Fracking clean-up concerns
17 October 2017
The British Safety Industry Federation (BSIF) general manager Frank Angear looks at the challenges of controlling site spills when it comes to shale gas extraction
At the moment UK energy supplies are provided by natural gas (40%), coal (10%), nuclear power (25%), biomass (12%) and renewables (12%). With climate change targets, the closure of coal mines, concerns surrounding nuclear power and the high cost of renewables, Britain needs additional diverse sources of energy.
Enormous effort is going into new technology such as clean gas power stations, thermo-voltaic light, new battery developments and seismic surveying, which will alter the relative attractions of nuclear, gas, and renewable sources, but predicting which technology will meet the increased demand at a sensible cost with acceptable carbon emissions is difficult.
One option under consideration is the extraction of shale gas through a process known as "fracking". It is argued that the cost of British shale gas would be low because it is believed that there are large volumes, it is relatively easy to extract and the cost of distribution is low as the gas infrastructure is already in place.
But a new industry would bring its own set of requirements on pollution control to avoid environmental spills. All energy sources, gas, coal, nuclear, biomass, and renewables carry environmental risks. Environmental concerns around shale gas focus on:
- Contamination of ground water.
- Although carbon emissions are lower, they may still not reach required levels.
- Heavy traffic in locations close to residential areas.
- Earthquake risk.
However, a major concern is the heavy goods vehicle transportation of the large volumes of flowback water created. The BSIF Liquid Pollution Control Group - which makes recommendations for tackling spills control when extracting shale gas - agrees with leading shale gas companies that the water should be processed on site.
Contamination of groundwater is of course a risk, but a peer reviewed study of contamination of groundwater by Duke University (The Effects of Shale Gas Exploration and Hydraulic Fracturing on the Quality of Water Resources in the United States by Avner Vengosh et al) found fracking has not contaminated ground water. However the study did find that accidental spills of fracking waste water could be dangerous to surface water in the area.
If extraction of shale gas is given the go-ahead in Britain, the BSIF Liquid Pollution Control Group makes the following recommendations:
- Flowback water from fracking should be treated on or near site to minimise vehicle movements and the associated disruption.
- Secondary spill containment (bunding of plant and machinery) as well as tertiary containment (membrane under the whole site) should be deployed on all drilling, fracking and production sites.
- Spill awareness and response training should be provided by accredited organisations to all site operators.