Subtitles section Play video Print subtitles This is the town of Staufen, near the Black Forest in south-west Germany. And as you walk around, it looks like a normal German town with one strange addition. Up on some buildings, there is a big fake piece of sticky tape with a slogan that translates as "Staufen must not fall apart". Unfortunately, it's a bit late for that. The government here tried to bore for geothermic energy and they bored, in total, seven boreholes right behind the town hall. Underneath of Staufen is a big layer of anhydrite and underneath that is a layer of groundwater in a confined aquifer. The pressurised groundwater went into the layer of anhydrite and formed gypsum which expands by about 50%. Unfortunately, that means that the ground is expanding, bulging up, and forming cracks in almost every single house that's standing here. It took two weeks for the first cracks to appear. In the decades since the drilling operation the town hall has risen more than half a metre and moved sideways by about the same amount. And that might not sound like much, and yes, if everything had shifted evenly it might not even be a problem. The trouble is that different parts of each building have shifted by slightly different amounts. Modern buildings couldn't cope with that, and that town hall was built in 1546. The result is cracking. There's water from this confined aquifer that's pushing up the boreholes. And what they are trying to do is get the water out, get the pressure down from the confined aquifer so that it doesn't even want to go up those holes anymore. So they are pumping at a speed of around a litre per second. The swelling started with about a centimetre per month, now it's down to about a millimetre per month. But it's still swelling, and even a millimetre is still way too much for every house. Theoretically, they can stop it, but you cannot just plug it like a bathtub. It's not a single plane. It's more three dimensional, so in reality you would need a big, big plug and you don't even know where it exactly is. The drilling company settled out of court for more than €1m, but the cost of the damage here is estimated at more than 50 times that. And there are eight other German towns with similar problems. Geothermal drilling was popular and not massively regulated. And while the industry and the country have learned from those mistakes, for this town that knowledge comes a little too late. Thank you very much to Constantijn Crijnen, he suggested this video in the first place. He also has his own YouTube channel where he's building a 3D printer from scratch, go check him out.
B1 UK town aquifer town hall confined drilling hall The German Town That's Literally Breaking Apart 168 10 Samuel posted on 2018/03/13 More Share Save Report Video vocabulary