Geohazards
Wales is not a particularly seismically active country, nevertheless earthquakes of lesser magnitude occur from time to time. Ground stability is more of an issue due both to natural causes and, in former areas of coal and other mineral exploitation, due to mining, surface excavation and spoil deposition. Deep-mining of coal in particular has led to reactivation of pre-existing landslips, notably in the steeply-sided valleys of the South Wales Coalfield. Inappropriate placing of spoil material on such slopes has both overloaded them and disturbed drainage patterns with occasional catastrophic effect as in the Aberfan Disaster of 1966. An extensive programme of stabilisation works across the coalfield followed that event.
The contamination of land, groundwater and watercourses is a risk in areas where mineral exploitation has taken place, notably in the central Wales orefield and in former coal mining districts.
Read more about this topic: Geology Of Wales