Question: Which company operates the railway line that bounds Peterhead, South Australia on the west side?
Related documents: [0]  [DOC] Peterhead is a north-western suburb of Adelaide 15 km from the CBD, on the LeFevre Peninsula, in the state of South Australia, Australia and falls under the City of Port Adelaide Enfield. It is adjacent to Largs Bay and Birkenhead. The postcode for Peterhead is 5016. It is bounded to the north by Wills Street, to the south by Hargrave Street and in the west and east by the Outer Harbor railway line and the Port River respectively. [END] 
[1]  [DOC] The Outer Harbor railway line is a suburban branch line in Adelaide, South Australia. It runs from Adelaide station through the north western suburbs to Port Adelaide and Outer Harbor. It is 21.9 kilometres in length, and shares part of its run with the Grange line. It is operated by Adelaide Metro. [END] 
Answer: 
Adelaide Metro
Adelaide Metro