Shale gas and groundwater

England and Wales groundwater use map, 2012. Plus the proportion of groundwater used in public supply across the UK. (Source: Defra.)

Dr Rob Ward, speaking in 2013, discusses the abstraction and consumption of water in the UK and relates that to how much may be used in hydraulic fracturing for shale gas.

We have undertaken research to provide information needed to understand potential impacts on groundwater from shale-gas exploitation.

BGS worked together with the Environment Agency to investigate whether any evidence exists for effects of abandoned hydrocarbon wells on groundwater quality in England.
The National Baseline Methane Survey of UK groundwaters helped assess future changes in methane concentrations.
Aquifers and shales is a set of national-scale maps showing the spatial relationships between principal aquifers and major shale units in England and Wales.
The 3D groundwater vulnerability project developed an approach to assess the vulnerability of groundwater to contamination from deep subsurface activities.

This has provided underpinning information of use to policy makers, regulators and decision makers.

Groundwater: a precious resource

Groundwater is a vital source of freshwater in the UK. It provides around 27 per cent of public water supply on average but this amount varies in different regions. For example, in south-east England it is nearly 90 per cent of public supply.

In addition to public supply groundwater has a number of other uses including bottled water, agriculture and irrigation and food and drink production. The relative proportions of groundwater used in the UK and how it is used can be seen in the map image.

Groundwater is also vital for maintaining river flows especially during dry periods and so is essential for maintaining ecosystem health.

Environmental concerns

There have been concerns expressed about the potential impacts of shale gas on groundwater with reports in the US claiming that contamination of drinking water has occurred.

Shale gas is natural gas trapped in low-permeability shales. The gas is held in pore spaces within the rock, or adsorbed onto minerals and organic material in the shale.

New technology for gas production from shale formations, horizontal drilling and hydraulic fracturing, evolved first in the USA, and has led to the rapid exploration of shale formations worldwide.

The UK has abundant shales at depth which have been the focus of research into their characterisation, resource evaluation and exploitation risks.

The BGS has had projects in a number of these areas. Part of this research considered some of the environmental concerns and in particular the potential impacts on groundwater.

We published a report in 2012 on the potential impacts on groundwater from exploitation of shale gas in the UK.

Research projects

Further baseline studies to investigate risks from onshore oil and gas activities
BGS and the Environment Agency collaborated in a project to characterise groundwater quality to support assessment of the risks to groundwater in England from any new developments in activities related to onshore oil and gas, including shale gas.

Sampling dissolved gases in groundwater with an evacuated flask.

National Baseline Methane Survey of UK groundwaters
We undertook a national survey of baseline methane concentrations in groundwaters across the UK.

Mapping of extent of shales and aquifers

Aquifers and shales
Helping to improve our understanding of the spatial relationships between potential shale gas source rocks and Principal Aquifers.