Dennis Dunham, Sales & Application Manager, Foam Concepts, LLC, Cloquet, Minnesota
Large or long mining booms and busts can leave a community with a number of legacy issues. These include, but are certainly not limited to, social, housing, employment, and physical hazards. Agencies such as the EPA and USACE primarily address the environmental issues, tailings ponds, slag, ARD, soil and water issues. Less often they address physical hazards such as mine openings, subsidence and surface structures. These hazards are usually left to others such as the USFS, BLM, OSM, state AML agencies or DNR or private landowners.
Physical hazards are dangerous in any number of ways. Old buildings that not only can collapse or burn; they can also contain heavy metal contamination or asbestos. Mill structures might also hide entries to mine workings, pits, sumps, wells and service tunnels. Open pits, benches and highwalls can be unstable, prone to collapse and water filled. Falls and drowning are a common danger. Subsidence features can introduce surface water to acid bearing rock, and can erode to the point they become an actual entry into the mine workings. And of course, shafts and adits are attractive nuisances that can trap, injure and kill.
Since 1977, many states (29 in the NAAMLP alone), Indian tribes and federal agencies have established programs to address physical hazards. These programs address demolition, grading, draining, guarding, and re–vegetation. They also work on sealing and plugging openings, including subsidence features. More recently they have begun to incorporate closures that help habitat use or continue to use mine features. Physical hazards can also be viewed as historical, so preserving while safeguarding is a consideration.
There are many methods to address physical hazards, including backfill, steel, concrete and polyurethane foam. This presentation showcased a number of methods and materials that have been used in different situations.
Dennis Dunham has been the Sales and Application Manager with Foam Concepts, LLC, in Cloquet, Minnesota, since November 2003. In October 2006, Dennis purchased the company along with Business and Operations Manager, Larry Poss. Dennis has over 24 years experience in mining, including 15 years in mining equipment development. He also has 10 years experience in mine operations and management at White Pine Copper, Elmhurst–Chicago Stone, Central Ohio Coal (AEP), and Georgia Pacific. Dennis earned a B.S. in Mining Engineering from Pennsylvania State University and pursued graduate studies at Virginia Tech. He is a Professional Engineer in Minnesota and Michigan and is member of the ISEE and SME.