Since the beginning of the modern mining industry, there have been hundreds of tailings collapses, slides, and floods. The immediate negative impacts of these releases first prompted the development of better storage methods, but the discovery of long-term environmental damage cemented the need for lining and containment. Tailings can appear fairly inert because the material largely consists of waste rock with the desired materials removed. However, it is far from just plain crushed rock. Tailings are rich in acidic chemicals, heavy metals, radioactive isotopes, and more. Understanding the true potential for environmental and human impact from tailings will drive home the importance of securing it at every stage from creation to permanent disposal.
Waterway Damage
The parts of the environment most sensitive to damage from the release of tailings or their leachates are the waterways. Streams, ponds, lakes, oceans, and even underground water tables are all sensitive to the chemicals and physical compounds found in tailings. Physical dusts and sands that wash out of the tailings pile end up clogging the beds of already shallow ponds and streams. The fine particles settle into the gills of the fish and other aquatic life, killing them outright or slowly their growth and reproduction. As the material settles in the bodies of water, they slowly release heavy metals and chemicals that also affect plant life in the water. After a few years of exposure, a thriving waterway ecosystem can become a barren feature that requires extensive remediation to get rid of lingering heavy metals like lead.
Soil Effects
It is not enough to simply keep tailings away from natural waterways and expect no further environmental effect. Even when it is allowed to leach into or mingle with soil, there is a long-term negative effect. Heavy metals and salts are the main issue with tailings. Lead, arsenic, and various sodium-based compounds are all either absorbed by plants or interfere with plant growth in the first place. If people or animals eat the plants, they can become ill from exposure. Soil holds onto these compounds for years, making remediation difficult as the natural bacterial and nutrient levels are slowly reduced. Dust from dry storage piles is particularly problematic even for properly lined impoundments since the dust can easily settle on plants or mix with the soil far from the storage area.
Groundwater Contamination
Most environmental risks to surrounding waterways are concentrated on surface water due to runoff. However, seepage also needs to be controlled because it threatens the groundwater below the surface. Unlined tailings storage ponds and pits allow water to slowly seep through the soil below if they are not lined, no matter how well runoff is controlled over the surface. Since aquifers and other groundwater deposits can stretch many miles, a mine that is located far from a town or city could still have an impact on the water supply. Lining the impoundment to control seepage as much as possible reduces the risk of groundwater contamination significantly, especially if none of the tailings are disposed of in the old mine itself.
Radioactivity
Uranium must be mined in large volumes to supply the current demand for power generation and weaponry, but it produces a highly radioactive tailings supply. Radioactive tailings are not just detrimental to the environment by reducing animal health and plant growth, but they also pose the greatest risk to human health. If radioactive tailings travel in the form of dust specifically, it is all too easy for thousands of people to be exposed to a risky dose of radiation before the problem is discovered. Dust control is essential to stop the transfer of heavy metals as well, so do not just consider it a must for uranium tailings alone.
Human Health
Humans are generally only exposed to tailings if there is a disaster or they work at a mine. While the workers have safety equipment to keep them from experiencing chemical burns or inhaling heavy metals, individuals visiting an area where tailings were spread may not be aware of the risks. Some tailings sites are still accessible by the public today who put themselves are risk for increased cancer rates and other long-term health effects. In general, it is important to secure tailings out of access from the public so that wandering hikers or residents of a new housing subdivision can’t accidentally come in contact with it.
With so many direct risks to both humans and the environment, it is essential to contain tailings properly. Let BTL Liners help with our toughest RPE liners.
