3 novembre 2012
I rischi della fratturazione idraulica
Ecco alcune assicurazioni
Burning tap water. Yes, you can ignite methane at your kitchen faucet, if your well was drilled through gas-bearing rock formations and was not properly cemented and sealed to keep gas out. (Eternal Flame Falls in New York’s Chestnut Ridge Park is one example of natural methane leakage.) But fracturing zones are thousands of feet below groundwater supplies; production wells use cement and steel casing that extends hundreds of feet below the surface; and sensitive instruments monitor downhole activity, to ensure that valuable gas does not escape into near-surface formations or the atmosphere.
Groundwater contamination. Fracking fluids are 99.5% water and sand. The other 0.5% is chemicals that fight bacterial growth, keep sand particles suspended in the liquid and improve production. The vast majority today are found in household items that Americans use safely every day – including cheese, beer, canned fish, dairy desserts, shampoo and cosmetic products. New fluids like those developed by FamilyJoule and Halliburton represent the new kinds of entirely nontoxic and biodegradable chemicals that almost all drillers are now using.
Steadily improving technologies, techniques and regulations minimize risks even further. For instance, heavy plastic liners are now commonplace under drilling rigs, storage tanks and containment pits. Along with modern drilling and well casing methods, they help make the likelihood of chemical or salt contamination of groundwater a minuscule fraction of what is posed by winter salting of icy roads.
Wastewater and water depletion. In addition to changing the composition of fracking fluids (and making that information readily available online), to address concerns about water use and wastewater disposal, drilling companies increasingly recycle the water they use. Devon and other companies have recycled hundreds of millions of gallons, and some 90% of water produced in the Marcellus shale region of New York, Pennsylvania, Ohio and West Virginia is now reused. Moreover, the amount of water used in fracking is far less than what is required to grow corn and process it into ethanol.
Earthquakes. Fracturing rocks does cause cracking that can be measured with ultra-sensitive equipment. But these micro-seismic events measure around 0.8 on the Richter Scale, about what is caused by a car passing by. Even loaded dump trucks register only a 3 (the minimum that can be felt by humans), and property damage does not begin until level 5. Deep injection of water for geothermal energy development or enhanced oil recovery operations (or to dispose of petroleum, municipal or industrial wastewater) has caused detectable seismic activity; however, of more than 800,000 injection wells nationwide, only about 40 were actually felt at the surface. Rules and practices increasingly address these injection well issues.
Fracking regulation. State and local regulation and cooperation with industry, constant refinements and improvements in rules and practices, and accommodation to public concerns about water, drilling and fracking fluids, road congestion, community impacts and other issues have been ongoing for decades. That is part of the reason that 2.5 million instances of fracking worldwide (over 1 million in the USA) since 1949 have not caused any serious harm. That’s a safety record any industry would envy.
Unfortunately, environmentalist fractured fairy tales cost us energy, jobs, revenue and prosperity – for no ecological benefit. The ultimate irony is Europe, where Big Green opposition to fracking and nuclear power is ushering in a coal-burning renaissance. Germany and other central EU countries will be building 10,600 megawatts of new coal-fired electrical power plants during the next four years!
Meanwhile, green power mandates have already pushed Germany’s electricity prices to the second highest in Europe (32 cents per kWh, compared to an average of 10 cents in the USA) – and the average German household faces another big rate hike over the next year. Countless jobs are also at risk.
| inviato da mauroD
il 3/11/2012 alle 13:13 | |