Friday, March 15, 2013

Frac Sand Mining: An Overview


Many of the man made operations in the world require the use of fossil fuels. Historically those fuels have been relatively easy to obtain directly either through mining or drilling operations. As we continue to move forward in the life of the Earth we are using up those resources that are easily obtainable. As a result companies have advanced their techniques in obtaining the much sought after resources. One of these advanced procedures involves the process of hydraulic fracturing. This process involves drilling into layers of shale rock formations which are buried deep in the Earth. These shale deposits house large quantities of fossil fuels; however, do to the nature of the shale the fuels are essentially trapped within them. In order to release the fuels, a mixture of chemicals and sand is pumped into the well at very high pressure which breaks up (fractures) the shale layers. The chemicals are then pumped out of the well and the sand remains in the fissures created basically holding the fractures in the shale open. Now the fuels can be pumped out. There is at least one essential piece of this puzzle that is mined right here in Wisconsin, the sand.
 The mining of sand in Wisconsin is not a new process, however historically it has been done on a much smaller scale than it is being done today and the sand was used more for manufacturing processes. Today, our sand is of particular interest to the energy industry for several reasons. The sand we have in Wisconsin has several properties that make it ideal for fracing including: it is readily available at or near the soil surface which reduces the cost to mine it, it has a high percentage of quartz which gives it a high amount of compressive strength. Finally, unlike many sand deposits the grains are more rounded rather than angular which reduces consolidation of the particles and allows the passage of the fuels through the sand. The rounding of the sand grains is due to the areas glacial history.
The process of removing the sand from the ground usually involves the removal of any vegetation and surface soils in an area and the construction of a large open pit mine. In some instances companies are able to remove an entire hill containing sand deposits. The sand is then transported to a facility where it is washed, sorted and loaded onto rail cars. This transportation can be as short as across the mine site or several miles across the state. Much of the land the mining is being done on was owned by private citizens, the large energy companies will buy the property from them in order to mine the sand.
Much of the sand mining in Wisconsin is occurring through a part of the state which has been called the sand belt. This is a sizable area that stretches from west-central Wisconsin (and into Minnesota) through the central portion of the state. This area has the highest concentration of available sand in the state. This area is unique due do to glacial processes which have removed much of the overburden exposing the underlying sand formations.
All mines are subject to certain regulations; however sand mining is considered non-metallic and as such has much less constrictive regulations. Registration of the mine with the state as a non-metallic mine is part of the process. Mines in the state must also have a plan in place for reclamation after the mining operations have been completed. They must also carry the necessary permits concerning air and water. Water permitting includes both surface water and ground water as high amounts of water are used during the sand washing process. Furthermore the mines have to compete with public opposition, many of the processes will affect those people living in the surrounding communities.
Much concern has been raised with issue of air quality around the mine and the effects silica dust can have on the health of local individuals and those that live along the transportation routes. There have also been concerns with ground water and noise pollution. Many of these issues are constantly in argument because nobody really knows; there has not been enough time to do good research into these cause effect relationships. Another concern that many people have is the effect the traffic has on the road system. Many of the roads were designed for personal vehicle traffic, farm traffic and occasional heavy truck traffic. With the creation of a mine the roads may see a dramatic increase in not only the number of vehicles traveling on the road but many of those vehicles are carrying a large amount of weight. Depending on the number of axels under a vehicle a typical semi can weigh up to 40 tons.         
With the aid of a geographic information system (GIS) we will address the last of these issues by examining the proximity of the mines to the wash plants and rail loading stations. We will determine the distance traveled by the trucks over what routes and try to assess what damage might occur as the result of the increased weight and traffic on the local roads. Our effort will be concentrated in Trempealeau County, Wisconsin and the surrounding area.

CITATIONS:
-University of Wisconsin Extension, Wisconsin Geological and Natural History Survey Factsheet 05, 2012.



-http://dnr.wi.gov/topic/Mines/Deposit.html, Last revised: Thursday July 12 2012




-http://dnr.wi.gov/topic/mines/silica.html, Last revised: Tuesday January 22 2013

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