When Sand Strikes Back: The Environmental Costs of Silica Extraction

Introduction

Silica sand, also known as industrial sand, is made up of quartz and silicon dioxide. It is mined for use in a variety of applications including glass manufacturing, road construction, foundry work, and hydraulic fracturing for oil and gas recovery.

Silica sand deposits are found throughout the world, with significant mining operations in the United States, Europe, and China. The demand for silica sand has increased in recent years, especially for use in fracking operations. However, silica sand mining has raised environmental concerns due to its potential impacts on air and water quality, noise and light pollution, wildlife habitat, and land use.

Silica sand mining involves removing sand and gravel from land or underground mines. The mining process generates large volumes of dust, noise, and vibrations. Once exposed, silica particles can become airborne during excavation and processing. Water used in mining operations can also become polluted with silts and chemicals. The lights, vehicles, and infrastructure of mining facilities can negatively impact wildlife behaviors. After mining is complete, the land may not be properly reclaimed if topsoil and vegetation are not adequately restored.

Land Use Changes

Silica sand mining results in significant changes to land use and habitats. Thousands of acres of land can be disturbed to access the sand deposits. In Wisconsin, a typical silica sand mine disturbs between 50-500 acres of land. In Minnesota, the average silica sand mine disturbs 81 acres.

Silica sand is often located beneath forests, wetlands, and grasslands. To access the sand, the land must be cleared of all vegetation and topsoil. This directly destroys habitat for wildlife. Forests that provide habitat for birds, small mammals and deer are removed. Wetlands that provide habitat for waterfowl, amphibians and fish are drained. Grasslands that provide habitat for songbirds and pollinators are dug up.

The mining activity fragments contiguous habitat areas. Large blocks of forest, wetland complexes, and grassland areas are broken up into smaller, disconnected parcels. This makes the habitat patches too small to support wildlife populations. Fragmentation isolates populations and disrupts migration patterns. It also creates edge effects where habitat quality declines along the edges that are newly exposed.

The loss of habitat from silica sand mining threatens biodiversity in the regions where it occurs. It has contributed to population declines in species that depend on the forests, wetlands and grasslands which are mined. More sustainable mining practices are needed to reduce the impacts to wildlife habitats. Requiring aggressive reclamation of mining sites can help restore some habitat, but often with loss of natural qualities.

Air Quality

Silica sand mining can have significant impacts on air quality if not properly regulated. The biggest air quality concerns with silica sand mining are silica dust and particulate matter generated during excavation and processing.

Silica, or crystalline silicon dioxide, is a common mineral found in sand, rock, and mineral ores like quartz. When silica-containing materials are crushed, ground, drilled, or otherwise disturbed, it can create fine particles that become airborne. Prolonged exposure to the small, respirable silica particles can lead to serious health effects.

The most notorious health effect associated with silica exposure is silicosis, a respiratory disease caused by silica particles becoming embedded in lung tissue. It can lead to inflammation, scarring, and reduce lung function. Silicosis increases the risk of other diseases like bronchitis, tuberculosis, and lung cancer. Those with silicosis may eventually require oxygen therapy as their lungs become unable to properly oxygenate blood.

Silica dust exposure has also been linked to autoimmune disorders, chronic kidney disease, and other lung diseases. The severity of health effects depends on the level of exposure over time. Even low-level chronic exposure that doesn’t cause silicosis can still damage the lungs and airways. Proper protective equipment and engineering controls are necessary to protect workers and reduce silica dust exposure.

In addition to silica dust, the large amount of particulate matter generated from silica sand mining operations can affect regional air quality. Particulates from mining activities contribute to haze and smog, reducing visibility and air quality for nearby communities. Fugitive dust from mining, processing, and transportation must be properly managed to minimize impacts. Air quality monitoring and dust suppression techniques are often required for permitted mining sites. Overall, silica sand mining companies must take substantial precautions to mitigate the amount of silica dust and other particulates released into the air. Proper regulations and enforcement are necessary to protect public health.

Water Quality

Silica sand mining can have significant impacts on water quality if not properly regulated and monitored. The two main areas of concern are sedimentation and chemical contamination.

1. Sedimentation and Erosion

One of the most common issues is the erosion of exposed earth and soil during mining activities. This can lead to increased sedimentation in nearby rivers, lakes, and wetlands as soil particles are transported by stormwater runoff. High sediment loads in water bodies can destroy habitat, suffocate fish eggs, increase turbidity, and fill in streambeds.

Sedimentation ponds and berms are often used to capture eroded soils before they reach surface waters. However, these controls must be properly maintained. There have been cases of berm failures during heavy rains, releasing large plumes of sediment into rivers. Strict permitting and inspection of erosion control measures is necessary.

2. Chemical Contamination

The actual sand mining process utilizes chemicals and compounds that can leach into groundwater and surface water supplies if not contained. This includes substances like flocculants and surfactants used to wash and process the sand. Fuels, lubricants, and other chemicals used to operate heavy machinery can also leak into water sources.

Wastewater discharge from sand processing facilities must be treated to remove contaminants before release. Routine groundwater monitoring is also critical to detect potential leaching from mine sites. Proper storage and containment of chemicals on mining properties reduces the risk of spills migrating off-site through soil, ditches, or drainage networks.

With careful monitoring and oversight, the water quality impacts of silica sand mining can be minimized. But negligence can lead to long-term damage to aquatic ecosystems. Strong regulations and enforcement are essential.

Noise & Light Pollution

Mining operations can generate high levels of noise from heavy machinery and transport activities. The noise levels often exceed recommended thresholds for residential areas. One study found average noise levels from a silica sand mining site that exceeded 55 dBA over 75% of the time [1]. This is well above EPA’s recommended daytime noise level of 55 dBA.

Prolonged exposure to noise above 70 dBA can lead to hearing impairment over time [2]. Noise pollution also disrupts wildlife that rely on sound for communication and predator evasion. Several studies have documented changes in bird vocalizations and reproduction near mining and industrial sites [3].

In addition to noise impacts, light pollution from mining can be significant. Bright lights are often used to illuminate processing facilities and mining pits at night. This artificial light at night can disrupt circadian rhythms and behaviors of wildlife in surrounding areas [4]. For example, artificial light near seabird nesting colonies has been shown to cause disorientation of fledglings [5]. Careful lighting design and shielding can help reduce ecological light pollution from mining facilities.

Wildlife

Silica sand mining operations can have significant impacts on wildlife and biodiversity through habitat destruction, fragmentation, and disturbance. Of particular concern are the effects on threatened and endangered species that depend on the habitat within mining sites and surrounding areas.

Habitat loss is one of the greatest threats to biodiversity from silica sand mining. Clearing vegetation and topsoil eliminates or degrades habitat for many species. Fragmentation of habitat blocks also occurs as mining cuts through contiguous natural areas, disrupting habitat connectivity. This can isolate populations of species, prevent migration and dispersal, and increase susceptibility to predators.

Specific species at risk include the Karner blue butterfly, which relies on wild lupine that grows in oak savannas and pine barrens – habitats directly within the range of silica sand deposits. The gopher tortoise is another threatened species affected by loss of its scrub, sandhill, and pine rockland habitat across the southeastern U.S.

Various measures can help mitigate the impacts on wildlife, such as avoiding critical habitat, reclaiming land after mining, and implementing conservation plans. However, there is no way to completely eliminate the damage of converting natural habitat into an industrial mining operation. The biodiversity risks must be carefully assessed and weighed before allowing silica sand mining to proceed. Maintaining functioning ecosystems and protecting vulnerable species should be a priority.

Reclamation

Reclamation is the process of restoring land after silica sand mining to a natural or economically usable state. There are typically legal requirements that mining companies must follow for reclamation. The process involves removing equipment and infrastructure, reshaping the land, and replanting vegetation.

The overall success rate of reclamation for silica sand mining sites is debated. Proponents argue that with proper oversight and regulations, mining companies can successfully rehabilitate the land. Techniques like saving and replacing topsoil can help restore productivity for agriculture or development. However, critics argue that the unique habitat and hydrology of sand dunes and prairies are impossible to fully restore.

One challenge with reclamation is that silica sand mines are often located in sensitive environments. Sand mines in Wisconsin are situated in ecologically significant areas along the Mississippi River. Environmental groups argue that even if the landform is restored, the biodiversity and water quality is permanently damaged. They advocate for avoiding sensitive areas entirely.

There are also concerns that erosion control measures may fail over long time periods after mining ceases. Some mines have legacy issues with revegetation and soil stability decades later. Even if regulations require reclamation, critics worry that long-term funding and oversight of sites may be insufficient. However, supporters argue that with conscientious reclamation planning and monitoring, the land can be returned to an ecologically healthy and productive state after mining.

Regulations

Silica sand mining in the United States is regulated at both the federal and state level. Key federal laws include the Clean Air Act, the Clean Water Act, and the Surface Mining Control and Reclamation Act. At the state level, laws vary, but common regulations address air emissions, water use and discharges, wetlands protection, reclamation requirements, financial assurance, permitting, and local zoning.

Despite existing regulations, there are concerns about potential gaps in oversight of the silica sand mining industry. Areas of concern include ambient air quality standards that do not address the fine particulate matter generated by silica sand mining and processing, loopholes in stormwater regulations, lack of groundwater monitoring requirements, variances in reclamation standards between states, and local zoning rules that may not fully account for all impacts.

Critics argue that some state regulations were initially tailored for mining metals and aggregate and have not been sufficiently adapted for the unique challenges of silica sand mining. There are also questions about agencies having adequate staff and resources to fully enforce permit conditions and conduct meaningful oversight. Additionally, there are currently no federal or state standards limiting the size and concentration of silica sand mines in a geographic region, which some argue should be addressed.

In summary, while silica sand mining is subject to various federal and state laws, there may be opportunities to update regulations to more comprehensively address the industry’s impacts on air and water quality, land use, and local communities. Stronger regulatory oversight and additional research on emerging mining practices could help achieve a better balance between natural resource development and environmental protection.

Case Studies

The Pattison Sand Company mine in Clayton, Iowa has been in operation since 2005 and produces high-purity silica sand for industrial uses. Environmental groups have raised concerns about the impacts to air and water quality.

– Air Quality: There have been citizen complaints about dust from mine activities causing respiratory issues. Ambient air monitoring has shown elevated levels of particulate matter during mining operations.

– Water Quality: The mine sits on top of an aquifer that connects to private drinking water wells. There is concern about potential groundwater contamination, but no issues have been detected in well water testing so far. Monitoring is ongoing.

– Reclamation: The mining company has been working to reclaim depleted areas by grading and revegetating the land. However, some reclaimed areas have had issues re-establishing vegetation. More research is needed on best practices for reclamation of silica sand mines.

The Lake County silica sand mine in Minnesota has also raised environmental concerns. This mine is located near Lake Superior and the St. Louis River watershed.

– Wetlands Impacts: The mine expansion required draining wetlands, fragmenting wildlife habitat. Attempts were made to mitigate wetland loss through wetland restoration activities elsewhere.

– Transportation: Transporting silica sand via truck has increased noise, air emissions, road wear and safety issues on local roads. The company and local government are exploring other transportation options like rail.

More long-term monitoring data is needed to fully understand the impacts of silica sand mining at these and other sites. Case studies help elucidate site-specific issues that may arise.

Conclusions

The environmental impacts of silica sand mining are significant and must be carefully managed. Increased silica sand mining to meet growing demand is concerning due to the potential threats to air and water quality, land use, wildlife, and human health.

The key environmental concerns surrounding silica sand mining include air pollution from silica dust and diesel emissions, groundwater and surface water contamination from chemicals and wastewater, noise and light pollution, loss of agricultural land and natural habitats, and health effects on miners and nearby communities. Strict regulations and mitigation strategies are necessary, but not always sufficient to prevent harm. Additional research into emerging mining and processing technologies could identify cleaner alternatives.

To mitigate the impacts, best practices include enclosing operations and using water spray and baghouses to capture silica dust, lining ponds and recycling water to prevent groundwater pollution, implementing noise and light reduction strategies, phased mining and concurrent reclamation of land, protecting sensitive habitats and species, and rigorous monitoring of air and water quality. Regulations need to be tailored to specific regions and continually updated as we learn more.

More research is needed to develop cleaner practices and technologies, quantify cumulative regional impacts, and identify solutions that balance economic benefits of silica sand mining with environmental protection. A precautionary approach should be taken regarding expansion into new areas until potential impacts are fully understood. With careful planning, regulation, and innovation, it may be possible to extract this important resource while safeguarding communities and ecosystems.