Types of Mining and Fracking
Felicia and Natalie
Mining
The process or industry of obtaining coal or other minerals from a mine
Types of Mining
- Surface: when soil and rock overlying the mineral deposit are removed
- Subsurface: when minerals are extracted from underground
Differences between Surface and Subsurface Mining
Surface:
- Safer and easier
- Does more damage
- Creates more of a mess
Subsurface:
- Not as much damage
- Difficult
- Expensive
- Very dangerous
Surface Mining
Strip
Removal of soil and rock above a layer or seam, followed by the removal of the exposed mineral.
Effects:
- Surface vegetation is removed
- Waste from coal mining can seep into ground into drinking water
- Wind-borne particles negatively effect air quality
- Increases in soil erosion affects native aquatic life, and leaves behind fewer species
Open Pit
A surface mining technique of extracting rocks and minerals from the earth by the removal from an open pit or borrow
Effects:
- Large-scale removal of soil, vegetation, and overburden
- Changes characteristics in soils through accelerated water and wind erosion
- Changes surface water qualities & can cause water shortages
- Carbon emissions from trucks and machines lead to global warming
- Chemicals can seep into soil killing off plants
Mountain Top Removal
Any method of surface coal mining that destroys a mountaintop or ridge line
Effects:
- Streams buried by mountain top spoil or polluted by heavy metals
- Destroys habitats of endangered/threatened species
- Fish migration routes cut off
- Damages aesthetic quality of an area
- Changes in water quality can directly kill aquatic species
- Forests destroyed
Subsurface Mining
Slope
When rocks and minerals are mined by using a sloping access shaft that travels downwards towards desired material
Effects:
- Causes huge amounts of waste earth and rock to be brought to surface
- Waste is often toxic when comes in contact with water or air
- Land above slope shaft can become unstable and start to sink (subsidence)
- Lowers water table
- Dangerous working conditions for miners working underground
Drift
Mining using underground methods and a near-horizontal passageway
Effects:
- Large amount of waste is produced as earth is removed from underground and displaced to surface
- Toxic waste is produced
- Contaminants are released that harm environment
- Disrupts biodiversity
- Water table is lowered - can change flow of ground water
Shaft
A method of excavating a vertical or near-vertical tunnel from the top down
Effects:
- Very dangerous working conditions for miners - risk of collapse, exposure to methane gas, or black lung disease
- Creates large amounts of waste as earth and rock are brought to surface
- Lowers water table
- Harmful effects to soil properties
- Disrupts biome
- Harmful greenhouse gasses are emitted
Fracking
The process of drilling and injecting fluid into the ground at a high pressure in order to fracture shale rocks to release natural gas inside
Steps of Fracking:
- A well is drilled vertically to the desired depth, then turns ninety degrees and continues horizontally for several thousand feet into the shale believed to contain the trapped natural gas.
- A mix of water, sand, and various chemicals is pumped into the well at high pressure in order to create fissures in the shale through which the gas can escape.
- Natural gas escapes through the fissures and is drawn back up the well to the surface, where it is processed, refined, and shipped to market.
- Wastewater (also called "flowback water" or "produced water") returns to the surface after the fracking process is completed. In Michigan, this water is contained in steel tanks until it can be stored long-term by deep injection in oil and gas waste wells.
Effects of Fracking on the Environment
-Releases harmful VOCs
-Up to 600 types of chemicals are used
-About 40,000 gallons of chemicals are used each time
-Groundwater can be contaminated
-Methane gas and toxic chemicals leach out from the system and contaminate nearby groundwater
-Methane concentrations 17x higher than usual
-Causes sensory, respiratory, and neurological damage
-Methane emissions from wells raise global warming concerns.