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.

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.