Chevron - Point Wells Tank Farm; Edmonds, WA

Edmonds, WA | 1990-Aug-30

Initial Notification: August 30, 1990, at 2332 the U.S. Coast Guard Marine Safety Office (MSO) Puget Sound was notified by the Chevron Point Wells Tank Farm that one of their shore side storage tanks had ruptured during a cargo transfer from the tank vessel CHEVRON WASHINGTON. Tank farm personnel had improperly aligned the valves on the shoreside piping, allowing cargo to enter a full tank and rupture it. Approximately 4,200 barrels of asphalt charge stock were estimated to have been lost, with most of the product believed to have been contained by the dike around the tank. An unknown quantity of product was known to have sprayed out of the rupture at the top of the tank, over the containment dike, and into the riprap and intertidal zone adjacent to the facility. The asphalt charge stock was characterized by Chevron as a very heavy, thick petroleum material used in asphalt production that had been cut with 20 percent diesel to allow it to be handled without having to be heated.