Hello!
I need to test my ground soil and ground water for contamination. Background story:
I live in the middle of a very big hill. Towards the bottom (of my property) my yard is always soggy. The previous owners said they think there is an underground spring. A few weeks ago I dug a hole for a bush and noticed there was an rainbow sheen on top of the water in the hole I had just dug. Now I’ve noticed that even further down the hill there is what appears to be a rusty looking oil slick on top of a puddle of water. We have dogs and kids. Where and how can I get this tested? I’ve googled for information but I’ve come up empty handed. Even further down the hill there is a stream which leads into a little pond that is horribly filthy (according to neighbors).
It is possible that the rusty looking oil slick that you are describing may be a byproduct of naturally occurring bacterial. (Google “iron bacteria sheen” and see if that looks like what you are seeing).
Of course it is possible that you may have oil contamination onsite. You may want to consult with your states Department of Environmental services for guidance.
I don’t have any specific guidance on where to go for testing. I would probably start by contacting my county health department and discussing what you are seeing with them.
Depending on your location, what you are seeing could well be a normal, natural occurrence. I lived in Medford New Jersey, on the edge of the Pine Barrens for years. The Pines are famous for bog iron, it was once the primary industry for the region. Any bog in that area will invariably look very similar to what you describe, due to the iron ore present.
Good luck in identifying the source, I hope that it turns out to be benign.
Shouldn’t there be a count agricultural extension office or the such to help with this?
Failing all else, call your local news outlet and get everybody all worked up about it. The local authorities will eventually emerge.
Are you on a septic? It could be a sign of a septic bed failure.
Yes it looks almost exactly like that. Thank you so much! Now I just need to figure out if I can plant fruits and veggies near it. I am one relieved momma 
Thanks, it does look like a combination of iron bacteria and bog iron, I will identify the source and I already feel much better.