I got some oil in my pond when it was filling from some uncovered 5 gallon buckets of oil on neighbors property. Every time it rained the oil overflowed out of the buckets. I removed the buckets of oil and solved that problem.

I noticed when the wind blew it caused all the oil to go to one end of the pond. I put straw on top of the oil and let it set all day, then removed all the straw the next day. It got out 90% of the oil.