ENVIRONMENT Minister Mark McGowan has given the go-ahead for Worsley Alumina’s plans to expand its Collie refinery but must still make a decision on Alcoa’s contentious plans to expand its Wagerup alumina refinery. The approval for the Worsely refinery expansion and associated mining operations is subject to a comprehensive package of environmental conditions. Mr McGowan said he had made the decision after carefully assessing the Environmental Protection Authority’s report and the recommendation by the appeals convenor.