Establishment of dispersant use zones in the state of California: A consensus approach for marine waters 3-200 nautical miles from shore

Abstract

It has long been the policy of the National Response Team (NRT) that the appropriate use of dispersants as a first strike method of response to marine oil spills could greatly minimise the impacts of such spills. Beginning in early 2000, the Region IX Regional Response Team (RRT) evaluated the appropriateness of dispersant use for the State of California. In January 2001, the RRT signed into effect a dispersant use policy for the federal waters off the coast of California from 3200 nm offshore. These revisions to the Regional Contingency Plan provided a streamlined decision making process for dispersant use and designation of zone. Specifically, the plan called for each of the six local area committees to develop and forward recommendations for dispersant-use zone designations into one of three categories: pre-approval, preapproval with consultation, or incident-specific RRT approval required. Each of the six local area committees utilized a modified Ecological Risk Assessment (ERA) known as a Net Environmental Benefit Analysis (NEBA) process to identify concerns and prioritize risk. Such an approach ensured consistency along the coast as well provided a mechanism by which all points of view were considered. Utilizing a "what if" oil scenario, each on-water response option (no-response, dispersants, in-situ burning, mechanical recovery) was evaluated for its ability to remove oil from the water surface and potential environmental impacts. A risk matrix allowed comparison bebveen species and habitats. Participants were encouraged to share their concerns along with the key drivers for their response decisions, often allowing then to think outside their typical agency-centered framework. Based on seasonality and species of special concern, zones for dispersant use were designated as a means of providing protection to sensitive shorelines and on-water species. As of November 2002, the RRT has adopted DispersantUse Zones for all designated off-shore waters. Current efforts are underway to incorporate the necessary dispersant planning information into the State and Federal Planning efforts. The response to the workshops was overwhelmingly positive. The NEBA/workshop approach facilitated the subsequent work undertaken by the U.S. Coast Guard and the RRT as an integral part of the implementation of the US-Mexico Agreement, further ensuring a coordinated bi-national oil spill response.