Inconel 718 is commonly used for cryogenic storage tanks, downhole shafts and wellhead parts. Undersea plumes may have been the result of the use of wellhead chemical dispersants. Well fluids from the Douglas Wellhead tower are treated in the 3-phase Douglas Production Separator. Once the leak was killed, the main fire on the Montara Wellhead platform was extinguished. There may be no escaping fluid flow at the wellhead. The leak initially emanated from the Montara Wellhead platform on 21 August 2009. Altogether, of dispersants were used; of this were released at the wellhead. In 2009, 89 percent of U.S. wellhead production of natural gas was non-associated. The wellhead and the ground rod form the two electrodes of a dipole antenna. The Christmas tree is installed on top of the wellhead. The castle has an adjoining medieval wellhead. Bourne Castle was built on land that is now the Wellhead Gardens in South Street. It can also be performed without having to remove the Christmas tree from the wellhead.