Authorities have spent the weekend working to contain an oil spill in waters off Kwinana.
The Department of Transport and Major Infrastructure (DTMI) has confirmed about 150 litres of heavy crude oil was released into waters near the Kwinana Fuel Terminal on Saturday, March 21.
"DTMI is working with Fremantle Ports in coordinating an appropriate response, and has appointed an Incident Controller," a DTMI spokesperson said.
"The area near the release has been boomed, and this has contained the majority of the oil.
"Some oil has been observed outside of the booms. As a precaution, the beach immediately surrounding the area was closed by the City of Kwinana at the request of DTMI to help ensure community safety.
"DTMI and Fremantle Ports personnel conducted a shoreline clean-up on the public beach yesterday, which was successful, and have returned today to clean up residual oil which has washed up overnight."

Dave Reid posted a photo on social media of the oil clinging to his dog's leg. PIC: Dave Reid/Facebook
Wells Park Beach remains closed and will be reassessed before it is re-opened.
The terminal operator is also being supported by the Australian Marine Oil Spill Centre who will assist with any wildlife that may be impacted by the oil.
Perth to Bunbury train service returns
Missing woman found safe and well
Community fed up with teenage hoons terrorising Halls Head oval
Southern suburbs electrician claims $1.8 million Lotto win
Works continue on Pinjarra's Munday Avenue extension
Halls Head support worker charged with historic child sex offences
Severe thunderstorm warning cancelled for Mandurah, Bunbury
Fortnightly red bin collections to remain in the City of Rockingham after council rejects motion
Rate rises on the way for Rockingham, Mandurah ratepayers