by Abrahm Lustgarten ProPublica, Dec. 11, 2012

Federal officials have given energy and mining companies permission to pollute aquifers in more than 1,500 places across the country, releasing toxic material into underground reservoirs that help supply more than half of the nation's drinking water.

In many cases, the Environmental Protection Agency has granted these so-called aquifer exemptions in Western states now stricken by drought and increasingly desperate for water.

by Abrahm Lustgarten ProPublica, July 9, 2012, 3 p.m.

New research has concluded that salty, mineral-rich fluids deep beneath Pennsylvania's natural gas fields are likely seeping upward thousands of feet into drinking water supplies.

Though the fluids were natural and not the byproduct of drilling or hydraulic fracturing, the finding further stokes the red-hot controversy over fracking in the Marcellus Shale, suggesting that drilling waste and chemicals could migrate in ways previously thought to be impossible.