaluating, permitting, and monitoring compliance for stormwater and process water management, treatment technologies, and methods for discharge. Given the lack of experience of Virginia regulatory entities in regulating metal and gold mining, regulators’ current expertise and familiarity with best practices may be limited. There are also key gaps in Virginia’s capacity to implement and enforce some of its laws and regulations, such as the inability to directly issue penalties or fines for noncompliance without lengthy adjudication, and the lack of requirements for impoundment inspections by the associated Engineer of Record. Higher-level technical reviews, third-party reviews, or audits would enhance the evaluations of Mineral Mining Plans and inspections of individual permits.
Public Engagement and Environmental Justice
The current requirements for public engagement in Virginia are inadequate and compare unfavorably with other states, the federal government, and modern best practices because they require the provision of limited information, place the burden of public notification on the mine permit applicant, and apply only to a limited scope of recipients. Industry best practices are adopting a greater emphasis on public engagement,
consultation, and partnership with communities before and after mining activities are initiated, as well as free, prior, informed consent to govern interactions with tribes. In Virginia, there is a scarcity of project details in the new permit notifications, a short deadline provided for filing objections or a request for hearing, and a limited number of area residents that are required to be notified, with no specific inclusion of tribal communities. In addition, Virginia Energy does not make technical reports, designs, and other components of the permit application package readily available for public review. Finally, there are no requirements in Virginia for public notice or opportunity for public input for exploratory drilling or when an application is renewed, a permitted project is expanded, or a bond is released. These permitting actions are critical milestones for the mining operation, and they warrant meaningful engagement with nearby landowners, communities, and other stakeholders.
Current Virginia regulations that are applicable to mineral mining will need to be amended to reach the goals set out in the Environmental Justice Act. In 2020, the Virginia legislature passed the Virginia Environmental Justice Act to better incorporate environmental justice into regulatory decision making in the Commonwealth. In the context of potential gold mining projects, an emphasis on environmental justice requires a regulatory structure that recognizes existing environmental injustice, population vulnerabilities, and economic and health disparities, and aims to reduce existing disparities and prevent future disparate impacts. This regulatory structure should ensure that those experiencing existing environmental injustice and health disparities are notified in a timely fashion about potential gold mining projects, are able to consult meaningfully with potential gold mining project proponents, and can contribute to decision making.
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As detailed above, Virginia’s present regulatory structure is not adequate to protect against the potential environmental degradations that could accompany gold mining activities. Stronger requirements for bonding, public engagement, and the review of environmental impacts are necessary; as well as updated regulatory capabilities, exemptions, performance standards, and guidance documents in order to protect human health and the environment.
RECOMMENDATION: To protect against the potential impacts of gold mining, the General Assembly and state agencies should update Virginia’s laws and its regulatory framework.
