When water pools up on my new property, I see an oily surface in some parts. Can that be natural, or does it necessarily mean that there is some contamination that I need to address?
I moved here about 6 months ago. I'd like to build a small pond, but if there is some kind of oil leak, then certainly that would need to be addressed first. There is no obvious source of oil like a car repair shop next door or anything.
I have seen that before, maybe a water test will help but I THINK its from particular plants
There are two main sources of oily film on water: hydrogen sulfide and iron bacteria. Here's your trick for being able to tell the difference: stir the water with a stick. ... If the oily film breaks up when you stir it, it's probably due caused by an iron oxide mineral.
John Daley Bendigo, Australia
The Enemy of progress is the hope of a perfect plan
A hydrocarbon sheen usually has a "rainbow" of colours. I'm not seeing that in the photo. Even if it was, a small amount of hydrocarbon isn't much of a concern IMO. Natural bacteria will take care of it. I would poke around with a shovel and see if more appears -- in the good ol' days, people were casual with oil changes, and would also toss used filters in ponds and sloughs to deter mosquitoes.
A sheen from plant decomposition is a new concept to me. Very interesting!
On a similar previous post on permies, someone suggested that I do a "stick test" where you pass a stick through the slick. If it immediately closes up the way it was, then it is some oil/petroleum product. But if it cracks and stays apart, it is iron oxide/bacteria. My test was definitely the latter. It cracked like dry desert ground and stayed apart. I guess that's good news?
I have the same thing on a natural spring on my property, gotta clean the dead leaves and stuff out of it. on my place its 1/2 way up a small, 1000' mountain there was never any development or anything like it there. its just wild forest
Todd Markey wrote:When water pools up on my new property, I see an oily surface in some parts. Can that be natural, or does it necessarily mean that there is some contamination that I need to address?
I'll ditto what others have said, and I believe it appears to be microbial activity, or what can often be referred to as a microbial bloom. It is more common in ponds, but surface sheens can appear in short lived puddles too. I believe only a water analysis can correctly identify this sheen as a chemical/petroleum residue.