Fluid migration, Legislation, Well integrity

“Dear Aunty, are all these US complaints of drinking water contamination relevant to the UK?”

No, sweeties, not really.

There’s been quite a lot of chatter today, I see, about some findings reported by the Associated Press (AP) concerning drinking water contamination in four US states where extraction of shale gas by fracking has boomed in recent years: Pennsylvania, Ohio, West Virginia and Texas.

But this experience is almost wholly irrelevant to us here in the UK, dears, because as the more observant readers amongst you will note, the reported cases are all concerned with the contamination of private well water.

Where does your drinking water come from cherubs? Your tap. And what supplies that? Well, for the vast majority of you, it’s a mains water supply, piped into your home after treatment to remove heavy metals and other contaminants.

Comparatively few of us have private water supplies, whereas in the US – where their land mass is much larger than ours and their communities more spread out – private water supplies are much more common simply because it wouldn’t be practical to get every property connected to a public supply.

According to a 2012 report by the Drinking Water Inspectorate: http://dwi.defra.gov.uk/about/annual-report/2012/private-england.pdf

“From Table 3 it can be seen that there are records for 86,218 private supplies in the whole of the UK, of which more than half (44,546) are in England. The area of England with the most private supplies is the South West of England (34%) and during 2012 local authorities in this part of England identified an additional 451 supplies, bringing the total recorded up to 15,309. There are also significant numbers of private supplies in the North West (14%) and the West Midlands (15%) although the number of private supplies recorded in 2012 in the North West (6,144) was notably lower (564 fewer) than the figure recorded in 2011.”

The same Table 3 tells us that there are 17,700 private supplies recorded in Wales.

According to the Office of National Statistics (ONS) National Census data for 2011, there were 23.4 million households in England and Wales.

Which means, my darlings, that just 0.26% of households in England and Wales draw water from private supplies and so, right away, you can see that the chances of residents here having their drinking water impacted by shale gas extraction is already very limited.

The likelihood of adverse impacts is even lower when you consider that, here, our much tighter regulatory framework insists that oil and gas extraction wells are constructed to a very high standard in order to prevent the escape of hydrocarbons (see my earlier posts on well integrity for details).

But then consider the AP findings themselves, as quoted by http://www.usatoday.com:

“Among the findings in the AP’s review: Pennsylvania has confirmed at least 106 water-well contamination cases since 2005, out of more than 5,000 new wells.”

So, in 8 years, the centre of modern-day natural gas extraction has seen confirmed private water well contamination in just 2.12% of cases. Nothing like the percentage failure rates often (wrongly) quoted of 6% and higher.

All of which means, dears, that the chances of you or I ever finding our drinking water polluted by fracking are so low as to be negligible – you’d have to be very unlucky to be one of the 2.12% of just 0.26% of households in England and Wales drawing water from your own well and finding it to be somehow spoilt by gas extraction.

Does that mean it won’t happen? Of course not, poppets, and it would be silly of me or anyone else to suggest that. A poorly constructed shale gas well situated near a property with an equally poorly cased and cemented drinking water well could cause a problem.

But, dare I say it, I think the chances of those twin sets of circumstances aligning that way are too low to be of any real concern.

Until next time xxx


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