35 Ill. Adm. Code 215.121
Storage Containers
Section 215
Section 215.121 Storage
Containers
No person shall cause or allow
the storage of any volatile organic liquid with a vapor pressure of 17.24 kPa
(2.5 psia) or greater at 294.3 K (70º F) or any gaseous organic material in any
stationary tank, reservoir or other container of more than 151 cubic meters
(40,000 gal) capacity unless such tank, reservoir or other container:
a) Is a pressure tank capable of withstanding the vapor pressure
of such liquid or the pressure of the gas, so as to prevent vapor or gas loss
to the atmosphere at all times; or,
b) Is designed and equipped with one of the following vapor loss
control devices:
1) A floating roof which rests on the surface of the volatile
organic liquid and is equipped with a closure seal or seals between the roof
edge and the tank wall. Such floating roof shall not be permitted if the
volatile organic liquid has a vapor pressure of 86.19 kPa (12.5 psia) or
greater at 294.3 K (70º F). No person shall cause or allow the emission of air
contaminants into the atmosphere from any gauging or sampling devices attached
to such tanks, except during sampling or maintenance operations.
2) A vapor recovery system consisting of:
A) A vapor gathering system capable of collecting 85% or more of
the uncontrolled volatile organic material that would be otherwise emitted to
the atmosphere; and,
B) A vapor disposal system capable of processing such volatile
organic material so as to prevent its emission to the atmosphere. No person
shall cause or allow the emission of air contaminants into the atmosphere from
any gauging or sampling devices attached to such tank, reservoir or other
container except during sampling.
3) Other equipment or means of equal efficiency approved by the
Agency according to the provisions of 35 Ill. Adm. Code 201.