Drinking water

[40Hands]

So we have these water coolers here at work and when I poured a cup today, I noticed oil-like swirls on the surface. It is not as colorful as when you see it in puddles on the street but it made me wonder what it could be. Ideas?

 

[Imported]

Maybe its the cup.

 

[Sleepsalot]

Most likely the cup you used was not real clean. I have had the same thing here where I work.
Wayne

 

[Lola]

if its a throw away cup, it could be a waxy residue from it. It could be soap residue if its a plastic/glass resuseable cup.
That also happens to me because of my chapstick/lipgloss too.

 

[leftyman]

Is there a sinking oil super tanker in your water cooler?