A US study has found that activities associated with hydraulic fracturing or fracking can pollute drinking water.

The US Environmental Protection Agency identified cases, ranging in severity from temporary changes in water quality to contamination that made private drinking wells unusable.

One cause was due to spills during the management of fracking fluids and chemicals that resulted in large volumes or high concentrations of chemicals reaching groundwater resources. Another was the injection of fracking fluids into wells with inadequate mechanical integrity, which allowed gases or liquids to mix with groundwater.

‘The EPA’s assessment provides the scientific foundation for local decision makers looking to protect public health and drinking water resources and make more informed decisions about hydraulic fracturing activities,’ said the regulator’s science adviser, Dr Thomas Burke.

Fracking for oil and gas is common in the US and the EPA study was published as Cuadrilla began preparing a site in Lancashire for fracking later this year. In October, communities and local government secretary Sajid Javid overturned the county council’s refusal to grant the onshore energy exploration company permission to extract gas from the site near Preston.

The government and regulators in the UK are confident fracking can take place without harming the environment and polluting water. John Barraclough, senior adviser in the Environment Agency’s onshore oil and gas programme, told the environmentalist: ‘We understand the oil and gas industrial process and techniques, and have been through a rigorous learning process on fracking and assessed the risks. We have expert hydrogeologists and other technical people to assess applications and enforce permits.’

See the February issue for more on fracking.