Acid mine drainage poses a major problem to the environment and drinking water resources in the surrounding area. We will explore remediation techniques, mitigation techniques, and the environmental and economic hazards which stem from acid mine drainage. Examples of sites that were not managed properly and the consequences are the Eagle Mine in Minturn, Colorado and the Gold King Mine/Animas River Disaster near Silverton, Colorado. The processes by which acid mine drainage occurs will also be examined.
Mine workings interrupt the natural cycle of water filtration through the earth. Where water would naturally flow through a rock body and into deeper aquifers or flow out into surface water it is instead coalesced into a void space (mine working) in the rock. This void space can either allow a steady flow of water out, or if it is plugged, the water will continue to collect until the plug bursts. The water within the void space now carries the minerals which were being extracted in the former mine. Where this would have naturally been removed when filtered through the non porous rock, it is instead concentrated. These minerals, such as iron sulfide, react with the water and air to form dissolved iron and sulfuric acid. Heavy metals such as lead, mercury, and copper are also carried out in the mine drainage. These lead to the buildup of red, orange, and yellow sediments often seen in surface water near unremediated mine sites. Unremediated mine sites have visible contamination with discolored soils and water as well as a dearth of vegetation.
Remediation of acid mine drainage and abandoned mine sites requires the same detailed analysis as the initial mining processes. Incorrect blasting or drilling can lead to exacerbation of the contamination, rather than mitigation, as in the Gold King Mine. Contaminated water was released into the Animas River when the EPA attempted to insert a pipe to drain contaminated water. Had the EPA done proper subsurface investigation at the site to find that the water was under pressure, they could have planned for it in advance saving millions of dollars in remediation and disaster aid for the people downstream.
Scientists at the University of West Virginia are working with the Department of Environmental Protection to find new uses for acid mine drainage sludge. The sludge, a byproduct of acid mine drainage, has concentrations of rare earth metals that equal that of some of the most lucrative mines in the world. This may give a new way forward for the waste products of acid mine drainage as its rare commodities can offset the cost or even incentivize the remediation of acid mine drainage.
IX Water is using its technology to remediate contaminated water from acid mine drainage, helping to protect the environment and return Colorado’s beautiful landscapes to their original grandeur!
Acid mine drainage is a major problem across the globe. Since humans in antiquity have mined minerals from the earth, natural processes have caused acid mine drainage. Now with the technology to not only remediate sites which harm the environment and human life, but also use the resources which exist in these sites the earth and human life can be improved.