UNOCAL Granite Point Platform; Granite Point, Upper Cook Inlet, Alaska

Granite Point, Upper Cook Inlet, Alaska | 1992-Apr-21

Initial Notification: On April 21, 1993, 2,000 gallons of diesel were spilled from the UNOCAL Granite Point Platform into Upper Cook Inlet. While transferring diesel from the main fuel tank to a day tank, a valve was inadvertently left open. The day tank overflowed and poured diesel into the inlet for about five hours before the valve was closed. UNOCAL mustered a full response team to the CISPRI command post in Nikiski and launched several CISPRI vessels with sorbent sweep. The strong tidal currents stretched the diesel sheen for a few miles. The USCG joined UNOCAL on overflights monitoring the rapidly dispersing diesel. Within three tidal cycles the diesel sheen had disappeared. Collecting the diesel from response vessels proved unsuccessful. During the incident, the weather was clear with light winds from the southwest. USCG district 17. Keyword: evaporation, dispersion.