WEBVTT
Kind: captions
Language: en

1
00:00:00.220 --> 00:00:03.580
This is the town of Staufen, near
the Black Forest in south-west Germany.

2
00:00:03.580 --> 00:00:06.680
And as you walk around,
it looks like a normal German town

3
00:00:06.680 --> 00:00:08.780
with one strange addition.

4
00:00:08.780 --> 00:00:11.580
Up on some buildings,
there is a big fake piece of sticky tape

5
00:00:11.580 --> 00:00:16.120
with a slogan that translates as
"Staufen must not fall apart".

6
00:00:16.120 --> 00:00:18.780
Unfortunately, it's a bit late for that.

7
00:00:18.800 --> 00:00:21.300
The government here tried to
bore for geothermic energy

8
00:00:21.300 --> 00:00:25.420
and they bored, in total,  seven boreholes
right behind the town hall.

9
00:00:25.420 --> 00:00:28.060
Underneath of Staufen is
a big layer of anhydrite

10
00:00:28.060 --> 00:00:31.460
and underneath that is a layer of groundwater
in a confined aquifer.

11
00:00:31.460 --> 00:00:34.860
The pressurised groundwater
went into the layer of anhydrite

12
00:00:34.865 --> 00:00:38.629
and formed gypsum
which expands by about 50%.

13
00:00:38.629 --> 00:00:41.660
Unfortunately, that means that the ground 
is expanding, bulging up,

14
00:00:41.660 --> 00:00:45.720
and forming cracks in almost every
single house that's standing here.

15
00:00:45.720 --> 00:00:48.460
It took two weeks for the
first cracks to appear.

16
00:00:48.460 --> 00:00:50.059
In the decades since
the drilling operation

17
00:00:50.059 --> 00:00:52.707
the town hall has risen
more than half a metre

18
00:00:52.707 --> 00:00:55.838
and moved sideways by
about the same amount.

19
00:00:55.838 --> 00:00:58.367
And that might not sound like
much, and yes, if everything

20
00:00:58.367 --> 00:01:01.116
had shifted evenly it might
not even be a problem.

21
00:01:01.116 --> 00:01:03.129
The trouble is that different
parts of each building

22
00:01:03.129 --> 00:01:05.848
have shifted by slightly
different amounts.

23
00:01:05.848 --> 00:01:07.532
Modern buildings couldn't cope with that,

24
00:01:07.532 --> 00:01:11.038
and that town hall was built in 1546.

25
00:01:11.038 --> 00:01:13.360
The result is cracking.

26
00:01:13.360 --> 00:01:16.420
There's water from this confined aquifer
that's pushing up the boreholes.

27
00:01:16.420 --> 00:01:19.600
And what they are trying
to do is get the water out,

28
00:01:19.618 --> 00:01:22.589
get the pressure down
from the confined aquifer

29
00:01:22.589 --> 00:01:25.348
so that it doesn't even want
to go up those holes anymore.

30
00:01:25.348 --> 00:01:28.977
So they are pumping at a speed
of around a litre per second.

31
00:01:28.977 --> 00:01:31.267
The swelling started with
about a centimetre per month,

32
00:01:31.267 --> 00:01:34.160
now it's down to about
a millimetre per month.

33
00:01:34.160 --> 00:01:38.000
But it's still swelling, and even a millimetre 
is still way too much for every house.

34
00:01:38.000 --> 00:01:40.140
Theoretically, they can stop it,

35
00:01:40.159 --> 00:01:44.057
but you cannot just
plug it like a bathtub.

36
00:01:44.057 --> 00:01:45.639
It's not a single plane.

37
00:01:45.639 --> 00:01:48.599
It's more three dimensional, so in reality

38
00:01:48.600 --> 00:01:52.700
you would need a big, big plug
and you don't even know where it exactly is.

39
00:01:52.700 --> 00:01:55.580
The drilling company settled out of court
for more than €1m,

40
00:01:55.580 --> 00:01:59.080
but the cost of the damage here
is estimated at more than 50 times that.

41
00:01:59.080 --> 00:02:01.840
And there are eight other German towns
with similar problems.

42
00:02:01.840 --> 00:02:05.739
Geothermal drilling was popular
and not massively regulated.

43
00:02:05.740 --> 00:02:09.960
And while the industry and the country
have learned from those mistakes,

44
00:02:09.960 --> 00:02:13.180
for this town that knowledge comes
a little too late.

45
00:02:13.180 --> 00:02:15.216
Thank you very much to
Constantijn Crijnen,

46
00:02:15.216 --> 00:02:16.898
he suggested this video
in the first place.

47
00:02:16.898 --> 00:02:18.910
He also has his own YouTube
channel where he's building

48
00:02:18.910 --> 00:02:21.760
a 3D printer from
scratch, go check him out.