Pre-spill dispersant authorization in the Gulf of Mexico

A dispersant seminar was sponsored in September 1991 by the Region VI Regional Response Team, the 19-company Industry Task-force on Offshore Lightering, and the 10-company Marine Industry Group. The seminar was attended by 138 people from federal agencies, state agencies, the fishing and environmental community, marine transportation companies, response organizations, and the scientific community. Domestic and foreign experts reviewed technical aspects of dispersants and the tradeoffs involved in making decisions about dispersant use. After this seminar, a dispersant prespill authorization plan was developed for the Upper Texas/Western Louisiana offshore coastal waters and submitted to the Region VI Regional Response Team. The proposed zone of preauthorization encompasses offshore waters of 30-foot depth or greater from longitude 95 degrees 30'W to 93 degrees W, out to latitude 28 degrees N. This encompasses an area from Freeport, Texas, to Cameron, Louisiana, to about 100 miles offshore. Dispersant application exclusion areas are provided around eight banks in the preauthorization zone. With prevailing east-to-west water currents and prevailing winds from the south and east, risk assessements suggest a significant likelihood that spilled oil will move toward the coast. The plan provides a basis for the on-scene coordinators to make prompt dispersant use/nonuse decisions