Managing Scotland's mine gas legacy
Learning from the past
Mine gas hazards have been with us for as long as we've had mines. A tragic early example of this was the Blantyre explosion of 1877 which claimed 207 lives. It remains Scotland's worst mining accidents. Thankfully, there have been relatively few repetitions of such tragedies in Scotland in the more than a century since Blantyre occurred.
Yet we still live with the hazards by Scotland's mining legacy, but until very recently, the potential for mine gases to cause harm to surface developments, has received little attention.
Of course, this has all changed due to the long shadow cast by the Gorebridge incident - rightly so. And in this blog we explore some of the advances recently made in this area and some of the important questions which the industry needs to consider further.
Research and new approaches
The Government and others have undertaken a lot of research into the prevalence and history of mines gas incidents, across Scotland and beyond. From the culmination of this process, we have seen the recent publication of CL:AIRE's 'Good practice for risk assessment for coal mine gas emissions'.
Much of this new guidance is based on existing, risk-based techniques for site investigation and risk assessment. These should be central pillars of every mines gas risk assessment. But too often we encounter projects that sit too far to one end of the spectrum or the other. For example, at one end of the spectrum, where a site's proximity to former workings is automatically equated with high risk. Or where ground stabalisation of mine workings is undertaken without any regard to the actual likely risk present.
Some have, understandably, argued for the universal provision of gas protection measures. But at GGS Scotland, we don't consider that the best approach. The unavoidable question of 'what level of protection to provide as standard' remains unanswered at this time. And as soon as you define a standard, the inevitable problem arises of 'how do you know that standard is sufficient in all cases?'
Furthermore, if gas protection measures become 'standard', are we confident that the installation quality will go up, instead of down? This is not an area where 'good enough' is actually good enough. Plus, if consideration of ground gas hazards (whether they be from mines or other sources) ceases to be a specialist consideration, are we confident that the next Gorebridge won't slip through the net? As an industry, we need to get to grips with what the answers to these challenging questions are.
One of the key advances of the new CL:AIRE guidance is to codify, perhaps for the first time, some of the particular characteristics of mines gas hazards. And, similarly, it sets out some of the screening issues which can help to quickly identify low or negligable risks. One important caveat which the new guidance offers, is the use of competent professionals in undertaking mines gas risk assessments. At GGS Scotland, we whole-heartedly endorse that message.
Striking the right balance
So much about appropriately managing and mitigating mines gas risks is about striking the right balance; insisting on appropriate measures where the risk genuinely warrants it, but also having the confidence to justify where risks are low or even entirely theoretical. All of this, of course, must be based on sound science and robust evidence.
Looking to the future
The years ahead will prove really interesting to see how the new guidance and assessment approach are adopted. Both by consultants, but just as importantly, developers and regulators alike. At GGS Scotland we stand ready to play our part in embedding this new approach to ensure all new developments are safe developments.