BP Whiting refinery returns to normal operations -sources

(Adds company declining comment)

HOUSTON, Aug 22 (Reuters) - BP Plc's 413,500 barrel per day Whiting, Indiana refinery returned to normal production by Monday morning for the first time since late July, sources familiar with plant operations said.

A BP spokesman declined on Monday to discuss operations at the Whiting refinery.

The refinery has been running at reduced production levels since the weekend of July 30-31, when a malfunctioning wastewater plant forced BP to cut production to prevent releasing sediment beyond permitted levels into Lake Michigan.

(Reporting by Erwin Seba Editing by W Simon)