Section 560 - STORAGE OF ORGANIC LIQUID560.1 A person shall not place, store or hold in any stationary tank, reservoir or other container of more than 40,000 gallons, any petroleum liquids or a tank greater than 6,000 gallons capacity or greater containing other organic liquids or solvents having a True Vapor Pressure of 1.5 pounds per square inch or greater under actual storage conditions, unless such tank, reservoir or other container is a pressure tank maintaining working pressure sufficient at all times to prevent hydrocarbon vapor or gas loss to the atmosphere, or is designed and equipped with one of the following vapor loss control devices, properly installed, in good working order and in operation: 560.11 A floating roof, consisting of a pontoon type or double-deck type roof, resting on the surface of the liquid contents and equipped with a closure seal, or seals, to close the space between the roof edge and tank wall. The control equipment provided for in this paragraph shall not be used if the gasoline or petroleum distillate has a True Vapor Pressure of 11.1 pounds per square inch or greater under actual storage conditions. All tank gauging and sampling devices shall be gas-tight except when gauging or sampling is taking place.560.12 A vapor recovery system, consisting of a vapor gathering system capable of collecting the hydrocarbon vapors and gases discharged and a vapor disposal system capable of processing such hydrocarbon vapors and gases so as to prevent their emission to the atmosphere and with all tank gauging devices gas-tight except when gauging or sampling is taking place.560.13 Other equipment of equal efficiency, provided such equipment is submitted to and approved by the Control Officer. Wash. Admin. Code Northwest Clean Air Agency, 500, 560
PASSED: February 14, 1973 AMENDED: August 8, 1978, April 14, 1993