BROOKLYN - The U.S. Coast Guard is overseeing the cleanup of 1,100 gallons of a petroleum-cement mixture from a Brooklyn waterway.

The Coast Guard says the spill started early Saturday when the utility National Grid was cementing a pipe in the Paerdegat Basin, near Canarsie.

New York City's Office of Emergency Management says contractors working for National Grid under the Coast Guard's direction are working to clean the spill.

The mixture in the water is a combination of natural gas condensate, compressor oil and turbine oil. Neighbors say they don't see the spill, but they can smell it.

City emergency officials say it's unclear how long the cleanup process will take, but they say there is no danger of an explosion.

The public is advised to avoid fishing and recreational activity in the area.AP wire reports contributed to this article.