The natural gas industry has argued that flawed casing practices used while drilling shale-gas wells were responsible for methane contamination in drinking water supplies surrounding shale-gas wells.
Earlier this month, scientists at Duke University published a paper in the Proceedings of the National Academies that provided evidence of a link between shale-gas wells and methane contamination in nearby drinking water supplied.
Natural gas formations are thousands of feet below drinking water aquifers so for contamination to occur the fracking solution would have to move through multiple layers of rocks.
The fields have been operated for roughly 12 years by Pluspetrol, the country's biggest oil and natural gas producer, and it will be obliged to clean up the contamination, said Environment Minister Manuel Pulgar-Vidal.
But critics of shale gas point to environmental concerns such as high water use and possible water contamination, the release of methane and, to a lesser extent, earth tremors caused by drilling.
Research scientists used microarrays to investigate how the microbial community responded to the contamination and how they may have consumed much of the oil and gas.
Contamination worries from local governments due to hydraulic fracturing and ongoing concerns about the climate impacts from burning natural gas continue to hamper development efforts.