Monday, September 20, 2010

BP Kills Oil Well; Cleanup and Recovery Continues

BP successfully killed the oil well that was leaking for much of the spring and summer. A relief well intercepted the original well shaft, and then the crew aboard a drilling rig (pictured above) pumped cement through the relief well to kill the original well. A pressure test early Sunday morning confirmed that the well was sealed. The failed well will be abandoned once BP finishes its work at the site. The company says that it will devote more attention to oil cleanup now that the well is killed permanently. However, BP also left open the possibility that it would drill a new well to exploit the same oil reservoir that the failed well was supposed to access.

The US government wants oil companies to plug any wells that they have not used in the past five years and will issue new regulations in October to reduce the likelihood of leaks from abandoned wells.

In the meantime, independent scientists have found some of the oil that BP and the government claimed had disappeared. It has settled on the ocean floor in a layer stretching 12 miles in both directions from the failed well.
The Research Vessel Oceanus sailed on Aug. 21 on a mission to figure out what happened to the more than 4 million barrels of oil that gushed into the water. Onboard, Samantha Joye, a professor in the Department of Marine Sciences at the University of Georgia, says she suddenly has a pretty good idea about where a lot of it ended up. It's showing up in samples of the seafloor, between the well site and the coast.

"I've collected literally hundreds of sediment cores from the Gulf of Mexico, including around this area. And I've never seen anything like this," she said in an interview via satellite phone from the boat.

Joye describes seeing layers of oily material — in some places more than 2 inches thick — covering the bottom of the seafloor....

It's very clearly a fresh layer. Right below it she finds much more typical seafloor mud. And in that layer, she finds recently dead shrimp, worms and other invertebrates.
There is some possibility that other leaking wells or natural seeps could contribute to the mess, so the UGA scientists will have to test the chemical fingerprint of the oil to determine its source. However, the volume and freshness of the oil suggests that BP's failed well was responsible for it. Scientists from the University of South Florida have also found oil at the bottom of the Gulf, but not in the amounts recorded by Joye and her colleagues. You can read more about the discovery and see photos of the core samples at UGA's Gulf Oil Blog. If past spills are any indication, that toxic oil could be sitting there for a long time. This episode, like several others during the course of the spill and cleanup, should serve as a caution against the optimistic predictions about the spill being offered by the government, BP, and the media. It should also be a reminder that the story is not over just because the well is killed.

The outlook for ecosystems in the Gulf remains uncertain and may not be known for quite some time. Some scientists, particularly ones affiliated with the government, see a relatively quick recovery. This optimistic take is supported by the lack of oil-triggered dead zones – one potential impact – in the areas affected by the spill. (There was a dead zone in the Gulf this summer, but it was the annual one triggered by nutrient runoff from the Mississippi.) However, there are still a variety of ways that oil could affect the Gulf over the long term. Aside from the oil sitting on the bottom of the Gulf, there is still a large amount buried in the beaches or just offshore. That oil could reappear during any storm that churns the sand and waves. Some oil and natural gas remains in underwater plumes.

The continued presence of toxic oil in and around the Gulf is a concern because of its potential effects on wildlife, both commercially valuable animals like shrimp and other species, including endangered species like the Piping Plover or Kemp's Ridley Sea Turtle. Oiled animals (both alive and dead) continue to be found; in fact, the numbers of some oiled animals have risen since the well was capped in July. According to the oiled wildlife report for September 17 (pdf), 8030 birds have been collected, of which 5959 were collected dead and 2071 were collected alive; of the latter, 1208 have been released. The oil has also affected 1114 sea turtles (586 of which were collected dead and 284 released), 101 mammals (92 collected dead; 3 released), and 2 other reptiles (1 dead). For a detailed breakdown of the collected birds, see this report (pdf). Updates to the detailed breakdown will be posted each Wednesday on the USFWS website. The ABA's Drew Whelan has an interview with James Van Remsen, an ornithologist at LSU, about the effects of the oil spill on birds and the Gulf Coast ecosystems.

Finally, BP has gone to great lengths to insist that the environmental damage and the health risks to cleanup workers will be minimal. Some of their PR and training materials downplay the risks posed by oil dispersants:
Representatives with BP, the U.S. Environmental Protection Agency and the Center for Toxicology and Environmental Health spoke during the meeting, which took place at Lafourche-branch NAACP official Bertha Shanklin's home.

Susan Shelnutt, a toxicologist with the center, a private consulting firm hired by BP to monitor health and environmental issues related to the spill, showed attendees how the dispersant Corexit contains some of the same chemical properties as everyday household items such as ice-cream bars, children's headache medicine, kitchen cleaners and skin lotion.
Dispersants may share some component chemicals with household products (including ice cream), but just because you would ingest cough syrup or eat a Klondike bar does not mean you would consider gulping down dish detergent, let alone oil dispersants. In the same way, having a few chemicals in common with household cleaners does not mean that dispersants are safe to touch or inhale.

Cleanup workers were exposed to both petroleum and dispersants, and the long range health effects of both are not well known. (There is already at least one disturbing case.) Of course, dispersants may also cause problems for wildlife. Since this was the first spill for which dispersants were applied in such massive amounts, their full effect (on humans or wildlife) has yet to be determined. It is too soon to assume that these chemicals will be benign.