The dispersion process does move the oil from the surface to the water column. This potentially exposes the water column and near shore shallow bottom-dwelling organisms to oil. These oil concentrations however, are extremely low and decrease quickly, thus limiting overall impact to sensitive environmental resources. Since the very small chemically dispersed oil droplets are not prone to re-coalescing, the treated oil is unlikely to form tar balls or patties. Modern dispersant formulations are a mixture of low toxicity solvents and surfactants designed for use in the marine environment to disperse oil with minimal toxic consequences. Approval must be obtained from the appropriate authorities before these chemical agents can be used. The U.S. Environmental Protection Agency (U.S. EPA) maintains the National Contingency Plan (NCP) Product Schedule that lists dispersants, other chemicals, and other spill mitigating substances that may be authorized for use on oil spills.

Historically in the United States, dispersants have been considered by decision makers and responders as a secondary response tool and have been given only minimal consideration during oil spills and in contingency planning efforts. Since the mid-1990’s, dispersant operations have become a more accepted alternative response technology. This is especially true in the U.S. Gulf of Mexico where dispersant operations have been conducted since 1989. The main reason for this difference is that approximately 90% of the U.S. oil supplies are transported through the Gulf, which creates more “opportunities” for spills that are likely to be dispersible. The objectives of current research are to examine and address the technical and environmental issues associated with the use of dispersants on the Outer Continental Shelf (OCS).

Desired Outcomes

1. Gather data to support decisions on the use of dispersants for oil spills located on the U.S. OCS.
    
2. Through Joint Industry Projects conduct research with agencies, organizations and industry on the use of chemical treating agents to contain, remove and remediate the effects of an oil spill. Identify oil types and scenarios where chemical treating agents may have potential to be utilized.

Tactical Plan (2005-2010)

1. Research whether dispersants work in cold water/broken ice conditions and identify oil types and scenarios where dispersants may have potential to be utilized. Proof of effectiveness will increase response options to oil spills in cold water/broken ice conditions.
    
2. Continue research to correlate the results of dispersant effectiveness experiments conducted at Ohmsett with laboratory and small wave tank experiments and at-sea field trials.
    
3. Work with state and federal agencies including the U.S. EPA to improve standardized laboratory dispersant effectiveness testing.
    
4. Work with state and federal agencies to improve the SMART (Surveillance and Monitoring for Alternative Response Technology) monitoring protocols where direct, independent, measurements of dispersant effectiveness are made in the field. This will include evaluations of new types of sensors (e.g., fluorometers, and particle size analyzers) used by response teams.
    
5. Work cooperatively with agencies, organizations and industry to determine the limiting viscosity for chemical dispersion at sea with different oil types and environmental conditions. This includes calm and low wave energy environments.
    
6. Work cooperatively with agencies, organizations and industry to improve aerial and ship borne dispersant delivery systems.
    
7. Work cooperatively with agencies, organizations and industry to determine the effects of chemically dispersed and biodegraded oils.
    
8. Research the use of chemical herders to thicken oil slicks among broken ice floes so that the oil can be ignited and burned effectively. Validate chemical herding action in ice with the primary purpose to enhance in situ burning by thickening oil slicks.
    
9. Take advantage of planned, experimental oil spills conducted outside of U.S. territorial waters to conduct experiments on the use of dispersants and chemical treating agents to improve oil spill response operations.

For more information on Oil Spill Chemical Treating Agents, contact Joseph Mullin at 703-787-1556 or via e-mail.

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Last Updated: 12/15/2008, 02:41 PM