A small number of dispersant effectiveness tests will be conducted at Ohmsett – The National Oil Spill Response Test Facility that will complete two important sections of the dispersant effectiveness test matrix not completed during the October 2003 experimental test series.  Testing will be conducted on IFO-180 fuel oil treated with Corexit 9500 dispersant at a DOR of 1:25.  In replicated tests at sea this combination yielded consistently high levels of dispersant performance. Replicated experimental tests and controls will be conducted at Ohmsett at wave energies of both 33.3 and 30 cycles per minute (cpm).

In October 2003, MMS sponsored a project entitled: “Correlate Ohmsett Dispersant Tests with At-Sea Trials” (TAR Project No. 477).  The primary objectives of this project were achieved however some important tests could not be performed due to time and adverse weather.  The objectives of the proposed work is to conduct a small number of tests to complete two important sections of the dispersant effectiveness test matrix, thereby solidifying our understanding of the correlation of Ohmsett dispersant effectiveness testing to at-sea dispersant effectiveness testing.  These objectives are:

1. Conduct replicated measurements of dispersant performance at Ohmsett under a number of oil-dispersant-DOR conditions that yielded high levels of dispersion at sea: and

2.  Conduct control runs for both test oils IFO-180 and IFO-380 fuel oils at both wave frequencies (30 and 33.3 cpm).