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.

WASHINGTON – The U.S. Environmental Protection Agency (EPA) published on May 1 a list of 28 chemicals and two viruses that approximately 6,000 public water systems will monitor from 2013 to 2015 as part of the agency’s unregulated contaminant monitoring program, which collects data for contaminants suspected to be present in drinking water but that do not have health-based standards set under the Safe Drinking Water Act.