Marcellus gas drilling produces radioactive waste water

After a gas well is drilled, millions of gallons of water, sand and chemical additives are pumped underground under high pressure to crack the shale formation and release the gas. The fracking fluid waste that returns to the surface with the gas contains a variety of radioactive minerals from the shale.

The New York Times reported that hydraulic fracturing wastewater at 116 of 179 deep gas wells in Pennsylvania contained high levels of radiation. Its effect on public drinking water supplies is unknown because water suppliers are required to conduct tests of radiation only sporadically.

From the Pittsburgh Post-Gazette:
Radiation-fracking link sparks swift reactions