Personnel from Coast Guard Sector Juneau investigated an oil sheen near Sandy Beach on Monday, said a Coast Guard officer.

Lt. Maren Balke, whose section is responsible for dealing with oil spills, discovered the sheen incidentally and called it into the National Response Center, said Lt. j.g. Stephen Mueller.

“Pollution responders went out and did a preliminary investigation and couldn’t determine the source,” Mueller said. “It looks like it’s non-recoverable. It looks weathered. It doesn’t look like a significant amount.”

There was a spill of heating oil from a breached tank in late December that has since been fully contained, Mueller said, but there’s no way to link this sheen to that leak. The sheen could also be from a different source that has only recently been opened by thawing ice and snow. The sheen could also come from something like snow scraped off a roadway, Mueller said.

“They think maybe it was old oil, but they can’t determine where it came from,” Mueller said.

The Coast Guard does not have any ongoing concerns about this spill at this time, Mueller said, as the amount spilled was very minor and doesn’t come from a continuous source.

• Contact reporter Michael S. Lockett at (757) 621-1197 or mlockett@juneauempire.com.