whilst we mark time , page-3

Dex,

Even if significant surface expression of subsidence as the result of ucg coal combustion did occur, there would still be minimal environmental disturbance apart from the actual subsidence. Successful remediation by backfilling would seem at least feasible. Not so easy though in the case of open-cut mining in which there usually appears to be significant environmental impact (access roads etc.) apart from the hole in the ground itself.