Just three days ago a local rider contacted CORBA about an oily sheen seen in some of the still water sections and mud holes along Las Virgenes Canyon. This appeared to be a new phenomena, and the thick, dark mud and oily sheen look suspiciously like petroleum or oil products to the untrained eye. While there are oil pipes in the area, they don’t pass under the creek at this particular area, and it is somewhat alarming to come across.
Nobody at CORBA was familiar with this problem, so we alerted the MRCA. Chief MRCA Ranger Walt Young toured the area and took water samples at the three water crossings. He reported that the petroleum like sheen was present, but there was no smell of petroleum, which is common in other areas where natural seepage occurs. There was also plenty of life in the stream in the form of tadpoles and plant life.
A sample of the dark muck which has the appearance of tarry oil, dries to a fine brown powder with no evidence of the presence of oil.
The local Pipeline operator was also brought in for an assessment. Their pipes are pressurized to 500 PSI, and they noted that any leakage at that pressure would be immediately evident. There was no evidence of any leakage. Also, the dark oily-looking muck would float if it were oil-based, and there would be a strong odor of oil.
The final conclusion is that whatever seepage is there is a natural phenomenon, and is not a cause for concern. It may be the result of an above average rainfall year, or recent earthquake activity, but is not from a man-made source.
There are places in Southern California (Tar Creek in the Sespe Wilderness comes to mind) where large amounts of oil and tar do seep to the surface naturally and globs can be found floating down the stream. This reported seepage along Las Virgenes Canyon is much more subtle.
If anybody riding or hiking any trail sees anything suspicious or out of the ordinary, it is always best to contact the local land manager, law enforcement, rangers or of course you can always contact CORBA and we will notify the land manager. Thanks to rider Gary Artis for bringing this to our attention so that we could have it investigated further.
