Getting rid of an oil slick on top of a pond.

[BIG FISH BOB]

I am helping a local elementary school with an outside pond they have. Somehow some oil/gas??? got in the pond. Fish are fine, but I want to remove it. Did a large water change....no luck. I've had a large indoor pond for years...but I have never had this problem. I would love any suggestions. Thanks Bob

 

[duanes]

Making a DIY protein skimmer would do it, but it would be a bit of an effort making one, but fairly simple in design, and it will do the work once made.
Protein skimming removes proteins, oils, DOC, algae and most other undesirable components in water.
I got the plans for one on Koiphen.com. Below is a video of mine working on a small koi/goldfish pond.
koi pond fractionation
I believe they call it foam phractionator on the site.

 

[tarheel96]

You can put paper towels on the surface and soak up a lot of it.

 

[thebiggerthebetter]

When this occurs after feeding fatty feeds, the surface oil disappears soon on its own, IME anyway. I always assumed some bacteria break it down.

The trivial way would be to remove (let run off) the surface layer of water. Changing the water column as in a WC cannot remove it.

 

[Scout1984]

They sell pads that will absorb the oil and not the water

 

[HarleyK]

Could you fill it up so that it overflows and the surface runs off?