Shale gas development impacts on water resources

Successful exploitation of  shale gas  will bring huge economic benefits, but its potential impact on the environment even more worrying: one is the exploitation of shale gas requires large amounts of fresh water resources, could threaten local and regional water resources sustainable use; shale gas on the other hand is the noise generated in the process, waste water, waste gas and mining disasters and other accidents caused by environmental pollution.
According to the U.S. Department of Energy statistics, Marcellus Shale gas drilling average water consumption for each of 3.88 million gal (approximately 15,000 cubic meters), where the amount of water used in  Hydraulic fracturing  98%. The Marcellus Shale gas well drilling for a day of water is estimated at 8.4 million gal. Because shale gas well drilling cycle is shorter (24h operation, a horizontal well to be 4 - 5 weeks, plus 3 - 5 days hydraulic fracturing treatment), during which a large number of local surface water or groundwater consumption (per mouth Marcellus shale gas wells need water every day about 30,000 gal), is likely to affect the survival of the local aquatic life, fishing industry, urban and industrial water.
Shale gas hydraulic fracturing technique used not only consume a lot of water, but also to the underground injection lysate may contaminate groundwater. Some experts pointed out that a lot of water to the shale, may encourage deep rock slide, causing earthquakes. University of Pennsylvania researchers said that in Pennsylvania using fracking shale gas areas, underground methane content in drinking water than the undrilled area 17 times higher, this methane pollution and hydraulic fracturing method on the application. Pennsylvania found methane in groundwater reason, probably where the wells themselves through the seam, so it into methane, shale gas wells or isolation means not doing enough.
Hydraulic fracturing fluid composition, but also a focus of controversy. U.S. three Democrats in April 2010 in a report that the United States 14 oil and gas companies in the past five years shale use for about 2.95 million cubic meters of fracturing additives, including 750 kinds of chemical products, and toxic substance benzene and lead. If you do not return the fracturing fluid leak or cause a timely manner, the impact on the ecological environment should not be underestimated.
Shale gas development impact on the environment
Shale gas resource development to flourish not only consume a lot of water, but also on the ecological environment will pose new threats. Shale gas well fracturing fluids and produced formation water potential environmental hazards, these two water collectively return water (back to the original water volume accounted for 30% of injecting high-pressure liquid - 70% return water drilling muds and generally will be stored in the site wastewater pond or storage cart, and then transported to a designated treatment center for post-processing. return water in addition to containing high-pressure liquid chemical additive components, but also contain hydrocarbons, heavy metals, and high dissolved solids (TDS), of which the TDS group of including calcium, potassium, sodium, chloride, and carbonates as well as from a natural gas reservoir formation radioactive substances such as uranium, thorium and their decay products, etc.