small mountain it was named after (El Cogulló, 474 meters above sea level). Literary references Richard Llewellyn's novel How Green Was My Valley (1939) describes the social and environmental effects of coal mining in Wales at the turn of the 20th century. The local mine's spoil tip, which he calls a slag heap, is the central figure of devastation. Eventually the pile overtakes the entire valley and crushes Huw Morgan's house: The slagheap is moving again. I can hear it whispering to itself, and as it whispers, the walls of this brave little house are girding themselves to withstand the assault. For months, more that I ever thought it would have the courage to withstand, that great mound has borne down upon these walls, this roof. And for those months the great bully has been beaten, for in my father’s day men built well for they were craftsmen. Stout beams, honest blocks, good work, and love for the job, all that is in this house. But the slag heap moves, pressing on, down and down, over and all round this house which was my father’s and my mother’s and now is mine. Soon, perhaps in an hour, the house will be buried, and the slag heap will stretch from the top of the mountain right down to the river in the Valley. Poor river, how beautiful you were, how gay your song, how clear your green waters, how you enjoyed your play among the sleepy rocks (102). See also Tailings Overburden Minestone Coal refuse References External links Video and commentary on the Gateside Colliery bing, Sanquhar, Scotland. Spoil heap 11/19 in Loos-en-Gohelle chainedesterrils.eu/ Turning coal waste into light, 8 October 2004 Waste Rock and ARD Environmental impact of mining Metallurgy Artificial hills Surface mining Waste