Tuesday, June 15, 2010

Gulf Oil Spill - use of nutrients

The Exxon Valdez: A drop in the ocean compared to BP

Tonight, President Obama will address the nation about the oil spill in the Gulf of Mexico. The BP spill, as it is now known, is the largest oil spill in US history. At present, it is eight times larger than second place, the spill of the Exxon Valdez in 1989. There are a lot of differences between the two but there are also similarities.

It all started a little after midnight on March 24, 1989. The Exxon Valdez, an oil tanker, ran aground on Bligh Reef in Prince William Sound off the shores of Valdez, Alaska. The resulting spill of 11 million gallons was the largest in US History at the time. With the spill taking place in a remote part of Alaska, the cleanup efforts were initially hampered. However, the mess could have been avoided accorded to the National Response Team Report to President Bush in May of 1989.

The three factors that led to the crash were these:
1. Captain Joseph Hazelwood had too much to drink. A a result, he placed a third mate in charge of a tanker with 11 million gallons of oil
2. The ship had inadequate sonar which would have been able to detect the reef and allowed the ship to steer clear.
3. The shipmate was unqualified, not rested, and had insufficient training to maneuver such a vessel.

As a result, over 1300 miles of coastline would be effected by the spill. Much like the BP spill, several different type of attempts were made to minimize the damage. A burning was first attempted followed by a mechanical cleanup, and then the use of chemical dispersants. As a result, the damage was inevitable and thousands of animals died and the coastline was severely damaged.

By July of 1989, the Environmental Protection Agency sent this letter to Exxon about the cleanup.

United States Environmental Protection Agency
Office of Research and Development
Washington, D.C. 20460
July 26, 1989

Mr. K. T. Koonce
Senior Vice President
Exxon Corporation
P.O. Box 670
Valdez, Alaska 99686

Dear Mr. Koonce:

As part of our cooperative agreement with Exxon on the Bioremediation Project in Prince William Sound, the Environmental Protection Agency (EPA) agreed to provide information that would help Exxon decide on whether to use nutrients as a technique to clean up oil contaminated shorelines in Alaska this summer. As you are aware, all data to make a definitive recommendation on the efficacy of bioremediation are not available at this time. However, given the data presently available, the significant potential positive benefits, the absence of adverse ecological effects, and the limited time remaining in the summer season in Alaska, EPA would support an Exxon proposal for nutrient addition on oil contaminated shorelines. We recommend the following regarding nutrient types, pretreatment application rates, and monitoring.

1. Nutrient Application. Application of both oleophilic fertilizer and a slow release soluble fertilizer is recommended for cobble and mixed sand and gravel shorelines. Preliminary information from our field studies show that the oleophilic fertilizer enhances the removal of oil from the surfaces of cobblestone and gravel. However, there is insufficient evidence to demonstrate that oleophilic fertilizer enhances the degradation of the less accessible oil found under large cobblestones and at any significant depth in the sediment. We believe oil degradation in these areas would be optimized by the application of slow release soluble nutrient formulations in conjunction with the oleophilic fertilizer. Nutrient release from these formulations will allow penetration into the less accessible areas through tidal flushing. While we recommend simultaneous application of both types of fertilizers, we recognize that there are beach situations where, due to the physical constraints or other factors, it would be appropriate to apply either one or the other fertilizer.

2. Pretreatment. For bioremediation to provide maximum cleanup to heavily and moderately oiled shoreline, physical cleaning should precede the application of nutrients. For lightly oiled shoreline, physical cleanup is not recommended prior to nutrient application.

3. Rates of Fertilizer Application. Rates of application are an important consideration to ensure maximum effective loading of fertilizer with the minimum environmental impact. It is recommended that an oleophilic fertilizer be used at an application rate that covers oiled areas completely with a thin coating of the product (approximately 0.06 lbs/ft2 of beach area). The slow release fertilizer should release nitrogen (ammonia or nitrate) and phosphate rates of 1-10 and 0.1-0.5 mg/1/day per 100 grams of granules, respectively, for periods of up to 40 days.

4. Ecological Effects and Monitoring. Fertilizer application should be initially conducted on those oil-contaminated shorelines that are exposed to adequate flushing through the action of the tides and wind. Based on mathematical model projections for tidal mixing and dilution and our monitoring studies to date, these areas should not experience any adverse ecological effects at recommended application rates.

The potential for algal blooms from nutrient addition and direct toxicity to marine biota from the oleophilic fertilizer (during or after application) is greatest in protected, poorly flushed embayments, particularly if large portions of the shorelines are treated. When such embayments are considered for bioremediation, the mixing characteristics should be established prior to nutrient application. It is recommended that you consult with NOAA and examine bays for obstructions to mixing and flushing, such as sills at bay entrances and strong stratifications as indicated by abrupt and large pycnoclines or sags in dissolved oxygen. If the information shows adequate flushing and dilution of the fertilizers under the worst-case situation (complete and rapid transport of the fertilizers off the beaches into receiving waters), then large scale application of nutrients in these types of embayments is appropriate. If the sufficiency of flushing and dilution are questionable for controlling algal blooms and toxicity, we recommend that ecological monitoring should be carried out along with the fertilizer application. The following monitoring parameters should be considered:

*total hexane-extractable hydrocarbons in the water column
*nitrogen and phosphorous nutrients
*plankton chlorophyll
*total aromatic hydrocarbons bioaccumulated in mussels (held in cages at the low tide zone of the fertilized shorelines)
*water sample toxicity using a standard effluent toxicity test program. (This test is designed to detect any general toxicity associated with the nutrient addition operation.)

If monitoring results demonstrate any adverse environmental effect, the application of the fertilizer should be terminated immediately.

We would be pleased to work with you to provide additional details, information, etc. regarding this activity.

Sincerely yours,

Erich Bretthauer
Acting Assistant Administrator for Research and Development

In all, Exxon would be fined $1 billion for damages and the cleanup with civil court settlements totaling $2.5 billion. In 1990, the Congress and President Bush passed the Oil Pollution Act of 1990. The act “required the Coast Guard to strengthen its regulations on oil tank vessels and oil tank owners and operators. Today, tank hulls provide better protection against spills resulting from a similar accident, and communications between vessel captains and vessel traffic centers have improved to make for safer sailing.” None of this would prevent the BP spill.

The BP Spill, or Deepwater Horizon Spill, is spewing 20,000 to 40,000barrels of oil day. With no end in sight, the gushing pipe has already pumped out eight times as much oil as one tanker did 21 years ago. However, to date, the impact on shore has not been as drastic as Valdez – that may change in the next few months as seasonal winds push gulf currents ashore. At sea, it is still unknown what the damage to life in the Gulf of Mexico will be. As of the writing of this post, the spill measures 2,500 square miles far surpassing the Exxon Valdez.

As President Obama addresses the nation, the nation is looking for someone to blame. Many blame British Petroleum as safety measures designed to shut down the valve failed and attempts to block the leak have been disastrous. Some have even placed blame on Obama as his response to crisis has been haphazard at best. The impact on marine and wildlife habitats has yet to be determined and the gulf coast oil and fishing industries have been disastrous. In the weeks ahead, I’m afraid, this spill will only get worse. The BP spill makes the Exxon Valdez look puny and insignificant. I can’t even imagine the damage when the pipe does get plugged…


The letter is available on EPA Website - http://www.epa.gov/history/topics/valdez/01.htm

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