When I saw a report over the weekend that workers in at least one beach area were being told to only clean the surface of oil and not to dig (causing the lead worker to quit), I was reminded of a prophetic study published just a few months before this tragedy began.
When the Exxon Valdez spill dropped 11 million gallons of Alaskan crude into that sad little bay we were assured that cleanup would continue as long as needed.
Anyone who doubts the long-term persistence of buried oil should remember where today’s oil came from and when, also how long it has remained underground.
It turns out that those in charge of the cleanup of the 1989 spill decided that “as long as needed” was a brief 3-4 years because they stopped cleaning beaches in 1992.
Nature Geoscience 3, 96 – 99 (2010)
http://www.nature.com/ngeo/journal/v3/n2/full/ngeo749.html
http://www.temple.edu/newsroom/2009_2010/01/stories/ExxonValdez.htm
In 2008, 20 years after the initial spill and 16 years after the clean up stopped having been deemed sufficiently completed, a team from Temple University dug a hole on one of the beaches and disclosed what for residents of the Gulf (and everyone actually) very disturbing information.
It turns out that the surface oil was gone and the first layer of oil in the sand was likewise being biodegraded but unfortunately the tidal action had caused oil to settle down into a second bottom layer of compacted sand and oil which is showing virtually no degradation after 20 years.
Oil initially degraded quickly but as it moved to the compacted layer where oxygen was almost nonexistent, the biodegradation of the oil had dropped to about 4% per year.
The Temple study determined that about 20,000 gallons of oil remained to this day.
At the measured and slowing rate of degradation this would take many centuries to completely disappear, if it ever does.
It is important to remember that the Exxon Valdez incident was a drop in the bucket compared to the number of people affected, the amount of oil spilled, and the shear area affected by the ongoing Gulf spill.
There were only 1100 miles of beach involved in Alaska and, although everyone affected is equally important individually, there are vastly more people living and working along the Gulf coast than there ever were in any part of Alaska.
The details of just what happened in Alaskan beaches are included in the Temple study (which took several years to evaluate all the data) but it is pretty clear that we probably face a similar situation in the Gulf, if not worse.
The oil in Alaska tended to form two layers with the top layer actually shielding the bottom layer from getting the biologic and oxygen exposure needed to biodegrade the remaining oil.
(Anyone who wonders why I would know anything about oil spills here in Pennsylvania would do well to recall that the first oil wells were drilled in Titusville, PA)
http://titusvillepa.com/
Today Titusville bills itself as “being in the valley which changed the world.”
They don’t actually say whether this was a good thing.
People tend to forget that lots of things have changed man’s world drastically, even y pestes would fit that description.
At this time we are beginning to hear complaints about how the public was manipulated into fearing nuclear power which had its worst U.S. accident at Three Mile Island – an accident which caused virtually no (if any pollution) and didn’t even cause any injuries.
