Controlling site spills

RISING LIVING standards and increasing use of personal computers, smart phones and tablets all mean energy consumption in the UK continues to rise. Conservation of energy through smart meters, improved fuel efficiency, and home insulation has had great effect in modifying demand, and such measures will continue to limit energy consumption, but they will not stop it increasing. 

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. No single source will supply all our requirements, and cost is important. 

Four million households in the UK live in fuel poverty, and the UK’s current energy costs are some of the highest in the world. One option under consideration is the extraction of shale gas. It is argued that the cost of British shale gas would be low because: 

• There are huge volumes;
• It is relatively easy to extract;
• It is an effective way of reducing carbon emissions compared to other sources; 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: 

• Although carbon emissions are lower, they may still not reach required levels;
• Heavy traffic in locations close to residential areas;
• Earthquake risk; and
• Contamination of ground water

Setting up a drilling site would need heavy equipment, sand and other inputs, causing initial disruption, and the drilling typically takes several weeks, but then gas production would go on for decades with few lorry movements. However, a major concern is the heavy goods vehicle transportation of the large volumes of flowback water created, and the BSIF Liquid Pollution Control Group agrees with leading shale gas companies that the water should be processed on site.

Contamination of groundwater is 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. This could become a risk to groundwater through seepage into the ground if there is no liner across the site. Both surface water and groundwater should be adequately protected, but groundwater is especially challenging and more costly to remediate once pollution has occurred. 

Some extraction activities are quoted as giving rise to environmental issues, when in fact they have already been addressed in the UK in regulations. The following activities are not allowed in the UK: Injection of hydraulic fracturing fluids directly into groundwater resources, discharge of inadequately treated fracturing wastewater to surface water and disposal or storage of hydraulic fracturing wastewater in unlined pits. 

If extraction of shale gas is permitted in Britain, the BSIF Liquid Pollution Control Group recommends that flowback water from fracking should be treated on or near site to minimize vehicle movements and the associated disruption. Spill control measures will be site-specific but they should reflect the requirements of the Environment Agency’s Onshore Oil & Gas Sector Guidance Version One.

They should also be relevant to recommendations from CIRIA 736 Containment systems for the prevention of pollution. The should encompass the best available technologies developed for shale gas sites, especially from the USA experience. Spill awareness and response training should also be provided by accredited organisations to all site operators. The BSIF is working with UK Onshore Oil and Gas to promote accredited training and spread of best practice. 

Alan Murray is chief executive officer of the British Safety Industry Federation. For more information, visit www.bsif.co.uk