THE SUNNYSIDE MINE

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Early in my career, I was provided with the opportunity to complete almost every aspect related to designing a raise to a tailings facility.  This particular tailings facility was located just to the east of the beautiful town of Silverton, Colorado.  I’ve mentioned Silverton previously, in a blog about rock hounding.  It began in about 1987, when I attended a site investigation of this TSF.  The TSF was a cycloned facility.  A cyclone is a clever little contraption that uses gravity to expedite the separation the sandy fraction of tailings slurry from the finer fraction.  The sands are used to build an embankment, and the embankment impounds the fines.  It is a technique that is used in many parts of the world, and can be especially popular (useful) in copper projects which tend to have more sand in their tailings, and thus can build more embankment.  You can have a single cyclone that gets moved frequently, or numerous cyclones that get moved less frequently.  Or, you can have one giant cyclone.  When a tailings slurry sediments, the coarser particles settle first, while the clay and silt-sized particles tend to settle later.  This is the same principle that a cyclone is based on.  The cyclone just speeds up the process.  In the case of a cyclone, the sandy fraction is called the “underflow” and the fines portion is called the “overflow”.  In the case of the Sunnyside mine, the single cyclone was moved around the embankment on an old school bus.  It was pretty…quaint. 

So, there I was for this site investigation.  We did cone penetration tests (CPTs), standard penetration tests (SPTs), self-boring pressuremeter testing, drilling and sampling and we installed some isolated tip well points (piezometers).  This was the first of three sites that we stopped at for this site investigation road trip.  The other two sites were in Utah and Nevada.  It was a really good trip, but also very long. 

Following the road trip, I got to analyze all of the field data and arrange the laboratory testing.  Next, I ran a series of geotechnical analyses, centering on slope stability.  In those analyses I modeled an elevated beach drain to mimic the construction of a blanket drain that extended from the embankment and to a distance of about 150 feet out onto the beach.  The purpose of the drain was to keep the pore pressures (and phreatic surface) safely away from the embankment.  Next I did most of the design work (which by today’s standards was pretty minimal).  I even drew many of the design drawings, and wrote much of the design report. 

One of the real benefits of our design was an earthen cover that we were going to be placing over the sandy embankment slopes.  Whenever the wind blew, so would the sand.  And even though the facility was on the leeward side of town, sometimes the wind would blow in the opposite direction, blowing into town.  The earth cover was much more friendly to the neighbors. 

During the late autumn of 1988 I returned to Silverton to complete a site investigation of the materials that we would use the construct the blanket drain, embankment and cover for the sandy slope.  The work was going well, but as the days passed, snow began to fall.  My last activity was to collect all of the 5-gallon bucket samples of the materials I had left scattered across the very hilly property.  It had been a long trip, and I was getting worn out from all of the physical activity.  It was snowing, and I had a lot of samples to carry down to my truck.  I was getting creative on how I was carrying these buckets so that I didn’t over-fatigue any one part of my body.  During the final trip, I was carrying the bucket in my arms,  as if I was carrying a baby.  I slipped and went down hard.  The bucket landed hard on my left wrist, the wrist I wore my watch on.  I say “had”, because to this day, I still can’t wear a watch on that wrist for very long.  I managed to get back to my motel room, and removed my coat.  My wrist was already badly bruised and swollen.  To make it worse, the roads out of town were all closed due to snow.  I got ice from the ice machine to relieve some pain and swelling.  I was trapped in town for three days due to the weather, and there was no doctor in town.  Tourist season had passed.  I eventually made the drive back to Denver, and after several months of medical treatment, I ended up having surgery on that wrist.  It was a long and painful lesson on the need for patience.  If I hadn’t been in such a hurry to get off of the mountain, I would not have been injured.  I could have completed a quick risk assessment that might have told me to go have a nice cold beer and come back tomorrow.

Anyway… all of that eventually got taken care of.  I completed the design report and provided it to the client.  There was a typo on the cover page of the drawings.  The name of the project.  Ugh.  And because of the way AutoCAD worked (at least in those days), that error was put on every single drawing in the set.  Pretty embarrassing.  Lesson:  check even the simplest things!

During the spring of 1989, shortly after the birth of my first child, I was once again sent back to Silverton, this time to watch after the construction of the facility, and to complete all of the material testing.  It was a really good summer, and the job was completed nearly without incident.

Then it was time to complete the record-of-construction report.  That report was largely completed by me. 

I still have a beautiful photograph of that construction job that I proudly display in my office.  I feel a real sense of pride and ownership for that project, mostly because I had completed so many aspects of the project single-handedly.  With plenty of mentoring, of course.

The take-away:  Get out there and accomplish something.  It’ll make you feel great!     

I didn’t even get a chance to talk about the time I walked into a local pub during the construction project to meet my client for a beer, and I was immediately met by some tough guy, who asked me, “Did you ever have your nose broke?” I responded to him that I’d broken it a few times. That gave him enough pause for my client to step in and tell him to back off. That beer tasted especially good!

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