(Adopted 6/91)

For petroleum storage tanks with a storage capacity of 150,000 liters (39,630 gallons) of a petroleum product with a true vapor pressure of 1.5 or greater, such tanks shall be a pressure tank or shall be equipped with either a vapor recovery system or a floating roof as described in this Rule. Underground storage and dispensing tanks of JP-4 Jet fuel with an annual through put volume of less than 20,000,000 gallons of JP-4 Jet fuel are exempt from the requirements of this Rule. Tanks subject to this Section shall be in compliance by September 30, 1982.

The following definitions shall apply to storage of petroleum products:

Pressure Tank is a tank which maintains working pressure sufficient at all time to prevent hydrocarbon vapor or gas loss to the atmosphere.
Vapor Recovery System consists 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, with all tank gauging and sampling devices gas tight except when gauging or sampling is taking place.
Floating Roof consists of a pontoon-type or double-deck type roof resting on the surface of the liquid contents and equipped with closure seals to close the space between the roof edge and tank wall. The control equipment provided for in the Rule shall not be used if the gasoline or petroleum distillate has a vapor pressure of 11.0 pounds per square inch absolute or greater under actual storage conditions. All tank gauging and sampling devices shall be gas-tight except when gauging or sampling is taking place.