If you have a degree in geotechnical engineering, being involved with the design of mine waste (and heap leach) facilities is a natural fit. There are very few aspect of geotechnical engineering that are not used for the design of a tailings facility. Well, in truth, I like to think that there are two main branches of geotechnical engineering, and for a tailings facility, we use a lot more of the soil mechanics branch than of the foundation engineering branch. FYI, foundation engineers are the people who design of foundation elements of structures. Foundation engineers are tasked with making sure that structures don’t settle too much, and that the differential settlement is tolerable.
Anyway, back to the point. For the design of mine waste (and heap leach) facilities, there are a lot of aspects of soil mechanics (and other science and engineering disciplines) involved. There is site investigation work (test pits, drilling and sampling and advanced in-situ testing), geotechnical laboratory testing, material characterization, consolidation, slope stability, seepage, earthquake engineering, liquefaction analyses, and more. And, once the facility is designed and permitted, you get to go watch it being built. What could be better than that? Aside from geotechnical engineering, tailings dam designs also require siting studies, risk analyses, alternatives assessments, multiple accounts analyses, environmental planning, permitting, social and socio-economic considerations, material and cost estimating, life cycle planning, scheduling, closure planning, hydrology, hydraulics, and lesser matters, like roadway design, fencing, etc.
Working with natural materials is so unlike other fields, where materials can be prescribed. For example, you can order 2000 psi concrete, or grade 60 steel, if you are a civil engineer. In geotechnical engineering, you have to establish the properties of the materials you are working with, and some material properties and parameters can vary widely. Permeability, as an example (basically the velocity that a fluid will flow through a porous media, like soil, or fractured rock), can vary as much as eleven orders of magnitude. Ground conditions can change spatially (laterally, and with depth), and a dam designer needs to know how and where these variances occur. Fractured bedrock may need to be grouted, and clay may need to be removed, or improved.
The materials used to build the dams need to be characterized too, and their properties can change as different portions of the borrow areas (places where the materials are excavated) are developed, and the engineer needs to take action, maybe requiring a different degree of compaction, or altogether rejecting the material. I recall a construction job in the Former Soviet Union, years ago, where I rejected several loads of concrete because it had segregated in the trucks that were being used to transport the concrete. I was actually detained in a police station for several hours after that, with no explanation, nor translator. Makes for good stories! Anyway, a dam designer needs to be constantly on their toes, because nearly anything can happen.
I have truly enjoyed my career as a tailings dam engineer. It has taken me to some of the most far-flung reaches of this planet, from the dense jungles of Colombia, to the desolate Kyzylkum Desert of Uzbekistan. Because of those travels, I have been privileged to visit Machu Piccu in Peru and Red Square in Moscow, Denali in Alaska and the Sturgis Bike Rally. I have been snowed in, in Silverton. I have worked at the Palabora mine in South Africa, which boasts housing all of the big five animals. There are hippos in their return water dam, and giraffe all around.
I have overseen the removal of a dam that should have never have been built in the first place. I have helped repair tailings facilities that were suffering horrible damage in South Africa and Nicaragua. I have led boardrooms filled with executives through discussions of various potential outcomes and possibilities for their ailing facilities. Yes, I have had several nights of miserable sleep because of that. I have worked for clients around the globe, and I have met many wonderful people along the way. It has been an amazing ride.
All of those experiences and more have formed me into being the person and the engineer that I am today. I truly believe that being a tailings engineer is the ultimate rewarding career for a geotechnical engineer. It certainly isn’t boring!