When land is disturbed in mining operations, there are a wide range of issues that can arise. Erosion can carry the topsoil away, while toxic chemicals can leach into the soil through groundwater contamination or accidental spills. There can be unintended consequences of your mining operations in the community. Finally, there can be issues with tailings ponds or dams that can cause additional contamination to surface water, air quality, or similar pollution. Let's take a look at each of these issues and then consider potential solutions, further on, to help the industry at large better manage these problems.
Erosion
Because mining operations disturb the soil's surface, erosion is a fairly common problem for many mining operations. From the heavy equipment that transfers significant weight and torque to the ground, to rainwater flowing across raw earth turned up during mining operations, erosion uses wind and water to move loose topsoil into waterways and low-lying areas. It can cause serious problems with clogging waterways, leading to fish die-off as well as dust storms. In fact, the dust bowl of the Great Depression was caused by erosion from bad farming practices. Much as it was solved in farming, there is a range of options available to help reduce erosion on mining sites, such as surface coverings, vegetative growth, and contour grading.
Chemical Contamination
Controlling the impact of chemical contamination on your mining site can help make the process of reclamation and remediation much easier. By using mediation throughout the entire process, you can ensure that you'll have minimal chemical cleanup and containment when it's time to close down the mine. However, whether the contamination process happens as part of daily mining operations or on an accidental basis, having the right tools in place to deal with the situation can make a big difference in how much your company will need to spend on the remediation process. Having barriers in place to help contain the contamination can limit the spread, making your final clean-up a much easier task than it may be otherwise.
Tailings Issues
Containing a highly toxic material either from the ore itself or chemicals from the extraction process, tailings ponds can cause serious issues; creating a substance that can leach sulfuric acid, cyanide, ammonia, naphthenic acids, arsenic, lead, selenium, mercury, uranium, and asbestos. These common refining features can cause serious issues with mining reclamation and rehabilitation but are not insurmountable. However, the design, maintenance, and constant management of these types of sites can provide a solid challenge for mining companies while continuing to represent significant economic burdens for the industry at large. If they leach or leak, they can contaminate both groundwater and surface water sources, which can have a strong impact on community health and safety.
Incidents Causing Significant Damage Due to Poor Practices in Mining Reclamation and Rehabilitation
Though these issues are serious, treating the solutions haphazardly has its own drawbacks. As a single example from the above hazard, we'll look at the impact tailings can have on the environment in real-world situations. There are approximately 18,000 mines reported worldwide. Of these mines, there has been a consistent rate over the past century of 1.2% failure of tailings dams, or three of the Earth's 3,500 tailings dams failing annually. About 75% of these failures happen in China, where 95% of tailings dams are constructed using the same economical design.
By comparison, it's 120% more likely that a tailings dam will fail than a water storage dam, whether a reservoir or a hydroelectric dam, given their 0.01% chance of failure. This is a serious problem that needs to be addressed at every mine with a tailings dam, as it will continue to impact the industry at large until these failures stop. Despite China's large numbers, it's North America that has the highest impact from tailings dam failures. However, it is still a worldwide problem, with three examples in relatively recent history including:
- Brumadinho Dam, Brazil, January 2019: Despite concerns about the dam's integrity reaching back to 2009, 3.17 million gallons of muddy iron waste flowed through the mine’s offices and cafeteria, while also flooding homes, farms, and roads en route to the Paraopeba River, which supplies water to the region. It's estimated at least 270 people died and the pollution reached 185 miles downstream. The mine's operators were aware that sensors monitoring structural integrity had failed days before the tailing dam gave way.
- Mount Polley Mine, Canada, August 2014: Though the government had issued no less than five warnings over the same number of years previously about excessive water levels, the dam disintegrated and released 2.6 billion gallons of water as well as 1.59 million cubic feet of tailings over a four-day period. This water reached Hazeltine Creek, Quesnel Lake, and Polley Lake, raising the water level of the last by nearly five feet, dumping 440 tons of arsenic, lead, and other heavy metals into the waterways.
- Baia Mare Cyanide Spill, Romania, January 2000: Referred to as the worst ecological disaster since Chernobyl, the failure of a dam containing gold mine tailings flooded the area with 260,000 gallons of water carrying 110 tons of cyanide and heavy metals. The water crossed productive farm and dairy land before reaching the Somes river, where it flowed for over 620 miles into Hungary and Yugoslavia, reaching the Danube. The catastrophe contaminated drinking supplies for 2.5 million Hungarians, with some sections of the river registering cyanide between 20 to 50 times accepted levels.
Dealing with these serious issues can cause a lot of problems in your mining operation, but they are not insurmountable given the many advancements that have happened in technology and materials science. By using quality geomembranes to seal contamination into your mining site, you'll be able to enjoy lower costs for remediation, reclamation, and rehabilitation down the road. Later, we'll discuss a range of materials that are commonly used in the mining reclamation and rehabilitation process, making it easier for you to find the solutions you need while minimizing the cost in the process.
Your mining company needs solid solutions with materials on the mining site that work effectively while still protecting the health and safety of the local community. BTL Liners' geomembranes provide industry leading performance, minimizing leakage as much as possible, making reclamation and rehabilitation much faster, cheaper, and easier. If you're concerned about your tailings ponds, dams, or similar structures, our liners give you the control needed to keep your site as clean and uncontaminated as possible.
