The New York Times on the hazards of fracking:
With hydrofracking, a well can produce over a million gallons of wastewater that is often laced with highly corrosive salts, carcinogens like benzene and radioactive elements like radium, all of which can occur naturally thousands of feet underground. Other carcinogenic materials can be added to the wastewater by the chemicals used in the hydrofracking itself. . . . [more]
Ian Urbina, "Regulation Lax as Gas Wells' Tainted Water Hits Rivers," New York Times, 27 February 2011.