2:52 PM ORIGINAL REPORT: From the state Department of Ecology, word of an oil spill in the Duwamish River:

The Washington Department of Ecology and U.S. Coast Guard are investigating the source of an oil spill on the Duwamish River about one half mile north of the South Park Bridge.

A sheen and diesel odor were reported to Ecology at 8:30 a.m. today and spill responders found an unknown amount of recoverable diesel oil in an inlet on private property at 7400 Eighth Ave. S. next to Boeing property.

A cleanup contractor called by Ecology and the Coast Guard has arrived at the scene and will begin work on recovering the diesel oil this afternoon. Further information will be released when it becomes available.

Here’s a map of the location, which is roughly across the river from the south end of West Marginal Way.

4:12 PM UPDATE: New information from Dan Partridge of Ecology:

There is no cleanup contractor working on site. A contractor hired by the Coast Guard arrived earlier and was about to begin work when the tide shifted. The diesel spill that was thought to be recoverable no longer was recoverable with the shifting of the tide so the contractor has left the site. There’s 100-by-3 foot sheen visible on the water but it’s expected to dissipate with the shifting of the tide. We still have not determined the source of the spill but Ecology will continue to investigate.

5:36 PM: Ecology estimates the spill at no more than 25 gallons. We went looking for, but didn’t find, any publicly visible sign of it.