By IAN URBINA of the New York Times
Published: March 1, 2011
"As drilling for natural gas started to climb sharply about 10 years ago, energy companies faced mounting criticism over an extraction process that involves pumping millions of gallons of water into the ground for each well and can leave significant amounts of hazardous contaminants in the water that comes back to the surface." [...]
"More than 90 percent of well operators in Pennsylvania use this process, known as hydrofracking, to get wells to produce. It involves injecting water mixed with sand and chemicals at high pressures to break up rock formations and release the gas. Between 10 percent and 40 percent of the water injected into each well resurfaces in the first few weeks of the process.
"Many states send their drilling waste to injection wells, for storage deep underground. But because of the geological formations in Pennsylvania, there are few injection wells, and other alternatives are expensive. So natural-gas well operators in the state have turned to recycling."
There is a very useful interactive that accompanies the New York Times article that explains really quickly what the process of injection into "fracked" wells involves as well as the environmental risks, risks that are not being discussed with the people likely to be effected the most: Chemicals and Toxic Materials That Come With Hydrofracking
Read the complete article at the New York Times.