Incident Name: UNOCAL Cook Inlet Baker Platform
Subject: Report - Final
Incident Date: 4/6/1994
Incident Location: Upper Cook Inlet, north of Forelands, Alaska
Author: John W. Whitney
Latitude: 60°49.45' N
Longitude: 151°20.01' W
USCG District: 17
Product: middle ground shoal crude oil
Type: 2
Volume: 96 barrels
Source:platform
RAR: none
Shoreline Type(s) Impacted: in-situ burn and dispersants were approved for use
Summary: The USCG received a report just before noon on April 6, 1994, from UNOCAL that a valve had been accidentally left open on their Baker Platform and 50 to 100 barrels of crude had escaped into Cook Inlet. UNOCAL immediately called their incident command team to Nikiski and established a command post at the Cook Inlet Spill Prevention and Response Inc. (CISPRI) headquarters. CISPRI immediately launched a mechanical cleanup capability (boats and skimmers) while completing the dispersant and in-situ burn (ISB) request forms. Neither of these alternative response techniques were needed because the oil thinned, evaporated, and dispersed too rapidly. A total of 40 barrels were collected mechanically. The USCG and the FOSC were onscene; however, their role was strictly one of consultation and monitoring. The response lasted about 8 hours. Weather was warm and sunny; although a small amount of floating ice (<10%) was in the area.
Behavior: The spilled oil was middle ground shoal crude, a very light oil with an API of 42, predicted to evaporate 50 percent within the first 12 hours with no predicted dispersion. However, due to the dynamics of Cook Inlet, less time is needed for dispersion. Initially the oil formed a slick 1 mile by 1/3 mile and moved predictably with the tidal currents. UNOCAL calculated that 96 barrels were spilled and about 40 barrels were recovered. The balance is believed to have evaporated and dispersed naturally. No significant winds were present and no areas were impacted.
Countermeasures/Mitigation: CISPRI maintains a 24-hour floating response vessel that immediately deployed boom and skimmers; other vessels were immediately launched from the nearby CISPRI warehouse. The rapidity of their response is the reason they were able to achieve a 40 percent open-water recovery. ISB and dispersants were both approved and staged but not used.
Other Special Interest(s): Approval was obtained to conduct an ISB; however, the oil thinned too rapidly to be re-concentrated sufficiently to conduct the burn. Similarly, dispersants were approved for use by the FOSC, but the oil evaporated and dispersed so rapidly that 5 or 6 hours after the release there no slicks remaining that could be dispersed.
Interestingly enough, after this response the Cook Inlet RCAC endorsed ISB as a primary response tool whenever there is ice present.
NOAA Activities: NOAA was notified of this incident on April 6, 1994, by the USCG who requested on-scene assistance. The SSC notified and consulted with the resource agencies and the weather service. Since both dispersants and ISB were considered, oil movement trajectories and oil behavior characteristics were provided to the FOSC, UNOCAL, CISPRI, and resource and regulatory agencies. Onscene, NOAA represented the FOSC on the dispersant's effectiveness spotter plane; however, after flying for about an hour, no oil was located. NOAA supported this incident for 10 hours.
References: NOAA. 1993. ADIOS(tm) (Automated Data Inquiry for
oil Spills) User's Manual. Seattle: Hazardous Materials Response and
Assessment Division, NOAA. 50 pp.
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