 Between 1999–2000, the area being mined was increased from 12 km² to 22 km², and then to 42.8 km².The resulting project in Roșia Montana has been a source of much controversy, with local people lining up on both sides of the issue, and some national and international environmental groups joining the opposition.One source of controversy involved the method used for mining, gold cyanidation, which causes pollution.