The U.S. government and energy companies have been fiddling with ways to get at gas trapped inside rock underground for decades. Now, using highly pressurized toxic liquid to extract the petro-bubbly is becoming standard practice, even as evidence mounts that it poisons drinking water. ProPublica charts government and industry’s decades-long regulatory dance. —ARK
1969 The government detonates a 43-kiloton nuclear bomb deep underground in an effort to get at natural gas deposits in Colorado. The gas unlocked by “Project Rusilon” is deemed too radioactive to use.
June 2004 An EPA report concludes that fracking is safe for drinking water. The report, which didn’t include a scientific study, has since been criticized as politically motivated.
August  In response to complaints of drinking water contamination, the EPA begins investigating wells in drilling areas of Pavillion, Wyoming. Initial testing finds at least three water wells that contain a chemical used for fracking.
December  An EPA draft report concludes that contaminants in Pavillion, Wyoming most likely seeped up from gas wells, scientifically linking water contamination to fracking for the first time.