Drinking water in thousands of homes 'contaminated with harmful levels of methane'



Contamination due to fracking, a process of hydraulic-fracturing drilling used in gas extraction



Scientists tested 68 drinking water samples from Pennsylvania and New York

A controversial natural gas production technique is contaminating drinking water in tens of thousands of homes, according to a study.



Scientists collected 68 drinking water samples from near gas drilling sites in Pennsylvania and New York.

They found potentially harmful levels of methane in the water due to its proximity to the process of hydraulic-fracturing, or fracking.

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Dangerous: Earlier this year, residents in areas where drilling for shale gas is taking place filmed themselves setting fire to their tap water. Scientists have now confirmed potentially harmful levels of methane in drinking water in Pennsylvania and New York

The gas from the tap ignites. It is extracted by drilling down and then horizontally through the ground and then by 'fracking', a process of hydraulic fracturing of the shale using high pressure liquid containing chemicals to release the gas

The report, released by the National Academy Of Sciences, said: 'In aquifers overlying the Marcellus and Utica shale formations of north-eastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale gas extraction.'

Fracking involves releasing natural gas trapped in shale formations by blasting a mix of water, sand and chemicals into the rock.

It has unlocked reserves that could supply the U.S. for 100 years, although environmentalists say that fracking can contaminate water supplies.

Methane concentrations were detected in 51 of 60 drinking water wells across the region, regardless of gas industry operations, but concentrations were much higher closer to natural-gas wells, the report said.

Levels were 17 times higher on average in shallow wells from active drilling areas than in wells from non-active areas, the report said.



The researchers concluded that 'greater stewardship, data, and possibly regulation are needed to ensure the sustainable future of shale gas extraction and to improve public confidence in its use'.

Outside a shale mine in Pennsylvania. The mining process of fracking involves releasing natural gas trapped in shale formations by blasting a mix of water, sand and chemicals into the rock

Last week, President Barack Obama asked the U.S. Department Of Energy to form a panel of academic and environmental experts to identify any immediate steps that can be taken to improve the safety and environmental performance of fracking after a series of high-profile natural gas drilling spills.

Fracking has opened up vast new supplies of natural gas that will reduce imports of the fuel, and drillers argue that methane contamination was present in drinking water before drilling began.



Backers also say it could reduce oil imports in the future, if vehicles are converted to run on natural gas.



But residents near drilling wells have complained fracking has polluted ground water supplies enough that they can light their drinking water on fire.

In addition, accidents at wells have led to fires and floods of fracking fluids have reached streams.



