The Saint-Jacques tip comprises 4 million cubic metres of black shale that came from working the Aiseau-Presles coal mines. It underwent major reprofiling in the 1970s but has been practically abandoned since then.
Man-made areas recolonised by wildlife existed side by side with illegal trash dumps and degraded areas without ecological value. The walls of shale were at risk of collapsing due to stability issues and the area was becoming dangerous, all the more so as quads and off-road bikes were zipping around it unsupervised. Measures against all activities detrimental to the site's protection were urgently needed.